Crustal melt granites and migmatites along the Himalaya: melt source, segregation, transport and granite emplacement mechanisms
Published:October 01, 2010
M. P. Searle, J. M. Cottle, M. J. Streule, D. J. Waters, 2010. "Crustal melt granites and migmatites along the Himalaya: melt source, segregation, transport and granite emplacement mechanisms", Sixth Hutton Symposium on The Origin of Granites and Related Rocks: Proceedings of a Symposium held in Stellenbosch, South Africa, 2- 6 July 2007, John D. Clemens, Colin Donaldson, Carol D. Frost, Alexander F.M. Kisters, Jean-François Moyen, Tracy Rushmer, Gary Stevens
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India–Asia collision resulted in crustal thickening and shortening, metamorphism and partial melting along the 2200 km-long Himalayan range. In the core of the Greater Himalaya, widespread in situ partial melting in sillimanite+K-feldspar gneisses resulted in formation of migmatites and Ms+Bt+Grt+Tur±Crd±Sil leucogranites, mainly by muscovite dehydration melting. Melting occurred at shallow depths (4–6 kbar; 15–20 km depth) in the middle crust, but not in the lower crust. 87Sr/86Sr ratios of leucogranites are very high (0·74–0·79) and heterogeneous, indicating a 100% crustal protolith. Melts were sourced from fertile muscovite-bearing pelites and quartzo-feldspathic gneisses of the Neo-Proterozoic Haimanta–Cheka Formations. Melting...