A mass of organic or inorganic solid fragmented material, or the solid fragment itself, that comes from the weathering of rock and is carried by, suspended in, or dropped by air, water, or ice. It refers also to a mass that is accumulated by any other natural agent and that forms in layers on the earth's surface, such as sand, gravel, silt, mud, fill, or loess. (McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed, p1689)
The salinated water of OCEANS AND SEAS that provides habitat for marine organisms.
Water containing no significant amounts of salts, such as water from RIVERS and LAKES.
The presence of bacteria, viruses, and fungi in water. This term is not restricted to pathogenic organisms.
Constituent of 30S subunit prokaryotic ribosomes containing 1600 nucleotides and 21 proteins. 16S rRNA is involved in initiation of polypeptide synthesis.
Chemical compounds which pollute the water of rivers, streams, lakes, the sea, reservoirs, or other bodies of water.
Large natural streams of FRESH WATER formed by converging tributaries and which empty into a body of water (lake or ocean).
DNA sequences encoding RIBOSOMAL RNA and the segments of DNA separating the individual ribosomal RNA genes, referred to as RIBOSOMAL SPACER DNA.
The relationships of groups of organisms as reflected by their genetic makeup.
One of the three domains of life (the others being Eukarya and ARCHAEA), also called Eubacteria. They are unicellular prokaryotic microorganisms which generally possess rigid cell walls, multiply by cell division, and exhibit three principal forms: round or coccal, rodlike or bacillary, and spiral or spirochetal. Bacteria can be classified by their response to OXYGEN: aerobic, anaerobic, or facultatively anaerobic; by the mode by which they obtain their energy: chemotrophy (via chemical reaction) or PHOTOTROPHY (via light reaction); for chemotrophs by their source of chemical energy: CHEMOLITHOTROPHY (from inorganic compounds) or chemoorganotrophy (from organic compounds); and by their source for CARBON; NITROGEN; etc.; HETEROTROPHY (from organic sources) or AUTOTROPHY (from CARBON DIOXIDE). They can also be classified by whether or not they stain (based on the structure of their CELL WALLS) with CRYSTAL VIOLET dye: gram-negative or gram-positive.
The simplest saturated hydrocarbon. It is a colorless, flammable gas, slightly soluble in water. It is one of the chief constituents of natural gas and is formed in the decomposition of organic matter. (Grant & Hackh's Chemical Dictionary, 5th ed)
Elimination of ENVIRONMENTAL POLLUTANTS; PESTICIDES and other waste using living organisms, usually involving intervention of environmental or sanitation engineers.
A group of PROTEOBACTERIA represented by morphologically diverse, anaerobic sulfidogens. Some members of this group are considered bacterial predators, having bacteriolytic properties.
A group of gram-negative, anaerobic bacteria that is able to oxidize acetate completely to carbon dioxide using elemental sulfur as the electron acceptor.
One of the three domains of life (the others being BACTERIA and Eukarya), formerly called Archaebacteria under the taxon Bacteria, but now considered separate and distinct. They are characterized by: (1) the presence of characteristic tRNAs and ribosomal RNAs; (2) the absence of peptidoglycan cell walls; (3) the presence of ether-linked lipids built from branched-chain subunits; and (4) their occurrence in unusual habitats. While archaea resemble bacteria in morphology and genomic organization, they resemble eukarya in their method of genomic replication. The domain contains at least four kingdoms: CRENARCHAEOTA; EURYARCHAEOTA; NANOARCHAEOTA; and KORARCHAEOTA.
Deoxyribonucleic acid that makes up the genetic material of bacteria.
A partially enclosed body of water, and its surrounding coastal habitats, where saltwater from the ocean mixes with fresh water from rivers or streams. The resulting mixture of seawater and fresh water is called brackish water and its salinity can range from 0.5 to 35 ppt. (accessed http://oceanservice.noaa.gov/education/kits/estuaries/estuaries01_whatis.html)
A great expanse of continuous bodies of salt water which together cover more than 70 percent of the earth's surface. Seas may be partially or entirely enclosed by land, and are smaller than the five oceans (Atlantic, Pacific, Indian, Arctic, and Antarctic).
Deoxyribonucleic acid that makes up the genetic material of archaea.
A multistage process that includes cloning, physical mapping, subcloning, determination of the DNA SEQUENCE, and information analysis.
A functional system which includes the organisms of a natural community together with their environment. (McGraw Hill Dictionary of Scientific and Technical Terms, 4th ed)
Inland bodies of still or slowly moving FRESH WATER or salt water, larger than a pond, and supplied by RIVERS and streams.
Genes, found in both prokaryotes and eukaryotes, which are transcribed to produce the RNA which is incorporated into RIBOSOMES. Prokaryotic rRNA genes are usually found in OPERONS dispersed throughout the GENOME, whereas eukaryotic rRNA genes are clustered, multicistronic transcriptional units.
Adverse effect upon bodies of water (LAKES; RIVERS; seas; groundwater etc.) caused by CHEMICAL WATER POLLUTANTS.
A plant family of the order Rhizophorales, subclass Rosidae, class Magnoliopsida, that includes mangrove trees.
The variety of all native living organisms and their various forms and interrelationships.
The presence of bacteria, viruses, and fungi in the soil. This term is not restricted to pathogenic organisms.
The complete absence, or (loosely) the paucity, of gaseous or dissolved elemental oxygen in a given place or environment. (From Singleton & Sainsbury, Dictionary of Microbiology and Molecular Biology, 2d ed)
Descriptions of specific amino acid, carbohydrate, or nucleotide sequences which have appeared in the published literature and/or are deposited in and maintained by databanks such as GENBANK, European Molecular Biology Laboratory (EMBL), National Biomedical Research Foundation (NBRF), or other sequence repositories.
Substances or organisms which pollute the water or bodies of water. Use for water pollutants in general or those for which there is no specific heading.
Environments or habitats at the interface between truly terrestrial ecosystems and truly aquatic systems making them different from each yet highly dependent on both. Adaptations to low soil oxygen characterize many wetland species.
Uranium. A radioactive element of the actinide series of metals. It has an atomic symbol U, atomic number 92, and atomic weight 238.03. U-235 is used as the fissionable fuel in nuclear weapons and as fuel in nuclear power reactors.
Contamination of bodies of water (such as LAKES; RIVERS; SEAS; and GROUNDWATER.)
The monitoring of the level of toxins, chemical pollutants, microbial contaminants, or other harmful substances in the environment (soil, air, and water), workplace, or in the bodies of people and animals present in that environment.
The relative amounts of the PURINES and PYRIMIDINES in a nucleic acid.
The science of the earth and other celestial bodies and their history as recorded in the rocks. It includes the study of geologic processes of an area such as rock formations, weathering and erosion, and sedimentation. (From McGraw-Hill Dictionary of Scientific and Technical Terms, 6th ed)
Inorganic salts of sulfuric acid.
The Arctic Ocean and the lands in it and adjacent to it. It includes Point Barrow, Alaska, most of the Franklin District in Canada, two thirds of Greenland, Svalbard, Franz Josef Land, Lapland, Novaya Zemlya, and Northern Siberia. (Webster's New Geographical Dictionary, 1988, p66)
The enrichment of a terrestrial or aquatic ECOSYSTEM by the addition of nutrients, especially nitrogen and phosphorus, that results in a superabundant growth of plants, ALGAE, or other primary producers. It can be a natural process or result from human activity such as agriculture runoff or sewage pollution. In aquatic ecosystems, an increase in the algae population is termed an algal bloom.
Ribonucleic acid in bacteria having regulatory and catalytic roles as well as involvement in protein synthesis.
Pollutants, present in water or bodies of water, which exhibit radioactivity.
A group of the proteobacteria comprised of facultatively anaerobic and fermentative gram-negative bacteria.
Industrial chemicals which have become widespread environmental pollutants. Each aroclor is a mixture of chlorinated biphenyls (1200 series) or chlorinated terphenyls (5400 series) or a combination of both (4400 series).
Substances which pollute the soil. Use for soil pollutants in general or for which there is no specific heading.
The flow of water in enviromental bodies of water such as rivers, oceans, water supplies, aquariums, etc. It includes currents, tides, and waves.
A major group of unsaturated cyclic hydrocarbons containing two or more rings. The vast number of compounds of this important group, derived chiefly from petroleum and coal tar, are rather highly reactive and chemically versatile. The name is due to the strong and not unpleasant odor characteristic of most substances of this nature. (From Hawley's Condensed Chemical Dictionary, 12th ed, p96)
A chemical reaction in which an electron is transferred from one molecule to another. The electron-donating molecule is the reducing agent or reductant; the electron-accepting molecule is the oxidizing agent or oxidant. Reducing and oxidizing agents function as conjugate reductant-oxidant pairs or redox pairs (Lehninger, Principles of Biochemistry, 1982, p471).
The spectrum of different living organisms inhabiting a particular region, habitat, or biotope.
Naturally occurring complex liquid hydrocarbons which, after distillation, yield combustible fuels, petrochemicals, and lubricants.
Liquid water present beneath the surface of the earth.
An area of water mostly surrounded by land, usually smaller than a gulf, and affording access to the sea.
Chemical groups containing the covalent sulfur bonds -S-. The sulfur atom can be bound to inorganic or organic moieties.
Organic matter in a state of advanced decay, after passing through the stages of COMPOST and PEAT and before becoming lignite (COAL). It is composed of a heterogenous mixture of compounds including phenolic radicals and acids that polymerize and are not easily separated nor analyzed. (E.A. Ghabbour & G. Davies, eds. Humic Substances, 2001).
The study of the origin, structure, development, growth, function, genetics, and reproduction of organisms which inhabit the OCEANS AND SEAS.
A nonmetallic element with atomic symbol C, atomic number 6, and atomic weight [12.0096; 12.0116]. It may occur as several different allotropes including DIAMOND; CHARCOAL; and GRAPHITE; and as SOOT from incompletely burned fuel.
The study of early forms of life through fossil remains.
Metals with high specific gravity, typically larger than 5. They have complex spectra, form colored salts and double salts, have a low electrode potential, are mainly amphoteric, yield weak bases and weak acids, and are oxidizing or reducing agents (From Grant & Hackh's Chemical Dictionary, 5th ed)
A kingdom in the domain ARCHAEA comprised of thermoacidophilic, sulfur-dependent organisms. The two orders are SULFOLOBALES and THERMOPROTEALES.
An order of amoeboid EUKARYOTES characterized by reticulating pseudopods and a complex life cycle with an alternation of generations. Most are less than 1mm in size and found in marine or brackish water.
A phylum of bacteria consisting of the purple bacteria and their relatives which form a branch of the eubacterial tree. This group of predominantly gram-negative bacteria is classified based on homology of equivalent nucleotide sequences of 16S ribosomal RNA or by hybridization of ribosomal RNA or DNA with 16S and 23S ribosomal RNA.
Organic, monobasic acids derived from hydrocarbons by the equivalent of oxidation of a methyl group to an alcohol, aldehyde, and then acid. Fatty acids are saturated and unsaturated (FATTY ACIDS, UNSATURATED). (Grant & Hackh's Chemical Dictionary, 5th ed)
The continent lying around the South Pole and the southern waters of the Atlantic, Pacific, and Indian Oceans. It includes the Falkland Islands Dependencies. (From Webster's New Geographical Dictionary, 1988, p55)
A family of colorless sulfur bacteria in the order Thiotrichales, class GAMMAPROTEOBACTERIA.
Procedures for identifying types and strains of bacteria. The most frequently employed typing systems are BACTERIOPHAGE TYPING and SEROTYPING as well as bacteriocin typing and biotyping.
The unconsolidated mineral or organic matter on the surface of the earth that serves as a natural medium for the growth of land plants.
Phenols substituted with one or more chlorine atoms in any position.

Desulfocella halophila gen. nov., sp. nov., a halophilic, fatty-acid-oxidizing, sulfate-reducing bacterium isolated from sediments of the Great Salt Lake. (1/2414)

A new halophilic sulfate-reducing bacterium, strain GSL-But2T, was isolated from surface sediment of the Southern arm of the Great Salt Lake, UT, USA. The organism grew with a number of straight-chain fatty acids (C4-C16), 2-methylbutyrate, L-alanine and pyruvate as electron donors. Butyrate was oxidized incompletely to acetate. Sulfate, but not sulfite or thiosulfate, served as an electron acceptor. Growth was observed between 2 and 19% (w/v) NaCl with an optimum at 4-5% (w/v) NaCl. The optimal temperature and pH for growth were around 34 degrees C and pH 6.5-7.3, respectively. The generation time under optimal conditions in defined medium was around 28 h, compared to 20 h in complex medium containing yeast extract. The G+C content was 35.0 mol%. 16S rRNA gene sequence analysis revealed that strain GSL-But2T belongs to the family Desulfobacteriaceae within the delta-subclass of the Proteobacteria and suggested that strain GSL-But2T represents a member of a new genus. The name Desulfocella halophila gen. nov., sp. nov. is proposed for this organism. The type strain of D. halophila is strain GSL-But2T (= DSM 11763T = ATCC 700426T).  (+info)

Isolation from estuarine sediments of a Desulfovibrio strain which can grow on lactate coupled to the reductive dehalogenation of 2,4, 6-tribromophenol. (2/2414)

Strain TBP-1, an anaerobic bacterium capable of reductively dehalogenating 2,4,6-tribromophenol to phenol, was isolated from estuarine sediments of the Arthur Kill in the New York/New Jersey harbor. It is a gram-negative, motile, vibrio-shaped, obligate anaerobe which grows on lactate, pyruvate, hydrogen, and fumarate when provided sulfate as an electron acceptor. The organism accumulates acetate when grown on lactate and sulfate, contains desulfoviridin, and will not grow in the absence of NaCl. It will not utilize acetate, succinate, propionate, or butyrate for growth via sulfate reduction. When supplied with lactate as an electron donor, strain TBP-1 will utilize sulfate, sulfite, sulfur, and thiosulfate for growth but not nitrate, fumarate, or acrylate. This organism debrominates 2-, 4-, 2,4-, 2,6-, and 2,4,6-bromophenol but not 3- or 2,3-bromophenol or monobrominated benzoates. It will not dehalogenate monochlorinated, fluorinated, or iodinated phenols or chlorinated benzoates. Together with its physiological characteristics, its 16S rRNA gene sequence places it in the genus Desulfovibrio. The average growth yield of strain TBP-1 grown on a defined medium supplemented with lactate and 2,4,6-bromophenol is 3.71 mg of protein/mmol of phenol produced, and the yield was 1.42 mg of protein/mmol of phenol produced when 4-bromophenol was the electron acceptor. Average growth yields (milligrams of protein per millimole of electrons utilized) for Desulfovibrio sp. strain TBP-1 grown with 2,4,6-bromophenol, 4-bromophenol, or sulfate are 0.62, 0.71, and 1.07, respectively. Growth did not occur when either lactate or 2,4,6-bromophenol was omitted from the growth medium. These results indicate that Desulfovibrio sp. strain TBP-1 is capable of growth via halorespiration.  (+info)

Diversity of nitrous oxide reductase (nosZ) genes in continental shelf sediments. (3/2414)

Diversity of the nitrous oxide reductase (nosZ) gene was examined in sediments obtained from the Atlantic Ocean and Pacific Ocean continental shelves. Approximately 1,100 bp of the nosZ gene were amplified via PCR, using nosZ gene-specific primers. Thirty-seven unique copies of the nosZ gene from these marine environments were characterized, increasing the nosZ sequence database fourfold. The average DNA similarity for comparisons between all 49 variants of the nosZ gene was 64% +/- 10%. Alignment of the derived amino acid sequences confirmed the conservation of important structural motifs. A highly conserved region is proposed as the copper binding, catalytic site (CuZ) of the mature protein. Phylogenetic analysis demonstrated three major clusters of nosZ genes, with little overlap between environmental and culture-based groups. Finally, the two non-culture-based gene clusters generally corresponded to sampling location, implying that denitrifier communities may be restricted geographically.  (+info)

Dense populations of a giant sulfur bacterium in Namibian shelf sediments. (4/2414)

A previously unknown giant sulfur bacterium is abundant in sediments underlying the oxygen minimum zone of the Benguela Current upwelling system. The bacterium has a spherical cell that exceeds by up to 100-fold the biovolume of the largest known prokaryotes. On the basis of 16S ribosomal DNA sequence data, these bacteria are closely related to the marine filamentous sulfur bacteria Thioploca, abundant in the upwelling area off Chile and Peru. Similar to Thioploca, the giant bacteria oxidize sulfide with nitrate that is accumulated to +info)

Environment and behavior of 2.5-million-year-old Bouri hominids. (5/2414)

The Hata Member of the Bouri Formation is defined for Pliocene sedimentary outcrops in the Middle Awash Valley, Ethiopia. The Hata Member is dated to 2.5 million years ago and has produced a new species of Australopithecus and hominid postcranial remains not currently assigned to species. Spatially associated zooarchaeological remains show that hominids acquired meat and marrow by 2.5 million years ago and that they are the near contemporary of Oldowan artifacts at nearby Gona. The combined evidence suggests that behavioral changes associated with lithic technology and enhanced carnivory may have been coincident with the emergence of the Homo clade from Australopithecus afarensis in eastern Africa.  (+info)

Rhodococcus erythropolis DCL14 contains a novel degradation pathway for limonene. (6/2414)

Strain DCL14, which is able to grow on limonene as a sole source of carbon and energy, was isolated from a freshwater sediment sample. This organism was identified as a strain of Rhodococcus erythropolis by chemotaxonomic and genetic studies. R. erythropolis DCL14 also assimilated the terpenes limonene-1,2-epoxide, limonene-1,2-diol, carveol, carvone, and (-)-menthol, while perillyl alcohol was not utilized as a carbon and energy source. Induction tests with cells grown on limonene revealed that the oxygen consumption rates with limonene-1,2-epoxide, limonene-1,2-diol, 1-hydroxy-2-oxolimonene, and carveol were high. Limonene-induced cells of R. erythropolis DCL14 contained the following four novel enzymatic activities involved in the limonene degradation pathway of this microorganism: a flavin adenine dinucleotide- and NADH-dependent limonene 1, 2-monooxygenase activity, a cofactor-independent limonene-1, 2-epoxide hydrolase activity, a dichlorophenolindophenol-dependent limonene-1,2-diol dehydrogenase activity, and an NADPH-dependent 1-hydroxy-2-oxolimonene 1,2-monooxygenase activity. Product accumulation studies showed that (1S,2S,4R)-limonene-1,2-diol, (1S, 4R)-1-hydroxy-2-oxolimonene, and (3R)-3-isopropenyl-6-oxoheptanoate were intermediates in the (4R)-limonene degradation pathway. The opposite enantiomers [(1R,2R,4S)-limonene-1,2-diol, (1R, 4S)-1-hydroxy-2-oxolimonene, and (3S)-3-isopropenyl-6-oxoheptanoate] were found in the (4S)-limonene degradation pathway, while accumulation of (1R,2S,4S)-limonene-1,2-diol from (4S)-limonene was also observed. These results show that R. erythropolis DCL14 metabolizes both enantiomers of limonene via a novel degradation pathway that starts with epoxidation at the 1,2 double bond forming limonene-1,2-epoxide. This epoxide is subsequently converted to limonene-1,2-diol, 1-hydroxy-2-oxolimonene, and 7-hydroxy-4-isopropenyl-7-methyl-2-oxo-oxepanone. This lactone spontaneously rearranges to form 3-isopropenyl-6-oxoheptanoate. In the presence of coenzyme A and ATP this acid is converted further, and this finding, together with the high levels of isocitrate lyase activity in extracts of limonene-grown cells, suggests that further degradation takes place via the beta-oxidation pathway.  (+info)

Role of methanogens and other bacteria in degradation of dimethyl sulfide and methanethiol in anoxic freshwater sediments. (7/2414)

