Organic geochemistry of the Argentine Basin sediments: Carbon-nitrogen relationships and Quaternary correlations

Stevenson, F. J.; Cheng, Chunyang

doi:10.1016/0016-7037(72)90109-3

Cited by 134 publications

(64 citation statements)

References 30 publications

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“…It is generally accepted that C/N values are higher for organic matter from a terrestrial rather than from a marine source (e.g., Calvert, 1983). However, modern marine sediments have C/N ratios in the range of 9 to 18 (Müller, 1977;Stevenson and Cheng, 1972) and diagenesis can alter C/N values (Müller, 1977;Waples and Sloan, 1980) which is in keeping with most of the C/N ratios observed at Site 797. Ratios outside this range at Site 797 are usually from sediments which are very low in nitrogen.…”

Section: Carbon Nitrogen and Sulfursupporting

confidence: 60%

Site 797

1990

Proceedings of the Ocean Drilling Program, 127 Initial Reports

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1 Tamaki, K., Pisciotto, K., Allan, J., et al., 1990. Proc. ODP, Init. Repts., 127: College Station, TX (Ocean Drilling Program). Principal results: The objectives at Site 797, located in the southern Yamato Basin, were (1) to determine the age and nature of acoustic basement, (2) to measure the direction and magnitude of the present stress field, and (3) to characterize the sedimentation, subsidence, and oceanographic evolution of the area. The results at Site 797 are summarized below and in Figure 1. The principal results at Site 797 are as follows:1. Acoustic basement and an overlying seismic interval at this site comprise basalts and dolerites and interlayered volcaniclastic sandstones, siltstones, and silty claystones. The age of the sediments which overlie the shallowest basalt layer is estimated to be about 19 Ma. Based on paleodepth estimates using microfossils within these sediments and the sedimentologic interpretation of the underlying volcaniclastic sediments, this part of the Yamato Basin probably subsided rapidly during the early Miocene. The uppermost basalts most likely represent submarine lava flows, whereas the bulk of the underlying igneous units are sills and dikes. The upper nine units are high-Al basalt in composition, consistent with generation during the early stages of arc rifting. However, the units below these are mildly alkaline basalts and enriched tholeiites, which are unrelated to the overlying basalts and were probably derived from a different mantle source.2. The in-situ stress field could not be determined, because poor hole conditions precluded packer/hydro fracture tests. A borehole televiewer log over one basalt interval showed fractures but no borehole breakouts for stress directions.3. The lithologic and paleontological data indicate at least four principal stages in the evolution of this part of the Yamato Basin: (a) an early Miocene period of submarine basaltic volcanism and concomitant deposition of gravity-flow and current-reworked volcani- 323 SITE 797clastic sandstones and siltstones on a shelf or slope, probably outboard of a delta; (b) a late early to early middle Miocene phase of diminishing submarine volcanic activity, warm surface waters, and deposition of calcareous and slightly phosphatic hemipelagic claystones at lower middle bathyal depths (1500-2000 m) in a poorly oxygenated basin; (c) a late Miocene to late Pliocene cooling period beginning with an interval of anomalously slow sedimentation (5 m/m.y.) or a hiatus and characterized by dominant but variable diatomaceous sedimentation at lower middle bathyal depths (1500-2000 m); and (d) a latest Pliocene to Holocene stage during which diatomaceous sedimentation diminished volcanic-ash production and terrigenous input increased, subsidence continued, and climate oscillated to produce a sequence of interlayered light-and dark-colored silty clays having variable organic-carbon contents. In contrast with the more northern sites drilled during Leg 127, the sediments at Site 797 contain more carbonate suggesting ...

