Crustal evolution of Palaeozoic in Beishan area,Gansu and Inner Mongolia,China
Crustal evolution of Palaeozoic in Beishan area,Gansu and Inner Mongolia,China
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作者：
He Shi-ping
AnZ古大陆是从早寒武世中国甘肃、内蒙古北山地区分裂出来的。石炭纪末洋盆最终闭合形成新的统一大陆，经历了两期板块构造体系和两次主要的逆冲-碰撞造山运动。第一期板块构造体系发生在早古生代(O_2~S_3)，哈萨克斯坦板块和塔里木板块首先沿红柳河-牛圈子-西场井划分。晚奥陶纪—志卢瑞期洋壳由南向北俯冲，志卢林末洋盆闭合，重新形成统一的大陆。第二次发生在晚古生代中期，随着红石山-白鹤山-蓬波山次生洋的形成，哈萨克斯坦板块和塔里木板块再次分裂。石炭纪末期板块构造框架已经结束，新的统一大陆已经形成。此后，北山地区进入陆内演化，在石炭-二叠纪出现了一系列陆内裂谷、裂谷、断陷盆地等扩张机制。
The AnZ ancient continent was been splited from the Early Cambrian in Beishan area bounded by Gansu and Inner Mongolia, China. The oceanic basin was finally been closed to form a new unified continent in the end of Carboniferous, went through two periods of plate tectonic system and two times of main underthrust-collision orogeny. The first period of plate tectonic system occured in Early Palaeozoic(O_2~S_3), Kazakhstan plate and Tarim plate were firstly divided along Hongliuhe-Niujuanzi-Xichangjing. The oceanic crust underthrusted from south to north in Late Ordovicain-Silurain and the oceanic basin was been closed to form a unified continent again in the end of Silurain. The second one took place in the middle period of Late Palaeozoic(C), Kazakhstan plate and Tarim plate were secondly divided, following the formation of Hongshishan-Baiheshan-Pengboshan seconddary ocean. The plate tectonic frame had been concluded in the end of Carboniferous, and a new unified continent had been formed. After this, Beishan area got into intracontinental evolution, and appeared a series of spreading mechanism in Carboniferous-Permian, such as intracontinental rifts, chasmic trough, faulted basins, and so on.