A Paleozoic Japan-type subduction-accretion system in the Beishan orogenic collage, southern Central Asian Orogenic Belt
A Paleozoic Japan-type subduction-accretion system in the Beishan orogenic collage, southern Central Asian Orogenic Belt
复制标题
中亚造山带南部北山造山带古生代日本型俯冲-增生系统
DOI：
10.1016/j.lithos.2015.03.005
复制
发表时间：
2015-05
期刊：
影响因子：
3.5
通讯作者：
Zhonghua Tian
中科院分区：
文献类型：
--
作者：
Dongfang Song;Wenjiao Xiao;Brian F. Windley;Chunming Han;Zhonghua Tian
大洋岩石圈俯冲作用形成的岩浆弧在增生型中亚造山带(CAOB)的形成中起着主导作用。北山造山带位于天山造山带的西侧和内蒙古造山带的东侧，是研究南中国大陆板块俯冲和增生过程的关键区域。然而，北山岩浆弧的性质和南CAOB不同构造单元之间的对比是非常模糊的。为了研究北山俯冲-吸积史，更好地了解北山南缘构造带之间的时空联系，我们在北山中段关键岩石构造单元的四个剖面上进行了详细的野外构造地质学和LA-ICPMS锆石U-Pb年代学和地球化学研究，主要集中在变质组合及其伴生的深成岩和火山岩。结果表明，深成岩和火山岩具有与俯冲有关的岩石相似的地球化学特征，有利于形成火山弧环境。所有深成岩中的锆石均产生显生宙年龄，深成岩的结晶年龄为464 Ma±0.2 Ma~398 Ma±2.3 Ma。两种火山-沉积岩产生的锆石年龄范围从显生宙到前寒武纪，最年轻的年龄峰分别为441 Ma和446 Ma，估计是火山岩的形成时间。结合已发表的北山中段蛇绿混杂岩的资料，这些新的结果支持了寒武纪至石炭纪的日本式俯冲-吸积系统。西昌井-牛圈子蛇绿岩可能代表了北山造山拼接中不同构造单元之间的一条主缝合带，而小黄山-鸡腿台子蛇绿混杂岩可能代表了牛圈子大洋岩石圈向北俯冲导致的板片退缩形成的石炭纪弧后盆地。该弧后盆地的俯冲作用可能发生在早石炭世，产生了广泛的与弧有关的花岗岩类，包括埃达克质深成岩体，并与早期的弧组合重叠。北山造山拼贴不是中国中天山的东延，而是由兴兴峡转换断裂隔开的同一北倾俯冲系统产生的，区域资料显示。这一贡献表明，与西南太平洋中新生代俯冲-吸积系统类似，弧后盆地的开启和闭合可能也是CAOB建造过程中的一个常见过程。
Magmatic arcs ascribed to oceanic lithosphere subduction played a dominant role in the construction of the accretionary Central Asian Orogenic Belt (CAOB). The Beishan orogenic collage, situated between the Tianshan Orogen to the west and the Inner Mongolia Orogen to the east, is a key area to understanding the subduction and accretionary processes of the southern CAOB. However, the nature of magmatic arcs in the Beishan and the correlation among different tectonic units along the southern CAOB are highly ambiguous. In order to investigate the subduction-accretion history of the Beishan and put a better spatial and temporal relationship among the tectonic belts along the southern CAOB, we carried out detailed field-based structural geology and LA-ICP-MS zircon U-Pb geochronological as well as geochemical studies along four cross-sections across crucial litho-tectonic units in the central segment of the Beishan, mainly focusing on the metamorphic assemblages and associated plutons and volcanic rocks. The results show that both the plutonic and volcanic rocks have geochemical characteristics similar to those of subduction-related rocks, which favors a volcanic arc setting. Zircons from all the plutonic rocks yield Phanerozoic ages and the plutons have crystallization ages ranging from 464 ± 2 Ma to 398 ± 3 Ma. Two volcanic-sedimentary rocks yield zircons with a wide age range from Phanerozoic to Precambrian with the youngest age peaks at 441 Ma and 446 Ma, estimated to be the time of formation of the volcanic rocks. These new results, combined with published data on ophiolitic mélanges from the central segment of the Beishan, favor a Japan-type subduction-accretion system in the Cambrian to Carboniferous in this part of the Paleo-Asian Ocean. The Xichangjing-Niujuanzi ophiolite probably represents a major suture zone separating different tectonic units across the Beishan orogenic collage, while the Xiaohuangshan-Jijitaizi ophiolitic mélange may represent a Carboniferous back-arc basin formed as a result of slab rollback ascribed to northward subduction of the Niujuanzi oceanic lithosphere. Subduction of this back-arc basin probably took place in the early Carboniferous, generating the widespread arc-related granitoids including adakitic plutons, and overlapping earlier arc assemblages. The Beishan orogenic collage is not the eastern extension of the Chinese Central Tianshan, but it was generated by the same north-dipping subduction system separated by the Xingxingxia transform fault, as revealed by available regional data. This contribution implies that in addition to fore-arc accretion, back-arc accretion ascribed to opening and closure of a back-arc basin may also have been a common process in the construction of the CAOB, resembling that of the Mesozoic-Cenozoic subduction-accretion system in the SW pacific.
登录
查看更多内容
阿尔泰山脉南部北山造山带片麻岩杂岩及相关花岗岩的年代学和地球化学研究
影响因子：
2.6
作者：
Dongfang Song;Wenjiao Xiao;Chunming Han;Zhonghua Tian
通讯作者：
Zhonghua Tian
影响因子：
3.5
作者：
Wen Zhang;V. Pease;Tairan Wu;Rongguo Zheng;Jicheng Feng;Yuankai He;Hongling Luo;Cao Xu
通讯作者：
Wen Zhang;V. Pease;Tairan Wu;Rongguo Zheng;Jicheng Feng;Yuankai He;Hongling Luo;Cao Xu
影响因子：
5.3
作者：
David A. Wood;J. Joron;M. Treuil
通讯作者：
David A. Wood;J. Joron;M. Treuil
影响因子：
3.8
作者：
Dongfang Song;W. Xiao;Chunming Han;Jiliang Li;J. Qu;Q. Guo;Lina Lin;Zhongmei Wang
通讯作者：
Dongfang Song;W. Xiao;Chunming Han;Jiliang Li;J. Qu;Q. Guo;Lina Lin;Zhongmei Wang
DOI：
10.1144/sp338.3
发表时间：
2010
期刊：
--
影响因子：
--
作者：
W. Xiao;Chunming Han;C. Yuan;M. Sun;Guochun Zhao;Y. Shan
通讯作者：
W. Xiao;Chunming Han;C. Yuan;M. Sun;Guochun Zhao;Y. Shan