| 中国内蒙古中部的古板块构造 |
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| 引用本文：王荃,刘雪亚,李锦轶.1991.中国内蒙古中部的古板块构造[J].地球学报,12(1):1-19. |
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| 中文摘要:基于近年的研究,笔者认为内蒙古南部华北地台北缘有二条东西走向的元古代裂谷带,并分别沉积了泻湖相或浅海相的渣尔泰群和白云鄂博群。白云鄂博群中部炭质白云岩中铅的同位素年龄为1500Ma。沿二裂谷带在阴山和燕山零星出露一系列碱性火山岩和侵入体。裂谷带以北的古生代造山带中,识别出6条蛇绿岩带,以及至少5个增生地体。介于西伯利亚和华北二地台间的古生代洋盆,因多次向两侧陆缘带俯冲,终于在二叠纪晚期导致华夏古陆与安加拉古陆的碰撞。其间的缝合线位于林西至索伦敖包一带。内蒙古及其邻区大地构造演化的研究表明,西伯利亚地台南缘与中新生代的亚洲东部陆缘甚为相似,而华北地台北缘则与北美的科迪勒拉山系大体相似。从华北与西伯利亚的分裂到二者的重新拼合构成一个巨大而完整的威尔逊旋回。 |
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| PALEOPLATE TECTONICS IN NEI MONGGOL OF CHINA |
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| Abstract:<正> In accordance with the studies concerning the tectonics of Nei Monggolmade by Huang Jiqing and others, two tectonic units occur in this area:Sino-Korean Platform to the south and Nei Monggol-Greater Khingan Mtsfold system to the north. The dividing line between the two units lies fromBaiyun'ebo on the west to Chifeng on the east. Geophysical studies demonst-rate that there are two gravity gradient zones trending ENE in the northernmargin of the North China Platform. The northern zone is a linear anomalyzone of--50 to--45 mGal extending from Baiyun'ebo in the west to theeast of Chifeng. The southern zone, 60--70km wide, lies from Guyang throughJining to Longhua in the east and its amplitude of gravity gradient amountsto 60 mGal. Field geological survey indicates that there are two main faultedzones. Our recent investigations suggests that there are two Proterozoic riftsof E-W trend in the northern margin of the North China Platform. |
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