东南极新元古代晚期-早古生代(泛非期)花岗岩类研究综述  

A REVIEW OF RESEARCH ON LATE NEOPROTEROZOIC-EARLY PALEOZOIC( PAN-AFRICAN) GRANITOIDS FROM EAST ANTARCTICA

作　　者：李淼[1] 刘晓春[1] 赵越[1] 

机构地区：[1]中国地质科学院地质力学研究所,北京100081

出　　处：《极地研究》2010年第4期348-374,共27页Chinese Journal of Polar Research

基　　金：国家自然科学基金(40702011);国土资源大调查项目(1212010711509)资助

摘　　要：东南极内部发育毛德和普里兹两条新元古代晚期-早古生代(泛非期)造山带,这两条造山带中均发育大量同-后构造花岗岩类。本文系统总结了以往东南极泛非期花岗岩类的岩石学、地球化学和年代学方面的研究成果,对不同地区岩体的岩石类型、岩浆源区及形成的构造环境进行了对比研究。结果表明:除南龙达讷山为I型花岗岩外,大部分花岗岩类表现出与碰撞造山作用相关的A型(或S型)花岗岩的特征。泛非期岩浆作用与区域高级变质作用的时代吻合(600—500Ma)。两条造山带中泛非期岩浆作用与碰撞后岩石圈减薄、岩浆底侵以及上地壳的伸展垮塌相联系,均具有碰撞造山带的构造演化特点。所以,冈瓦纳超大陆的形成很可能是通过西冈瓦纳、印度-南极陆块和澳大利亚-南极陆块等3个陆块沿着两条造山带(毛德造山带和普里兹造山带)近于同期发生拼合碰撞的结果。There exist two Pan-African orogenic belts,i. e. Maud and Prydz belts,in East Antarctica. Numerous syn-to post-tectonic granitoids occur in these two orogenic belts. In this paper we summarized the published petrological,geochemical and geochronological data of Pan-African intrusive rocks from the different areas in East Antarctica. A comparative study on rock types,magma sources and tectonic settings were performed. The results show that most granitoids have an affinity of A-or S-type granites related to collisional orogeny,except for granitoids from the Sr Rondane Mountains being I-type granites. The Pan-African granitoid magmatism occurred between 600 and 500 Ma,largely coeval with regional high-grade metamorphism. Granitoid magmatism in two orogenic belts is probably related to post-collisional lithospheric thinning,magmatic underplating and crustal relaxation,which is expected in a typical collisional tectonic setting. Therefore,The Gondwana supercontinent was probably formed by the final juxtaposition between West Gondwana,Indian-Antarctic and Australian-Antarctic continental blocks along the two sutures （ Maud and Prydz belts） during the Pan-African time.

关 键 词：东南极 泛非期 造山带 岩浆活动 花岗岩类 

分 类 号：P588.121[天文地球—岩石学]