Berner, Ulrich; Faber, Eckhard (1993): Light hydrocarbons in gas pockets and sediments of ODP Site 131-808 [dataset publication series]. PANGAEA, https://doi.org/10.1594/PANGAEA.785205, Supplement to: Berner, U; Faber, E (1993): Light hydrocarbons in sediments of the Nankai accretionary prism (Leg 131, Site 808). In: Hill, IA; Taira, A; Firth, JV; et al. (eds.), Proceedings of the Ocean Drilling Program, Scientific Results, College Station, TX (Ocean Drilling Program), 131, 185-195, https://doi.org/10.2973/odp.proc.sr.131.120.1993
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Published: 1993 (exact date unknown) • DOI registered: 2012-07-26
Abstract:
A suite of gas samples obtained from gas pockets and sediments of the Nankai accretionary prism (Site 808) has been analyzed for their gas composition and carbon and hydrogen isotope ratios. Gases collected from gas pockets between 10 and 555 mbsf consist of CH4 and CO2. Stable carbon isotope ratios of these two components point to a bacterial formation of methane via CO2-reduction that is also supported by D/H ratios of methane. Methane desorbed from sediments by a vacuum/acid treatment is of bacterial and thermal origin. Mixing between these gas types is indicated by molecular composition and carbon isotope ratios. Diagenetic processes at low temperatures can explain ethane to pentane concentrations from 0 to 850 mbsf. Between 850 mbsf and the basaltic basement hydrocarbon occurrences are related to catagenetic processes at elevated temperatures. Thermal alteration of organic matter is reflected through different gas parameters. Propane carbon isotope values of a sample from the zone of the frontal thrust indicate that the gas likely migrated from sediments of a higher maturity into the immature sediments at 366 mbsf.
Project(s):
Ocean Drilling Program (ODP)
Coverage:
Median Latitude: 32.352078 * Median Longitude: 134.944244 * South-bound Latitude: 32.351400 * West-bound Longitude: 134.943600 * North-bound Latitude: 32.352800 * East-bound Longitude: 134.944400
Date/Time Start: 1990-04-04T00:00:00 * Date/Time End: 1990-05-31T00:00:00
Event(s):
131-808 * Latitude: 32.352150 * Longitude: 134.944367 * Date/Time Start: 1990-04-04T00:00:00 * Date/Time End: 1990-05-31T00:00:00 * Elevation: -4685.1 m * Penetration: 4130.2 m * Recovery: 732.1 m * Location: Philippine Sea * Campaign: Leg131 * Basis: Joides Resolution * Method/Device: Composite Core (COMPCORE) * Comment: 163 cores; 1463.3 m cored; 1980 m drilled; 50% recovery
131-808A * Latitude: 32.352000 * Longitude: 134.944400 * Date/Time Start: 1990-04-04T22:30:00 * Date/Time End: 1990-04-06T15:45:00 * Elevation: -4687.0 m * Penetration: 111.4 m * Recovery: 88.68 m * Location: Philippine Sea * Campaign: Leg131 * Basis: Joides Resolution * Method/Device: Drilling/drill rig (DRILL) * Comment: 13 cores; 111.4 m cored; 0 m drilled; 79.6 % recovery
131-808B * Latitude: 32.351400 * Longitude: 134.943600 * Date/Time Start: 1990-04-06T15:45:00 * Date/Time End: 1990-04-16T04:00:00 * Elevation: -4685.0 m * Penetration: 358.8 m * Recovery: 59.71 m * Location: Philippine Sea * Campaign: Leg131 * Basis: Joides Resolution * Method/Device: Drilling/drill rig (DRILL) * Comment: 28 cores; 247.8 m cored; 0 m drilled; 24.1 % recovery
License:
Creative Commons Attribution 3.0 Unported (CC-BY-3.0)
Size:
3 datasets
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Datasets listed in this publication series
- Berner, U; Faber, E (1993): (Table 3) Gas ratios and stable isotopic composition of gases in sediments of ODP Site 131-808. https://doi.org/10.1594/PANGAEA.785204
- Berner, U; Faber, E (1993): (Table 1) Molecular composition and isotope ratios of gases from gas pockets of ODP Site 131-808. https://doi.org/10.1594/PANGAEA.785202
- Berner, U; Faber, E (1993): (Table 2) Gas concentrations in sediments of ODP Site 131-808. https://doi.org/10.1594/PANGAEA.785203