The roles of several trophic groups of organisms (methanogens and sulfate- and nitrate-reducing bacteria) in the microbial degradation of methanethiol (MT) and dimethyl sulfide (DMS) were studied in freshwater sediments. The incubation of DMS- and MT-amended slurries revealed that methanogens are the dominant DMS and MT utilizers in sulfate-poor freshwater systems. In sediment slurries, which were depleted of sulfate, 75 micromol of DMS was stoichiometrically converted into 112 micromol of methane. The addition of methanol or MT to DMS-degrading slurries at concentrations similar to that of DMS reduced DMS degradation rates. This indicates that the methanogens in freshwater sediments, which degrade DMS, are also consumers of methanol and MT. To verify whether a competition between sulfate-reducing and methanogenic bacteria for DMS or MT takes place in sulfate-rich freshwater systems, the effects of sulfate and inhibitors, like bromoethanesulfonic acid, molybdate, and tungstate, on the degradation of MT and DMS were studied. The results for these sulfate-rich and sulfate-amended slurry incubations clearly demonstrated that besides methanogens, sulfate-reducing bacteria take part in MT and DMS degradation in freshwater sediments, provided that sulfate is available. The possible involvement of an interspecies hydrogen transfer in these processes is discussed. In general, our study provides evidence for methanogenesis as a major sink for MT and DMS in freshwater sediments.  (+info)

Molecular analysis of microbial community structures in pristine and contaminated aquifers: field and laboratory microcosm experiments. (8/2414)

This study used phylogenetic probes in hybridization analysis to (i) determine in situ microbial community structures in regions of a shallow sand aquifer that were oxygen depleted and fuel contaminated (FC) or aerobic and noncontaminated (NC) and (ii) examine alterations in microbial community structures resulting from exposure to toluene and/or electron acceptor supplementation (nitrate). The latter objective was addressed by using the NC and FC aquifer materials for anaerobic microcosm studies in which phylogenetic probe analysis was complemented by microbial activity assays. Domain probe analysis of the aquifer samples showed that the communities were predominantly Bacteria; Eucarya and Archaea were not detectable. At the phylum and subclass levels, the FC and NC aquifer material had similar relative abundance distributions of 43 to 65% beta- and gamma-Proteobacteria (B+G), 31 to 35% alpha-Proteobacteria (ALF), 15 to 18% sulfate-reducing bacteria, and 5 to 10% high G+C gram positive bacteria. Compared to that of the NC region, the community structure of the FC material differed mainly in an increased abundance of B+G relative to that of ALF. The microcosm communities were like those of the field samples in that they were predominantly Bacteria (83 to 101%) and lacked detectable Archaea but differed in that a small fraction (2 to 8%) of Eucarya was detected regardless of the treatment applied. The latter result was hypothesized to reflect enrichment of anaerobic protozoa. Addition of nitrate and/or toluene stimulated microbial activity in the microcosms, but only supplementation of toluene alone significantly altered community structures. For the NC material, the dominant subclass shifted from B+G to ALF, while in the FC microcosms 55 to 65% of the Bacteria community was no longer identifiable by the phylum or subclass probes used. The latter result suggested that toluene exposure fostered the proliferation of phylotype(s) that were otherwise minor constituents of the FC aquifer community. These studies demonstrated that alterations in aquifer microbial communities resulting from specific anthropogenic perturbances can be inferred from microcosm studies integrating chemical and phylogenetic probe analysis and in the case of hydrocarbon contamination may facilitate the identification of organisms important for in situ biodegradation processes. Further work integrating and coordinating microcosm and field experiments is needed to explore how differences in scale, substrate complexity, and other hydrogeological conditions may affect patterns observed in these systems.  (+info)

