Eclogite facies rocks in this area are diverse in rock type. The field occurrence androck-chemistry reflect their in-situ origin. Based on their regional geology and field occurrence,two groups of eclogites are divide...Eclogite facies rocks in this area are diverse in rock type. The field occurrence androck-chemistry reflect their in-situ origin. Based on their regional geology and field occurrence,two groups of eclogites are divided in terms of their peak temperature of metamorphism. Medi-um-temperature eclogites (MT), as Group B, occur in the Dabie Group. They were formedfrom epidote-amphibolite facies. The metamorphism of eclogite facies has two stages: the co-esite eclogite facies stage (the peak condition: T = 600-700℃, P = 2. 7 - 3. 0 GPa) and theglaucophane eclogite facies stage (the pressure decreases, may be lower than 2. 5 GPa while thetemperature has little change). Low temperature eclogites (LT), as Group C, occur in the Qi-jiaoshan Formation. They were formed from blue schist facies (the peak condition: T = 490 -560℃, P< 1. 5 GPa). The appearance of hydrous minerals in the eclogites indicates the im-portant role of water in metamorphism. Medium-temperature eclogites are different from low-temperature ones in metamorphism. At last, the evolution of the high-pressure metamorphicbelt is discussed as well.展开更多
Xiangfan city, located in the northwest of Hubei Province, is an economic, cultural and material distribution centre bordering Hubei, Henan, Sichuan and Shanxi provinces. It enjoys exceptional advantages in the develo...Xiangfan city, located in the northwest of Hubei Province, is an economic, cultural and material distribution centre bordering Hubei, Henan, Sichuan and Shanxi provinces. It enjoys exceptional advantages in the development of foreign economic relations and trade, and has a bright future. In recent years, rapid growth has been achicved in foreign展开更多
文摘Eclogite facies rocks in this area are diverse in rock type. The field occurrence androck-chemistry reflect their in-situ origin. Based on their regional geology and field occurrence,two groups of eclogites are divided in terms of their peak temperature of metamorphism. Medi-um-temperature eclogites (MT), as Group B, occur in the Dabie Group. They were formedfrom epidote-amphibolite facies. The metamorphism of eclogite facies has two stages: the co-esite eclogite facies stage (the peak condition: T = 600-700℃, P = 2. 7 - 3. 0 GPa) and theglaucophane eclogite facies stage (the pressure decreases, may be lower than 2. 5 GPa while thetemperature has little change). Low temperature eclogites (LT), as Group C, occur in the Qi-jiaoshan Formation. They were formed from blue schist facies (the peak condition: T = 490 -560℃, P< 1. 5 GPa). The appearance of hydrous minerals in the eclogites indicates the im-portant role of water in metamorphism. Medium-temperature eclogites are different from low-temperature ones in metamorphism. At last, the evolution of the high-pressure metamorphicbelt is discussed as well.
文摘Xiangfan city, located in the northwest of Hubei Province, is an economic, cultural and material distribution centre bordering Hubei, Henan, Sichuan and Shanxi provinces. It enjoys exceptional advantages in the development of foreign economic relations and trade, and has a bright future. In recent years, rapid growth has been achicved in foreign
