Vestiges of the Kerguelen Mantle Plume in Southern Tibet:Evidence from 123-117 Ma Magmatism in the Dingri Area of the Central Tethys Himalaya  

作　　者：YAN Songtao WU Qingsong LI Hu DAI Xuejian ZHU Lidong WANG Jie XIN Chongyang 

机构地区：[1]Civil-Military Integration Center of China Geological Survey,China Geological Survey,Chengdu 610036,China [2]Institute of Sedimentary Geology,Chengdu University of Technology,Chengdu 610059,China [3]College of Earth Science,Chengdu University of Technology,Chengdu 610059,China

出　　处：《Acta Geologica Sinica(English Edition)》2023年第4期1163-1180,共18页地质学报（英文版）

基　　金：supported by the Geological Survey Project of China Geological Survey(Grant No.DD20211547);the Basic Survey Project of Command Center of Natural Resources Comprehensive Survey(Grant No.ZD20220508)。

摘　　要：The widely distributed Early Cretaceous magmatism in the Tethys Himalaya(TH)of southern Tibet is related to the Kerguelen mantle plume.Associated magmatic activity products are distributed in the eastern TH,where the active age is earlier than the peak ages of the Kerguelen mantle plume.This study investigated magmatic activity of the Dingri area in the central TH which was coeval with the Kerguelen mantle plume.The intrusion in the Dingri area contains diabases and monzonites.The zircon age of diabase is 123±1 Ma,and that of monzonite is 117±1 Ma.Geochemistry and Sr-Nd isotopic analyses show that the mafic-intermediate dikes were formed in an intraplate extensional environment.The diabase is derived from the enriched lithospheric mantle and monzonite is derived from partial melting of the lower crust,with both magmatic evolutions being contaminated by crustal materials.These characteristics are similar to those of the Rajmahal-Sylhet basalt,a typical Kerguelen mantle plume product.The discovery of the Dingri mafic-intermediate dikes of the central TH suggests that the TH and Rajmahal-Sylhet Traps formed a continuous mantle plume overflow magmatic belt which was a product of the continuous eruption of the Kerguelen mantle plume.

关 键 词：GEOCHRONOLOGY mafic-intermediate dikes Kerguelen mantle plume central Tethys Himalaya East Gondwana 

分 类 号：P588.11[天文地球—岩石学] P542.5[天文地球—地质学]