Composition and evolution of the continental crust:Retrospect and prospect  

作　　者：J.L.R.Touret M.Santosh J.M.Huizenga 

机构地区：[1]Institut de Minéralogie,Physique des Matériaux,Cosmochimie,Sorbonne Universités,4 Place Jussieu,F-75005 Paris,France [2]121 Rue de la Réunion,75020 Paris,France [3]School of Earth Sciences and Resources,China University of Geosciences,Beijing 100083,China [4]Department of Earth Science,University of Adelaide,Adelaide,SA 5005,Australia [5]Faculty of Environmental Sciences and Natural Resource Management,Norwegian University of Life Sciences,P.O.Box 5003,NO-1432Ås,Norway [6]EGRU(Economic Geology Research Centre),James Cook University,Townsville,Queensland 4811,Australia [7]Department of Geology,University of Johannesburg,PO Box 524,Auckland Park 2006,South Africa

出　　处：《Geoscience Frontiers》2022年第5期1-15,共15页地学前缘（英文版）

摘　　要：Until the middle of the 20th century,the continental crust was considered to be dominantly granitic.This hypothesis was revised after the Second World War when several new studies led to the realization that the continental crust is dominantly made of metamorphic rocks.Magmatic rocks were emplaced at peak metamorphic conditions in domains,which can be defined by geophysical discontinuities.Low to medium-grade metamorphic rocks constitute the upper crust,granitic migmatites and intrusive granites occur in the middle crust,and the lower crust,situated between the Conrad and Moho discontinuities,comprises charnockites and granulites.The continental crust acquired its final structure during metamorphic episodes associated with mantle upwelling,which mostly occurred in supercontinents prior to their disruption,during which the base of the crust experienced ultrahigh temperatures(>1000℃,ultrahigh temperature granulite-facies metamorphism).Heat is provided by underplating of mantle-derived mafic magmas,as well as by a massive influx of low H_(2)O activity mantle fluids,i.e.high-density CO_(2) and highsalinity brines.These fluids are initially stored in ultrahigh temperature domains,and subsequently infiltrate the lower crust,where they generate anhydrous granulite mineral assemblages.The brines can reach upper crustal levels,possibly even the surface,along major shear zones,where granitoids are generated through brine streaming in addition to those formed by dehydration melting in upper crustal levels.

关 键 词：BRINES CO_(2) Continental crust GRANULITE Lower crust 

分 类 号：P542[天文地球—构造地质学]