TY - JOUR. T1 - Integrated ocean drilling program expedition 317 preliminary report canterbury basin sea level global and local controls on continental margin stratigraphy. AU - Fulthorpe, Craig S.. AU - Hoyanagi, Koichi. AU - Blum, Peter. AU - Guèrin, Gilles. AU - Slagle, Angela L.. AU - Blair, Stacie A.. AU - Browne, Gregory H.. AU - Carter, Robert M.. AU - Ciobanu, Maria Cristina. AU - Claypool, George E.. AU - Crundwell, Martin P.. AU - Dinarès-Turell, Jaume. AU - Ding, Xuan. AU - George, Simon C.. AU - Hepp, Daniel A.. AU - Jaeger, John. AU - Kawagata, Shungo. AU - Kemp, David B.. AU - Kim, Young Gyun. AU - Kominz, Michelle A.. AU - Lever, Helen. AU - Lipp, Julius Sebastian. AU - Marsaglia, Kathleen M.. AU - McHugh, Cecilia M.. AU - Murakoshi, Naomi. AU - Ohi, Takeshi. AU - Pea, Laura. AU - Richaud, Mathieu. AU - Suto, Itsuki. AU - Tanabe, Susumu. AU - Tinto, Kirsteen J.. AU - Uramoto, Goichiro. AU - Yoshimura, Toshihiro. PY - 2010. Y1 - 2010. N2 - Integrated Ocean Drilling Program (IODP) ...
Sediment community oxygen consumption (SCOC) is a proxy for organic matter processing and thus provides a useful proxy of benthic ecosystem function. Oxygen uptake in deep-sea sediments is mainly driven by bacteria, and the direct contribution of benthic macro- and mega-infauna respiration is thought to be relatively modest. However, the main contribution of infaunal organisms to benthic respiration, particularly large burrowing organisms, is likely to be indirect and mainly driven by processes such as feeding and bioturbation that stimulate bacterial metabolism and promote the chemical oxidation of reduced solutes. Here, we estimate the direct and indirect contributions of burrowing shrimp (Eucalastacus cf. torbeni) to sediment community oxygen consumption based on incubations of sediment cores from 490 m depth on the continental slope of New Zealand. Results indicate that the presence of one shrimp in the sediment is responsible for an oxygen uptake rate of about 40 µmol d−1, only 1% of ...
Sediments in the Trinity River were chemically, physically and biologically characterized and assessed for toxicity. Laboratory bioassays were conducted to identify sediments which induced toxic responses in test organisms and to document these responses through time. Metal and organic contaminant concentrations in bottom sediments were measured. Relationships between these concentrations and biological responses observed in laboratory bioassays were determined. Toxicity identification / reduction methods were used to characterize sediment toxicants. Sediment oxygen demand was also measured in resuspended and undisturbed bottom sediments through time. The Background Sediment Chemistry Approach and the Sediment Bioassay Approach were used to assess sediment quality. Sediment toxicity was observed in whole sediment bioassays using Chironomus tentans as the test species. A relationship between sediment contaminant concentration and toxicity was observed in approximately sixty percent of the sediments.
The effects of increasing atmospheric CO2 on ocean ecosystems are a major environmental concern, as rapid shoaling of the carbonate saturation horizon is exposing vast areas of marine sediments to corrosive waters worldwide. Natural CO2 gradients off Vulcano, Italy, have revealed profound ecosystem changes along rocky shore habitats as carbonate saturation levels decrease, but no investigations have yet been made of the sedimentary habitat. Here, we sampled the upper 2 cm of volcanic sand in three zones, ambient (median pCO(2) 419 mu atm, minimum Omega(arag) 3.77), moderately CO2-enriched (median pCO(2) 592 mu atm, minimum Omega(arag) 2.96), and highly CO2-enriched (median pCO(2) 1611 mu atm, minimum Omega(arag) 0.35). We tested the hypothesis that increasing levels of seawater pCO(2) would cause significant shifts in sediment bacterial community composition, as shown recently in epilithic biofilms at the study site. In this study, 454 pyrosequencing of the V1 to V3 region of the 16S rRNA gene ...
This map shows the stacked vertical distribution of nonlithified surficial earth materials within the Marlborough quadrangle. This series of maps shows these deposits as they are vertically arranged in units from bottom to top. Surficial materials include mineral and rock particles in glacial deposits, and mineral, rock, and organic particles in postglacial deposits. Surficial materials also are known in engineering classifications as unconsolidated soils, which include coarse grained soils, fine grained soils, or organic fine grained soils. Surficial materials underlie and are the parent materials of modem pedogenic soils which have developed in them at the land surface. Delineation of the materials is based on surficial geologic mapping (Stone, 1978, Hildreth, 2003, 2004), the identification of glacial meltwater morphosequence deposits, knowledge of the deglaciation history of New England, and examination of borehole logs and water well records. For this set of maps, glacial meltwater deposits ...
Callianassid shrimps are the dominant endofauna of reef-top sediments on John Brewer Reef, a small platform reef in the central section of Australias Great Barrier Reef Province. Sediment reworking by these shrimps was investigated using the 210 Pb radioisotope in conjunction with 14 C radiometry and textural data. 210 Pb analyses of cores from two reef-top sites revealed a classical tripartite subdivision characteristic of depositional settings in which sediment reworking dominates over sediment accumulation: (1) A vertical surface mixed layer (SML) extending to a depth of nearly equal 50 cm beneath the sediment surface and representing a zone of intensive callianassid reworking; (2) An intermediate region of radioactive attenuation in which excess 210 Pb activity decreases logarithmically to a depth of slightly more than one meter beneath the sediment surface, and interpreted as representing a region utilized less frequently by Callianassa for coarse grain storage and predator avoidance; (3) ...
The microbial communities associated with electrodes from underwater fuel cells harvesting electricity from five different aquatic sediments were investigated. Three fuel cells were constructed with marine, salt-marsh, or freshwater sediments incubated in the laboratory. Fuel cells were also deployed in the field in salt marsh sediments in New Jersey and estuarine sediments in Oregon, USA. All of the sediments produced comparable amounts of power. Analysis of 16S rRNA gene sequences after 3-7 months of incubation demonstrated that all of the energy-harvesting anodes were highly enriched in microorganisms in the delta-Proteobacteria when compared with control electrodes not connected to a cathode. Geobacteraceae accounted for the majority of delta-Proteobacterial sequences or all of the energy-harvesting anodes, except the one deployed at the Oregon estuarine site. Quantitative PCR analysis of 16S rRNA genes and culturing studies indicated that Geobacteraceae were 100-fold more abundant on the ...
TY - JOUR. T1 - The effect of particle size on sorption of estrogens, androgens and progestagens in aquatic sediment. AU - Sangster, Jodi L.. AU - Oke, Hugues. AU - Zhang, Yun. AU - Bartelt-Hunt, Shannon L. PY - 2015/12/5. Y1 - 2015/12/5. N2 - There is increasing evidence of enhanced transport and biological effects stemming from steroid hormones associated with soils or sediments; however, there are limited studies evaluating how steroid hormone distribution between various particle sizes within whole sediments affects steroid fate. In this study, sorption of 17β-estradiol, estrone, progesterone, and testosterone was evaluated to different size fractions of two natural sediments, a silty loam and a sandy sediment, to determine the steroid sorption capacity to each fraction and distribution within the whole sediment. Sorption isotherms for all steroid hormones fit linear sorption models. Sorption capacity was influenced more by organic carbon content than particle size. Interactions between ...
Sediment management includes different steps in handling (uptake/dredging, transport and disposal), characterization, and sediment quality assessment, which are necessary during construction activities and for the protection and remediation of water bodies. Often, sediment management concepts need holistic understanding of the processes, which are involved in sediment genesis and erosion under specific conditions in different river basins, to work together with the forces of nature and not against them. Sediment management also includes the understanding of sediment contamination such as source control and remediation. In order to protect water bodies, it is therefore necessary to deepen our knowledge on the interaction of water, sediments, microorganisms and rocks, the mobility and transport of pollutants, the development of new technologies for the remediation of contaminated sediments, and the hydrogeochemical modeling of the interaction of contaminants with the sediments.. The symposium will ...
The factors controlling the relative abundances of Archaea and Bacteria in marine sediments are poorly understood. We determined depth distributions of archaeal and bacterial 16S rRNA genes by quantitative PCR at eight stations in Aarhus Bay, Denmark. Bacterial outnumber archaeal genes 10-60-fold in uppermost sediments that are irrigated and mixed by macrofauna. This bioturbation is indicated by visual observations of sediment color and faunal tracks, by porewater profiles of dissolved inorganic carbon and sulfate, and by distributions of unsupported 210Pb and 137Cs. Below the depth of bioturbation, the relative abundances of archaeal genes increase, accounting for one third of 16S rRNA genes in the sulfate zone, and half of 16S rRNA genes in the sulfate-methane transition zone and methane zone. Phylogenetic analyses reveal a strong shift in bacterial and archaeal community structure from bioturbated sediments to underlying layers. Stable isotopic analyses on organic matter and porewater ...
Lanthanum-modified bentonite clay (Phoslock®) is a lake remediation tool designed to strip dissolved phosphorus (P) from the water column and increase the sediment P-sorption capacity. This study investigated short term alterations in sediment elemental composition and sediment P-fractions based on sediment cores taken 2 days before and 28 days following the application of 24 t of Phoslock® to a 9 ha, man-made reservoir. Following the application, sediment lanthanum (La) content increased significantly (p , 0.05; n = 4) in the top 8 cm of the sediment, thereby theoretically increasing sediment P-binding capacity on the whole reservoir scale by 250 kg. Mass balance calculations were used to estimate the theoretical binding of release-sensitive P (Pmobile; sum of labile P, reductant-soluble P and organic P fraction) by La across the top 4 cm and 10 cm depth of sediment. The amended mass of La in the sediment had the potential to bind 42% of Pmobile present in the top 4 cm or 17% of Pmobile ...
Natural organic matter, such as humic and fulvic acids and humin, plays a key role in determining the fate and mobility of radioiodine in soil and sediments. The radioisotope I-129 is continuously produced and released from nuclear fuel reprocessing plants, and as a biophilic element, its environmental mobility is strongly linked to organic matter.. Due to its long half-life (15.7 million years), I-129 builds up in the environment and can be traced since the beginning of the nuclear era in reservoirs such as soils and marine sediments. Nevertheless, partition of the isotope between the different types of organic matter in soil and sediment is rarely explored. Here we present a sequential extraction of I-129 and I-127 chemical forms encountered in a Danish soil, a soil reference material (IAEA-375), an anoxic marine sediment from Southern Norway and an oxic sediment from the Barents Sea. The different forms of iodine are related to water soluble, exchangeable, carbonates, oxides as well as iodine ...
Suess, Erwin, von Huene, Roland, Emeis, Kay-Christian, Bourgois, Jacques, Cruzado Castaneda, Jose del C., De Wever, Patrick, Eglinton, Geoffrey, Garrison, Robert, Greenberg, Matt, Paz, Elard Herrera, Hill, Philip R., Ibaraki, Masako, Kastner, Miriam, Kemp, Alan E.S., Kvenvolden, Keith A., Langridge, Robert, Lindsley-Griffin, Nancy, Marsters, Janice, Martini, Erlend, McCabe, Robert; Ocola, Leonidas, Resig, Johanna, Sanchez Fernandez, Agapito Wilfredo, Schrader, Hans-Joachim, Thornburg, Todd M, Wefer, Gerold, and Yamano, Makoto, 1988, Proceedings of the Ocean Drilling Program, Peru continental margin; covering Leg 112 of the cruises of the drilling vessel JOIDES Resolution, 20 October 1986-25 December 1986, in Stewart, Sondra K., ed., Proceedings of the Ocean Drilling Program, Peru continental margin; covering Leg 112 of the cruises of the drilling vessel JOIDES Resolution, 20 October 1986-25 December 1986: Proceedings of the Ocean Drilling Program, Part A: Initial Reports, v. 112, 1015 p. Suess, ...
Aggregates is the collective term for sand, gravel and crushed rock. They are used as raw materials for the construction industry as well as for beach replenishment schemes. During aggregate extraction, the unwanted part of the sediment is discarded back into the water or onto the seabed. Consequently, changes occur to the size of sediment particles, which can alter the natural seabed and the invertebrates living on or inside it (De Groot 1996). Limits for acceptable change in particle size during aggregate extraction can be set, with the aim of reducing the amount of alteration to seabed sediment properties. This may facilitate recovery following cessation of activities post-extraction (Cooper 2013). Additional evidence for intervention related to sediment discard during aggregate extraction and other activities are summarised under Threat: Energy production and mining - Limit, cease, or prohibit sediment discard during aggregate extraction, Remove discarded sediment material from the ...
Polynuclear aromatic hydrocarbons (PAHs) are a class of contaminants commonly found in bottom sediments near highly industrialized areas. Resuspension of these sediments can make these contaminants more available for dispersal into the marine environment. The process will also cause the oxidation-reduction characteristics of the sediments to change from anaerobic to aerobic. Bacteria in these sediments have been shown capable of degrading 2 and 3 ring PAHs under aerobic conditions. This research examined the relationship between resuspension and biodegradation of PAHs in laboratory scale slurry reactors. Phenanthrene was used as the model compound. Radiolabeled compound was used to monitor mineralization, and mass balances were performed to determine final partitioning of carbon from degraded phenanthrene. Sediments were kept anaerobic from collection, through the contamination process, and through the loading of test reactors. Aeration of and contaminant release in sediment/water slurries was ...
Article Towards Ecosystem Based Sediment Quality Guidelines for PCB. To investigate whether Sediment Quality Guidelines (SQG) for PCBs in Canada and British Columbia achieve their objective of protecting ecosystems, we measured and compiled concentra...
Quantifying the mass transport through marine sediments, and the geochemical response to such flow with numerical models has become a common and powerful approach for geochemical data interpretation. In this dissertation, I developed and applied transport-reaction models to unravel complex and interdependent reactions involving carbon, sulfur and silica transformations in shallow marine sediments, and the impact of physical (mass transport deposits) and depositional events (volcanic ash input) on the overall geochemical state of the system. Carbon cycling in the gas hydrate bearing sediments of the Ulleung Basin was quantified using both box and kinetic modeling approaches. The box model balances mass, flux, and carbon isotopes of carbon (Chapter 2), and led to a better understanding of how methane is cycled in the marine sediments of this area. This effort demonstrates the significance of CO₂ reduction, a previously overlooked reaction. The picture of reaction network derived from this work ...
River sediment microorganisms have the capacity to metabolize, uptake and decompose flowing water organic materials, which strongly depend on their metabolic capabilities. The changes of microbial functional diversity in river sediments were analysed at five sites along the River Llobregat (NE Spain), using the Biolog EcoPlates incubation method. In parallel, we tested the potential application of the EcoPlates with preserved frozen samples (-80 °C). Although functional diversity (Shannon index) did not show significant differences, the specific carbon substrates that were used differed between sampling sites. The microbial community from the upstream site was the most active as shown by the highest respiratory activity and abundance of living bacteria, being able to metabolize more labile substrates. Downstream sediment communities showed a decrease in bacterial viability, respiration activity and EPS content, suggesting a less structured biofilm. The functional fingerprint analyses clearly ...
A testate amoeba with organic test, isolated from sediments in the Firth of Clyde, Scotland, has been assigned to a new genus as Ovulina parva (Protista: Filosea) based on its unique light microscopic and fine structural morphology. The hyaline to amber test is ovate (similar to 15x11 mu m) with a terminal aperture that is either unadorned or with a shallow collar. Hyaline, long-tapering, pointed, sometimes branched, pseudopodia emerge directly from the aperture or from the periphery of a thin web of hyaline cytoplasm. The nucleus (similar to 5 mu m) with a central nucleolus (similar to 2 mu m) is located at the posterior of the cytoplasm. The fine structure of the test, examined by scanning and transmission electron microscopy, shows it is entirely organic with an irregular to granular surface. Scattered elongate pits (similar to 1 mu m long) without perforations are distributed irregularly on the surface. Ectoplasm is distributed within a fine fibrillar envelope lining the test. The endoplasm ...
TY - JOUR. T1 - Carbon and hydrogen isotopic compositions of sterols from riverine and marine sediments. AU - Chikaraishi, Yoshito. AU - Yamada, Yusuke. AU - Naraoka, Hiroshi. PY - 2005/1/1. Y1 - 2005/1/1. N2 - The sources (marine algae, terrestrial C3 and C4 plants) of sterols deposited to sediments along a riverine-marine transect from Ohtsuchi River in Iwate Prefecture, Japan, to the northwestern Pacific Ocean were estimated using carbon (δ13C) and hydrogen isotopic compositions (δD) in surface sediments. In marine sediments, algal sterols such as 24-methylcholesta-5,22-dien-3β-ol had δ13C values of -22.7 ± 0.4‰ and δD values of -292 ± 3‰. In contrast, sterols derived from multiple potential sources, such as 24-methylcholest-5-en-3β-ol and 24-ethylcholest-5-en-3β-ol, were gradually enriched in 13C from riverine (-30.7‰ and -30.5‰, respectively) to marine sediments (-22.3‰ and -24.4‰, respectively), but showed little variation in δD values (-262 ± 1‰). These isotopic ...
With the yearly increasing marine culture activities in floating cages in Daya Bay, China, the effects of pollution may overlap and lead to more severe water environmental problems. In order to track the impacts of the marine culture in floating cages on water environment, sediments and overlying water were sampled by cylindrical samplers at three representative aquaculture areas of Daya Bay. The water content, porosity, density of sediments as well as the vertical distributions of ammonia nitrogen and active phosphate in pore water along sediments depth were measured. The release rate and annual released quantity of the nutrients across sediment-water interface were calculated using Ficks Law. A horizontal two-dimensional mathematical model was developed to compute the spatial and temporal distributions of the nutrients in seawater after being released across the sediment-water interface. The results showed that the sediments, with a high content and a large annual released quantity of nitrogen and
The following methods of measurement of sediment parameters are discussed: (1) rate of diffusional exchange of reactants and products across the sediment-water interface; (2) the concentration profiles of these reactants and profiles in the sediment, and (3) profiles and integrated rates of reactions in the sediment. The interaction of the processes of reaction and diffusion are illustrated using a simulation model. The effect of increasing organic loading (6.2, 37.2 and 62.0 mmol C m-2 d-1), with organic matter distributed in three ways: close to the sediment surface, a linear gradient downwards or evenly mixed throughout the sediment. Predictable increases in anoxic processes occurred with increasing organic loading. There were higher diffusional losses of dissolved organic matter when organic degradation occurred close to the sediment-water interface. The model predicted that degradation of organic matter at depth could have the following effects: an increase in the depth of oxygen ...
The radiogenic isotopic composition of both detrital and Fe-Mn fractions in marine sediments can be used in paleoceanography to infer changes of bottom-water circulation. We have examined various chemical techniques for the analysis of Sr and Nd isotope ratios in these fractions and present a robust method that can be used to separate both the Fe-Mn oxides and the detrital fraction from a marine sediment sample for isotopic analysis. Our sequential leaching procedure involves the use of 10% acetic acid, followed by 1 M hydroxylamine hydrochloride in 25% acetic acid to remove the carbonate component and the Fe-Mn oxide fraction, respectively. The applicability of our chemical procedure is illustrated with examples from a marine sediment core raised from the northern Cape Basin, southeast Atlantic Ocean.. ...
A three-year study of seasonal variation in water-column and sediment nitrogen species was conducted in the transition zone of the Potomac River 35 m from the Virginia shore at a site with an average water-column depth of approximately 1 m over sandy sediment. A diffusion-controlled sampler was used to collect water samples from the water column, at the interface between the water column and sediment, and at several tens of centimeters into the sediment. Nitrate was the predominant dissolved nitrogen species in the water column. The importance of denitrification was inferred by nitrate fluxes which were directed into the sediment from the water column during approximately 75% of the sampling periods and ranged from 0??02 to 0??69 mmol m-2 day-1. Flux of nitrate from the sediment into the water column, ???0??1 mmol m-2 day-1, due possibly to nitrification in surficial sediment, occurred during one spring and two summer sampling periods....
Temperate mangrove and salt marsh sediments are a small methane and nitrous oxide source but important carbon store Journal Articles Refereed ...
Studies of phosphorus (P) dynamics in surface sediments of lakes and coastal seas typically emphasize the role of coupled iron (Fe), sulfur (S) and P cycling for sediment P burial and release. Here, we show that anaerobic oxidation of methane (AOM) also may impact sediment P cycling in such systems. Using porewater and sediment profiles for sites in an oligotrophic coastal basin (Bothnian Sea), we provide evidence for the formation of Fe-bound P (possibly vivianite; Fe-3(PO4)(2)center dot 8H(2)O) below the zone of AOM with sulfate. Here, dissolved Fe2+ released from oxides is no longer scavenged by sulfide and high concentrations of both dissolved Fe2+ (,1 mM) and PO4 in the porewater allow supersaturation with respect to vivianite to be reached. Besides formation of Fe(II)-P, preservation of Fe-oxide bound P likely also contributes to permanent burial of P in Bothnian Sea sediments. Preliminary budget calculations suggest that the burial of Fe-bound P allows these sediments to act as a major ...
Scientific ocean drilling has greatly advanced the understanding of subseafloor sedimentary life. Studies of Ocean Drilling Program (ODP) and Integrated ODP samples and data show that mean per-cell rates of catabolic activity, energy flux, and biomass turnover are orders of magnitude slower in subseafloor sediment than in the surface world. They have also shown that potentially competing metabolic pathways co-occur for hundreds of meter depth in subseafloor sediment deposited over millions of years. Our study of an example site (eastern equatorial Pacific ODP Site 1226) indicates that the energy yields of these competing reactions are pinned to a thermodynamic minimum. The simplest explanation of this long-term coexistence is thermodynamic cooperation, where microorganisms utilize different but coexisting pathways that remove each others reaction products. Our Site 1226 results indicate that the energy flux to subseafloor sedimentary microbes is extremely low. Comparison to biomass turnover ...
Grandel, Sibylle; Rickert, Dirk; Schlüter, Michael; Wallmann, Klaus (2000): Geochemistry of porewater of sediment core SO129_MC-39. PANGAEA, https://doi.org/10.1594/PANGAEA.58226, In supplement to: Grandel, S et al. (2000): Pore-water distribution and quantification of diffusive benthic fluxes of silicic acid, nitrate, and phosphate in surface sediments of the deep Arabian Sea. Deep Sea Research Part II: Topical Studies in Oceanography, 47(14), 2707-2734, https://doi.org/10.1016/S0967-0645(00)00046-1