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Section: Carbon Nitrogen and Sulfursupporting

confidence: 60%

Site 797

1990

Proceedings of the Ocean Drilling Program, 127 Initial Reports

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“…The mean values recorded in this study are slightly higher than expected (1.02 ± 0.3%, range 0.41-1.42%,), but lower than those recorded in the continental margins (>1.5% in Seiter et al, 2004;4-16% in Arthur et al, 1998). The TOC values are similar to those recorded in the northern Gulf of Mexico (0.34-1.59% in Goni et al, 1997;1998;Gordon and Goni, 2004;0.37-1.3% in Morse and Beazley, 2008) and those from other basins at similar latitudes, i.e.,: The Argentina Basin (0.26-1.72% in Stevenson and Cheng, 1972) and the Arabian Sea (0.04-1.5% in Grandel et al, 2000). The highest value of this study is in agreement with the values described by Seiter et al (2004) for tropical regions, including the continental margin of western Africa.…”

Section: Total Mercurysupporting

confidence: 84%

The Correlations Between Mercury Speciation and Dissolved Organic Matter in the Sediment of the Red Sea

Wedyan

Ababneh

Al-Rousan

2012

American Journal of Environmental Sciences

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This study addresses the correlations between Hg and organic matter in recent sediment; samples were collected from the Gulf of Aqaba, Red Sea coasts (oligotrophic regions) during 2010. In the present study TOC analyzer was used to determine Total Organic Carbon (TOC) and Total Nitrogen (TN) concentrations and the total amount of mercury (Hg T ) in sediment samples were analyzed by Hydra-C mercury analyzer. The obtained results indicated that, mercury, TOC and TN average concentrations in the Red Sea were 85.42 ng g −1 , 5.10 and 4.45 mg L −1 , respectively. The results show that the Total Organic Carbon (TOC) in sediment represents the sum of various organic compounds, which may play a completely different role in the distribution and accumulation of Hg. slightly correlations between the TOC and the concentration of Hg in the studied sediment arise mainly from the labile portion of organic matter released. These compounds primarily consist of easily degradable algal-derived lipids and various pigments, which are petrographically described as a soluble Organic Matter (OM). The preserved OM in sediment is commonly entrapped within the cell walls of phytoplankton and also appears as a surface coating on sediment particles. The strong affinity between Hg and OM is due not only to its chemical reactivity, but also to the physical characteristic of these labile compounds, which plays the most important role in the distribution of Hg in sediment.

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“…Discrimination of organic matter between two sources has often been con ducted by ratio of total organic carbon (TOC) to nitrogen content (C/N) (Stevenson and Cheng, 1972;Muller, 1977) and isotopic composition of TOC (e.g. Degens, 1969;Sackett, 1987).…”

Section: Introductionmentioning

confidence: 99%

Carbon isotopic difference of saturated long-chain n-fatty acids between a terrestrial and a marine sediment.

1995

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Stable carbon isotopic compositions of individual n-fatty acids ranging from C20 to C30 in a terrestrial (riverine) and a marine (pelagic) sediment were determined using gas chromatography/isotope ratio moni toring mass spectrometry (GC/IRMS). These fatty acids in a terrestrial sediment at the Ohtsuchi river in northern Honshu Island, Japan, showed 613C values (from -35 to -32%.o relative to PDB) lighter than that of the total organic carbon (TOC; -26.4%o) by about 6 to 9%o. The 813C values from a marine sediment in the Pacific Ocean ca. 500 km off the coast of Honshu Island varied from -31 to -26%o, which were also lighter than that of the TOC (-20.5%o) by 6 to 9%o. The 613C values of n-fatty acids ranging from C20 to C30 in the marine sediment were heavier by about 5 to 6%o than those at the corresponding carbon numbers in the terrestrial one. Isotopically, the marine n-fatty acids were clearly distinguished from the terrestrial ones. These results suggest that long-chain n-fatty acids in marine sediment were not derived from land higher plant but from marine organisms, although long-chain n-fatty acids (>_C20) in marine sediments have often been used to assess terrestrial material contribution to the ocean.

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Organic geochemistry of the Argentine Basin sediments: Carbon-nitrogen relationships and Quaternary correlations

Cited by 134 publications

References 30 publications

Site 797

Site 797

The Correlations Between Mercury Speciation and Dissolved Organic Matter in the Sediment of the Red Sea

Carbon isotopic difference of saturated long-chain n-fatty acids between a terrestrial and a marine sediment.

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