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GEOCHEMISTRY AND MICROTHERMOMETRY OF HOMR
AKAREM AND HOMRET MIKPID RARE-METAL GRANITES,
SOUTH EASTERN DESERT, EGYPT

Research Abstract
ABSTRACT Homr Akarem and Homret Mikpid rare-metal granite are associated with Sn, Mo and F mineralizations. Generally, rare metal granites have special mineralogical and geochemical compositions. The studied granites are syeno- to alkali feldspar granite in composition and crystallized from F-rich melt. They were affected by weak to moderate whole rock hydrothermal alterations. The studied granites are highly fractionated (SiO2 up to 77 wt. %), and characterized by high contents of alkalis, Nb, Ta, Sn, Y, Th, Zr, Hf, Rb and F. They are post-orogenic, subalkaline and metaluminous to slightly peraluminous (ASI 0.93 to 1.07). Homr Akarem and Homret Mikpid granites are characterized by normal REEs patterns with strong negative Eu anomalies and LREE/HREE ratio is generally 1, while Homr Akarem muscovite granite shows moderate negative Eu anomalies and LREE/HREE > 1. The calculated tetrad effects of Homr Akarem and Homret Mikpid granites are low ( 0.2). This in addition to the regular distribution of high field strength elements reflects the magmatic origin. They have A2-subtype affinity which was probably derived from continental crust of igneous origin. Fluid inclusions investigation indicates the presence of three fluid generations trapped the studied granites. The early fluid generation is responsible for the pervasive alterations (feldspathization and sericitization). The second one is responsible for chloritization of biotite as well as silicification. The third generation is responsible for kaolinization process. One fluid generation was detected in Homr Akarem muscovite granite which is responsible for K-metasomatic alteration (microclinization and muscovitization).
Research Authors
M. A. Mohamed, G. H. El Habaak, W. W. Bishara and H. H. El Hadek
Research Department
Research Journal
THE SIXTH INTERNATIONAL CONFERENCE
ON THE GEOLOGY OF AFRICA, (OCT. 2009) ASSIUT-EGYPT
Research Member
Research Pages
P-P V- 61 – V-87
Research Rank
3
Research Year
2009