Grandel, Sibylle; Rickert, Dirk; Schlüter, Michael; Wallmann, Klaus (2000): Geochemistry of porewater of sediment core M33/1_MC-23. PANGAEA, https://doi.org/10.1594/PANGAEA.58246, In supplement to: Grandel, S et al. (2000): Pore-water distribution and quantification of diffusive benthic fluxes of silicic acid, nitrate, and phosphate in surface sediments of the deep Arabian Sea. Deep Sea Research Part II: Topical Studies in Oceanography, 47(14), 2707-2734, https://doi.org/10.1016/S0967-0645(00)00046-1
A Gram-stain-negative, non-flagellated, non-gliding and rod-shaped bacterial strain, designated TM-6T, was isolated from a tidal flat sediment in the Korean peninsula. Strain TM-6T was found to grow optimally at pH 7.0-8.0, at 30 °C and in the presence of 2-3% (w/v) NaCl. A neighbour-joining phylogenetic tree based on 16S rRNA gene sequences showed that strain TM-6T joined the clade comprising recognized species of the genus Fulvivirga , with which it exhibited 94.7- 95.2 % sequence similarity. Strain TM-6T was found to contain iso-C15 : 0, iso-C15 : 1 G and iso-C17 : 0 3-OH as major fatty acids. The only isoprenoid quinone was menaquinone-7 (MK-7). The major polar lipids were identified as phosphatidylethanolamine and three unidentified lipids. The DNA G+C content of strain TM-6T was 50.9 mol%. Differential phenotypic properties, together with the phylogenetic distinctiveness, revealed that strain TM-6T is distinguishable from recognized Fulvivirgaspecies. On the basis of the data presented, strain
Most often the increase of nutrients loads to coastal waters and sediment are the main cause of eutrophication-associated hypoxia. The consequent hypoxia can demolish the benthos and converted the flow of energy in the food chain downward instead of upward, thus feeding microbes in sediment [9]. Simultaneously, the pursuant hypoxia-induced release of nutrients such as phosphorus and nitrogen from deposited organic matter can be substantial and hold down the tainted consequences of external loading [10, 11]. Thermodynamically, oxygen is the most favorable electron acceptor, but the oxygen depletion in the sediment may contribute to liberate nitrogen from sediment into the water [12]. So increased nitrogen concentration and algal blooms conduct to more intense anoxia and there is a mutual prolonged effect between these processes [13]. Hypoxia can also enhance the release of nutrients from organic compounds in the sediment as ammonium is released from organic compounds by bacterial degradation ...
Overview: A primary objective of marine science classes is to learn the location and formation of ocean sediment types. Paper text and online multimedia both fall short of the experience of handling real ocean sediment. Real samples enhance learning through sight, touch, and smell, and microscope slides (smear slides for use with a petrographic microscope) allow students to better comprehend the tiny sizes and forms of various sediment components.. Real samples provide only pinpoint examples of the ocean floor, yet they swim within a virtual ocean of geological data that is best utilized with online visualization tools like Google Earth. We have merged both the real and the virtual by creating a Google Earth based supplemental information resource for each example of ocean sediment from an IODP sediment Core Kit consisting of core catcher sections and sediment smear slides that teachers may borrow for classroom instruction. 47 years of scientific ocean drilling has produced over 50,000 short ...
A 3-D hydrodynamic model is used to investigate how different size classes of river-derived sediment are transported, exported and trapped on an idealized, river-dominated tidal flat. The model is composed of a river channel flanked by sloping tidal flats, a configuration motivated by the intertidal region of the Skagit River mouth in Washington State, United States. It is forced by mixed tides and a pulse of freshwater and sediment with various settling velocities. In this system, the river not only influences stratification but also contributes a significant cross-shore transport. As a result, the bottom stress is strongly ebb-dominated in the channel because of the seaward advance of strong river flow as the tidal flats drain during ebbs. Sediment deposition patterns and mass budgets are sensitive to settling velocity. The lateral sediment spreading scales with an advective distance (settling time multiplied by lateral flow speed), thereby confining the fast settling sediment...
The aim of present work was to assess the concentration levels as well as vertical distribution of indicator bacteria including total coliform, fecal coliform, Pseudomonas aeruginosa, and Heterotrophic Plate Count (HPC) in the marine environment (seawater and coastal sediments) and evaluate the correlation between indicator bacteria and some physicochemical parameters of surface sediments as well as seawaters. A total number of 48 seawater and sediment samples were taken from 8 stations (each site 6 times with an interval time of 2 weeks) between June and September 2014. Seawater and sediment samples were collected from 30 cm under the surface samples and different sediment depths (0, 4, 7, 10, 15, and 20 cm) respectively, along the Persian Gulf in Bushehr coastal areas. Based on the results, the average numbers of bacterial indicators including total coliform, fecal coliform, and Pseudomonas aeruginosa as well as HPC in seawater samples were 1238.13, 150.87, 8.22 MPN/100 ml and 1742.91 CFU/ml,
TY - JOUR. T1 - Temperature Driven Changes in Benthic Bacterial Diversity Influences Biogeochemical Cycling in Coastal Sediments. AU - Hicks, Natalie. AU - Liu, Xuan. AU - Gregory, Richard. AU - Kenny, John. AU - Lucaci, Anita. AU - Lenzi, Luca. AU - Paterson, David M.. AU - Duncan, Katherine R.. N1 - © 2018 Hicks, Liu, Gregory, Kenny, Lucaci, Lenzi, Paterson and Duncan. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). PY - 2018/8/22. Y1 - 2018/8/22. N2 - Marine sediments are important sites for global biogeochemical cycling, mediated by macrofauna and microalgae. However, it is the microorganisms that drive these key processes. There is strong evidence that coastal benthic habitats will be affected by changing environmental variables (rising temperature, elevated CO2), and research has generally focused on the impact on macrofaunal biodiversity and ecosystem services. Despite their importance, there is less understanding of how ...
Fluxes of TDCu and Cu ligands have been determined at two sites in the Chesapeake Bay for June and October 95, and in March 96. TDCu appears to flux out of the sediments at both sites in both spring and summer. In March 95, the TDCu flux out of site M (mid-Bay) sediments (41 + or - 10 nmol/sq m/d) exceeded that at site S (southern Bay: 7 + or - 3 nmol/sq m/d). However, in June 95, the TDCu flux out at site S (52 + or - 25 nmol/sq m/d) exceeded that at site M (13 + or - 15 nmol/sq m/d). There is a significant out-flux (200 to 800 nmol/sq m/d) of total Cu-binding ligands (TLcu) from the sediments at both sites in both spring and summer, but the TLcu flux at site M exceeded that at site S. The TLcu is 3-60x greater than the TDCu flux, and the ligands fluxing out are comparable in strength (log K=15) to that of the very strong L1 class that controls the speciation of TDCu in most marine surface waters, and previously only observed in these surface waters. Sediment fluxes of this very strong ligand in June
TY - JOUR. T1 - Urban sediment particle size and pollutants in Southern Brazil. AU - Poleto, Cristiano. AU - Bortoluzzi, Edson C.. AU - Charlesworth, Susanne M.. AU - Merten, Gustavo H.. N1 - Funding Information: Acknowledgements This study was supported by CAPES, CNPq and USGS.. PY - 2009. Y1 - 2009. N2 - Background, aim and scope Studies of particulate-associated pollutants, or PAPs, in urban areas have become necessary due to their potentially deleterious effects on the environment. However, it is not just the sediments themselves which are problematic but also their particle size composition, which has a great influence on their capacity to adsorb and transport pollutants. This paper presents the particle size distributions and concentrations of five metals (Cr, Cu, Ni, Pb and Zn) of urban sediments collected from paved streets and gully pots from 20 cities in southern Brazil. The cities have different characteristics and hence sources of PAPs associated with differing geologies, soil types ...
The coupling of subseafloor microbial life to oceanographic and atmospheric conditions is poorly understood. Contreras et al. examined diagenetic imprints and lipid biomarkers of past subseafloor microbial activity to evaluate its response to glacial-interglacial cycles in a sedimentary section drilled on the Peruvian shelf (Ocean Drilling Program Leg 201, Site 1229). Multiple and distinct layers of diagenetic barite and dolomite, i.e., minerals that typically form at the sulfate−methane transition (SMT), occur at much shallower burial depth than the present SMT around 30 meters below seafloor. These shallow layers co-occur with peaks of 13C-depleted archaeol, a molecular fossil of anaerobic methane-oxidizing Archaea. Present-day, non-steady state distributions of dissolved sulfate also suggest that the SMT is highly sensitive to variations in organic carbon flux to the surface shelf sediments that may lead to shoaling of the SMT. Reaction-transport modeling substantiates our hypothesis that ...
The EFSA Panel on Plant Protection Products and their Residues (PPR Panel) was tasked to revise the Guidance Document (GD) on Aquatic Ecotoxicology under Council Directive 91/414/EEC (SANCO/3268/2001 rev. 4 (final), 17 October 2002). This scientific opinion of the PPR Panel is the second of three requested deliverables within this mandate. The scientific background for the risk assessment on sediment organisms in edge-of-field surface waters is provided, with reference to benthic ecology and ecotoxicology, available test protocols and current knowledge on exposure and effects of sediment-bound plant protection products (PPPs). The scientific opinion provides approaches on how to derive regulatory acceptable concentrations (RACs) for sediment organisms and exposure to active substances of PPPs and transformation products of these substances, and how to link them in a tiered approach to predicted environmental concentrations (PECs) for the sediment compartment. A list of uncertainties in relation ...
We investigated the impact of temperature on the microbial turnover of organic matter (OM) in a hydrothermal vent system in Guaymas Basin, by calculating microbial bio- and necromass turnover times based on the culture-independent D:L-amino acid model. Sediments were recovered from two stations near hydrothermal mounds (|74°C) and from one cold station (|9°C). Cell abundance at the two hydrothermal stations dropped from 108 to 106 cells cm-3 within ∼5 m of sediment depth resulting in a 100-fold lower cell number at this depth than at the cold site where numbers remained constant at 108 cells cm-3 throughout the recovered sediment. There were strong indications that the drop in cell abundance was controlled by decreasing OM quality. The quality of the sedimentary OM was determined by the diagenetic indicators %TAAC (percentage of total organic carbon present as amino acid carbon), %TAAN (percentage of total nitrogen present as amino acid nitrogen), aspartic acid:β-alanine ratios, and glutamic acid
We investigated the impact of temperature on the microbial turnover of organic matter (OM) in a hydrothermal vent system in Guaymas Basin, by calculating microbial bio- and necromass turnover times based on the culture-independent D:L-amino acid model. Sediments were recovered from two stations near hydrothermal mounds (8 to 106 cells cm-3 within ∼5 m of sediment depth resulting in a 100-fold lower cell number at this depth than at the cold site where numbers remained constant at 108 cells cm-3 throughout the recovered sediment. There were strong indications that the drop in cell abundance was controlled by decreasing OM quality. The quality of the sedimentary OM was determined by the diagenetic indicators %TAAC (percentage of total organic carbon present as amino acid carbon), %TAAN (percentage of total nitrogen present as amino acid nitrogen), aspartic acid:β-alanine ratios, and glutamic acid:γ-amino butyric acid ratios. All parameters indicated that the OM became progressively degraded with
679 m3 s−1 by the 2090s, an increase of between 23% and 39% relative to the baseline period, depending on the specific climate model run.. In terms of future sediment fluxes, Fig. 6c shows that under the Q0 run sediment loads on the Ganges are projected to significantly increase relative to the 1981-2000 baseline of 521 Mt per year, to 613 Mt per year by the 2050s and then 696 Mt per year by the end of the century, the latter representing an overall increase of 175 Mt per year (34%) relative to the baseline period. Under the Q8 run a similar increase in sediment load with time is also evident, with projected values of 609 Mt per year by the 2050s (a 16% increase relative to the Q8 baseline) and 714 Mt per year by the 2090s, an end of century value which is around 191 Mt per year (37%) greater than the baseline. For the Ganges, sediment loads for the Q16 run are less than both the Q0 and Q8 runs, reflecting the lower precipitation in this catchment for the Q16 run (see Fig. 3). Thus, a mean ...
The porewater chemistry was in broad agreement with the observed petrology and, in the case of the urban site, the data provides evidence of sediment disturbance. The periodic resuspension of the sediment by boat traffic results in a significant change to the surface porewater chemistry of iron and sulphate in the urban sediment and results in changes to the stability of certain authigenic phases, most notably vivianite. In the rural sediment, although physical disturbance of the sediment was observed, there was no chemical evidence in the porewater results. However, it does perhaps subtly enhance the organic matter degradation processes that are occurring, although this could not be confirmed by the results of this investigation ...
Open full size. Gas bubble emissions from bottom sediments of Lake Baikal. Methane emissions from bottom sediments in Lake Baikal have been known for a long time. Even the first travelers, who visited the lake in the 17th century, noticed gas emissions. Later gas emissions in Baikal were explored by the East Siberian Branch of the Russian Imperial Geographical Society. A review of the available materials on gas seeps in Baikal is presented in the publication [Granin and Granina, 2002]. A new stage of research on gas seeps in Baikal started after the discovery of gas hydrates [Kuzmin et al., 1998] and mud volcanoes at the bottom of the lake [Van Rensbergen et al., 2002] at the turn of the 20th century.. Gas seeps are found in oceans, seas and freshwater bodies. To study gas seeps hydroacoustic methods are used, as they enable an extensive search due to the strong backscattering of sound from the bubbles of floating-up gas. To locate and monitor the activity of gas plumes a digital record of ...
The factor analysis, used in this work for the interpretation of maturation parameters observed in an exploration study of a group of surface sediments of diverse age originating from different localities in Serbia, resulted in two significant factors. Factor 1 involved parameters related mainly to maturation changes within the aliphatic chains of the organic matter and factor 2 involved parameters based mainly on changes in the terpane and sterane rings. A statistically significant inversely proportional linear dependence between factors 1 and 2 was observed with older, in contrast to younger sediments, suggesting that the reactions of the aliphatic chains in the older sediments did not occur simultaneously with the reactions in the rings and, also, that the older surface sediments examined in this study may be characterized by a degree of thermal maturity corresponding to changes in the biomarker sterane and terpane rings, while the younger sediments by intensive changes in the aliph...atic ...
In humid, tropical regions, where chemical weathering rates are high, the relationship between bedrock lithology, stream sediment mineralogy, and stream water chemistry is neither straightforward nor well known. For a country such as Cuba, which has been isolated from much of the worlds geologic community for decades, data are sparse; yet, such data are important for understanding landscape change over time, including deciphering trends in stream water geochemistry and rates of erosion, both natural and human-caused. Here, as part of a collaborative Cuban-American project focused on understanding mass transfer from the island to the ocean, we used quantitative X-ray diffraction to determine the bulk mineral composition of river sediment in two grain sizes. We used this data to determine the relationship between sediment mineralogy and water chemistry, weathering rates, sediment elemental composition, and mapped bedrock geology in 26 central Cuban drainage basins. Diffraction data show that quartz,
We developed a microsensor for the amperometric detection of dissolved hydrogen sulfide,H2S, in sedirnents and biofilms. The mlcrosensor exhibits a fast (tgOc 0.2 to 0.5 S) and linear response to H2S over a concentration range of 1 to ,l000 pm01 H2S-I and has a low stirring dependency of the microsensor signal (c1 to 2%). We used the new mlcrosensor to obtain the first microprofiles of H2S in an acidic lake sediment with a several cm thick flocculant surface layer. Despite the low pH of 4.6, a relative low SO,- level in the lake water, and a broad O2 respiration zone of ca 6 mm, we were able to measure H2S depth profiles in the sediment at a good resolution, that allowed for calculation of specific sulfate reduction and H2S oxidation activities. Such calculations showed highest sulfate reduction activity in the anoxic sediment down to ca 20 mm depth A comparison of calculated area1 rates of O2 consumption and sulfate reduction Indicated that sulfate reduction accounted for up to 13 % of total ...
Lower Eocene to Holocene sediments recovered from Ocean Drilling Program Sites 918 and 919 were studied to determine the grain-size distribution (sand to clay sizes) and mineralogy of the ,2 m size fraction. The minerals are believed to be of detrital origin. The clay minerals consist of chlorite, smectite, illite, kaolinite, and a mixed-layer illite/smectite. Several non-clay minerals were identified as well, including quartz, plagioclase, alkali-feldspar, amphibole, pyroxene, zeolite, and calcite.. Relative abundances of the clay minerals were semiquantified using an oriented internal standard. Smectite abundances were found to increase with depth, while illite and chlorite abundances decrease with depth.. The Eocene sediments of Site 918 are characterized by a predominance of smectite with some kaolinite and very small amounts of chlorite and illite. This mineral assemblage is indicative of warm climatic conditions at the time of deposition. Oligocene sediments show an increase in chlorite ...
Background. Methane oxidizing prokaryotes in marine sediments are believed to function as a methane filter reducing the oceanic contribution to the global methane emission. In the anoxic parts of the sediments, oxidation of methane is accomplished by anaerobic methanotrophic archaea (ANME) living in syntrophy with sulphate reducing bacteria. This anaerobic oxidation of methane is assumed to be a coupling of reversed methanogenesis and dissimilatory sulphate reduction. Where oxygen is available aerobic methanotrophs take part in methane oxidation. In this study, we used metagenomics to characterize the taxonomic and metabolic potential for methane oxidation at the Tonya seep in the Coal Oil Point area, California. Two metagenomes from different sediment depth horizons (0-4 cm and 10-15 cm below sea floor) were sequenced by 454 technology. The metagenomes were analysed to characterize the distribution of aerobic and anaerobic methanotrophic taxa at the two sediment depths. To gain insight into the ...
Two new secondary metabolites, namely, pinodiketopiperazine A (1) and 6,7-dihydroxy-3-methoxy-3-methylphthalide (2), along with alternariol 2,4-dimethyl ether (3) and l-5-oxoproline methyl ester (4), which were isolated from a natural source for the first time but have been previously synthesized, were characterized from the marine sediment-derived fungus Penicillium pinophilum SD-272. In addition, six known metabolites (5-10) were also identified. Their structures were elucidated by analysis of the NMR and mass spectroscopic data. The absolute configuration of compound 1 was determined by experimental and calculated ECD spectra. Compound 2 displayed potent brine shrimp (Artemia salina) lethality with LD50 11.2 μM.
Rhodopsins are broadly distributed. In this work, we analyzed 23 metagenomes corresponding to marine sediment samples from four regions that share cold climate conditions (Norway; Sweden; Argentina and Antarctica). In order to investigate the genes evolution of viral rhodopsins, an initial set of 6224 bacterial rhodopsin sequences according to COG5524 were retrieved from the 23 metagenomes. After selection by the presence of transmembrane domains and alignment, 123 viral (51) and non-viral (72) sequences (>50 amino acids) were finally included in further analysis. Viral rhodopsin genes were homologs of Phaeocystis globosa virus and Organic lake Phycodnavirus. Non-viral microbial rhodopsin genes were ascribed to Bacteroidetes, Planctomycetes, Firmicutes, Actinobacteria, Cyanobacteria, Proteobacteria, Deinococcus-Thermus and Cryptophyta and Fungi. A rescreening using Blastp, using as queries the viral sequences previously described, retrieved 30 sequences (>100 amino acids). Phylogeographic ...
Lake sediments constitute an important compartment in the carbon cycle of lakes, by burying carbon over geological timescales and by production and emission of greenhouse gases. The degradation of organic carbon (OC) in lake sediments is linked to both temperature and oxygen (O-2), but the interactive nature of this regulation has not been studied in lake sediments in a quantitative way. We present the first systematic investigation of the effects of temperature on the apparent respiratory quotient (RQ, i.e., the molar ratio between carbon dioxide (CO2) production and O-2 consumption) in two contrasting lake sediments. Laboratory incubations of sediment cores of a humic lake and an eutrophic lake across a 1-21 degrees C temperature gradient over 157days revealed that both CO2 production and O-2 consumption were positively, exponentially, and similarly dependent on temperature. The apparent RQ differed significantly between the lake sediments (0.630.26 and 0.990.28 in the humic and the eutrophic ...
Cold seeps in the Aleutian deep-sea trench support prolific benthic communities and generate carbonate precipitates which are dependent on carbon dioxide delivered from anaerobic methane oxidation. This process is active in the anaerobic sediments at the sulfate reduction-methane production boundary and is probably performed by archaea working in syntrophic co-operation with sulfate-reducing bacteria. Diagnostic lipid biomarkers of archaeal origin include irregular isoprenoids such as 2,6,11,15-tetramethylhexadecane (crocetane) and 2,6,10,15,19-pentamethylicosane (PMI) as well as the glycerol ether lipid archaeol (2,3-di-O-phytanyl-sn-glycerol). These biomarkers are prominent lipid constituents in the anaerobic sediments as well as in the carbonate precipitates. Carbon isotopic compositions of the biomarkers are strongly depleted in 13C with values of δ13C as low as −130.3‰ PDB. The process of anaerobic methane oxidation is also reflected in the carbon isotope composition of organic matter ...
The anaerobic oxidation of methane (AOM) is a globally significant sink that regulates methane flux from sediments into the oceans and atmosphere. Here we examine mesophilic to thermophilic AOM in hydrothermal sediments recovered from the Middle Valley vent field, on the Juan de Fuca Ridge. Using continuous-flow sediment bioreactors and batch incubations, we characterized (i) the degree to which AOM contributes to net dissolved inorganic carbon flux, (ii) AOM and sulfate reduction (SR) rates as a function of temperature and (iii) the distribution and density of known anaerobic methanotrophs (ANMEs). In sediment bioreactors, inorganic carbon stable isotope mass balances results indicated that AOM accounted for between 16% and 86% of the inorganic carbon produced, underscoring the role of AOM in governing inorganic carbon flux from these sediments. At 90°C, AOM occurred in the absence of SR, demonstrating a striking decoupling of AOM from SR. An abundance of Fe(III)-bearing minerals resembling ...
United States Geological Survey, Florida Integrated Science Center, Saint Petersburg (Terrestrial, Freshwater, and Marine Ecosystems Program),United States Army Corps of Engineers,Everglades National Park. Chief Scientists: Tom Smith, Gordon Anderson, Karen Balentine. Sampling of sediment surface elevation tables data of field activity 08LME02 (E-2-08-FL) in Everglades National Park, Florida, Ten Thousand Islands National Wildlife Refuge from 10/01/2008 to 09/30/2008, ,http://walrus.wr.usgs.gov/infobank/e/e208fl/html/e-2-08-fl.meta.html, ...
