This paper discusses generahon of muscovite/ two-mica granite and their genetic relations to intracontinental subduchon. The major constraints of the formation of muscovite granite,taking Higher Himalaya for an examp...This paper discusses generahon of muscovite/ two-mica granite and their genetic relations to intracontinental subduchon. The major constraints of the formation of muscovite granite,taking Higher Himalaya for an example, are demostrated from multiple-aspects of geology,petrology, geochemistry, experimental petrology and geophysics .We suggest that the magma generates in the Main Central Thrust (Mad ) (30-35km ), and has higher temperature of 750-800℃, H2O-undersatorated and large capability to be emplacement into the sedimentary covers to form real igneous intrusion, rather than generster at the base of the thickened continental crust and has lower temperature of 600-650 ℃, H2O-saturated and less capability of emplacement to form intrusion in silo/semi-situ. A reasonable model of thermal structure of the intracontinental subduction zone is presented. Combining the possible material of magma source and the experimental phase relatioedps, we demonstrate in detail that the main magma source of the muscovite granitc is the pelitic rocks at top of the subduedon slab at the adjacent region of the subduction end. In addition, the H2O-saturate and wear saturated granitic magmas are formed at the wedge comer of the overlying slab. A new conclusion is reached that the generation Of muscovite granite is a result of the intracontinental subduction, in other words,the development of muscovite granite is a main signature to recognize the indacontinental subduction zone.展开更多
文摘This paper discusses generahon of muscovite/ two-mica granite and their genetic relations to intracontinental subduchon. The major constraints of the formation of muscovite granite,taking Higher Himalaya for an example, are demostrated from multiple-aspects of geology,petrology, geochemistry, experimental petrology and geophysics .We suggest that the magma generates in the Main Central Thrust (Mad ) (30-35km ), and has higher temperature of 750-800℃, H2O-undersatorated and large capability to be emplacement into the sedimentary covers to form real igneous intrusion, rather than generster at the base of the thickened continental crust and has lower temperature of 600-650 ℃, H2O-saturated and less capability of emplacement to form intrusion in silo/semi-situ. A reasonable model of thermal structure of the intracontinental subduction zone is presented. Combining the possible material of magma source and the experimental phase relatioedps, we demonstrate in detail that the main magma source of the muscovite granitc is the pelitic rocks at top of the subduedon slab at the adjacent region of the subduction end. In addition, the H2O-saturate and wear saturated granitic magmas are formed at the wedge comer of the overlying slab. A new conclusion is reached that the generation Of muscovite granite is a result of the intracontinental subduction, in other words,the development of muscovite granite is a main signature to recognize the indacontinental subduction zone.
