Paleoceanography and paleolimnology of petroleum source rocks

Journal Article · Thu Nov 01 00:00:00 EST 1990 · AAPG Bulletin (American Association of Petroleum Geologists); (USA)

OSTI ID:5901201

Pratt, L M ^[1]

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1. Indiana Univ., Bloomington (USA)

Sedimentary strata containing greater than 0.5 wt. % organic carbon are unusual in both modern and ancient depositional settings. Rates of primary production (photosynthesis), recycling (decompositional efficiency), and sediment accumulation (clastic dilution) are the principal factors determining organic carbon contents of sediments and sedimentary rocks. Clastic dilution is the dominant factor in all aquatic environments when sediment accumulation rates are above about 100 mg/cm{sup 2}/yr or sedimentation rates are above about 300 m/10{sup 6}/yr. Enhanced primary productivity associated with upwelling is the dominant control on burial and preservation of organic matter in modern marine environments, but benthic anoxia related to restricted circulation may be the dominant factor in many modern lakes and most ancient epicontinental seas. During transportation and sedimentation in marine and lacustrine environments, organic detritus can by oxidized to carbon dioxide or incorporated into new biomass by bacterial communities that sequentially transfer electrons from organic matter to oxygen, nitrate, iron (Fe{sup 3+}), manganese (Mn{sup 4+}), sulfate, and carbon dioxide. Zonation of early diagenetic minerals results from progressive changes in the composition of pore water and sediment as organic matter is buried to depths of about 10 m. Mineralic and stable isotopic (carbon and sulfur) compositions of diagenetic carbonates and iron sulfides reflect depth-related bacterial and redox zones. Data bearing on these processes contribute to development of comprehensive basin models because they can be used to reconstruct changes in salinity and oxygen content of bottom water.

• OSTI ID: 5901201
• Journal Information: AAPG Bulletin (American Association of Petroleum Geologists); (USA), Vol. 74:11; ISSN 0149-1423
• Country of Publication: United States
• Language: English

Related Subjects

02 PETROLEUM
58 GEOSCIENCES
PETROLEUM DEPOSITS
SOURCE ROCKS
ORIGIN
CARBON
CARBONATE ROCKS
DEPOSITION
DIAGENESIS
ENERGY SOURCE DEVELOPMENT
IRON SULFIDES
MANGANESE
MATURATION
ORGANIC MATTER
OXIDATION
PRODUCTION
SALINITY
SEDIMENTARY BASINS
SEDIMENTATION
SEDIMENTS
CHALCOGENIDES
CHEMICAL REACTIONS
ELEMENTS
GEOLOGIC DEPOSITS
GEOLOGIC STRUCTURES
IRON COMPOUNDS
METALS
MINERAL RESOURCES
NONMETALS
RESOURCES
ROCKS
SEDIMENTARY ROCKS
SULFIDES
SULFUR COMPOUNDS
TRANSITION ELEMENT COMPOUNDS
TRANSITION ELEMENTS
020200* - Petroleum- Reserves
Geology
& Exploration
580000 - Geosciences