Gas-hydrate-bearing sand-core samples have been obtained from the Canadian Mallik wells, and the Nankai Trough wells of offshore Japan. The chloride-content anomalies in extracted pore waters, core-temperature depression, core observations, and visible gas hydrates, as well as continuous down-hole well-log data, confirm the presence of pore-space hydrateas an intergranular pore filling within sandy layers, clarifying the characteristics of subsurface natural gas hydrate in marine and permafrost zones. Gas-hydrate saturations (percent of pore volume) as high as 80% have been measured, which requires enough original pore space in the host sediment to allow the gas to accumulate. Carbon and hydrogen isotopic compositions of methane and hydrocarbon compositions in gas hydrate and gas-hydrate-bearing shallow sediments in the Nankai Trough show that methane is generated by microbial reduction of CO2 and suggest progressive decreases in microbial (biogenic) activity with depth and upward gas migration ...
In the present study, effect-directed analysis was used to identify teratogenic compounds in porewater collected from a Superfund site along the Elizabeth River estuary (VA, USA). Zebrafish (Danio rerio) exposed to the porewater displayed acute developmental toxicity and cardiac teratogenesis, presumably because of elevated sediment levels of polycyclic aromatic hydrocarbons (PAHs) from historical creosote use. Pretreatment of porewater with several physical and chemical particle removal methods revealed that colloid-bound chemicals constituted the bulk of the observed toxicity. Size-exclusive chromatography and normal-phase high-performance liquid chromatography were used to fractionate Elizabeth River porewater. Acute toxicity of porewater extracts and extract fractions was assessed as the pericardial area in embryonic zebrafish. The most toxic fraction contained several known aryl hydrocarbon receptor (AhR) agonists (e.g., 1,2-benzofluorene and 1,2-benzanthracene) and cytochrome P450 A1 ...
It has previously been demonstrated that [14C]-labeled polycyclic aromatic hydrocarbons (PAHs) can be oxidized to 14CO2 in anoxic, PAH-contaminated, marine harbor sediments in which sulfate reduction is the terminal electron-accepting process. However, it has not previously been determined whether t …
We compared the burial efficiency of organic carbon (buried OC: deposited OC) in a diverse set of 27 different sediments from 11 lakes, focusing on the potential effects of organic matter source, oxygen exposure, and protective sorption of OC onto mineral surfaces. Average OC burial efficiency was high (mean 48%), and it was particularly high in sediments receiving high input of allochthonous organic matter (mean 67%). Further, OC burial efficiency was strongly negatively related to the oxygen exposure time, again particularly so in sediments receiving high allochthonous loads. On the other hand, OC burial efficiency was not related to the mineral surface area, which was used as a proxy of the sorption capacity of the mineral phase for OC. The high OC burial efficiency in many lake sediments can thus be attributed to the frequent and significant input of allochthonous organic matter to lakes, as well as to a strong dependence of OC burial efficiency on oxygen exposure time. This study ...
Surficial geologic mapping of the Arctic Ocean was undertaken to provide a basis for understanding different geologic environments in this polar setting. Mapping was based on data acquired from numerous icebreaker and submarine missions to the polar region. The intent was to create a geologic layer overlying the International Bathymetric Chart of the Arctic Ocean. Analysis of subbottom profiler and multibeam bathymetric data in conjunction with sediment cores and the regional morphology rendered from the IBCAO data were used to map different surficial geologic units. For a relatively small ocean basin, the Arctic Ocean reveals a plethora of margin and basin types reflecting both the complex tectonic origins of the basin and its diverse sedimentation history. Broad and narrow shelves were subjected to a complex ice-margin history in the Quaternary, and bear the sediment types and morphological features as a result. Some shelfal areas are heavily influenced by rivers. Extensive deep water ridges and
Most sulfate-reducing microorganisms (SRM) present in subsurface marine sediments belong to uncultured groups only distantly related to known SRM and it remains unclear how changing geochemical zones and sediment depth influence their community structure. We mapped the community composition and abundance of SRM by amplicon-sequencing and quantifying dsrB, which encodes dissimilatory sulfite reductase subunit beta, in sediment samples covering different vertical geochemical zones ranging from the surface sediment to the deep sulfate-depleted subsurface at four locations in Aarhus Bay, Denmark. SRM were present in all geochemical zones including sulfate-depleted methanogenic sediment. The biggest shift in SRM community composition and abundance occurring across the transition from bioturbated surface sediments into non-bioturbated sediments below, where redox fluctuations and input of fresh organic matter due to macrofaunal activity are absent. SRM abundance correlated with sulfate reduction rates ...
Current set contains data on the molecular composition of lignin derived phenols and organic carbon content in bottom sediments and subsea permafrost rocks from five sediment cores obtained in the Buor-Khaya Bay (Laptev Sea). The substantially irregular distribution of lignin concentration and lignin-based molecular proxies revealed in the investigated samples reflect drastic environmental and depositional changes in the study area of the Laptev Sea. The increased OC content (2-5%) at some horizons and the highest concentrations (up to 23%) are related to the presence of vegetable residues such as wood and moss. Riverine flux and coastal thermoabrasion are considerable in lignin supply. Vanillyl and syringyl phenols dominate the lignin pool. Gymnosperm wood accounts for a significant fraction of the lignin. Concentration of lignin in sediments varies in five orders of magnitude. Strong share of lignin consists of biochemically unaltered compounds. Distribution of specific lignin phenols and related
Methane (CH4) flux to the atmosphere is mitigated via microbial CH4 oxidation in sediments and water. As arctic temperaturesincrease, understanding the effects of temperature on the activity and identity of methanotrophs in arctic lake sediments is importantto predicting future CH4 emissions. We used DNA-based stable-isotope probing (SIP), quantitative PCR (Q-PCR), andpyrosequencing analyses to identify and characterize methanotrophic communities active at a range of temperatures (4°C, 10°C,and 21°C) in sediments (to a depth of 25 cm) sampled from Lake Qalluuraq on the North Slope of Alaska. CH4 oxidation activitywas measured in microcosm incubations containing sediments at all temperatures, with the highest CH4 oxidation potential of37.5 mol g1 day1 in the uppermost (depth, 0 to 1 cm) sediment at 21°C after 2 to 5 days of incubation. Q-PCR of pmoA and ofthe 16S rRNA genes of type I and type II methanotrophs, and pyrosequencing of 16S rRNA genes in 13C-labeled DNA obtained bySIP demonstrated ...
Particle Size of River Sediments. The relationships between particle size of river sediments and the variation in stream discharge are studied. The results of a study carried out to determine the variation of both bed material and suspended sediment particle size for differing flow conditions is presented. A significant finding is presented which shows that the particle size of suspended and bed sediments remains relatively constant with variation in stream discharge. This condition was found from the analysis of results at four river sections on three rivers in Scotland and was also corroborated by results from research in the United States. Conclusions are presented which attempt to explain these findings in terms of the availability of material for transport by streams rather than on purely hydraulic considerations.
Water radiolysis continuously produces H2 and oxidized chemicals in wet sediment and rock. Radiolytic H2 has been identified as the primary electron donor (food) for microorganisms in continental aquifers kilometers below Earths surface. Radiolytic products may also be significant for sustaining life in subseafloor sediment and subsurface environments of other planets. However, the extent to which most subsurface ecosystems rely on radiolytic products has been poorly constrained, due to incomplete understanding of radiolytic chemical yields in natural environments. Here we show that all common marine sediment types catalyse radiolytic H2 production, amplifying yields by up to 27X relative to pure water. In electron equivalents, the global rate of radiolytic H2 production in marine sediment appears to be 1-2% of the global organic flux to the seafloor. However, most organic matter is consumed at or near the seafloor, whereas radiolytic H2 is produced at all sediment depths. Comparison of radiolytic H2
Data & statistics on Particle size distribution of sediments from South West Spit: Particle size distribution of sediments from South West Spit, Particle Size Distribution (psd) of sediment particles, Sieve sizes used for sediment particle distribution and the Wentworth sediment size categories (Buchanan 1984) Sieve Number...
Wang, N., Consbrock, R. A., Ingersoll, C. G. and Barnhart, M. C. (2011), Evaluation of influence of sediment on the sensitivity of a unionid mussel (Lampsilis siliquoidea) to ammonia in 28-day water exposures. Environmental Toxicology and Chemistry, 30: 2270-2276. doi: 10.1002/etc.616 ...
In this study, redox-dependent phosphorus (P) recycling and burial at 6 sites in the Baltic Sea is investigated using a combination of porewater and sediment analyses and sediment age dating (Pb-210 and Cs-117). We focus on sites in the Kattegat, Danish Straits and Baltic Proper where present-day bottom water redox conditions range from fully oxygenated and seasonally hypoxic to almost permanently anoxic and sulfidic. Strong surface enrichments of Fe-oxide bound P are observed at oxic and seasonally hypoxic sites but not in the anoxic basins. Reductive dissolution of Fe-oxides and release of the associated P supports higher sediment-water exchange of PO4 at hypoxic sites (up to similar to 800 mu mol P m(-2) d(-1)) than in the anoxic basins. This confirms that Fe-bound P in surface sediments in the Baltic acts as a major internal source of P during seasonal hypoxia, as suggested previously from water column studies. Most burial of P takes place as organic P. We find no evidence for significant ...
Sediment is not a sedimentary rock unless the little grains become stuck together. The material that holds sediment together into a rock is called cement. Cement is mineral that forms when seawater or groundwater travels through the empty spaces between sediment. If the water contains the chemicals that are needed, mineral crystals will form in-between the sediment. The mineral holds the sediment together. Minerals like calcite, quartz, and sometimes hematite form the cement in sedimentary rocks. A pile of sediment becomes a sedimentary rock more quickly when it is buried deep underground. This makes the sediment grains become squished closely together. However, the whole process can take tens to hundreds of thousands of years.. ...
The degradation of organic matter in the deep-sea is a critical microbial process that facilitates global carbon cycling and affects all organisms. Typically, deep-sea microbial communities experience very low organic carbon availability, however, at deep-sea whalefalls these bacteria are provided with organic carbon levels ~2000x greater than usual. This creates an ideal environment in which to examine the metabolism of marine microbes and to further understand carbon cycling on and within the deep-sea floor. Only a handful of papers have investigated marine sediments, thus, we first had to develop a method for measuring enzymatic activity. We focused on proteases, enzymes responsible for the breakdown of proteins, one of a number of organic carbon sources in the environment. Protease activity was measured in marine sediments associated with a whalefall at 1800 meters depth in Monterey Bay, collected at zero, three and ten meters distance. As expected, the highest protease activity was found ...
Heavy metal content in relation to particle size and organic content of surficial sediments in Miami River and transport potential Article ...
Abstract. Thaumarchaeota are amongst the most abundant microorganisms in aquatic environments, however, their metabolism in marine sediments is still debated. Labeling studies in marine sediments have previously been undertaken, but focused on complex organic carbon substrates which Thaumarchaeota have not yet been shown to take up. In this study, we investigated the activity of Thaumarchaeota in sediments by supplying different 13C-labeled substrates which have previously been shown to be incorporated into archaeal cells in water incubations and/or enrichment cultures. We determined the incorporation of 13C-label from bicarbonate, pyruvate, glucose and amino acids into thaumarchaeal intact polar lipid-glycerol dibiphytanyl glycerol tetraethers (IPL-GDGTs) during 4-6 day incubations of marine sediment cores from three sites on the Iceland shelf. Thaumarchaeal intact polar lipids, in particular crenarchaeol, were detected at all stations and concentrations remained constant or decreased slightly ...
Mass-transport deposits reveal something of the timing, source areas and depositional processes that contributed to the evolution of the New Jersey continental margin. Many of the mass-transport deposits rest upon prominent stratal surfaces and sequence boundaries permitting evaluation of the relationship between mass wasting and eustatic change. Five distinct mass-transport facies representative of intercanyon regions of the slope, canyons and continental rise settings are recognized in the Ocean Drilling Program Leg 150 Sites (902-906). These mass-transport deposits consist predominantly of muddy slumps and debris flows, and to a lesser extent sandy mass flows and gravity-related flows. The styles of soft-sediment deformation, mineralogy, and biostratigraphy of these mass-transport deposits provide new information on the mass-wasting history of the continental margin. At intercanyon sites beneath the continental slope (Sites 902-904), mud with disseminated sand occurs mainly at sequence ...
Two Gram-staining-positive, strictly aerobic bacilli, designated as strains Ma50-5T and Ma50-6T, were isolated from the hydrothermal sediments of Manus Basin in the western Pacific Ocean. Based on 16S rRNA gene sequence, strains Ma50-5T and Ma50-6T were most closely related to Bacillus alveayuensis (97.0 and 97.2 % identity, respectively). The 16S rRNA gene sequence identity between strains Ma50-5T and Ma50-6T was 97.4 %. The identities between strains Ma50-5T and Ma50-6T and other closely related organisms were below 97.0 %. The G+C contents of the genomic DNA of strains Ma50-5T and Ma50-6T were 43.4 and 47.6 mol%, respectively. The major fatty acids (>10 %) of both strains were iso-C15 : 0 and iso-C17 : 0. The predominant isoprenoid quinone detected in both strains was menaquinone-7. Phylogenetic, physiological, biochemical and morphological analyses suggested that strains Ma50-5T and Ma50-6T represent two novel species of the genus Bacillus , for which the names Bacillus kexueae sp. nov. (type
The seafloor is a unique environment, which allows insights into how geochemical processes affect the diversity of biological life. Among its diverse ecosystems are deep-sea brine pools - water bodies characterized by a unique combination of extreme conditions. The polyextremophiles that constitute the microbial assemblage of these deep hot brines have not been comprehensively studied. We report a comparative taxonomic analysis of the prokaryotic communities of the sediments directly below the Red Sea brine pools, namely, Atlantis II, Discovery, Chain Deep, and an adjacent brine-influenced site. Analyses of sediment samples and high-throughput pyrosequencing of PCR-amplified environmental 16S ribosomal RNA genes (16S rDNA) revealed that one sulfur (S)-rich Atlantis II and one nitrogen (N)-rich Discovery Deep section contained distinct microbial populations that differed from those found in the other sediment samples examined. Proteobacteria, Actinobacteria, Cyanobacteria, Deferribacteres, and ...
Knowledge of fine sediment delivery (both timing and loading) is fundamental to the assessment of non-point source pollution in estuarine environments. This study comprised three key components that led to the development of a fine sediment and particulate associated phosphorus budget in a typical agricultural estuary. Firstly, to explore catchment inputs, turbidity and flow were monitored continuously upstream of the freshwater/saline interface on the main stem channel of the south Devon River Avon, which drains a medium sized agricultural catchment (area 340 km2), in southwest UK. Thirty-five storms were studied in detail; and the hydrological and suspended sediment load response was observed to be highly variable. Suspended sediment concentrations (SSC) reached a maximum of 804 mg L-1 and sediment load varied from 3 to 227 t per hydrological event. Most sediment load was concentrated in winter months when competent flows occur frequently. Hydrological response was also variable in terms of ...
The main purpose of this study was to examine the effect on a lake as a result of sulfide mining. The mining industry leads to problems with acid mine drainage and leaching of heavy metals. This study examines concentrations of lead, copper, zinc and arsenic in the sediment of Lake Storjuktan close to the Blaikenmine. The main objective was to compare concentrations before mining operations started 2006 with samples from the same sediment basin 2015. Cores (n=2) was taken upstream and downstream the mining site at the same coordinates. To reveal spatial variations in concentrations six more sediment samples were taken. I found that; i) zinc concentration was distinctively higher in the surface sediment sampled in 2015 than 2006 while lead, copper and arsenic showed small to insignificant changes; ii) approximately an area of 22 hectare anthropogenic sediment has formed within Storjuktan with extremely high concentrations of zinc and high concentrations of lead and copper. In the latter case, the ...
Article Abundances, Depositional Fluxes, and Homologue Patterns of Polychlorinated Biphenyls in Dated Sediment Cores from the Pearl River Delta, China. Despite the recent efforts to investigate the distribution and fate of persistent organic pollutan...
Foraminifera are single-celled eukaryotes (protists) of large ecological importance, as well as environmental and paleoenvironmental indicators and biostratigraphic tools. In addition, they are capable of surviving in anoxic marine environments where they represent a major component of the benthic community. However, the cellular adaptations of Foraminifera to the anoxic environment remain poorly constrained. We sampled an oxic-anoxic transition zone in marine sediments from the Namibian shelf, where the genera Bolivina and Stainforthia dominated the Foraminifera community, and use metatranscriptomics to characterize Foraminifera metabolism across the different geochemical conditions. Relative Foraminifera gene expression in anoxic sediment increased an order of magnitude, which was confirmed in a 10-day incubation experiment where the development of anoxia coincided with a 20-40-fold increase in the relative abundance of Foraminifera protein encoding transcripts, attributed primarily to those involved
Sediment Transport and Diffusion: Columbia Estuary and Entrance. Review of past studies and investigations, including prototype measurements and hydraulic model tests; reveal some indications of sediment transport and diffusion in the vicinity of the Columbia Estuary and Entrance. These indications reveal a unique pattern of sediment transport and diffusion prevailing in this region. This leads to the conclusion that the estuary is acting as a trap for collection of bottom sediments and that, immediately offshore, the forces of erosion and accretion have established a regime that is also worthy of detailed further study.
In order to find the effect of intertidal sediments on nutrient cycle in coastal environment, we measured ammonia, nitrate, phosphate, and silicate concentrations every hour during at least 12 hours in the entrance of Keunso Bay during four seasons. The content of ammonia and silicate do not change considerably with season, but nitrate shows large seasonal variation. In summer, nitrate concentration was much lower than in other seasons, which resulted from large biological uptake and active denitrification in intertidal sediments during summer. Phosphate also exhibit seasonal variations, but not that large like nitrate. N/P and N/Si ratios were lower in summer than in other seasons, which was due to active denitrification in the intertidal sediments during summer. For all seasons, ammonia concentrations were higher at low tide than at high tide, but nitrate concentrations were higher at high tide. Dissolved inorganic nitrogen concentrations measured in spring, summer, and winter were higher at high
1] "Geologic Map Legends". Coastal Plain Rocks and Sediments. Maryland Geological Survey. Archived from the original on 26 May ... "Geologic Unit: Arundel". National Geologic Map Database. USGS. Harris, Jerald D. (1998). "Large, Early Cretaceous theropods in ...
Maslin, Mark A.; Swann, George E.A. (2006). "Isotopes in marine sediments". In Leng, Melanie J. Isotopes in Palaeoenvironmental ... Rasskazov, Sergei V.; Brandt, Sergei Borisovich; Brandt, Ivan S. (2009). Radiogenic Isotopes in Geologic Processes. Dordrecht: ...
The Escarpment Grit is a Triassic geologic formation. It is also referred to as the Nyoka Grit. The formation is composed of ... d'Engelbronner, E.R. (1996). "New palynological data from Karoo sediments, Mana Pools basin, northern Zimbabwe". Journal of ... fluvial sediments, mainly gritstones and coarse sandstones. Uranium is present in the Escarpment Grit of southern Zambia. The ...
On the geologic map, "Trenton Gravel" is used to describe most of these sediments. However, much of the alluvial sediments that ... The sediments deposited in that sea are now located in the Great Valley section. (See below) The sediments placed from the ... ISBN 0-87842-227-7 The Pennsylvania Geologic Survey Physiographic Provinces and Sections of Pennsylvania The Geologic Story of ... The sediments that were deposited in a sea between an island-arc and the Iapetus eventually were squeezed and deformed along a ...
Lexicon of Canadian Geologic Units. "Belloy Formation". Archived from the original on 2012-07-08. Retrieved 2009-02-12. CS1 ... John Group). It is unconformably overlies Mississippian sediments such as those of the Rundle Group. The Belloy Formation is ...
The sediments were deposited during the Late Ordovician glaciation. The following fossils were reported from the formation: ... The Tenjong Dendang Formation is a geologic formation in Malaysia. The band of graptolite- and trilobite-bearing shales ...
... can be preserved in sediments. Sedimentology Sequence stratigraphy Tectonic-climatic interaction Sadler, Peter M. "Sediment ... "The stratigraphic filter and bias in measurement of geologic rates." Geophysical Research Letters 38.11 (2011): L11405. Schumer ... Conversely, it also explains that the maximum sediment accumulation rates seen in the Cambrian at the start of the Phanerozoic ... The Sadler effect describes variation in apparent sediment accumulation rates and bed thicknesses back through time inherent to ...
However, extensive sediments and landforms remain from the last 2.5 million years of the Quaternary. A thin blanket of ... The geology of Estonia is the study of rocks, minerals, water, landforms and geologic history in Estonia. The crust is part of ... The Haanja Heights and Otepaa Heights have up to 100 meters of glacial sediment, or up to 207 meters in the Abja Valley in the ... They are linked by the Latvian Saddle, which is shallower with two kilometers of sediment. Precambrian rocks do not outcrop ...
Before the Rove sediments were laid down, during the Archean Eon, the Algoman orogeny added landmass along a border from South ... "Voyageurs National Park, Geologic History". National Park Service, Explore Geology: 1. Retrieved March 25, 2010. Cite journal ... The Rove Formation is the youngest of the many Animikie layers; it consists of gently tilted fine-grained sediments. It is ... After the Rove Formation sediments were deposited, the Penokean orogeny added more land mass by accretion that occurred from ...
"A Brief Summary of the Geologic History of Ohio", page 1. Madin; "3. Early Sediments: Oregon's first coast". Murray (1974); " ... This was a major boon to his reputation as his research was foundational to understanding that interval of American geologic ... "A Brief Summary of the Geologic History of Ohio". GeoFacts. Number 23. Ohio Department of Natural Resources, Division of ... ISBN 0-691-11345-9. Madin, Ian P. "Oregon: A Geologic History." Interpretive Map Series 28. Oregon Department of Geology and ...
The Futaba Group is a Late Cretaceous geologic group in Japan. Dinosaur remains are among the fossils that have been recovered ... It consists of both fluvial and shallow marine sediments. The plesiosaur Futabasaurus was found in this unit (specifically the ...
The sediments of the formation reflect a marine near-shore depositional environment. Cardozo, M. (1990). "The Copara ... Metallotect in Central Peru: Geologic Evolution and Ore Formation". In Fontboté, L.; Amstutz, G.C.; Cardozo, M.; Cedillo, E.; ...
