Paleozoic Multi-Stage Magmatic Events Related to Proto-Tethys and Paleo-Tethys Evolution:Insights from Intrusive Rocks in the Eastern Altyn Orogen,NW China  

作　　者：Jiyong Li Yanqing Xia Xilong Zhang Haoyuan Jiang Tianzhu Lei Yongchao Wang Yanhong Liu Shanpin Liu Xiaobao Zhang 

机构地区：[1]Northwest Institute of Eco-Environment and Resources,Chinese Academy of Sciences,Lanzhou,730000,China [2]Key Laboratory of Petroleum Resources,Gansu Province,Lanzhou,730000,China [3]University of Chinese Academy of Sciences,Beijing,100049,China

出　　处：《Journal of Earth Science》2024年第4期1130-1148,共19页地球科学学刊（英文版）

基　　金：supported by the Opening Fund of Qinghai Provincial Key Laboratory of Geology and Environment of Salt Lakes(No.Y840041117);the National Natural Science Foundation of China(No.42102199).

摘　　要：Abundant mafic-felsic intrusions distributed in the Altyn Orogen record orogenic histories related to Proto-Tethys and Paleo-Tethys evolution.Zircon U-Pb dating of the intrusive rocks in the eastern Altyn Orogen identifies at least three major tectono-magmatic episodes,yielding ages of∼426,∼376–373 and∼269–254 Ma.The first two emplacement episodes correspond to the post-collisional magmatism in the Altyn Orogen.The∼426 Ma granitoids possess adakitic characteristics coupled with enriched isotopes,suggesting that they originated from partial melting of thickened lower continental crust induced by upwelling asthenospheric mantle after slab break-off of the South Altyn Ocean Plate.Next,the∼376–373 Ma mafic-intermediate rocks and coeval granitoids represent a large thermal event that involved mantle melting with induced new juvenile lower continental crust melting in a post-collisional extensional setting.Finally,the∼254 Ma diabase dykes intruded into the∼269 Ma granitoids,which were related to the widespread Late Paleozoic magmatism resulting from Paleo-Tethys Ocean subduction.Post-collisional magmatism in the Altyn Orogen significantly enhances understanding of the tectono-magmatic evolution in the northern Tibetan Plateau.The penetrative influence of Paleo-Tethys Ocean subduction was more extensive than previously thought.

关 键 词：Proto-Tethys PALEO-TETHYS Altyn Orogen multi-stage magmatic events magnetic cores 

分 类 号：P534.4[天文地球—古生物学与地层学] P588.1[天文地球—地质学]