Petroleum geology and geochemistry of the Middle Proterozoic McArthur Basin, Northern Australia: III. Composition of extractable hydrocarbons

Journal Article · Fri Jul 01 04:00:00 EDT 1988 · Geochimica et Cosmochimica Acta; (USA)

DOI:https://doi.org/10.1016/0016-7037(88)90001-4· OSTI ID:5275903

Summons, R E; Powell, T G; Boreham, C J ^[1]

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1. Bureau of Mineral Resources, Canberra City (Australia)

Middle Proterozoic organic-rich sediments from the McArthur Basin in northern Australia contain abundant hydrocarbons which are derived from syngenetic kerogen and hence, are representative of the organic remains of microorganisms living at that time. The major classes of hydrocarbons identified were n-alkanes, monomethyl branched alkanes, cyclohexyl alkanes and acyclic isoprenoids. There were also low abundances of pentacyclic triterpanes comprising hopanes and methyl hopanes. Low concentrations of steranes were present in most samples, but like the triterpanes, they were only easily detected in the least thermally altered sediments, and hence were of limited use in detailed assessments of thermal maturity. The presence of steranes in sediments of this age is strong evidence for the existence of eukaryotic organisms as far back at 1690 Ma, although the relatively high abundances of branched alkanes indicates that most of this primitive organic matter was probably derived from prokaryotes.

• OSTI ID: 5275903
• Journal Information: Geochimica et Cosmochimica Acta; (USA), Journal Name: Geochimica et Cosmochimica Acta; (USA) Vol. 52:7; ISSN GCACA; ISSN 0016-7037
• Country of Publication: United States
• Language: English

Related Subjects

02 PETROLEUM
023000* -- Petroleum-- Properties & Composition
58 GEOSCIENCES
580000 -- Geosciences
AUSTRALASIA
AUSTRALIA
BITUMINOUS MATERIALS
CARBONACEOUS MATERIALS
CHEMICAL COMPOSITION
CHEMISTRY
ENERGY SOURCES
FOSSIL FUELS
FUELS
GEOCHEMISTRY
GEOLOGIC AGES
GEOLOGIC DEPOSITS
GEOLOGIC STRUCTURES
GEOLOGY
HYDROCARBONS
KEROGEN
MATERIALS
MATURATION
MINERAL RESOURCES
ORGANIC COMPOUNDS
ORGANIC MATTER
PETROLEUM
PETROLEUM DEPOSITS
PETROLEUM GEOLOGY
PRECAMBRIAN ERA
RESOURCES
SEDIMENTARY BASINS
SEDIMENTS
SOURCE ROCKS