Unknown
PANGAEA
In:
Supplement to: Schaefer, Rainer G; Leythaeuser, Detlev (1986): Low-molecular-weight hydrocarbons in sediments of Deep Sea Drilling Project Leg 89, Sites 585, East Mariana Basin, and 586, Ontong-Java Plateau. In: Moberly, R; Schlanger, SO; et al. (eds.), Initial Reports of the Deep Sea Drilling Project, Washington (U.S. Govt. Printing Office), 89, 577-586, https://doi.org/10.2973/dsdp.proc.89.123.1986
Publication Date:
2023-05-12
Description:
C2-C8 hydrocarbon concentrations (about 35 compounds identified, including saturated, aromatic, and olefinic compounds) from 38 shipboard sealed, deep-frozen core samples of Deep Sea Drilling Project Sites 585 (East Mariana Basin) and 586 (Ontong-Java Plateau) were determined by a gas stripping-thermovaporization method. Total concentrations, which represent the hydrocarbons dissolved in the pore water and adsorbed on the mineral surfaces of the sediment, vary from 20 to 630 ng/g of rock at Site 585 (sub-bottom depth range 332-868 m). Likewise, organic-carbon normalized yields range from 3*10**4 to 9*10**5 ng/g Corg, indicating that the organic matter is still in the initial, diagenetic evolutionary stage. The highest value (based on both rock weight and organic carbon) is measured in an extremely organic-carbon-poor sample of Lithologic Subunit VB (Core 585-30). In this unit (504-550 m) several samples with elevated organic-carbon contents and favorable kerogen quality including two thin "black-shale" layers deposited at the Cenomanian/Turonian boundary (not sampled for this study) were encountered. We conclude from a detailed comparison of light hydrocarbon compositions that the Core 585-30 sample is enriched in hydrocarbons of the C2-C8 molecular range, particularly in gas compounds, which probably migrated from nearby black-shale source layers.
C2-C8 hydrocarbon yields in Site 586 samples (sub-bottom depth range 27-298 m) did not exceed 118 ng/g of dry sediment weight (average 56 ng/g), indicating the immaturity of these samples.
Keywords:
Deep Sea Drilling Project; DSDP
Type:
Dataset
Format:
application/zip, 3 datasets
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