Latest Jurassic-early Cretaceous regressive facies, northeast Africa craton
Nonmarine to paralic detrital deposits accumulated in six large basins between Algeria and the Arabo-Nubian shield during major regression in latest Jurassic and Early Cretaceous time. The Ghadames Sirte (north-central Libya), and Northern (Egypt) basins lay along the cratonic margin of northeastern Africa. The Murzuk, Kufra, and Southern (Egypt) basins lay in the south within the craton. Data for reconstructing distribution, facies, and thickness of relevant sequences are adequate for the three northern basins only. High detrital influx near the end of Jurassic time and in mid-Cretaceous time produced regressive nubian facies composed largely of low-sinuosity stream and fahdelta deposits. In the west and southwest the Ghadames, Murzuk, and Kufra basins were filled with a few hundred meters of detritus after long-continued earlier Mesozoic aggradation. In northern Egypt the regressive sequence succeeded earlier Mesozoic marine sedimentation; in the Sirte and Southern basins correlative deposits accumulated on Precambrian and Variscan terranes after earlier Mesozoic uplift and erosion. Waning of detrital influx into southern Tunisia and adjacent Libya in the west and into Israel in the east initiated an Albian to early Cenomanian transgression of Tethys. By late Cenomanian time it had flooded the entire cratonic margin, and spread southward into the Murzuk and Southern basins, as well as onto the Arabo-Nubian shield. Latest Jurassic-earliest Cretaceous, mid-Cretaceous, and Late Cretaceous transgressions across northeastern Africa recorded in these sequences may reflect worldwide eustatic sea-level rises. In contrast, renewed large supply of detritus during each regression and a comparable subsidence history of intracratonic and marginal basins imply regional tectonic control. 6 figures.
- Research Organization:
- Princeton Univ., NJ
- OSTI ID:
- 6772544
- Journal Information:
- Am. Assoc. Pet. Geol. Bull.; (United States), Journal Name: Am. Assoc. Pet. Geol. Bull.; (United States) Vol. 64:6; ISSN AAPGB
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
020200 -- Petroleum-- Reserves
Geology
& Exploration
58 GEOSCIENCES
580100 -- Geology & Hydrology-- (-1989)
580201* -- Geophysics-- Seismology & Tectonics-- (1980-1989)
AFRICA
ALGERIA
CRETACEOUS PERIOD
DETRITUS
DEVELOPING COUNTRIES
EXPLORATION
GEOLOGIC AGES
GEOLOGIC DEPOSITS
HYDROCARBONS
JURASSIC PERIOD
LEVELS
LIBYA
MATHEMATICS
MESOZOIC ERA
ORGANIC COMPOUNDS
REGRESSION ANALYSIS
SEA LEVEL
SEDIMENTATION
SHORES
STATISTICS
TECTONICS