全球早古生代造山带(Ⅳ):板块重建与Carolina超大陆  

Global Early Paleozoic Orogens(Ⅳ):Plate Reconstruction and Supercontinent Carolina

作　　者：李三忠[1,2,3] 杨朝[1,2] 赵淑娟[1,2] 刘鑫[1,2] 余珊[1,2] 李玺瑶 郭玲莉[1,2] 索艳慧[1,2] 戴黎明[1,2] 郭润华[1,2] 张国伟[1,2] 

机构地区：[1]中国海洋大学海洋地球科学学院,山东青岛266100 [2]海底科学与探测技术教育部重点实验室,山东青岛266100 [3]青岛海洋科学与技术国家实验室海洋地质功能实验室,山东青岛266061

出　　处：《吉林大学学报（地球科学版）》2016年第4期1026-1041,共16页Journal of Jilin University：Earth Science Edition

基　　金：国家自然科学基金重大项目(41190072;41190070;U1606401);国家杰出青年基金项目(41325009);泰山学者特聘教授项目;鳌山卓越科学家计划项目~~

摘　　要：古元古代与显生宙的板块构造特征和旋回演化过程具有明显区别,反映出地质记录为两种不同的板块构造体制。早古生代为这两个时期的过渡阶段,其构造过程研究与板块重建是地球板块构造旋回机制和周期分析的关键。本文采用综合集成的方法,在总结对比罗迪尼亚超大陆裂解以来全球早古生代主要碰撞造山带的地质事件基础上,分析早古生代碰撞造山带的演化特征,总结出与冈瓦纳大陆拼合、劳俄大陆拼合、古中华陆块群增生相关的7期碰撞-增生造山事件群:Brasiliano、东非、Kuunga、东亚与原特提斯洋和古亚洲洋演化相关的的加里东期造山事件、经典加里东造山、中欧加里东造山、Appalachian造山。再在这7期造山事件群基础上,结合古地磁、古生物、古地理等资料,重建了新元古代-早古生代末全球板块的拼合过程:罗迪尼亚超大陆从新元古代的~950 Ma开始经历了3个阶段裂解,此时存在泛大洋、莫桑比克洋和古太平洋3个大洋,随后615~560 Ma Iapetus洋打开,~560 Ma波罗的陆块与西冈瓦纳裂离导致狭窄的Ran洋打开;~540 Ma南半球Brasiliano、东非和Kuunga造山运动导致冈瓦纳大陆分阶段最终完成拼贴;~500 Ma冈瓦纳大陆北缘西段的微陆块群局部向北裂离,导致Rheic洋和Tornquist洋打开,并于~420 Ma随经典加里东造山带和中欧缝合带形成导致Iapetus洋闭合,此时斯瓦尔巴特和英国可能位于格陵兰地盾东南缘,同时冈瓦纳大陆北缘东段华北为代表的微陆块基本拼合在冈瓦纳大陆北缘;此外,虽然425 Ma西伯利亚板块有远离聚合了的劳俄大陆的趋势,但晚奥陶世-早泥盆世南美和北美板块靠近,北美板块与环冈瓦纳北缘西段的地体拼合碰撞。在大约400 Ma时,南、北美洲的混合生物群和古地理重建显示两者非常接近,因此,推测此时存在一个初始的逐步稳定的超大陆的可能,本文称为Carolina超大陆,�Paleoproterozoic and Phanerozoic plate tectonics and periodic evolutionary processes have obvious difference,reflecting in the geological records developed in two different plate tectonic regimes.The Early Paleozoic is a transition era of these two regimes,the Early Paleozoic tectonic processes and plate reconstructions are the key to understand tectonic mechanism and cycle of the Earth＇s plate tectonics.This paper summarizes and compares the global geological events of the Early Paleozoic collisional orogenic belts since the rifting of the Supercontinent Rodinia based on the analysis of the evolutions of the Early Paleozoic collisional orogenic belts,summing up seven Gondwana-,Larussia-,Paleo-Chinese blocks-related collisional or accretionary orogenic events：the Brasiliano Orogeny,East African Orogeny,the Kuunga Orogeny,the Caledonian-stage proto-Tethyan-and Paleo-Asian Oceanrelated orogeny in East Asia,and classic Caledonian Orogeny,central Eurasian Caledonian suturing,Appalachian Orogeny.After synthesizing seven-stage orogneic events,based on the combination of paleomagnetism,paleontology and paleogeographic data,this paper reconstructs assembly processes of global plates from the Neoproterozoic to Early Paleozoic as follows.Supercontient Rodinia began to experience three stages of rifting since the Neoproterozoic ~950 Ma,developing the Panthalassa,Mozambique and the Paleo-Pacific oceans.The Iapetus ocean opened in 615-560 Ma.In about 560 Ma the dispersal of the Baltica from the West Gondwana resulted in the opening of the narrow Ran Ocean.The Brasiliano Orogeny,the East African orogeny and the Kuunga orogeny in the southern hemisphere completed the final assembly of the Gondwanaland in ~540 Ma.Some terranes in the western segment of the northern margin of the Gondwana locally drifted away to result inthe opening of the Rheic and the Tornquist oceans since^500Ma.In^420Ma the formation of the classic Caledonian orogenic belt and the Central Eurasian suture zone closed the Iapetus Ocean.Coevally the Svalbard

关 键 词：早古生代 造山带 洋陆格局 板块重建 超大陆 RODINIA GONDWANA PANGEA 

分 类 号：P542[天文地球—构造地质学]