Late Cretaceous multicolored shales and phosphatic sedimentary rocks in Egypt

Conference · Tue Mar 01 04:00:00 EST 1983 · Am. Assoc. Pet. Geol., Bull.; (United States)

OSTI ID:6326445

Glenn, C R; Garrison, R E; Arthur, M A

Upper Cretaceous transitional fluvial to marine variegated shale (upper Nubia Formation) and the fully marine Duwi (phosphate) Formation occur as thin, widespread, shallow-marine deposits in an east-west-trending belt spanning the lower-middle latitudes of Egypt. On a larger scale, the phosphoritic rocks in Egypt represent but a small portion of a laterally extensive Middle Eastern-North African phosphogenic province of Upper Cretaceous-Lower Tertiary age that accounts for accumulation of minable marine phosphate in excess of 70 billion tons. Phosphorites, porcelanites/cherts, organic carbon-rich shales, glauconitic sandstones, and bioclastic and fine-grained carbonate rocks variously reflect major hemipelagic and shallow-water carbonate sedimentation. Biosiliceous hemipelagic deposits, now diagenetically altered to procelanite and chert, reflect low energy depositional conditions that were periodically interrupted by high energy, possibly storm-induced currents and/or down-slope redeposition. Both dark shales and porcelanites locally contain abundant organic matter and are commonly finely laminated. Porcelanites and black shales are phosphatic, containing phosphatic grains identical, morphologically and chemically, to those found in associated phosphorites, and are probably the source from which the phosphorites were derived. The organic carbon-rich shales of the Duwi Formation appear to be quite laterally extensive and may, depending on thermal maturity, represent potential hydrocarbon source rocks in other portions of the region (e.g., Western Desert, Gulf of Suez), where they are more deeply buried.

• Research Organization: Univ. of South Carolina, Columbia
• OSTI ID: 6326445
• Report Number(s): CONF-8304200-
• Conference Information: Journal Name: Am. Assoc. Pet. Geol., Bull.; (United States) Journal Volume: 67:3
• Country of Publication: United States
• Language: English

Related Subjects

02 PETROLEUM
020200* -- Petroleum-- Reserves
Geology
& Exploration
03 NATURAL GAS
030200 -- Natural Gas-- Reserves
Geology
& Exploration
AFRICA
CRETACEOUS PERIOD
DEPOSITION
DEVELOPING COUNTRIES
EGYPTIAN ARAB REPUBLIC
ENERGY SOURCES
FLUIDS
FOSSIL FUELS
FUEL GAS
FUELS
GAS FUELS
GASES
GEOLOGIC AGES
MESOZOIC ERA
NATURAL GAS
PETROLEUM
PHOSPHATE ROCKS
ROCKS
SEDIMENTARY ROCKS
SHALES
SOURCE ROCKS