Early Tertiary subsidence and sedimentary facies - Northern Sirte Basin, Libya

Journal Article · Sun Dec 01 00:00:00 EST 1985 · Am. Assoc. Pet. Geol., Bull.; (United States)

OSTI ID:5961893

Gumati, Y D; Kanes, W H

The subsidence curves and subsidence rate curves for the Sirte basin, constructed from the stratigraphic record, show that subsidence was continuous throughout Late Cretaceous and Tertiary times, reaching a maximum during the Paleocene and Eocene, when a major reactivation of faults occurred. Shales and carbonates were deposited during all of the Late Cretaceous and Tertiary. Abrupt lateral facies changes occur from the platform areas toward the deeper troughs along with steep downdip thickening. The absence of upper Paleozoic and lower Mesozoic sediments suggests that the area was domed, faulted, and eroded during the late Mesozoic. As a result of crustal extension during the Paleocene, a marked lithologic and structural change occurred. The Heira Shale succeeded the Kalash Limestone in the Marada trough. Reactivation of the earlier faults, accompanied by an increase in the sediment supply from the south, caused these lower Paleocene shales to cover the entire area, with the exception of the old highs where carbonate deposition continued. An intercalation of shales and carbonates provides a sensitive indicator of change of depth and sediment type. 14 figures.

• Research Organization: Univ. of South Carolina, Columbia
• OSTI ID: 5961893
• Journal Information: Am. Assoc. Pet. Geol., Bull.; (United States), Vol. 69:12
• Country of Publication: United States
• Language: English

Related Subjects

02 PETROLEUM
LIBYA
SEDIMENTARY BASINS
GEOLOGIC HISTORY
CRETACEOUS PERIOD
GEOLOGIC FAULTS
GEOLOGIC FORMATIONS
LIMESTONE
SHALES
TERTIARY PERIOD
AFRICA
CARBONATE ROCKS
CENOZOIC ERA
DEVELOPING COUNTRIES
GEOLOGIC AGES
GEOLOGIC FRACTURES
GEOLOGIC STRUCTURES
MESOZOIC ERA
ROCKS
SEDIMENTARY ROCKS
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