Geosciences Research

Download PDF (2223 KB) PP. 29 - 50 Pub. Date: November 1, 2018

DOI: 10.22606/gr.2018.34001

• Maher I. Dawoud
  Geology Department, Faculty of Science, Minufiya University, Egypt
• Gehad M. Saleh^*
  Nuclear Materials Authority, P.O. Box 530, El Maadi, Cairo, Egypt
• Hassan A. Shahin
  Nuclear Materials Authority, P.O. Box 530, El Maadi, Cairo, Egypt
• Farrage M. Khaleal
  Nuclear Materials Authority, P.O. Box 530, El Maadi, Cairo, Egypt
• Bahaa M. Emad
  Nuclear Materials Authority, P.O. Box 530, El Maadi, Cairo, Egypt

Lithologically, the rock types of G. El Fereyid - W. Rahaba area are dominantly granites associated with pegmatites. The granitic rocks comprise tonalite and monzogranite with (minor acidic dykes), quartz and pegmatites occur as a vein type (granitic and perthitic pegmatites) hosted within the monzogranite. Structural analysis shows the presence of a prominent set of folds with axes striking WNW to NW and a less prominent set with pronounced ENE and NNW trends. Petrochemical studies and tectonic discrimination diagrams for the monzogranite reveal that it is classified as post orogenic granites (POG). Geochemically, monzogranite shows enrichment (peaks) of large ion lithophile elements (LILE; Pb, Rb, Ba, Sr) and high field strength elements (HFSE; Y, Zr, Nd,) and depletion (troughs) of K, P and Ti. Pegmatite shows enrichment (peaks) of large ion lithophile elements (LILE; Pb, Rb, Sr) and high field strength elements (HFSE; Y, Zr, Th, U, Nb) and depletion (troughs) of K, P and Ti. They exhibit high K-calc alkaline magma and peraluminous characteristics and considered as post orogenic granites (POG). The monzogranite reveal small to moderate negative Eu anomaly, while the pegmatites reveal moderate to large negative Eu anomaly. The pegmatite displays clear W-type tetrad effect of the REE while, the studied monzogranite do not show tetrad effect.

Petrology, Geochemistry, G. El Fereyid - W. Rahaba granites, Pegmatites, Egypt.

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