Gas hydrates in deep ocean sediments. Annual report 1 Apr 81-31 Mar 82

Technical Report · Tue Jun 01 00:00:00 EDT 1982

OSTI ID:6513836

Wiesenburg, D A; Kennicutt, M C

The purpose of this research is to elucidate the composition, state, and origin of gas in marine sediments, with particular emphasis on gas hydrates. Gas samples from DSDP/IPOD Site 533 on the Blake Outer Ridge in the Northwest Aatlantic were obtained for molecular and isotopic analyses. Gas samples were collected from the first successful deployment of a pressure core barrel (PCB) in a hydrate region. Two of the four PCB retrievals at in situ pressures suggested the presence of small amounts of gas hydrates. Compositional and isotopic measurements of gases from several points along the pressure decline curve indicated that (1) biogenic methane was the dominant gas (2) little fractionation in C/sub 1//C/sub 2/ ratio or the C/sub 1/ carbon isotopic composition occurred as gas hydrates decomposed during pressure decline experiments; (3) the percent of C/sub 3/, i-C/sub 4/, and CO/sub 2/ degassed increased as the pressure declined; and (4) excess nitrogen was present during initial degassing. The PCB gas also contained trace amounts of saturated, acyclic, cyclic, and aromatic C/sub 5/-C/sub 14/ hydrocarbons, as well as alkenes and tetrahydrothiophenes.

• Research Organization: Texas A and M Univ., College Station (USA). Dept. of Oceanography
• OSTI ID: 6513836
• Report Number(s): PB-83-109892
• Country of Publication: United States
• Language: English

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ATLANTIC OCEAN
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CARBON 14
DEGASSING
DRILL CORES
ETHANE
GAS HYDRATES
HYDROCARBONS
ISOTOPE SEPARATION
METHANE
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SEDIMENTS
ALKANES
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BETA-MINUS DECAY RADIOISOTOPES
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HYDRATES
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MINERAL RESOURCES
NUCLEI
ORGANIC COMPOUNDS
RADIOISOTOPES
RESOURCES
SEAS
SEPARATION PROCESSES
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