昆仑造山带二叠纪岩相古地理特征及盆山转换探讨  

The Permian lithofacies paleogeographic characteristics and basin-mountain conversion in the Kunlun orogenic belt

作　　者：陈守建[1] 李荣社[1] 计文化[1] 赵振明[1] 刘荣丽[1] 贾宝华 张振福 王国灿[4] 

机构地区：[1]西安地质矿产研究所,陕西西安710054 [2]湖南省地质调查研究院,湖南长沙410011 [3]山西省地质调查研究院,山西太原030001 [4]中国地质大学,湖北武汉430074

出　　处：《中国地质》2010年第2期374-393,共20页Geology in China

基　　金：中国地质调查局重点项目"青藏高原北部空白区基础地质调查与研究"(1212010310101);"青藏高原前寒武纪地质古生代构造-古地理研究"(1212010610102);国家自然科学基金(40872084)联合资助

摘　　要：昆仑造山带基本构造-地层格架主要奠基于古生代,是早古生代和晚古生代多次洋陆转换、碰撞造山的结果。早中二叠世是晚古生代昆仑多岛洋盆(昆南洋)伸展裂陷最为强烈期,海相沉积广布,昆北为活动边缘裂谷,大部分区域为滨浅海相沉积,局部为火山盆地相沉积;昆中洋岛大部分为海水淹没,发育滨浅海相沉积;康西瓦—木孜塔格—阿尼玛卿一线及其以北昆南区为深海-半深海相沉积。早中二叠世总体表现为南深北浅的多岛小洋盆构造-古地理格局。中二叠世晚期昆仑地区发生了一次显著的汇聚作用(华力西运动),洋盆和活动大陆边缘裂谷闭合,隆升遭受剥蚀,完成了一次盆山转换。晚二叠世早期,大部分地区仍为剥蚀区,局部地区形成陆相红色碎屑岩建造,其后东昆仑东部海水从东南进入,西昆仑东部海水从西北进入,在较局限的区域内沉积了滨浅海相碎屑岩和碳酸盐岩沉积,进入了另一个盆山发展时期。笔者通过多年的野外观察、分析测试和综合研究,结合覆盖全区的1∶25万区域地质调查资料及其他前人研究成果,选择昆仑造山带晚古生代盆山转换关键时期——二叠纪,对其地层、岩相特征及构造古地理环境进行研究,并探讨了其构造演化,以期对提高昆仑造山带的研究水平和指导找矿工作有所禆益。The Kunlun orogenic belt was basically formed in Paleozoic, resulting from ocean-continent conversion and collision orogenic activity. In the early and middle Permian, the south Kunlun was a multi -island ocean basin, the north Kunlun was an active margin rift and contained mainly shallow sea sediments and partly volcanic basin sediments, the middle part was a seashore -shallow sea, and the Kangxiwa -Muztagh - Animaqing belt contained deep-semi-deep sediments and formed a multi-island ocean basin paleogeographic framework in this period. In the middle and late Permian, convergence took place, ocean basin and active margin rift were closed, uplifting began, and basin-mountain conversion was completed. In the late Permian, the Kunlun orogenic belt entered into another basin-mountain conversion period, sea water came from southeast in the east part and from northwest in the west part, with the deposition of seashore- shallow sea fragmental rocks and carbonate rocks in local areas. Based on field work, analytical tests and integrated studies in association with the 1：250 000 regional geological data and other data available, the authors chose the Permian strata of late Palaeozoic as the study object and discussed the Permian lithofacies characteristics and tectono -paleogeography with the purpose of improving the research level of the Kunlun orogenic belt.

关 键 词：昆仑造山带 二叠纪 岩相特征 构造古地理 多岛洋盆 盆山转换 构造演化 

分 类 号：P531[天文地球—古生物学与地层学]