A review on developments in the electrical structure of craton lithosphere  

作　　者：Xiangyun HU Wule LIN Wencai YANG Bo YANG 

机构地区：[1]Hubei Subsurface Multiscale Imaging Laboratory,Institute of Geophysics and Geomatics,China University of Geosciences,Wuhan 430074,China [2]School of Earth Sciences,Zhejiang University,Hangzhou 310058,China

出　　处：《Science China Earth Sciences》2020年第11期1661-1677,共17页中国科学（地球科学英文版）

基　　金：supported by the National Natural Science Foundation of China(Grant Nos.41630317 and 41474055);the National Key Research and Development Program of China(Grant No.2017YFC0602405)。

摘　　要：Cratons have a long history of evolution.In this paper,applications of the magnetotelluric method used in the study of craton lithosphere over the past 30 years were reviewed,examining case studies of cratons in North America,South America,Asia,Australia,and Africa.The nuclei of the Archean cratons,for example the Kalahari Craton and Rae Craton,are usually characterized by thick and highly resistive lithospheric roots.During or after the formation of the cratons,tectonothermal events,such as collision,mantle plume,and asthenosphere upwelling led to the formation of high-conductivity zones in the craton lithosphere,which could be attributed to the increased hydrogen content(of nominally anhydrous minerals),higher iron content,and formation of graphite films or sulfides along the grain boundary of minerals.These conductive zones are characterized by resistivity discontinuities in craton lithosphere.In particular,the conductive zones include(1)large-scale lithospheric mantle conductors beneath the Slave Craton,Gawler Craton,and central part of North China Craton(Trans-North China Orogen);(2)near-vertical high-conductivity zone associated with the fossil subduction zone beneath the Dharwar Craton and Slave Craton;and(3)regional lateral electrical discontinuities,such as a conductive anomaly under the Bushveld Complex of the Kaapvaal Craton.The eMoho refers to the electrical discontinuity in the crust-mantle boundary.In existing research,this has been detected under the condition of extremely high lithospheric resistivity with only a slight decrease in the lower crust,and in the case of a very thin conductive lower crust or the lack thereof.In the resistivity model,the unique"mushroom-like"lower crust-lithosphere mantle conductor and very thin lower crust layer of the North China Craton may represent lithosphere destruction and/or thinning.We also find that some of the cratons are still not well understood.Therefore,extensive three-dimensional inversion and joint interpretation of geochemical,geophysical,and geologic

关 键 词：CRATON Lithospheric electrical structure MAGNETOTELLURICS 

分 类 号：P31[天文地球—固体地球物理学]