"A Brief Summary of the Geologic History of Ohio", page 1. Madin; "3. Early Sediments: Oregon's first coast". Murray (1974); " ... Braden, Angela K. The Arkansas Dinosaur "Arkansaurus fridayi". Arkansas Geologic Survey. 2007. "A Brief Summary of the Geologic ... The geologic turmoil on the west coast was maintained as the Pacific Plate continued to slide under the North American Plate. ... Powerful geologic forces began to fold and distort the rocks of Idaho, Utah, and Wyoming, beginning the processes that would ...
The result is a sequence of sediments that wedges out in one direction. This is usually the case on the margins of geologic ... When a tectonic phase occurred while sedimentation of new sediments continued, every new layer will have a slightly different ...
Geologic Activity. National Park Service. Irvin, James R. Great Plains Gallery Archived July 20, 2006, at the Wayback Machine ( ... Subsequent erosion stripped the granite of the overlying sediments and the softer adjacent schist. Some schist does remain and ... The Black Hills area was uplifted as an elongated geologic dome. ... so the geologic formations of the heart of the Black Hills ... but were later buried by sandstone and other sediments during the Cambrian. Remaining buried throughout the Paleozoic, they ...
Other sediments may have been added but, if they ever existed, were completely removed by erosion. Such gaps in the geologic ... At the same time, sediment filled the lakes behind the dams. Sediment would fill a lake behind a 150-foot (46 m)-high dam in ... A geologic formation is a rock unit that has one or more sediment beds, and a member is a minor unit in a formation. Groups are ... Next in the geologic column is the 200-foot (60 m)-thick Toroweap Formation (see 6c in figure 1). It consists of red and yellow ...
Formal geologic reports of clastic dikes began to emerge in the early 19th century.[excessive citations] Terms synonymous with ... However, clastic dikes are typically produced by seismic disturbance and liquefaction of high water content sediments. Examples ... Clastic dikes are paleoseismic indicators in certain geologic settings. Several qualitative, field-based systems have been ... sediment swept into open cracks). Diagenesis may play a role in the formation of some dikes. Clastic dikes are commonly ...
Sometimes the sediment would be mixed with huge chunks of ice, which would leave voids, or kettles, in the soil. These kettles ... Geologic Atlas of Ramsey County, Atlas C-7 (Map) (1992 ed.). Minnesota Geological Survey, University of Minnesota. § Plate 2. , ... S. S. Goldich (2), H. Baadsgaard (2 (1959). "Investigations in Radioactivity-Dating of Sediments". AAPG Bulletin. 43. doi: ...
Geologic evolution of the non-mountainous topography of the Texas region. An introduction to the study of the Great Plains. The ... This land of reddish brown sediments and rock has been carved by years of erosion leaving behind scenic mesas and buttes that ... Geologic and geographic aspects of Mexico. The Mining World 25:370-372, 459, 540-541, 596. Hill, R.T. 1906. On the origin of ... Geographic and geologic features of Mexico. The Engineering and Mining Journal 72:501-564. Hill, R.T. 1901. The coast prairie ...
The park's geologic record preserves three different groups of rock and sediment. The oldest rocks are Early to Middle ... Geologic map of the Colorado National Monument and adjacent areas, Mesa County, Colorado: U.S. Geological Survey, Geologic ...
Sediments from the surrounding mountains filled the valley over geologic time periods. After lakes within the valley receded, ... Large amounts of sediment from the volcanic San Juan Mountains continued to wash down into these lakes, along with some sand ... Sediments from both mountain ranges filled the deep chasm of the valley, along with huge amounts of water from melting glaciers ... and in buried deposits indicates that some of the sediment has been washed down in torrential flash floods. In 2002, geologists ...
... looks at geologic sediments and rocks, for signs of ancient earthquakes. It is used to supplement seismic ... Paleoseismology is usually restricted to geologic regimes that have undergone continuous sediment creation for the last few ...
The Titus Canyon Formation is an Eocene geologic formation in California. H. Donald Curry collected the type specimens of the ... Both of these genera are present in the Titus Canyon Formation sediments of Death Valley National Park. "Death Valley National ...
In the geologic record of a drowned carbonate platform, neritic deposits change rapidly into deep-marine sediments. Typically ... This depositional environment acts as sink for excess carbonate sediment: most of the sediment produced in the lagoon and reef ... slope readjustment processes and sediment sourcing. Their progradation is independent from platform sediment shedding and ... Sediment production of a platform increases with its size, and during highstand the top of the platform is flooded and the ...
The La Caja Formation is a geologic formation in Mexico. It preserves fossils datiting from the Kimmeridgian to the lower ... It was deposited in hemipelagic conditions, and predominantly consists of siliclastic sediments, including marl, with limestone ...
The sediments fall in the Bridgerian and Uintan stages of the NALMA classification. The Washakie Formation has provided many ... The Washakie Formation is a geologic formation in northern Colorado and southern Wyoming. It preserves many mammal, bird, ...
After millions of years, these sediments have been titled and uplifted. Weathering has removed more easily eroded material ... Structurally, the Marlboro Mountains constitute a geologic formation known as a dip slope. The sedimentary layers comprising ... The Marlboro Mountains are primarily formed of shallow marine/delta sediments deposited during the late Ordovician, ... form an imposing geologic barrier just west of the Hudson River. They subdivide the relatively flat Hudson River Valley (a ...
The formation comprises siliciclastic sediments. The fossil fauna suggests a warm water, nearshore current was active allowing ... The Llallagua Formation is a Rhuddanian to Homerian geologic formation of western Bolivia. ...
In V. L. Santucci & L. McClelland (eds.), National Park Service Geologic Resources Division Technical Report NPS/NRGRD/GRDTR-98 ... Cranial remains of Quetzalcoatlus (Pterosauria, Azhdarchidae) from Late Cretaceous sediments of Big Bend National Park, Texas. ...
The geologic time scale was developed during the 19th century, based on the evidence of biologic stratigraphy and faunal ... This may be the result of a halt in the deposition of sediment. Alternatively, the gap may be due to removal by erosion, in ... The continuous nature of the sampling means that it is also a powerful technique for the estimation of sediment-accumulation ... thickness of sediment layers (varves) and fossil diversity with time, related to seasonal or longer term changes in ...
Of the modern geologic features, only the land bridge between South America and North America was absent, although South ... with long term burial of carbon in sediments, produced a carbon and water vapor sink. This, combined with higher surface albedo ...
After deposition, sediments are compacted as they are buried beneath successive layers of sediment and cemented by minerals ... The study of diagenesis in rocks is used to understand the geologic history they have undergone and the nature and type of ... Diagenesis ( /ˌdaɪəˈdʒɛnɪsɪs/) is the change of sediments or existing sedimentary rocks into a different sedimentary rock ... Grains of sediment, rock fragments and fossils can be replaced by other minerals during diagenesis. Porosity usually decreases ...
crystallization during diagenesis of sediments. *formation by oxidation and weathering of rocks exposed to the atmosphere or ...
It was also during this geologic era that an ocean shift took place, causing the present-day location of the mountains to be ... In the mid Paleozoic era (between 360 and 290 mya), an initial substratum of ancient granites and sediments started bending and ...
For the geologic eon, see Archean. For the spider genus, see Archaea (spider). For the spider family, see Archaeidae. For the ... Teske A; Sørensen KB (January 2008). "Uncultured archaea in deep marine subsurface sediments: have we caught them all?". ISME J ... The oldest such traces come from the Isua district, which includes Earth's oldest known sediments, formed 3.8 billion years ago ... Chappe B; Albrecht P; Michaelis W (July 1982). "Polar Lipids of Archaebacteria in Sediments and Petroleums". Science. 217 (4554 ...
... heat then consolidated the sediment into stone, and uplifted it into new lands. This theory, known as "Plutonism", stood in ... a b c d These unit names were taken from the lunar geologic timescale and refer to geologic events that did not occur on Earth ... "Geologic Time Scale". EnchantedLearning.com.. *^ "How the discovery of geologic time changed our view of the world". Bristol ... Formulation of geologic time scaleEdit. The first serious attempts to formulate a geologic time scale that could be applied ...
Sedimentary basin: in sedimentology, an area thickly filled with sediment[1] in which the weight of the sediment further ... "Dictionary of Geologic Terms - K". US Geochemical. Retrieved 2017-09-09.. *^ "Glossary of Important Terms in Glacial Geology - ... Kettle: a shallow, sediment-filled body of water formed by melting glacial remnants in terminal moraines.[3] ... "Dictionary of Geologic Terms - B". US Geochemical. Retrieved 2017-09-09.. .mw-parser-output cite.citation{font-style:inherit}. ...
The frustules of dead diatoms are a major constituent of deep ocean sediment, and of diatomaceous earth.[citation needed] ... Living organisms also contribute to this geologic cycle. For example, a type of plankton known as diatoms construct their ...
These rare compounds contain organic carbon, but can be formed by a geologic process. For example, whewellite, CaC2O4⋅H2O is an ... Carbonates are most often formed as biogenic or chemical sediments in marine environments. The carbonate group is structurally ... Epidotes are found in variety of geologic settings, ranging from mid-ocean ridge to granites to metapelites. Epidotes are built ...
"Geologic Time: Radiometric Time Scale". U.S. Geological Survey. Archived from the original on September 21, 2008. Retrieved ... These lagerstätten allow paleontologists to examine the internal anatomy of animals that in other sediments are represented ... to a rapid increase in knowledge about the history of life on Earth and to progress in the definition of the geologic time ... of the 19th century saw geological and paleontological activity become increasingly well organised with the growth of geologic ...
The sediments containing the fossil logs are part of the widespread and colorful Chinle Formation, from which the Painted ... Streams flowing across the plain from the highlands deposited inorganic sediment and organic matter, including trees as well as ... the sediments containing the fossil logs for which the park is named are part of the Chinle Formation.[12] ... flattened by the weight of the sediments above until only a thin film remains in the rock.[16] ...
... sediments; the sediments are underlain by rhyolite and basalt, and overlain by basalt. The western plain began to form around ... The Snake River Plain is a geologic feature located primarily within the U.S. state of Idaho. It stretches about 400 miles (640 ...
Water-related sediments have been found dating from as early as 3.8 billion years ago.[11] About 3.4 billion years ago, ... See also: List of periods and events in climate history, Geologic time scale, and History of Earth ... Older sediments are also more prone to corruption by diagenesis. Resolution and confidence in the data decrease over time. ... Sediments, sometimes lithified to form rock, may contain remnants of preserved vegetation, animals, plankton, or pollen, which ...
Meade, R. H., and J. A. Moody, 1984, Causes for the decline of suspended-sediment discharge in the Mississippi River system, ... Over geologic time, the Mississippi River has experienced numerous large and small changes to its main course, as well as ... This occurs because the deposits of silt and sediment begin to clog its channel, raising the river's level and causing it to ... When the ice sheet began to recede, hundreds of feet of rich sediment were deposited, creating the flat and fertile landscape ...
In the geologic record, the K-Pg event is marked by a thin layer of sediment called the K-Pg boundary, which can be found ... Bourgeois J (2009). "Chapter 3. Geologic effects and records of tsunamis". In Robinson, A.R.; Bernard, E.N. The Sea (Ideas and ... In the sediments below the K-Pg boundary the dominant plant remains are angiosperm pollen grains, but the boundary layer ... Ogg, James G.; Gradstein, F. M; Gradstein, Felix M. (2004). A geologic time scale 2004. Cambridge, UK: Cambridge University ...
Its sediments are approximately 400 feet thick, and its upper layers feature fossiliferous invertebrates.[105] ... Wheeler Geologic. *White Rocks. *Williams Creek. *Yanks Gulch/Upper Greasewood Creek Natural Area ... period of uplift and rock tilting towards the south caused these streams to cut rapidly into the rock removing loose sediment ...
"Geologic Map Legends : Allegheny Plateau and Valley and Ridge". Geologic Map of Maryland. Maryland Geological Survey. 1968. ... Smol, J. P.; Last, William M. (2001). Tracking environmental change using lake sediments. Vol. 2: Physical and Geochemical ... Hoskins, Donald M. T. (1976). Geologic Map of the Millerstown 15 Minute Quadrangle, PA (Map). 1:24,000. Cartography by United ... Conlin, Richard R.; Hoskins, Donald M. Geologic Map of the Mifflintown Qd., PA (Map). 1:24,000. Cartography by United States ...
Geologic principles and processes. Stratigraphic principles. *Principle of original horizontality. *Law of superposition ... In this equation ws is the sediment settling velocity, g is acceleration due to gravity, and D is mean sediment diameter. ν. {\ ... "Lecture 21-Suspended Sediment Transport" (PDF). Lecture Notes: Fluvial Sediment Transport. Kent State. Retrieved 25 December ... Sediment moved by water can be larger than sediment moved by air because water has both a higher density and viscosity. In ...
Stromatolites: Interaction of Microbes with Sediments. Cellular Origin, Life in Extreme Habitats and Astrobiology. 18. pp. 571- ... are found throughout the geologic record up to 3.2 billion years old. They are formed by the interaction of microbial mats and ... Such interactions occur in the geosphere (rocks, minerals, soils, and sediments), the atmosphere and the hydrosphere.[2] ... Interactions between microbes and sediment record some of the earliest evidence of life on earth. Information on the life ...
Gaylord, DR, AJ Busacca, and MR Sweeney (2003) The Palouse loess and the Channeled Scabland: A paired Ice-Age geologic system. ... non-glacial Pliocene fluvial sediments of the Ringold Formation, or Pleistocene glacial outburst flood sediments that are known ... Busacca, AJ, and EV McDonald (1994) Regional sedimentation of late Quaternary loess on the Columbia plateau: sediment source ... The peculiar and picturesque loess hills which characterize the Palouse Prairie are underlain by wind-blown sediments of the ...
Paleomagnetism: Magnetic domains to geologic terranes. Blackwell. ISBN 978-0-86542-070-0. . Archived from the original (PDF) on ... and found that the floor of the seabed beneath the layer of sediments consisted of basalt, not the granite which is the main ... and that most geologic features such as basin development and mountain ranges could be explained by vertical crustal movement, ... why there is so little sediment accumulation on the ocean floor, and why oceanic rocks are much younger than continental rocks ...
The Oligocene ( /ˈɒlɪɡoʊsiːn/) is a geologic epoch of the Paleogene Period and extends from about 33.9 million to 23 million ... Evidence for the early Oligocene onset of chilled North Atlantic deep water lies in the beginnings of sediment drift deposition ... Wilmarth, Mary Grace (1925). Bulletin 769: The Geologic Time Classification of the United States Geological Survey Compared ... Through study of Pacific Ocean sediments, other researchers have shown that the transition from warm Eocene ocean temperatures ...
"Geologic Timescale Foundation. Cyrchwyd 7 Medi 2013.. *↑ Dave Lawrence (2003). "Microfossil lineages support sloshy snowball ... Warren, John K. (2006). Evaporites: sediments, resources and hydrocarbons. Birkhäuser. t. 289. ISBN 978-3-540-26011-0. .. .mw- ...
Generalized Geologic Map of Louisiana, 2008. *Generalized Geology of Louisiana (text to Generalized Geologic Map of Louisiana) ... In between the Tertiary rocks of the north, and the relatively new sediments along the coast, is a vast belt known as the ... Bernard, Lafourche, the modern Mississippi, and now the Atchafalaya.[16] The sediments were carried from north to south by the ... Much of the state's lands were formed from sediment washed down the Mississippi River, leaving enormous deltas and vast areas ...
Sediment samples document that up to half of the native plants had become extinct and that the vegetation of the island ... Easter Island lies atop the Rano Kau Ridge, and consists of three shield volcanoes with parallel geologic histories. Poike and ... but pollen analysis of lake sediments shows these reeds have grown on the island for over 30,000 years.[citation needed] Before ...
There are the slow geomorphological changes associated with the geologic processes that cause tectonic uplift and subsidence, ... or shifting sediment exposes new areas for colonisation. Another cause of disturbance is when an area may be overwhelmed by an ...
These reactions are exothermic and occur naturally (e.g., the weathering of rock over geologic time periods).[96][97] ... These measures include "geochemical, sediment, gravitational and hydrate formation." Because CO. 2 hydrate is denser than CO. 2 ... If it is disturbed somehow, the carbon stored in the plants and sediments will be released back into the atmosphere and the ... The gas comes in part from anthropogenic sources, but is principally from large naturally occurring geologic formations of CO. ...
Jon Erickson; Ernest Hathaway Muller (2009). Rock Formations and Unusual Geologic Structures: Exploring the Earth's Surface. ... Since opening the South China Sea has been the repository of large sediment volumes delivered by the Mekong River, Red River ...
... and thus its presence in ocean sediments to date these sediments by measuring the ratio of 232Th to 230Th.[31][32] Both of ... Rafferty, J. P. (2010), Geochronology, Dating, and Precambrian Time: The Beginning of the World As We Know It, The Geologic ... that the sediment did not already contain thorium before contributions from the decay of uranium, and that the thorium cannot ... but 230Th is insoluble and precipitates into the sediment. Uranium ores with low thorium concentrations can be purified to ...
Associations of Geologic Sediments with chemical compounds. *Reductive dechlorination of DDE to DDMU in marine sediment ... Gene context of Geologic Sediments. *Three unique marine sediment nosZ genes were identified and sequenced [20]. ... High impact information on Geologic Sediments. *A large fraction of globally produced methane is converted to CO2 by anaerobic ... Chemical compound and disease context of Geologic Sediments. *Gram-positive bacteria might play an important role in ...
Theme_Keyword: sediment data. Theme_Keyword: marine sediment data. Theme_Keyword: legacy data. Theme_Keyword: geologic data. ... Theme_Keyword: offshore sediments. Theme_Keyword: coastal sediments. Theme_Keyword: beach sediments. Theme_Keyword: estuary. ... Enumerated_Domain_Value: SEDIMENT DRILL. Enumerated_Domain: Enumerated_Domain_Value: SEDIMENT TRAP. Enumerated_Domain: ... Theme_Keyword: sediment samples. Theme_Keyword: USGS. Theme_Keyword: Coastal and Marine Geology Program. Theme_Keyword: GIS. ...
Geologic principles and processes. Stratigraphic principles. *Principle of original horizontality. *Law of superposition ... In this equation ws is the sediment settling velocity, g is acceleration due to gravity, and D is mean sediment diameter. ν. {\ ... "Lecture 21-Suspended Sediment Transport" (PDF). Lecture Notes: Fluvial Sediment Transport. Kent State. Retrieved 25 December ... Sediment moved by water can be larger than sediment moved by air because water has both a higher density and viscosity. In ...
Miami: Miami Geologic Society.Google Scholar. *. Gilman, E., J. Ellison, and R. Coleman. 2007. Assessment of mangrove response ... Hurricane Wilma Sediment deposition Mangroves Accretion Nutrient biogeochemistry Florida Everglades This is a preview of ... Hurricane signals in salt marsh sediments: Inorganic sources and soil volume. Limnology and Oceanography 52: 1231-1238.CrossRef ... Sediment accretion in coastal wetlands: A review and simulation model of processes. Current Topics in Wetland Biogeochemistry 2 ...
Walker Lane geologic trough - E. California, W. Nevada. May 22, 2019. Mysterious Ringing of the Earth. May 22, 2019 ... the metal contained in the sediments can move from the particulate phase (associated with the sediment) to the soluble part (to ... "The highly polluted sediments of the Ego stream reflect how far away it is from the optimum quality conditions that should be ... Although sediments act as a drain for pollutants, they can also act as a source of pollutants under certain environmental ...
Lawrence are as high as has been observed in the worlds most contaminated marine sediments. ... Walker Lane geologic trough - E. California, W. Nevada. May 22, 2019. Mysterious Ringing of the Earth. May 22, 2019 ... Lawrence River sediments. by Canadian Science Publishing (NRC Research Press) Credit: Canadian Science Publishing (NRC Research ... Lawrence River sediments". Canadian Journal of Fisheries and Aquatic Sciences. www.nrcresearchpress.com/doi/a … 1139/cjfas-2014 ...
Geologic Sediments / chemistry* * Hydrogen-Ion Concentration * Phosphates / analysis * Phosphates / chemistry* * Silicon ... Enhanced attenuation of septic system phosphate in noncalcareous sediments Ground Water. Jan-Feb 2003;41(1):48-56. doi: 10.1111 ...
Geologic Sediments / chemistry* * Geologic Sediments / microbiology* * Hydrogen Sulfide / analysis * Hydrogen Sulfide / ... Here we provide evidence that electric currents running through defaunated sediment couple oxygen consumption at the sediment ... Electric currents couple spatially separated biogeochemical processes in marine sediment Nature. 2010 Feb 25;463(7284):1071-4. ... Altering the oxygen concentration in the sea water overlying the sediment resulted in a rapid (,1-h) change in the hydrogen ...
... that also present abundant geologic hazards. ... The high sediment load in the creek has required that the ... the distribution of bedload sediment across the alluvial fan. *the flux of suspended sediment down Swift Creek (sampling, ... The US Environmental Protection Agency has determined that there is sufficient asbestos in the Swift Creek sediments to pose a ... In addition, hydrologic modeling will predict the discharge and sediment flux from the watershed under different climate ...
Deep-sea sediments lead to new understanding of solar system. Results from deep-ocean sediments advance dating in geologic ... A "calendar" of the past has revolutionized the dating of geologic archives, identifying ages of geologic periods based on ... The team used geologic records from deep-sea drilling cores recovered using the NSF-funded research drillship JOIDES Resolution ... On geologic time scales (thousands to millions of years), variations in Earths orbit are the pacemakers of the ice ages. ...
... and relative intensity of sediment mobility/resuspension along the fringing coral reef off southern Molokai (February 2000-May ... Sediment traps were used to evaluate the frequency, cause, ... Geologic Sediments / analysis*. Hawaii. Magnetics. Metals / ... Sediment traps were used to evaluate the frequency, cause, and relative intensity of sediment mobility/resuspension along the ... The trapped sediments have low concentrations of anthropogenic metals. The magnetic properties of trapped sediment may provide ...
... was isolated from tidal flat sediments of the Yellow Sea in the region of Tae-An. A 16S rRNA gene sequence analysis ... Geologic Sediments / microbiology*. Molecular Sequence Data. Nucleic Acid Hybridization. Phylogeny. Quinones / analysis. RNA, ... A Gram-positive, rod-shaped, endospore-forming organism, strain BL3-6(T), was isolated from tidal flat sediments of the Yellow ...
... In: Illinois State Geological Survey (Ed.), Illinois Preliminary Geologic Map. Illinois Department of Natural Resources, ... Lake sediment records of preindustrial metal pollution. In: Blais, J.M., Rosen, M.R., Smol, J.P. (Eds.), Environmental ... Lake sediments as archives of recurrence rates and intensities of past flood events. In: Beniston, M. (Ed.), Dating Torrential ...
Effects of proposed sediment borrow pits on nearshore wave climate and longshore sediment transport rate along Breton Island, ... Geologic Evolution of Cat Island, Mississippi The geologic evolution of Cat Island has been influenced by deltaic, lagoonal/ ... Geologic Evolution of Cat Island, Mississippi. The geologic evolution of Cat Island has been influenced by deltaic, lagoonal/ ... and geologic (decades to millennia) evolution of coastal systems. Investigations utilize a combination of geophysics, sediment ...
