XU Yi-gang1, ZHONG Yu-ting1, WEI Xun2, CHEN Jun1, LIU Hai-quan3, XIE Wei1, LUO Zhen-yu1, LI Hong-yan1, HE Bin1, HUANG Xiao-long1, WANG Yan4, CHEN Yun5
1. State Key Laboratory of Isotope Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640, China;
2. Key Laboratory of Marine Sedimentology and Environmental Geology, The First Institute of Oceanography, State Oceanic Administration, Qingdao Shandong 266061, China;
3. Key Laboratory of Marginal Sea Geology, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640, China;
4. Key Laboratory of Mineralogy and Metallogeny, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640, China;
5. State Key Laboratory of Lithospheric Evolution, Institute of Geology and Geophysics, Chinese Academy of Sciences, Beijing 100083, China
Abstract:This paper highlights the main research progresses made under the support of the National 973 project entitled "Permian Large Igneous Province and Surface System Evolution".(1)The Emeishan Large Igneous Province(LIP) was emplaced at ~259 Ma with a duration of <1 Ma, most likely resulted from melting of a mantle plume head. The Tarim LIP was emplaced at three episodes with a duration of >20 Ma, most likely related to an incubating mantle plume under a thick craton. (2)Comprehensive geophysical survery revealed that the crust in the inner zone of the Emeishan LIP is characterized by the lack of the upper-lower crust boundary, presence of a thick and high velocity lower crust and a thinned lithospheric mantle. All these features are attributable to upwelling of an ancient mantle plume and associated magmatic underplating and intraplating at different level of the crust. (3)The formation mechanism of magmatic ore deposits associated with LIPs is refined, and a framework of plume-related mineralization system is established. Following has been identified as key controlling factors in plume-related mineralization: Structure of a plume, magma source, crystal fractionation, sulfide saturation, crustal contamination, and intrusion processes. (4)Both relative temporal correlation and absolute dating confirm the links between the Siberian Traps and Permo-Triassic Boundary(PTB)mass extinction, and between the Emeishan LIP and Guadlupian-Lopingian Boundary(GLB)mass extinction. The reconstruction of Permian-Triassic seawater temperature and pH makes it possible to discriminate the triggers of the end-Permian mass extinction.
Key words: Large Igneous Province mantle plume Permian mineralization system mass extinction
E-Mail: yigangxu@gig.ac.cn
Bulletin of Mineralogy, Petrology and Geochemistry Vol.36, No.3, 2017, page 359-373