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Characterization of the Source Horizons within the Late Cretaceous Transgressive Sequence of Northeast Previous HitAfricaNext Hit

ROBINSON, VAUGHN, Texaco, Inc., Houston, TX, and MICHAEL ENGEL, University of Oklahoma, Norman, TX

Source rocks were deposited in northeastern Previous HitAfricaNext Hit during a major Late Cretaceous transgression. The preserved stratigraphic sequence begins with a series of fluvio-deltaic sands and progresses up into a thick marine carbonate section. These deposits represent ever increasing water depths and isolation from the continental landmass. Across northeast Previous HitAfricaNext Hit and portions of Arabia, oil-prone source facies were deposited along the mid to outer shelf during the initial phases of this Late Cretaceous transgression. Within the source sequence itself, variations in the organic matter record the changing influences of coastal upwelling, development of anoxia, and terrigenous input. In Egypt, the transgression deposited sediments found today in the upper portion of the Nubian through Thebes fo mations. The source facies found within this sequence include portions of the Duwi and Dakhla formations. Both the Duwi and Dakhla record changes in salinity, depth of the water column, and oxygen concentration, which are depicted in the organic matter content, quality, and type. The variability observed in the source sequence in Egypt can be related to the Late Cretaceous source facies preserved across northeast Previous HitAfricaTop.


AAPG Search and Discovery Article #91004 © 1991 AAPG Annual Convention Dallas, Texas, April 7-10, 1991 (2009)