Petrographic investigation of the Precambrian basement rocks of Esh El Mallaha area, North Eastern Desert, Egypt

Document Type : Original Article

Authors

1 Nuclear Materials Authority, Cairo, Egypt.

2 Geology Department, Faculty of Science, Port Said University, Port Said, 42522, Egypt

3 Faculty of Science, Geology Department, Benha University, Benha 13518, Egypt

Abstract

The Esh El-Mallaha mountain range is located in the northwestern segment of the Arabian-Nubian Shield. The area encompassing it is of especial significance owing to its hydrocarbon resources. This works aims to present a comprehensive and detailed petrographic characterization of the major Precambrian basement rock units cropping out there, namely; the Dokhan Volcanics and Younger Granites. The Dokhan Volcanics are petrographically differentiated into basaltic andesite, andesite, and dacite lavas along with their pyroclastic equivalents. Their main volcanic textures include porphyritic, glomeroporphyritic, visecular, amygdalloidal and granophyric textures. Pyroclastics, particularly welded ignimbrites, are typified by eutaxitic texture. The Younger Granites of Um Dirrah and El-Esh are dominated by monzogranites and syenogranites, respectively, while those of Homra El Gerigab are mainly alkali feldspar granites. They are typically medium- to coarse-grained hypidiomorphic rocks, although porphyritic varieties are not uncommon.

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