Rubidium-Sr isotope is one of the most widely used radiogenic isotopic systems in planetary geochronology and geochemistry for tracing and dating igneous processes or events.This utility stems from the distinct geoche...Rubidium-Sr isotope is one of the most widely used radiogenic isotopic systems in planetary geochronology and geochemistry for tracing and dating igneous processes or events.This utility stems from the distinct geochemical properties of Rb and Sr,which drive substantial Rb/Sr fractionation during planetary differentiation,resulting in a large variation of ^(87)Sr/^(86)Sramong different reservoirs.展开更多
Through petrography, mineral compositions and P-T estimate results, an ultrahigh-temperature(UHT) metapelitic granulite has recently been identified from near Kalasu in the east of Altay city, with an assemblage gt-op...Through petrography, mineral compositions and P-T estimate results, an ultrahigh-temperature(UHT) metapelitic granulite has recently been identified from near Kalasu in the east of Altay city, with an assemblage gt-opx-silcd-sp-bt-pl-qtz. The orthopyroxene has a high-Al feature, and its Al2O3 content is as high as 8.7 wt%, indicating a UHT metamorphic condition. Its peak metamorphic condition is estimated as: P = *0.80 GPa, T = *960 °C. Metamorphic textural relations and P-T estimate results show a post-peak near-isobaric cooling anticlockwise P-T path. Zircon U-Pb age results(271 ± 5 Ma) support that the UHT metamorphic event in the region occurred in the Permian. The identification of the UHT metapelitic granulite from near Kalasu confirms the existence of the Permian UHT metamorphism in the Altay orogen, implying that the Permian extensional tectonic setting of a high-heat flow in the southern part of the Altay orogen may be closely associated with the Permian Tarim mantle plume activity.展开更多
基金financially supported by the Chinese Academy of Sciences(XDB 1180000 and ZDBS-SSW-JSC007-11)the Lunar research program of GIGCAS(2022SZJJZD-03)+2 种基金the Guangzhou city program(2025A04J7199)the National Natural Science Foundation of China(42241104)the Technical Talent Program of CAS.
文摘Rubidium-Sr isotope is one of the most widely used radiogenic isotopic systems in planetary geochronology and geochemistry for tracing and dating igneous processes or events.This utility stems from the distinct geochemical properties of Rb and Sr,which drive substantial Rb/Sr fractionation during planetary differentiation,resulting in a large variation of ^(87)Sr/^(86)Sramong different reservoirs.
基金supported by the National Basic Research Program of China (2011CB080901)
文摘Through petrography, mineral compositions and P-T estimate results, an ultrahigh-temperature(UHT) metapelitic granulite has recently been identified from near Kalasu in the east of Altay city, with an assemblage gt-opx-silcd-sp-bt-pl-qtz. The orthopyroxene has a high-Al feature, and its Al2O3 content is as high as 8.7 wt%, indicating a UHT metamorphic condition. Its peak metamorphic condition is estimated as: P = *0.80 GPa, T = *960 °C. Metamorphic textural relations and P-T estimate results show a post-peak near-isobaric cooling anticlockwise P-T path. Zircon U-Pb age results(271 ± 5 Ma) support that the UHT metamorphic event in the region occurred in the Permian. The identification of the UHT metapelitic granulite from near Kalasu confirms the existence of the Permian UHT metamorphism in the Altay orogen, implying that the Permian extensional tectonic setting of a high-heat flow in the southern part of the Altay orogen may be closely associated with the Permian Tarim mantle plume activity.
