What kind of migmatties are they? how and when they formed and exhumed ?microstructural, petrofabric, PTtx studie? Are there spatially and temporally related leucogranites? and a good map?
Dear Munazzam,
You have asked several questions, and tough ones, I must say. The Thakot area may as well be a part of the Besham Group. Besham is a domal structure. These rocks probably underwent Early Proterozoic (Ar-Ar ages of 2000-1865 Ma) metamorphism, and I would not rule out Late Archean age for them. The rocks contain phases of granitic magmatism. I would think that the leucosomes in the migmatites are Early Proterozoic. Stratigraphy, structure and tectonics of the area have been studied by several workers, however, there certainly is more scope for metamorphic and geochronological studies. A summary of the pre-1997 work has been given in our book (Kazmi & Jan, 1997- Geology and Tectonics of Pakistan, but I am not sure if you would have the book).
I quickly dug out the following publications for you:
Williams, MP, 1989. Geological Bulletin, University of Peshawar 22 (available on line under National Centre of Excellence in Geology, Uni Peshawar)
Treloar PJ et al, 1989. Tectonophysics 165.
Treloar et al. 1989. Tectonics 4, 881-909.
Shah, MT et al. 1992. Geo Bull Univ Peshawar 25.
DiPietro et al, 1999. GSA Spec. Pap. 328
DiPietro & Isachsen, 2001. Tectonics 20(4)
Baig, MS, 1990. Structure and geochronology of Pre-Himalayan orogenic events in Northwest Himalaya, Pakistan. PhD thesis, Oregon State University, Corvallis. (Shahid Baig published much of his work in the Kashmir Journal of Geology and am not sure if it is digitized).
I am trying to get for you GSP map of the Besham area (Hussain et al.).
If you send me your e-mail, it will be helpful. Mine is [email protected]
I am interested in getting U-Pb dating done on Khewra trap. Have been too busy over the past couple of months. I shall get back to you on this later when you send me your e-mail.
Kind wishes, Qasim
They are said to have traces of Uranium ore. I'm also interested to know more about the formation, succession and stratigraphy of the zone. If so, I think Uraninites can be prospected in entire Kohistan Arc.
Arun,
The Thakot-Besham rocks are >2000 Ma, much older than the Creto-Tertiary Kohistan magmatic arc. The two have been juxtaposed by the Indus Suture.
The Thakot area has some graphitic schists/black "shales" which were studied by a MPhil student of mine. I am attaching a copy of our paper. The Indus River sand derived partly from the Kohistan section was studied a long time ago by Tahirkheli (Geological Bulletin, University of Peshawar, Vol. 2a, 11-15, 1965--available on-line) and others. While the granitoids in Kohistan may have accessory uranium, there are no graphitic schists.
Dear Qasim, thanks for providing these details and references. My email: [email protected]
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