Here we present the results of dehydration melting, melt morphology and fluid migration based on the dehydration melting experiments on natural bio-tite-plagioclase gneiss performed at the pressure of 1.0-1.4 GPa, and...Here we present the results of dehydration melting, melt morphology and fluid migration based on the dehydration melting experiments on natural bio-tite-plagioclase gneiss performed at the pressure of 1.0-1.4 GPa, and at the temperature of 770-1028℃. Experimental results demonstrate that: (i) most of melt tends to be distributed along mineral boundaries forming 'melt film' even the amount of melt is less than 5 vol%; melt connectivity is controlled not only by melt topology but also by melt fraction; (ii) dehydration melting involves a series of subprocesses including subsoiidus dehydration reaction, fluid migration, vapor-present melting and vapor-absent melting; (iii) experiments produce peraluminous granitic melt whose composition is similar to that of High Himalayan leucogranites (HHLG) and the residual phase assemblage is Pl+Qz+ Gat+Bio+Opx±Cpx+IIm/Rut±Kfs and can be comparable with granulites observed in Himalayas. The experiments provide the evidence that biotite-plagioclase gneiss is one of展开更多
基金This work was sponsored by the State Key Basic Research and Development Program of China (Grant No. G1998040800) GeoForschungsZentrum in Germany for International Cooperation and the Foundation of the Opened Laboratory of Constitution Interaction and
文摘Here we present the results of dehydration melting, melt morphology and fluid migration based on the dehydration melting experiments on natural bio-tite-plagioclase gneiss performed at the pressure of 1.0-1.4 GPa, and at the temperature of 770-1028℃. Experimental results demonstrate that: (i) most of melt tends to be distributed along mineral boundaries forming 'melt film' even the amount of melt is less than 5 vol%; melt connectivity is controlled not only by melt topology but also by melt fraction; (ii) dehydration melting involves a series of subprocesses including subsoiidus dehydration reaction, fluid migration, vapor-present melting and vapor-absent melting; (iii) experiments produce peraluminous granitic melt whose composition is similar to that of High Himalayan leucogranites (HHLG) and the residual phase assemblage is Pl+Qz+ Gat+Bio+Opx±Cpx+IIm/Rut±Kfs and can be comparable with granulites observed in Himalayas. The experiments provide the evidence that biotite-plagioclase gneiss is one of
