Geology and Petrology of the Malakand Granite, gneiss and Metasedimentary Complex
Abstract
The Malakand granite intrudes a series of low grade metasediments and granitic gneisses. It appears to be Calc-alkaline in characters. A temperature ranges of c. > 875-650oC and PH2O of c. 5 to < 5 Kb has been suggested for the development of various phases in the granite. The chemical features and age relationship also indicate that the Malakand granite is not genetically related to the alkaline igneous complex of the Peshawar plain. Three types of gneisses have been distinguished; (a) siliceous gneiss, (b) silica-rich granitic gneiss and (c) normal granite gneiss. Among these only the normal granitic gneiss seems to be genetically related to the Malakand granite. The metasediments indicate several episodes of regional metamorphism ranging from lower green-schist facies to upper green-schist facies environments. The presence of garnet in schist at the contacts of granite has been related to the thermal effects of the intruding granitic magma.
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