Abstract:
The Kohistan terrane in N. Pakistan is sandwiched between the Shyok suture in the north and Indus suture in the south. The SE base of the terrane is occupied by the stratiform Spat mafic-ultramafic complex., which overrides crust of the Indian plate along the Indus suture. The complex was intruded into the base of a thick pile of meta volcanics (now amphibolites) of different environments (the Kamila belt). The Kamila belt is intruded by various rocks including gabbros, diorites, tonalities, granodiorites, granites and trondhjemites. The trondhjemites occur as thin veins and dykes, mostly in the northern part of the Kamila amphibolite belt. Here, the belt is in contact with the Chilas Complex along the Jal shear zone. The trondhjemites contain feldspar, quartz and amphibole with minor epidote, muscovite, biotite, sphene, garnet and ore, and display parallel alignment of mineral grains in one major direction. They show very spiked pattern for mantel normalized incompatible trace elements and are depleted in all High Field Strength Elements (HFSE) particularly strongly in Ti, P and Nb relative to the other granitoids of the studies area. The trondhjemites are probably a product of partial melting of Kamila amphibolites, and a direct role of subduction is not observed.
Page(s):
39-48
DOI:
DOI not available
Published:
Journal: Geological bulletin (university of peshawar), Volume: 36, Issue: 1, Year: 2003