Mass/age distribution of organic carbon for the Phanerozoic

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

OSTI ID:5803903

Hay, W W; Wold, C N ^[1]

---

1. Univ. of Colorado, Boulder (United States) Geomar, Kiel (West Germany)

The mass/age distribution of organic carbon in Phanerozoic sedimentary rocks is dominated by disseminated organic carbon in pelitic rocks. Even during the major times of coal formation, the mass of organic carbon in coal is small compared with that included in fine-grained marine sediments. The mass/age distribution shows maxima in the Middle and Late Ordovician, Late Devonian, Late Jurassic and Early Cretaceous, and Neogene. Minima in accumulation of organic carbon mark the Early Ordovician, Early Devonian, Permian and Triassic, Late Cretaceous and Paleogene. Reconstruction of the ancient fluxes of organic carbon into the sediments shows that the distribution is almost symmetrical about the Paleozoic-Mesozoic boundary. Major hydrocarbon source rock accumulations coincide with peaks of organic carbon deposition, but modes of formation of the source rocks at each peak may have been different. The peaks of organic carbon accumulation correspond to times of flooding of the continents. The Ordovician, Late Jurassic-Early Cretaceous peaks also correspond to an increase in the ratio of carbon being deposited as organic carbon relative to that deposited as carbonate; they also correspond to times of deposition of large amounts of siliceous sediment. The Lake Devonian peak also formed at a time of flooding of the continents, but shows a low ratio of organic carbon to carbonate, and few siliceous rocks accumulated contemporaneously. The Neogene peak may represent a fundamentally different accumulation mechanism, resulting mostly from coastal upwelling during a time of emergence of the continents.

• OSTI ID: 5803903
• Report Number(s): CONF-910403-; CODEN: AABUD
• Journal Information: AAPG Bulletin (American Association of Petroleum Geologists); (United States), Vol. 75:3; Conference: Annual meeting of the American Association of Petroleum Geologists (AAPG), Dallas, TX (United States), 7-10 Apr 1991; ISSN 0149-1423
• Country of Publication: United States
• Language: English

Related Subjects

01 COAL, LIGNITE, AND PEAT
03 NATURAL GAS
58 GEOSCIENCES
COAL DEPOSITS
GEOCHEMISTRY
NATURAL GAS DEPOSITS
ORGANIC MATTER
DISTRIBUTION
AGE ESTIMATION
CARBON
CARBONACEOUS MATERIALS
DEPOSITION
ELEMENT ABUNDANCE
GEOLOGIC HISTORY
GLOBAL ASPECTS
MESOZOIC ERA
PALEOZOIC ERA
SEDIMENTARY ROCKS
SOURCE ROCKS
ABUNDANCE
CHEMISTRY
ELEMENTS
GEOLOGIC AGES
GEOLOGIC DEPOSITS
MATERIALS
MATTER
MINERAL RESOURCES
NONMETALS
RESOURCES
ROCKS
011000* - Coal
Lignite
& Peat- Reserves
Geology
& Exploration
030200 - Natural Gas- Reserves
Geology
& Exploration
580000 - Geosciences