Blueschist exposed in the northwestern Qiangtang terrane, northern Tibet, western China （84 30＇ E, 34024＇ N）, provides new constraints on the tectonic evolution of Qiangtang as well as northern Tibet. The blueschi...Blueschist exposed in the northwestern Qiangtang terrane, northern Tibet, western China （84 30＇ E, 34024＇ N）, provides new constraints on the tectonic evolution of Qiangtang as well as northern Tibet. The blueschist represented by lawsonite- and glaucophane-bearing assemblages equilibrated at 375-400 C and 11 kbar. 4Ar-39Ar analysis on mineral separate from one blueschist sample yielded a well-defined plateau age of 242 Ma. Geochemical studies show the blueschist is metamorphosed within-plate basalts. The high pressure-low temperature blueschist indicates a Triassic event of lithosphere subduction, and clearly represents an extension of the central Qiangtang metamorphic belt, and defines an in situ suture between eastern and western Qiangtang.展开更多
Late Paleozoic igneous rocks are extensively developed in Qiangtang terrene,including west Qiangtang(WQT),east Qiangtang(EQT)and the central Qiangtang(CQT)metamorphic belt.The igneous rocks distributed in WQT display ...Late Paleozoic igneous rocks are extensively developed in Qiangtang terrene,including west Qiangtang(WQT),east Qiangtang(EQT)and the central Qiangtang(CQT)metamorphic belt.The igneous rocks distributed in WQT display the typical characters of rifted igneous rock(e.g.Wang et al.,1987,2001;Deng et al.1996;Zhang and Zhang,in press).The blueschist-and eclogite-bearing CQT metamorphic belt is characterized by ubiquitous blocks of OIB-type meta-basalts(Zhang et al.,2006a,2006b,2007a;Tang and Zhang,2012a,2012b,2014;Zhang and Zhang,in press).However,the distribution,age and geological responses of these igneous rocks remain open to be discussed.展开更多
History has shown that mega engineering projects co-evolve with advancements in fundamental science.For instance,new research opportunities encountered inNational Aeronautics and Space Administration’s(NASA’s)Apollo...History has shown that mega engineering projects co-evolve with advancements in fundamental science.For instance,new research opportunities encountered inNational Aeronautics and Space Administration’s(NASA’s)Apollo Project led to the formulation of system science,and the development of sea-floor drilling for submarine oil exploration provided key evidence for the theory of plate tectonics.Today,there are high expectations that new data sources and technologies,such as big data,artificial intelligence,and digital twins,will bring about a step change in Earth SystemScience(ESS).1 Consequently,the ESS community anticipates the availability of broader,deeper,and higher-resolution data,complemented by longer time series than are currently available.2 Theworld’smost challenging plateau railway,named the Sichuan-Tibet railway(STR)project,aligns well with these emerging scientific requirements.展开更多
文摘Blueschist exposed in the northwestern Qiangtang terrane, northern Tibet, western China （84 30＇ E, 34024＇ N）, provides new constraints on the tectonic evolution of Qiangtang as well as northern Tibet. The blueschist represented by lawsonite- and glaucophane-bearing assemblages equilibrated at 375-400 C and 11 kbar. 4Ar-39Ar analysis on mineral separate from one blueschist sample yielded a well-defined plateau age of 242 Ma. Geochemical studies show the blueschist is metamorphosed within-plate basalts. The high pressure-low temperature blueschist indicates a Triassic event of lithosphere subduction, and clearly represents an extension of the central Qiangtang metamorphic belt, and defines an in situ suture between eastern and western Qiangtang.
基金supported by the Natural Science Foundation of China(41472209 and 40802048)the Chinese Academy of Sciences(Y129012EA2 and 118900EA12)the President Fund for Science and Education Fusion of UCAS(Y552011Y00)
文摘Late Paleozoic igneous rocks are extensively developed in Qiangtang terrene,including west Qiangtang(WQT),east Qiangtang(EQT)and the central Qiangtang(CQT)metamorphic belt.The igneous rocks distributed in WQT display the typical characters of rifted igneous rock(e.g.Wang et al.,1987,2001;Deng et al.1996;Zhang and Zhang,in press).The blueschist-and eclogite-bearing CQT metamorphic belt is characterized by ubiquitous blocks of OIB-type meta-basalts(Zhang et al.,2006a,2006b,2007a;Tang and Zhang,2012a,2012b,2014;Zhang and Zhang,in press).However,the distribution,age and geological responses of these igneous rocks remain open to be discussed.
基金supported by the National Natural Science Foundation of China(grant no.41941017)the Second Tibetan Plateau Scientific Expedition and Research Program(STEP)(grant no.2019QZKK0900).
文摘History has shown that mega engineering projects co-evolve with advancements in fundamental science.For instance,new research opportunities encountered inNational Aeronautics and Space Administration’s(NASA’s)Apollo Project led to the formulation of system science,and the development of sea-floor drilling for submarine oil exploration provided key evidence for the theory of plate tectonics.Today,there are high expectations that new data sources and technologies,such as big data,artificial intelligence,and digital twins,will bring about a step change in Earth SystemScience(ESS).1 Consequently,the ESS community anticipates the availability of broader,deeper,and higher-resolution data,complemented by longer time series than are currently available.2 Theworld’smost challenging plateau railway,named the Sichuan-Tibet railway(STR)project,aligns well with these emerging scientific requirements.
