Department of Geology, Faculty of Science, Mansoura University, Mansoura, Egypt
ABSTRACT
The Late Cretaceous-Early Tertiary sediments exposed at Bir Murr, Bir Kiseiba and Gabal Bargat El Shab in the southern part of the Western Desert of Egypt have been studied. Algal lime wackestones and foraminifera1 packstones are the dominant lithofacies encountered in the Kurkur and Dungal Formations, respectively. These shallow marine carbonates are composed almost entirely of low-Mg calcite. They are characterized by low Mg, Na and Sr contents and high Ca and Fe contents.
Montmorillonite, kaolinite, illite and illite-montmorillonite mixed layer are the major clay
minerals detected in the shales of the Dakhla and Garra Formations. Chlorite, palygorskite and glauconite are rare. The non-clay minerals include quartz, potassium feldspar, calcite, gypsum and anhydrite. Most trace elements are associated with detrital material and their abundance is mainly controlled by the distribution of carbonates, clay minerals and iron oxides.