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Volume :13 Issue : 2 1986
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Composition of some Egyptian calcretes
Auther : ADAM EL-SHAHAT
Department of Geology, Faculty of Science, University of Mansoura, Mansoura, Egypt
ABSTRACT
Calcrctes are commonly developed on the Pleistocene limestone that crops out on the western coastal plain of Egypt. The calcretes have been studied petrographically, examined by X-ray diffraction and 14 samples were analysed for major and trace elements mainly by X-ray spectrornetry. Heavy minerals were also identified. The calcretes consist mainly of low-Mg calcite, present as micrite in nodules, coated grains and pelletoids and sparmicrospar void filling cement. Comparison with the chemistry of world calcretes and averagc carbonates suggests that the studied Egyptian calcretes are characterized by high Zr, low Mn, Ni and normal contents of major elements and P, Zn. As, Rb, Sr and Pb.