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Arc magmatism in eastern Kumaun Himalaya, India: A study based on geochemistry of granitoid rocks
Author(s) -
RAMESHWAR RAO D.,
SHARMA RAJESH
Publication year - 2011
Publication title -
island arc
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.554
H-Index - 58
eISSN - 1440-1738
pISSN - 1038-4871
DOI - 10.1111/j.1440-1738.2011.00781.x
Subject(s) - geology , geochemistry , subduction , mafic , nappe , eclogite , island arc , amphibole , petrology , gneiss , partial melting , granulite , protolith , basalt , metamorphism , metamorphic rock , geomorphology , tectonics , seismology , paleontology , structural basin , facies , quartz
Petrochemical studies of granitoid rocks from the eastern part of Kumaun region suggest that the leading edge of India represents an active arc during Late Paleoproterozoic times. It has been observed that melt generation for granodiorite rocks from the eastern Almora Nappe and Chhiplakot klippe along with the Askot klippe was caused through a subduction‐related process involving hydrous partial melting of a Paleoproterozoic amphibole‐ and/or garnet‐bearing mafic source with the involvement of sediments from the subduction zone. The medium‐ to high‐K basic rocks, common in subduction‐related magmatic arcs, can also explain the generation of the high‐K granodiorites of the Chhiplakot klippe. The augen gneisses from the eastern Almora nappe and Chhiplakot klippe along with the Askot klippe further show geochemical similarity with the associated granodiorites, suggesting there is a genetic linkage with one another.