Streamflow and sediment yield: Rapid variations of water-surface level in river channels through time, in combination with the ... In a geologic context, this may be a temporary resting place; sediment, for example, when it reaches the coast, may be ... Sediment yield and sediment load*Measurement of the load. *Sources of sediment and nature of deposition*Erosion in drainage ... Sediment yield and sediment load. All of the water that reaches a stream and its tributaries carries sediment eroded from the ...
Sampling Bed Sediments. Photographs or techniques and equipment used to sample bed sediments (17K JPEG) 21. Sources and Sinks ... 4. Geologic Settings. Maps and Vignettes of the Mississippi River showing different geologic settings (132K JPEG) 5.Water ... PCBs in Bed Sediments. Graphs showing the concentrations of polychlorinate biphenyls (PCBs) in bed sediments stored in the ... Lead in River Waters and Sediments. Map and pie diagrams showing distributions of lead in waters and suspended sediments of the ...
Based on simulations, large volumes of sediment eroded from the hillslopes were redeposited within the channel network ... results provide a quantitative framework for assessing the potential of runoff-generated debris flows based on sediment supply ... throughout the storm, leading to the initiation of numerous debris flows as a result of the mass failure of sediment dams that ... Geologic Hazards Science Center. Description. 10 p.. First page. 7310. Last page. 7319. ...
The sediment volume data represent a broad sample of conditions found in Ventura, Los Angeles and San Bernardino Counties, ... In this study, we supplement existing data for the volumes of sediment deposited at watershed outlets with newly acquired data ... Debris-retention basins protect communities and infrastructure from the impacts of debris flows and sediment-laden floods and ... The measured volumes of sediment, watershed morphology, distributions of burn severity within each watershed, the time since ...
... sediments; the deposition, erosion, and distribution of marine sediments; geologic and oceanographic processes controlling ... paleoenvironmental controls on fossil groups and sediment types; and interactions of continental and oceanic geologic processes ... The Marine Geosciences Section supports research on processes that occur on and below the sea floor and at the water/sediment/ ... The drilling process involves collecting and logging geologic samples from the floor of deep ocean basins through rotary coring ...
Geologic Sediments Metagenome Norway Phycodnaviridae Phylogeny Rhodopsin Seawater Sweden Viral Proteins Substances Viral ... Microbial and viral-like rhodopsins present in coastal marine sediments from four polar and subpolar regions. José L López, ... Microbial and viral-like rhodopsins present in coastal marine sediments from four polar and subpolar regions. FEMS microbiology ... In this work, we analyzed 23 metagenomes corresponding to marine sediment samples from four regions that share cold climate ...
Purchase Synchrotron-Based Techniques in Soils and Sediments, Volume 34 - 1st Edition. Print Book & E-Book. ISBN 9780444532619 ... Chapter 4 Synchrotron Infrared Spectromicroscopy for Studying Chemistry of Microbial Activity in Geologic Materials ... This book provides the most up-to-date information on synchrotron-based research applications in the field of soil, sediment ... Chapter 5 Application of Extended X-Ray Emission Fine Structure Spectroscopy in Soil and Sediments ...
Geologic cross section of Kittatinny Mountain. This cross section shows metamorphic rocks, overlain by younger sediments ... Main articles: History of Earth and Geologic time scale. The geologic time scale encompasses the history of the Earth.[10] It ... "Surficial Geologic Maps" in New Hampshire Geological Survey, Geologic maps. des.nh.gov ... Geologic materials[edit]. The majority of geological data comes from research on solid Earth materials. These typically fall ...
Geologic Ages. PRESENT DAY TEMPERATURES. Thermal regimes. Present day temperatures. Drilling-induced complications. Geologic ... Recent sediments. Petroleum generation. Biogenic gas. Petroleum migration. Maturation and alteration of petroleum in reservoirs ... Sediment accumulation rates. Compaction. Unconformities. Rotation of beds (including folding). Faulting. Intrusions and diapirs ... Geologic setting. Direct measurement. Calculation from thermal conductivity and heat flow. Paleosurface temperatures. ...
Wabasha County Geologic Atlas Part B. SDOVBDPY metadata. Sediments Overlying Bedrock. Minnesota DNR Waters County Geologic ... County Geologic Atlas and Regional Hydrogeologic Assessment Program, Wabasha County Geologic Atlas, Part B, County Geologic ... Wabasha County Geologic Atlas, Part A, County Geologic Atlas Series C-14, published by the Minnesota Geological Survey, 2001. ... Overlying sediment type: alluvium; outwash or colluvium; shallow bedrock (refers to areas with little or no sediment ...
Geologic Sediments • Geology • Haplorhini • Locomotion • Mammals • Paleontology • Phylogeny • Platyrrhini • Primates • ... Andean uplift also generates the sediment fill, nutrient supply, river routing, and soil composition of the adjacent lowland ... But the interactions are bi-directional, because changes in climate, hydrology, and sediment supply influence rates of uplift ... 2. To establish a more precise geologic chronology for the mammalian faunas between the Late Eocene and Middle Miocene (between ...
Quaternary Sediments: Miscellaneous Geologic Point Features. Legacy. 1998 Quarternary Sediments. Sub-United States 1:1,000,000 ...
Quaternary Sediments: Miscellaneous Geologic Point Features. Legacy. 1998 Quarternary Sediments. Sub-United States 1:1,000,000 ... Geologic Age, Geological Structures, Geologic Formations, Geologic Hazards, Geologic Maps, Geologic Provinces, Geology, ... East Coast Sediment Analysis: CONMAP Sediment Maps. Legacy. 2000 East Coast Sediment Analysis. Sub-United States 1:1,000,000 ... World Energy Project: Geologic Age and Geologic Contacts. Legacy. 1999 World Energy Project. World 1:5,000,000 ...
These research objectives can only be achieved through targeted detailed bedrock and surficial geologic mapping, coupled with ... the regional geologic framework, 2) paleoseismogenic history, and 3) the extent of regional seismic risk. In coordination with ... develop the regional geologic framework through detailed bedrock and surficial mapping; 2) quantify the regional Cenozoic ... the Paleozoic-Mesozoic geologic framework, active and potentially active structures, paleoseismic and neotectonic history, ...
Microstructures of sediment flow deposits and subglacial sediments: a comparison. Boreas, 30, 254-264. ... Glacial Geologic Processes. Edward Arnold, London, 276 p.. 49Evans, D.J.A., Phillips, E.R., Hiemstra, J.F. & Auton, C.A., 2006 ... Keywords : Lower Congo region, Neoproterozoic, sediment gravity flow, soft-sediment deformation microstructures, tectonics ... In the UDF, the pebbles are attributed to fine-grained pebble type-III, which is the result of reworking of the host sediment ...
  • Knowledge of sediment transport is most often used to determine whether erosion or deposition will occur, the magnitude of this erosion or deposition, and the time and distance over which it will occur. (wikipedia.org)
  • This river, like other braided streams , rapidly changes the positions of its channels through processes of erosion , sediment transport, and deposition . (wikipedia.org)
  • Fluvial sediment transport can result in the formation of ripples and dunes , in fractal -shaped patterns of erosion, in complex patterns of natural river systems, and in the development of floodplains . (wikipedia.org)
  • The Earth-sculpting processes of weathering, erosion, sediment transport and deposition occur everywhere on Earth's surface. (carleton.edu)
  • We hypothesize that these human impacts increased soil erosion, producing new sediment sources from deeper soil horizons, and shifted dissolved transport to the lake, producing lower carbonate δ 13 C values, higher concentrations of lead, copper, potassium, and aluminum, and increased δ 15 N, likely due to contributions of enriched nitrogen from sewage. (cambridge.org)
  • Objective, measurable and unambiguous erosion and sediment control planning and design - the foundation of effective and defensible erosion and sediment control practice. (neia.org)
  • It is highly recommended that the Erosion and Sediment Control Practitioner (ESCP) course be completed prior to taking this more advanced course. (neia.org)
  • Erosion and Sediment Control - Planning and Design builds on the principles of effective erosion and sediment control practice developed and applied in Erosion and Sediment Control Practitioner (ESCP™) . (neia.org)
  • With a sound understanding of effective erosion and sediment control principles, the erosion and sediment practitioner can influence erosion and sediment control outcomes through erosion and sediment control planning and design that is realistic, timely and effective. (neia.org)
  • Erosion and Sediment Control - Planning and Design , through a series of practical exercises and case-studies, gives the course participants experience in site and construction methodology assessment as it pertains to erosion and sediment control and the application, design, quantification and prescription of erosion and sediment control practices. (neia.org)
  • The premise of the course is that most erosion and sediment control challenges can be identified prior to the start of construction and, therefore, many erosion and sediment requirements can also be designed and prescribed prior to the start of construction. (neia.org)
  • Erosion and sediment control must be proactive. (neia.org)
  • To be proactive, erosion and sediment control prescriptions must be objective, measurable and unambiguous. (neia.org)
  • This course promotes and provides a significant opportunity for participants to discuss the decision making and application challenges associated with erosion and sediment control. (neia.org)
  • During Pleistocene times, multiple glacial events provided the meltwater and sediments to vertically erode a deep valley into bedrock and to widen this valley by lateral erosion. (ku.edu)
  • Aggradation, degradation, and lateral erosion are controlled by the ability of the stream to move sediments, which in turn is controlled by the channel morphology, water velocity, and discharge. (ku.edu)
  • Abstract - Accelerated sediment production by mass failures and other erosion processes is an important link between management of forest resources and fish resources. (usda.gov)
  • Natural Slumping It has been determined that a combination of surface runoff and streambank erosion have contributed the most to sediment transport into the river. (scribd.com)
  • This uplift was accompanied by erosion and the overlying sediments were removed, with the exception of the small remnants of Meers quartzite. (fws.gov)
  • Geologic time is conceived to be continuous, and a land surface produced or modified by erosion cannot originate instantaneously. (ku.edu)
  • Geologic material as rocks, soils and cliffs are permanently exposed to Erosion process. (geocaching.com)
  • Erosion is the process of weathering and transport of smaller solids (dust, sediments, sand,etc.) in the environment. (geocaching.com)
  • Theoretical and numerical‐model considerations indicate that incident offshore waves interacting with even subtle shoreline curvature can drive gradients in net alongshore sediment flux that can cause significant erosion or accretion. (soton.ac.uk)
  • Glaciers can carry the largest sediment, and areas of glacial deposition often contain a large number of glacial erratics , many of which are several metres in diameter. (wikipedia.org)
  • The passage of Hurricane Wilma across Shark River estuary in 2005 allowed us to quantify sediment deposition and nutrient inputs in FCE mangrove forests associated with this storm event and to evaluate whether these pulsing events are sufficient to regulate nutrient biogeochemistry in mangrove forests of south Florida. (springer.com)
  • Off active major deposition centres, such as the Mississippi delta, slope sequences may accumulate through progradation, while the active slope front is continuously shedding sediments downslope by gravity processes. (britannica.com)
  • We have higher atmospheric deposition of contaminants than other states that are drier just because rainfall is so efficient at scavenging some of these metals and acids from the atmosphere, (knocking) it down into sediments and soils. (dailypress.com)
  • Study of geologic records of dust composition, sources and deposition rates is important for understanding the role of dust in the overall planetary radiation balance, fertilization of organisms in the world's oceans, nutrient additions to the terrestrial biosphere and soils, and for paleoclimatic reconstructions. (unl.edu)
  • Because these sediment layers can be many hundreds of meters thick, and because it's assumed that sedimentation rates have always been slow, secular scientists believe the sediment deposition required many millions of years. (icr.org)
  • Although creation scientists reject the millions of years that secular scientists have assigned to the seafloor sediments, they do agree that their deposition has been slow and gradual for at least the last few thousand years. (icr.org)
  • But even a few thousand years of slow deposition could only account for a tiny fraction of the total sediments on the ocean floor. (icr.org)
  • Sometime after the deposition of the sediments, a hot lava formed at considerable depth below the surface in the Wichita area. (fws.gov)
  • Presentations at the workshop provided a guide to our present knowledge of the entire spectrum of processes and phenomena important to the generation, transport, and deposition of eolian terrigenous material that ultimately becomes part of the geologic record and the modeling techniques that used to represent these processes. (bookdepository.com)
  • The presenta- tions on the geologic record of eolian deposition documented our present understanding of the na~e and causes of climate change on time scales of the last glacial ages (tens of thousands of years) to time scales over which the arrangement of continents, mountains, and oceans has changed sub- stantially (tens of millions of years). (bookdepository.com)
  • Most of the tilting developed after deposition of Permian sediments. (ku.edu)
  • In that time there have been many sediment collection projects conducted by USGS scientists and technicians for the research and study of seabed environments and processes. (usgs.gov)
  • In geology , physical geography , and sediment transport, fluvial processes relate to flowing water in natural systems. (wikipedia.org)
  • At the mouths of rivers, coastal sediment and fluvial sediment transport processes mesh to create river deltas . (wikipedia.org)
  • 1996. Sediment accretion in coastal wetlands: A review and simulation model of processes. (springer.com)
  • A distinct pH peak in the oxic zone could be explained by electrochemical oxygen reduction, but not by any conventional sets of aerobic sediment processes. (nih.gov)
  • The geologic evolution of Cat Island has been influenced by deltaic, lagoonal/estuarine, tidal, and oceanographic processes, resulting in a complex stratigraphic record. (usgs.gov)
  • Historical and newly acquired data were used to assess and monitor changes in the aerial and subaqueous extent of islands, habitat types, sediment properties, environmental processes, and vegetation composition. (usgs.gov)
  • The Marine Geosciences Section supports research on processes that occur on and below the sea floor and at the water/sediment/rock interface. (nsf.gov)
  • and interactions of continental and oceanic geologic processes. (nsf.gov)
  • Luminescence is also used to date paleoseismology sites, fluvial terraces (including paleoflood deposits), eolian deposits, and is increasingly used to calibrate wildfire temperatures, sediment transport processes, and thermochronology. (usgs.gov)
  • During highstands of sea level, these processes slow down as the coastline retreats landward across the continental shelf, and more of the sediments delivered to the coast are trapped in estuaries and lagoons . (britannica.com)
  • This paper presents an overview of such "hydromechanical" coupling and examines current understanding of its role in geologic processes. (springer.com)
  • Much of what is known about hydromechanical processes in geologic systems is derived from simpler analyses that ignore certain aspects of solid-fluid coupling. (springer.com)
  • The analysis presented here draws heavily on previously published material, while presenting a simple but complete picture of the factors that control sediment transport processes in the Kansas River. (ku.edu)
  • Dominant processes and the rates of sediment production vary greatly throughout the Pacific Northwest in response to geologic and climatic factors. (usda.gov)
  • They may look like meteor craters, but the circular features in the surface of northern Canada's Melville Island actually formed from geologic processes deep underground. (nasa.gov)
  • Sediment transport is important in the fields of sedimentary geology , geomorphology , civil engineering and environmental engineering (see applications , below). (wikipedia.org)
  • The majority of research in geology is associated with the study of rock, as rock provides the primary record of the majority of the geologic history of the Earth. (wikipedia.org)
  • When atmospheric particles fall into a lake or anywhere within the lake's catchment, anywhere that water and the land surface makes its way into the lake, some of that material falls to the bottom and gets archived in the sediments and is preserved there," said Nick Balascio, assistant geology professor at the College of William and Mary. (dailypress.com)
  • The study of geologic time is encompassed within the larger subject of historical geology. (encyclopedia.com)
  • In terms of geology, the absolute age of a geologic phenomenon is its age in Earth years. (encyclopedia.com)
  • The essays Historical Geology and Geologic Time offer several comparisons to emphasize the proportions involved and to illustrate the very short period during which human life has existed on this planet. (encyclopedia.com)
  • The geology of Scotts Bluff is significant from a natural resource standpoint because it affords a view of 740 feet of continuous geologic strata that spans a time period extending from 33 to 22 million years before present. (nps.gov)
  • We hope that the publication of a sediment curve for this entire era will enhance interest in Paleozoic geology,' said Haq, 'and help the exploration industry in its efforts to look at older and deeper sediments. (windows2universe.org)
  • About one-half of all continental slopes descend into deep-sea trenches or shallower depressions, and most of the remainder terminate in fans of marine sediment or in continental rises . (britannica.com)
  • Marine sediment was frozen at either −80°C or −20°C for 10 days prior to pasteurization and incubation at +50°C for 21 days to assess thermospore viability. (frontiersin.org)
  • found that thermospores are supplied to Arctic marine sediment at a rate of 10 8 m −2 y −1 . (frontiersin.org)
  • Deposits of fine-grained wind-blown glacial sediment are called loess . (wikipedia.org)
  • We sampled the spatial pattern of sediment deposits and their chemical properties in mangrove forests along FCE sites in December 2005 and October 2006. (springer.com)
  • The thickness (0.5 to 4.5 cm) of hurricane sediment deposits decreased with distance inland at each site. (springer.com)
  • Bulk density, organic matter content, total nitrogen (N) and phosphorus (P) concentrations, and inorganic and organic P pools of hurricane sediment deposits differed from surface (0-10 cm) mangrove soils at each site. (springer.com)
  • The Perseverance rover will look for similar deposits at Jezero to learn more about its geologic history. (nasa.gov)
  • When geologic uplifting brings deposits of diatomite above sea level, the diatomite is easily mined. (bartleby.com)
  • Scotts Bluff, like the adjoining Wildcat Hills and nearby Chimney Rock, Courthouse and Jail Rock, has been and continues to be weathered out of geologic deposits of alluvial origin that made up the ancient high plains of the region prior to regional uplifting. (nps.gov)
  • The Kansas River is a dynamic fluvial river system that transports sediments, erodes existing soil and rock, and creates new sediment deposits. (ku.edu)
  • It provides case-studies from around the world, gives guidance on appropriate applications of techniques, and their limitations, synthesizes methods that can be used to decipher complex deposits, and includes chemical deposits (speleothems) as well as clastic sediments. (helsinki.fi)
  • over geologic time, these sediments consolidate to form carbonate sedimentary rocks such as limestone. (cia.gov)
  • Sedimentary rocks are, as the name suggests, formed from the buildup of sediment. (icsantos.com.br)
  • Sedimentary rocks are formed by the accumulation of sediments. (icsantos.com.br)
  • Lithification is the process by which sediments combine to form sedimentary rocks. (icsantos.com.br)
  • Geologists have developed a new sediment curve which shows where sediment-on-the-move is deposited during the development of sedimentary rocks . (windows2universe.org)
  • The weathered rock forms sediment and can eventually be lithified to form sedimentary rocks. (ipl.org)
  • To discuss the divisions of geologic time, it is necessary first to discuss the concepts of relative and absolute time. (encyclopedia.com)
  • For the present, however, let us set our bearings for a discussion of the Phanerozoic eon, the fourth and last of the major divisions of geologic time. (encyclopedia.com)
  • The divisions of geologic time are not arranged in terms of strict mathematical relationships of the type to which we are accustomed, for example, ten years in a decade, ten decades in a century, and so on. (encyclopedia.com)
  • The earthquake potential of an area can be determined by studying the geologic history of the rock strata, both locally and regionally. (iris.edu)
  • Cores and sediment samples may be examined without constraint. (usgs.gov)
  • The team used geologic records from deep-sea drilling cores recovered using the NSF-funded research drillship JOIDES Resolution to extend the astronomical time scale by about eight million years. (nsf.gov)
  • The bathymetry, sidescan sonar, and sediment cores provide information about the extent and texture of the seafloor features. (usgs.gov)
  • The two previous articles in this series demonstrated problems with the old-earth timescales that secular scientists have assigned to deep seafloor sediments and ice cores. (icr.org)
  • Cores from Lake E reach back in geologic time nearly 25 times farther than Greenland ice cores that span only the past 140,000 years. (nsf.gov)
  • There were no highly contaminated sediments found in the cores from the three new boreholes in UP-1 operable unit, especially for uranium. (unt.edu)
  • Sediments overlying the quaternary aquifer. (mn.us)
  • Quaternary sediment. (usgs.gov)
  • Kachchh region of India is a rift basin filled with sediments from Jurassic to Quaternary ages. (springer.com)
  • Over the past 20 years, synchrotron-based research applications have provided important insight into the geochemical cycling of ions and the chemical and crystallographic properties of minerals in soils and sediments. (elsevier.com)
  • and magnetic properties of sediments, oceanic basalts, and polar ice. (columbia.edu)
  • What is currently San Diego started as sediment produced above an oceanic rift. (bartleby.com)
  • This data layer is a point coverage of sediment samples collected by the U.S. Geological Survey Woods Hole Science Center's field operations. (usgs.gov)
  • The scientific interest of this site has been apparent since the late 1890s when the U.S. Geological Survey made the first formal geologic investigation of the area. (nps.gov)
  • The data were created by aggregating available sediment point data collected from the United States Geological Survey's (USGS) usSEABED, version 1.0, U.S. Geological Survey Data Series 118 (Reid 2005), the Massachusetts Water Resources Authority, the Massachusetts Division of Marine Fisheries, and the United States Environmental Protection Agency. (noaa.gov)
  • Although sediments act as a drain for pollutants, they can also act as a source of pollutants under certain environmental conditions (like changes in the composition of the water or movement of the sediments owing to a flood event). (phys.org)
  • Quantity, composition, and source of sediment collected in sediment traps along the fringing coral reef off Molokai, Hawaii. (biomedsearch.com)
  • Based on quantity and composition of trapped sediment, floods recharged the reef flat with land-derived sediment, but had a low potential for burying coral on the fore reef when accompanied by high waves. (biomedsearch.com)
  • The sources, abundances, and quality (i.e., labile or recalcitrant) of the organic matter and the composition of the microbial assemblages vary between sediments. (nih.gov)
  • Third, aeolian sediment particle size and composition can be determined so that dust source areas can be ascertained and dust transport pathways can be reconstructed. (unl.edu)
  • 5 Second, buried nodules do not exhibit any clear trends in chemical composition with depth, as one might expect if they were in various stages of dissolving, suggesting that "buried nodules neither grow nor dissolve after their burial in the sediment column. (icr.org)
  • The use of the metagenomics, where bulk samples of sediment are sequences without separation, allows recognition of unknown organism and determination of the composition of the ecosystem. (dailygalaxy.com)
