%0 Journal Article
%T Zircon U-Pb Ages of Paleoproterozoic Metabasites from the Tongbai Orogen and Their Geological Significance<br>桐柏造山带古元古代变质基性岩的锆石U-Pb年龄及其地质意义
%A HU Juan
%A LIU Xiao-chun
%A QU Wei
%A CUI Jian-jun
%A <br>胡娟
%A 刘晓春
%A 曲玮
%A 崔建军
%J 地球学报
%D 2012
%I 
%X The Tongbai orogen is situated at the junction between the Qinling and Dabie orogenic belts.Its northern part corresponds to the North Qinling medium-to high-grade metamorphic complexes,whereas the southern part belongs to the westward continuation of the Dabie HP/UHP metamorphic complexes.Zircon U-Pb dating reveals a protolith age of(1961±23) Ma and a zircon recrystallization or growth age of(1949±51) Ma for an eclogite,and a metamorphic age of(1936±26) Ma for a garnet amphibolite(retrograded eclogite?).These data suggest that these rocks might have suffered Paleoproterozoic metamorphism prior to Permian-Triassic HP metamorphism.Based on the available geochronological data from the Tongbai-Dabie-Sulu orogen,the authors have inferred the existence of two episodes of Paleoproterozoic tectonothermal events in northern Yangtze block.The first episode occurred at 1.97-1.93 Ga,probably related to the assembly of the Columbia supercontinent.The second episode took place at 1.85-1.82 Ga,resulting either from the protracted assembly of the Columbia supercontinent or from the accretionary orogenesis along the northern margin of the Yangtze block.
%K Paleoproterozoic
%K two metamorphic episodes
%K Yangtze block
%K Tongbai orogen<br>古元古代
%K 两幕变质
%K 扬子陆块
%K 桐柏造山带
%U http://www.alljournals.cn/get_abstract_url.aspx?pcid=E62459D214FD64A3C8082E4ED1ABABED5711027BBBDDD35B&cid=621CF755B1A341E5&jid=1DF69A47DE80569EC8F859DF61571180&aid=4471C9E6A56983952907387761D1C172&yid=99E9153A83D4CB11&vid=27746BCEEE58E9DC&iid=38B194292C032A66&sid=407C905D8F0449C4&eid=0C3F9E980968AF79&journal_id=1006-3021&journal_name=地球学报&referenced_num=0&reference_num=0