Equilibrium vs.disequilibrium melting relations in the Higher Himalayan Crystalline(HHC) pelitic migmatites,Sikkim Himalaya  

作　　者：Bhaskar Kundu 

机构地区：[1]National Geophysical Research Institute,Council of Scientific and Industrial Research,Uppal Road,Hyderabad 500007,India

出　　处：《Geoscience Frontiers》2011年第4期539-549,共11页地学前缘（英文版）

摘　　要：Higher Himalayan Crystalline（HHC） complex of the Sikkim Himalaya predominantly consists of high-grade pelitic migmatites.In this study,reaction textures,mineral/bulk rare earth elements （REE）,trace element partition coefficients and trace element zoning profiles in garnet are used to demonstrate a complex petrogenetic process during crustal anatexis.With the help of equilibrium REE and trace element partitioning model,it is shown that strong enrichment of Effective Bulk Composition（EBC） is responsible for the zoning in garnet in these rocks.The data strongly support disequilibrium element partitioning and suggest that the anatectic melts associated with mafic selvedges are likely produced by disequilibrium melting because of fast melt segregation process.Higher Himalayan Crystalline（HHC） complex of the Sikkim Himalaya predominantly consists of high-grade pelitic migmatites.In this study,reaction textures,mineral/bulk rare earth elements （REE）,trace element partition coefficients and trace element zoning profiles in garnet are used to demonstrate a complex petrogenetic process during crustal anatexis.With the help of equilibrium REE and trace element partitioning model,it is shown that strong enrichment of Effective Bulk Composition（EBC） is responsible for the zoning in garnet in these rocks.The data strongly support disequilibrium element partitioning and suggest that the anatectic melts associated with mafic selvedges are likely produced by disequilibrium melting because of fast melt segregation process.

关 键 词：Pelitic migmatites Crustal anatexis Mafic selvedge Disequilibrium melting 

分 类 号：P588.36[天文地球—岩石学]