雅鲁藏布构造带在喜马拉雅东构造结地区大致呈弧形展布,宽2km～10km的蛇绿混杂岩带,带内岩石类型为云母石英(片)岩、绿片岩和变超镁铁岩块体等。其中云母石英(片)岩类广泛分布,宏观上呈巨大而狭长且岩性较单一的岩片,或与绿片岩(变玄... 雅鲁藏布构造带在喜马拉雅东构造结地区大致呈弧形展布,宽2km～10km的蛇绿混杂岩带,带内岩石类型为云母石英(片)岩、绿片岩和变超镁铁岩块体等。其中云母石英(片)岩类广泛分布,宏观上呈巨大而狭长且岩性较单一的岩片,或与绿片岩(变玄武岩)混杂在一起。在化学成份上,MnO/TiO2比值低,Al/(Al+Fe+Mn)比值高,与洋脊附近热水成因深海硅质岩有很大的区别。在Al Fe Mn图解上,落在"生物成因硅质岩"范围内,原岩应为不纯的硅质岩类和砂、泥质岩,形成于弧后盆地小洋盆。矿物温压计算及多硅白云母的特点说明变质作用曾经历了角闪岩相,变质温压条件可能达到T=500℃～650℃,P=0.75GPa～0.8GPa,之后,构造带边界阿尼桥断层和米林 鲁朗断层发生强烈走滑,产生低温高压动力变质作用,形成高压、超高压型多硅白云母。展开更多
Eastern Himalayan Syntaxis consists of Namche Barwa and Assam syntaxis. Namche Barwa, located at south east edge Tibet plateau, is the least\|known place for geologist, because there are thick trees and more rains as ...Eastern Himalayan Syntaxis consists of Namche Barwa and Assam syntaxis. Namche Barwa, located at south east edge Tibet plateau, is the least\|known place for geologist, because there are thick trees and more rains as well as difficult traffic condition, but Namche Barwa syntaxis is very important to Himalayan and Tibet plateau research. A Big Bend of Yalu Tsangpo and the deepest Grand Canyon in the word developed in Namche Barwa region. From core to surrounding Namche Barwa syntaxis may be divided into Himalayan,Yalu Tsangpo as well as Gangdise three tectonic units and three boundary fault zone.The core of syntaxis is Himalayan unit with Zircon U\|Pb age 1312±6Ma which is correlated to High Himalayan unit in central Himalayan, major rocks of core are garnet\|plagioclase gneiss and hornblende\|plagioclase gneiss as well as layered migmatites, some lens or band of high pressure granulite,garnet\|clinopyroxenite(ecologite) and rare marbles also exist in this unit. Research result indicates that rock of core may have experienced poly\|phase metamorphism and deformation, from early granulite or eclogite facies to late amphibole face.展开更多
文摘 雅鲁藏布构造带在喜马拉雅东构造结地区大致呈弧形展布,宽2km～10km的蛇绿混杂岩带,带内岩石类型为云母石英(片)岩、绿片岩和变超镁铁岩块体等。其中云母石英(片)岩类广泛分布,宏观上呈巨大而狭长且岩性较单一的岩片,或与绿片岩(变玄武岩)混杂在一起。在化学成份上,MnO/TiO2比值低,Al/(Al+Fe+Mn)比值高,与洋脊附近热水成因深海硅质岩有很大的区别。在Al Fe Mn图解上,落在"生物成因硅质岩"范围内,原岩应为不纯的硅质岩类和砂、泥质岩,形成于弧后盆地小洋盆。矿物温压计算及多硅白云母的特点说明变质作用曾经历了角闪岩相,变质温压条件可能达到T=500℃～650℃,P=0.75GPa～0.8GPa,之后,构造带边界阿尼桥断层和米林 鲁朗断层发生强烈走滑,产生低温高压动力变质作用,形成高压、超高压型多硅白云母。
文摘Eastern Himalayan Syntaxis consists of Namche Barwa and Assam syntaxis. Namche Barwa, located at south east edge Tibet plateau, is the least\|known place for geologist, because there are thick trees and more rains as well as difficult traffic condition, but Namche Barwa syntaxis is very important to Himalayan and Tibet plateau research. A Big Bend of Yalu Tsangpo and the deepest Grand Canyon in the word developed in Namche Barwa region. From core to surrounding Namche Barwa syntaxis may be divided into Himalayan,Yalu Tsangpo as well as Gangdise three tectonic units and three boundary fault zone.The core of syntaxis is Himalayan unit with Zircon U\|Pb age 1312±6Ma which is correlated to High Himalayan unit in central Himalayan, major rocks of core are garnet\|plagioclase gneiss and hornblende\|plagioclase gneiss as well as layered migmatites, some lens or band of high pressure granulite,garnet\|clinopyroxenite(ecologite) and rare marbles also exist in this unit. Research result indicates that rock of core may have experienced poly\|phase metamorphism and deformation, from early granulite or eclogite facies to late amphibole face.
