Petroleum geochemistry of Texas and Oklahoma oils from the Marathon/Ouachita fold belt

Conference · Fri Mar 01 04:00:00 EST 1991 · AAPG Bulletin (American Association of Petroleum Geologists); (United States)

OSTI ID:5791968

Curiale, J A ^[1]

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1. Unocal, Inc., Brea, CA (United States)

The Marathon uplift of west Texas and the Ouachita Mountains of Oklahoma and Arkansas comprise the surface expressions of a Paleozoic orogenic belt extending across the south-central United States. A century of petroleum exploration in the Marathon and Ouachita exposures has yielded several oil discoveries. In this study, detailed molecular, elemental, and isotopic data are presented for nine Texas oils, five Oklahoma oils, and four Oklahoma solid bitumens, all associated with thrust belt rocks of the Marathons and Ouachitas. Oil-oil and oil-solid bitumen correlations are proposed, and the character of the organic matter in the source rock(s) is deduced from the chemistry of the oils and solid bitumens. All 18 samples are sourced from the same (or very similar) organic matter. This indicates that they are probably cogenetic, despite geographic separations of hundreds of miles. Chemical differences in these samples derive from secondary effects, including biodegradation (e.g., solid bitumens) and differing levels of thermal maturity. The occurrence of unusual chemical compounds (certain bisnor- and trisnor-hopanes) in all samples probably indicates the presence of anaerobic bacteria in the depositional environment. Source deductions from oil chemistry suggest that an Ordovician unit is responsible for these oils and solid bitumens. This conclusion is consistent with previous literature suggesting an Upper Ordovician source for Oklahoma Ouachita oils and supports tectonic reconstructions of the region during Ordovician time.

• OSTI ID: 5791968
• Report Number(s): CONF-910403--
• Conference Information: Journal Name: AAPG Bulletin (American Association of Petroleum Geologists); (United States) Journal Volume: 75:3
• Country of Publication: United States
• Language: English

Related Subjects

02 PETROLEUM
020200 -- Petroleum-- Reserves
Geology
& Exploration
023000* -- Petroleum-- Properties & Composition
58 GEOSCIENCES
580000 -- Geosciences
ABUNDANCE
BITUMENS
CHEMICAL COMPOSITION
CHEMISTRY
COMPARATIVE EVALUATIONS
DEVELOPED COUNTRIES
ELEMENT ABUNDANCE
ENERGY SOURCES
EVALUATION
FEDERAL REGION VI
FOSSIL FUELS
FUELS
GEOCHEMISTRY
GEOLOGIC AGES
GEOLOGIC DEPOSITS
ISOTOPE RATIO
MINERAL RESOURCES
NORTH AMERICA
OKLAHOMA
ORDOVICIAN PERIOD
ORGANIC COMPOUNDS
OTHER ORGANIC COMPOUNDS
PALEOZOIC ERA
PETROLEUM
PETROLEUM DEPOSITS
RESOURCES
SOURCE ROCKS
TAR
TEXAS
USA