  • This GIS data layer represents point coverage of seafloor sediment size and composition in Massachusetts territorial waters. (noaa.gov)
  • 2010. Seafloor sediment composition in Massachusetts determined using point data. (noaa.gov)
  • [4] This sediment is important to the soil budget and ecology of several islands. (wikipedia.org)
  • Total P inputs from storm-derived sediments were equivalent to twice the average surface soil nutrient P density (0.19 mg cm −3 ). (springer.com)
  • Allochthonous mineral inputs from Hurricane Wilma represent a significant source of sediment to soil vertical accretion rates and nutrient resources in mangroves of southwestern Everglades. (springer.com)
  • The measured volumes of sediment, watershed morphology, distributions of burn severity within each watershed, the time since the most recent fire, triggering storm rainfall conditions, and engineering soil properties were analyzed using multiple linear regressions to develop two models. (usgs.gov)
  • This book provides the most up-to-date information on synchrotron-based research applications in the field of soil, sediment and earth sciences. (elsevier.com)
  • When buried, the sediments lose water and become cemented to form rock… This constant friction of the elements against the Earth's surface erode rock and soil, turning it into small sedimentary particles or debris. (icsantos.com.br)
  • A perspective model of the morphology and geologic framework near Petit Bois Island showing the relationships between seafloor features and the subsurface. (usgs.gov)
  • Diverse organic matter hydrolysis encoding genes were present in sediments between 0.25 and 67 meters below seafloor and were in higher relative abundances in those sediments that contained more organic matter. (nih.gov)
  • 1,2 This article presents a positive argument for the youthfulness of the seafloor sediments-an argument that has ominous implications for the vast ages assigned to the high-latitude ice sheets. (icr.org)
  • Secular scientists assign ages to these layers by using the astronomical or Milankovitch hypothesis of ice ages to interpret chemical clues within the seafloor sediments. (icr.org)
  • Why are nodules generally missing from the deeper seafloor sediments? (icr.org)
  • If the present really is the "key to the past," one would expect nodules to be found at all depths within the seafloor sediments. (icr.org)
  • Creation scientists have an extremely straightforward and logical explanation for the rarity of manganese nodules within the deep seafloor sediments: Since nodule growth is apparently possible only at the surface or below a shallow layer of sediment, the absence of nodules in the deeper sediments implies that these deeper sediments were simply deposited too rapidly for nodules to form and grow. (icr.org)
  • With up to 40 cm thickness the zones of AOM activity were unusually large and occurred in deeper sediment horizons (20-50 cm below seafloor) as compared to diffusion-dominated deep-sea seeps, which is likely caused by advective flow of pore water due to the shallow water depth and permeability of the sands. (frontiersin.org)
  • These chemicals originate in seawater or within water trapped between the sediment grains below the sea floor. (icr.org)
  • Caves serve as unique repositories for geologic, biologic, and anthropologic information. (helsinki.fi)
  • Using a bit of circular reasoning, the geologic column is used as support for biologic evolution, which is then sometimes used to confirm the order of the layers in the geologic column. (answersingenesis.org)
  • lake sediments, and their fossilized remains are called diatomite. (bartleby.com)
  • The photo below shows beach sediments along the northeastern edge of the lake. (nasa.gov)
  • Lithofacies And Transport Of Clastic Sediments In Karstic Aquifers. (helsinki.fi)
  • How are the clastic sediments different from precipitate sediments? (icsantos.com.br)
  • This paper presents a detailed macro- and microscale analysis of soft-sediment deformation structures in order (1) to resolve the long-standing debate on the genetic origin of the Upper Diamictite Formation, and (2) to constrain the paleoenvironmental conditions during the Marinoan global event. (ac.be)
  • An outline of the theory of hydromechanics and rheological models for geologic deformation is included to place various analytical approaches in proper context and to provide an introduction to this broad topic for nonspecialists. (springer.com)
  • However, rigorous application of full coupling is often difficult because (1) the rheological behavior of geologic media is complex and poorly understood and (2) the architecture, mechanical properties and boundary conditions, and deformation history of most geologic systems are not well known. (springer.com)
  • The topics in shallow surface geophysics include field geophysical surveys of glaciotectonic deformation of Long Island sediments using ground penetrating radar, electrical resistivity, seismic reflection and refraction as well as borehole geophysics. (stonybrook.edu)
  • The high trapping rate and low sediment cover indicate that coral surfaces on the fore reef are exposed to transient resuspended sediment, and that the traps do not measure net sediment accumulation on the reef surface. (biomedsearch.com)
  • Sediment accumulation rates. (elsevier.com)
  • The main types of sediment in a glacial environment are described below. (icsantos.com.br)
  • Coastal sediment transport results in these evenly spaced ripples along the shore. (wikipedia.org)
  • Coastal sediment transport takes place in near-shore environments due to the motions of waves and currents. (wikipedia.org)
  • Coastal sediment transport results in the formation of characteristic coastal landforms such as beaches , barrier islands , and capes. (wikipedia.org)
  • 1995. The influence of Hurricane Andrew on sediment distribution in Louisiana coastal marshes. (springer.com)
  • A combination of geophysics, sediment sampling, and chronology techniques are used to characterize the regional geomorphologic response of coastal systems to environmental changes. (usgs.gov)
  • The Geologic and Morphologic Evolution of Coastal Margins (GeoEvo) project seeks to understand the historic (years to decades) and geologic (decades to millennia) evolution of coastal systems. (usgs.gov)
  • Understanding how and why coasts have changed in the past can provide insight into modern coastal behavior, future coastal evolution, the extent and quality of sediment resources, and spatial variability in the resilience of coastal ecosystems, all of which inform coastal resource management. (usgs.gov)
  • Microbial and viral-like rhodopsins present in coastal marine sediments from four polar and subpolar regions. (nextbio.com)
  • Coastal Plain Rocks and Sediments. (wikipedia.org)
  • Bedforms are generated by aeolian sediment transport in the terrestrial near-surface environment. (wikipedia.org)
  • Aeolian sediment transport is common on beaches and in the arid regions of the world, because it is in these environments that vegetation does not prevent the presence and motion of fields of sand. (wikipedia.org)
  • These studies will allow engineers to design sediment retention structures of appropriate size and residence time. (carleton.edu)
  • On geologic time scales (thousands to millions of years), variations in Earth's orbit are the pacemakers of the ice ages. (nsf.gov)
  • This astronomical answer has a built-in clock (computing planetary orbits backward in time), providing an accurate chronology for the geologic record. (nsf.gov)
  • Further application of the new method promises to reach farther back, one step and geologic record at a time. (nsf.gov)
  • A "long-term model" was developed for predicting volumes of sediment deposited by both debris flows and floods at various times since the most recent fire from a database of volumes of sediment deposited by a combination of debris flows and sediment-laden floods with no time limit since the most recent fire (n = 344). (usgs.gov)
  • IMPORTANCE Sediments sequester organic matter over geologic time scales and impact global climate regulation. (nih.gov)
  • Over geologic time , the continental slopes are temporary depositional sites for sediments. (britannica.com)
  • The expression geologic time refers to the vast span from Earth 's beginnings to the present, about 4.6 billion years. (encyclopedia.com)
  • Instead of thinking in terms of years, centuries, or even millennia, the most basic unit is a million years, and even that is rather small when compared with the four eons into which geologic time is divided. (encyclopedia.com)
  • Geologic time is divided according to two scales. (encyclopedia.com)
  • The more well-known of these is the geologic scale, which divides time into named groupings according to six basic units: eon, era, period, epoch, age, and chron. (encyclopedia.com)
  • As noted earlier, stratigraphy is the study of rock layers, or strata, beneath Earth's surface, while chronostratigraphy is a subdiscipline devoted to studying the ages of rocks and what they reveal about geologic time. (encyclopedia.com)
  • The term geologic time refers to the great sweep of Earth's history, a timescale that dwarfs the span of human existence. (encyclopedia.com)
  • As one example shows, if all of geologic time were compressed into a single year, the first Homo sapiens would have appeared on the scene at about 8:00 p.m. on December 31. (encyclopedia.com)
  • In another example, geologic time is compared to the distance from Los Angeles to New York City. (encyclopedia.com)
  • Needless to say, the scope of geologic time compared with the units with which we are accustomed to measuring our lives (or even the history of our civilization) is more than a little intimidating. (encyclopedia.com)
  • The Arctic was very warm during a period roughly 3.5 to 2 million years ago--a time when research suggests that the level of carbon dioxide in the atmosphere was roughly comparable to today's--leading to the conclusion that relatively small fluctuations in carbon dioxide levels can have a major influence on Arctic climate, according to a new analysis of the longest terrestrial sediment core ever collected in the Arctic. (nsf.gov)
  • While existing geologic records from the Arctic contain important hints about this time period, what we are presenting is the most continuous archive of information about past climate change from the entire Arctic borderlands,' she said. (nsf.gov)
  • In this animation, no strata are overturned, thus the following laws apply: The law of superposition simply says that for non-deformed geologic strata, ?sedimentary layers are deposited in a time sequence, with the oldest on the bottom and the youngest on the top? (iris.edu)
  • The first known geologic event in this region took place 550 to 600 million years ago (Early of Middle Cambrian time). (fws.gov)
  • The next major geologic event took place in the Middle Cambrian time (500 to 550 million years ago). (fws.gov)
  • It follows that placement of the surface in geologic time is only approximate, that is, partly pre-Tertiary, or late Cretaceous, and partly post-Cretaceous, or early Tertiary. (ku.edu)
  • 02/12/2015 Fri 02/13/2015 (Additional information) Topic The Geologic Time Scale Early Earth Geologic History Illinois Learning/Common Core State Standards (CCSS) Cite specific textual evidence to support analysis of science and technical texts.CC6-8.R.ST.1 Cite several pieces of textual evidence to support analysis of what the text says explicitly as well as inferences from the text. (majortests.com)
  • The sediment which comprise of clay, sand, boulder or carbonate are being deposited in the sedimentary basin over a geologic time (million years). (wikibooks.org)
  • These sediments have formed over a period of numerous geologic time periods. (everything-everywhere.com)
  • Microbial Organic Matter Degradation Potential in Baltic Sea Sediments Is Influenced by Depositional Conditions and In Situ Geochemistry. (nih.gov)
  • The islands of the Bahamas in the Caribbean Sea are situated on large depositional platforms (the Great and Little Bahama Banks) composed mainly of carbonate sediments ringed by fringing reefs - the islands themselves are only the parts of the platform currently exposed above sea level. (cia.gov)
  • Based on simulations, large volumes of sediment eroded from the hillslopes were redeposited within the channel network throughout the storm, leading to the initiation of numerous debris flows as a result of the mass failure of sediment dams that built up within the channel. (usgs.gov)
  • Debris-retention basins protect communities and infrastructure from the impacts of debris flows and sediment-laden floods and also provide critical data for volumes of sediment deposited at watershed outlets. (usgs.gov)
  • In this study, we supplement existing data for the volumes of sediment deposited at watershed outlets with newly acquired data to develop new empirical models for predicting volumes of sediment produced by watersheds located in the Transverse Ranges of southern California. (usgs.gov)
  • A subset of this database was used to develop an "emergency assessment model" for predicting volumes of sediment deposited by debris flows within two years of a fire (n = 92). (usgs.gov)
  • Prior to developing the models, 32 volumes of sediment, and related parameters for watershed morphology, burn severity and rainfall conditions were retained to independently validate the long-term model. (usgs.gov)
  • Ten of these volumes of sediment were deposited by debris flows within two years of a fire and were used to validate the emergency assessment model. (usgs.gov)
  • The models were validated by comparing predicted and measured volumes of sediment. (usgs.gov)
  • These validations were also performed for previously developed models and identify that the models developed here best predict volumes of sediment for burned watersheds in comparison to previously developed models. (usgs.gov)
  • 1976. A semi-automated method for the determination of inorganic, organic and total phosphate in sediments. (springer.com)
  • The collecting of fine sediment along the riverbed as well as the subsequent analysis of it in the laboratory have revealed that the main anthropogenic source of organic matter and metals is untreated or partially treated industrial and municipal effluent. (phys.org)
  • This is reflected in the high organic load found in the sediments of the Ego stream, which until 2014 was receiving the untreated sewage of the municipality of Ermua. (phys.org)
  • Yet the diversion of the organic effluent of the municipality of Oñati to the Epele treatment plant in 2012 has had a beneficial effect on sediment quality as its organic load has been considerably reduced and, as a result, so have the metals associated with these organic complexes. (phys.org)
  • Here we provide evidence that electric currents running through defaunated sediment couple oxygen consumption at the sediment surface to oxidation of hydrogen sulphide and organic carbon deep within the sediment. (nih.gov)
  • Globally, marine sediments are a vast repository of organic matter, which is degraded through various microbial pathways, including polymer hydrolysis and monomer fermentation. (nih.gov)
  • Here, we examine new and previously published sediment metagenomes from the Baltic Sea and the nearby Kattegat region to determine connections between geochemistry and the community potential to degrade organic carbon. (nih.gov)
  • New analysis of previously published metatranscriptomes demonstrated that many of these genes were transcribed in two organic-rich Holocene sediments. (nih.gov)
  • Microbial communities in marine sediments drive organic matter degradation, but the factors controlling their assemblages and activities, which in turn impact their role in organic matter degradation, are not well understood. (nih.gov)
  • We examined microbial communities in Baltic Sea sediments, which were deposited across various climatic and geographical regimes to determine the relationship between microbial potential for breakdown of organic matter and abiotic factors, including geochemistry and sediment lithology. (nih.gov)
  • Sensitivity values were assigned based on the type of sediment at the surface and the depth to bedrock. (mn.us)
  • The shoreline and surrounding bedrock around Lake Salda contain sediments of different origins. (nasa.gov)
  • The darker-toned sediments were eroded from the steep exposures of the surrounding bedrock. (nasa.gov)
  • Enhanced adsorption behavior for Tc, and Cr and perhaps Se on the sediments was considered an ?artifact? (unt.edu)
  • This indicates that shoreline changes observed in these reaches can be explained in part by gradients in alongshore sediment flux acting to smooth spatial variations in shoreline curvature. (soton.ac.uk)
  • The present and paleo-alluvial areas representing unconsolidated sediments were mapped using Landsat-TM data and field reflectance spectra. (springer.com)
  • The UPV/EHU's Hydrology-Environment Group has conducted research on the River Deba and its tributaries to assess the influence of anthropogenic inputs and the effect exerted by major flooding events on the distribution of the metals associated with the sediments. (phys.org)
  • The trapped sediments have low concentrations of anthropogenic metals. (biomedsearch.com)
  • The model assumes that the sediment type at the land surface is representative of the entire sediment thickness. (mn.us)
  • How, then, can creation scientists explain the great thickness of these sediments? (icr.org)
  • This sedimentary process may accummulate sediment with cumulative thickness of several thousand meters. (wikibooks.org)
  • The data can be used with geographic information systems (GIS) software to display geologic and oceanographic information. (usgs.gov)
  • In addition, hydrologic modeling will predict the discharge and sediment flux from the watershed under different climate conditions. (carleton.edu)
  • The Hydraulics Characteristics section presents a survey of the hydraulic characteristics of the river, examining a number of variables that affect water discharge and sediment load. (ku.edu)
  • The volume of sediments transported (sediment load) and the grain-size distribution of those sediments is controlled by the hydraulic parameters of the river channel including the supply of sediments, depth and width of the stream, cross sectional area and slope of the channel, and velocity and discharge of the water. (ku.edu)
  • By lowering the peak flood discharge, reservoirs lower the volume of sediment moved during a given flood. (ku.edu)
  • A geologic province is a spatial entity with common geologic attributes. (mcgill.ca)
  • AOM is largely mediated by consortia of anaerobic methanotrophic archaea (ANME) and sulfate-reducing bacteria (SRB), and has mainly been investigated in deep-sea sediments. (frontiersin.org)
  • The anaerobic oxidation of methane (AOM) is a key biogeochemical process regulating methane emission from marine sediments and is mediated by anaerobic methane-oxidizing archaea (ANME) and sulfate-reducing bacteria (SRB) ( Knittel and Boetius, 2009 ). (frontiersin.org)
  • Dormant endospores of anaerobic, thermophilic bacteria found in cold marine sediments offer a useful model for studying microbial biogeography, dispersal, and survival. (frontiersin.org)
  • that also present abundant geologic hazards. (carleton.edu)
  • Debris flows and sediment-laden floods in the Transverse Ranges of southern California pose severe hazards to nearby communities and infrastructure. (usgs.gov)
  • I teach classes related to earth history, geologic hazards, and sediment transport. (earlham.edu)
  • Previously undocumented in North American rivers, concentrations of microplastic particles in the St. Lawrence are as high as has been observed in the world's most contaminated marine sediments. (phys.org)
  • At some locations, the researchers measured over 1000 microbeads per liter of sediment, a magnitude that rivals the world's most contaminated ocean sediments. (phys.org)
  • Palaeomagnetic Analysis Of Sediments In The Buchan Caves, Southeastern Australia, Provides A Pre-Late Pleistocene Date For Landscape And Climate Evolution. (helsinki.fi)
  • Hence, determining the role of microbial communities in carbon cycling in various sediment types is necessary for predicting future sediment carbon cycling. (nih.gov)
  • Between 20 and 80% of the methane (around 10 6 tons of carbon per year) is consumed at the sediment water interface by methanotrophic microbial communities ( Boetius and Wenzhöfer, 2013 ). (frontiersin.org)
  • Hydromagnesite sediments may be similar to carbonate minerals detected at Jezero. (nasa.gov)
  • There are few sediments and minerals that are consistent with a wet planet. (go.com)
  • In other words, these minerals would not exist if water was common anytime in the near geologic past. (go.com)
  • Thanks to a certain 1993 blockbuster, most people know the name of at least one period in geologic history. (encyclopedia.com)
  • This north face of Scotts Bluff has exposed the most geologic history of any location in the state of Nebraska. (nps.gov)
  • What can road cuts tell us about the geologic history of an area? (iris.edu)
  • A hypothetical cross section is studied by going back to the beginning to study its progressive geologic history. (iris.edu)
  • This complex impact crater has a diverse geologic history, as indicated by various features on the crater rim and floor. (esa.int)
  • The crater's shallow interior has been infilled by sediments over its history. (esa.int)
  • The rugged yet protected landscape of the Wichita Mountains Wildlife Refuge is the result of over half a billion years of geologic history. (fws.gov)
  • Recognition of these interruptions in the record is extremely important in helping to understand the geologic history of the area. (ku.edu)
  • The present land surface in Kansas is an important key to understanding the geologic history of the area (Jewett and Merriam, 1959). (ku.edu)
  • Ancient sediments like these in Brittany, France, help reconstruct Paleozoic sea-level history. (windows2universe.org)
  • nov., isolated from foreshore tidal flat sediment from the Yellow Sea. (biomedsearch.com)
  • A Gram-positive, rod-shaped, endospore-forming organism, strain BL3-6(T), was isolated from tidal flat sediments of the Yellow Sea in the region of Tae-An. (biomedsearch.com)
  • The light-toned sediments are made up of the carbonate mineral hydromagnesite. (nasa.gov)
  • All the sediment on the banks, including the material that forms the islands, is calcium carbonate (lime) precipitated from sea water by animals and plants. (cia.gov)
  • In these carbonate aquifers, directions of groundwater flow may be difficult to predict, because of their anisotropic nature and existing geologic structures. (nature.com)
  • But if nodules don't dissolve after burial, then their absence in the deep sediments implies that nodules simply were not being formed when the deeper sediments were deposited. (icr.org)
  • Sediment data were collected between 1884 to 2008 from a variety of published and unpublished sediment texture and other geologic data. (noaa.gov)
  • The UPV/EHU's Hydrology and Environment Research Group has located the stretches in the River Deba and its tributaries posing the greatest potential hazard owing to their high metal content, has identified the sources of pollution and has assessed the effect that a certain type of flood event has on the carrying away and distribution of sediments and associated metals. (phys.org)
  • The drilling process involves collecting and logging geologic samples from the floor of deep ocean basins through rotary coring and hydraulic piston coring. (nsf.gov)
  • Sediment core samples from Lake Matoaka on the campus of William & Mary are being studied for the types and concentrations of pollution that have affected the area for over 300 years. (dailypress.com)
  • The ability of accelerator mass spectrometry (AMS) to measure very small concentrations of the nuclides 10 Be, 14 C, 26 Al, 36 Cl, and 129 I has led to many innovative applications in geologic research. (semanticscholar.org)
  • Reading Virginia's Paleoclimate From The Geochemistry And Sedimentology Of Clastic Cave Sediments. (helsinki.fi)
  • In typical rivers the largest carried sediment is of sand and gravel size, but larger floods can carry cobbles and even boulders . (wikipedia.org)
  • there are smaller amounts of sediments of sand or gravel . (britannica.com)
  • Rivers carried clay, sand and gravel into this sea and thick layers of sediments were formed. (fws.gov)
  • chemical and magnetic records of pollution in sediments and mineral dust. (colorado.edu)
  • The hydromagnesite sediments around Lake Salda are thought to have eroded from large mounds called "microbialites"-rocks formed with the help of microbes. (nasa.gov)
  • These rocks often start as sediments carried in rivers and deposited in lakes and oceans. (icsantos.com.br)
  • Every effort has been made to ensure the interpretation shown conforms to sound geologic and cartographic principles. (mn.us)
  • Sediment transport due to fluid motion occurs in rivers , oceans , lakes , seas , and other bodies of water due to currents and tides . (wikipedia.org)
  • The Abundan of riverS nd sltrems is the resul of the presnce of impe .oble Ond IA preObilRty sediments of the Hawthorn Group undeOlRng the mapped aM. (ufl.edu)
  • More generally, results provide a quantitative framework for assessing the potential of runoff-generated debris flows based on sediment supply and hydrologic conditions. (usgs.gov)