Scientific Quarterly Journal of Geosciences

Scientific Quarterly Journal of Geosciences

Petrogenesis of the Moghanlu Granite

Document Type : Original Research Paper

Authors
Mohammad Vali Valizadeh
Daryoush Esmaili
Department of Geology, Faculty of Science, Tehran University, Tehran, Iran
Abstract
The Moghanlu's Granite crop out in an area which is situated between 47º 52' 30" and 48º 5' 40" longitude 36º 36' 40" and 36º 43' 16" and North latitude in the 1:250,000 Geological Map of Takab- Sainghalah.
The central part of this area is composed of high grade metamorphic rocks (mainly "augen gneiss") which encircles as a ring, the Moghanlu Granite. The latter itself has been surrounded by a white and ferro- magnesian minerals- free granite, known as the Doran- Shahboulaghi Granites.
These granites are composed of quartz, alkali- feldspars, plagioclase, and variable amount of biotite. Biotite which reaches at most 7% weight, is the only ferro- magnesian mineral present in these rocks.
The constituent magma of the Moghanlu Granite is calcalkaline. Although no field evidences for gradual changes between these granites and gneisses has been observed, but the geochemical and petrological investigations show that these granites are probably derived by fractional melting of the gneisses, that it may occur at depth in the base of the gneisses.
The diagrams pertaining to the tectonic setting, show that the Moghanlu's granites have been formed during post- orogenic stages, and as field evidences reveal, it is older than Doran’s granite. It is concluded that, the Moghanlu's Granite has probably been formed in a post-Katangaian orogenic event.
Subjects
 
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Scientific Quarterly Journal of Geosciences
Volume 3, Issue 10
Winter 1994, Vol. 3, No. 10
Winter 1994
Pages 28-39