【摘要】 通过对大量野外露头资料的详细分析,结合前人对该区的研究成果,对北祁连山—阿拉善地区的地层划分,构造演化及沉积相类型进行了研究。对香山群、韩母山群进行了重新厘定,将香山群的时代厘定为寒武纪—奥陶纪,韩母山群厘定为震旦纪—寒武纪。在研究区共识别出4种沉积相类型:海岸相、浅海相、半深海相及深海—洋盆相。在上述研究的基础上,采用造山带与沉积盆地密切结合,地质与地球物理交叉渗透的研究方法,编制研究区寒武纪构造—岩相古地理图。研究区寒武纪构造—岩相古地理是在继承震旦纪格局基础上发展起来的,沉积区主要分布于古地块之间或地块的边缘地带,不同构造背景的地域呈现出不同的沉积环境。目前区内所保存的寒武纪沉积物均为海相沉积。更多还原

【Abstract】 Based on the vast field outcrop data analysis,integrated with the completed research achievements,stratigraphic division,structure evolution and sedimentary facies of the Cambrian in North Qilian Mountain-Alxa area are studied.Redefining of the Xiangshan group and Hanmushan group,we define the age of Xianshan group as the Cambrian-Ordovician period and the age of Hanmushan group as the Sinian-Cambrian period.Four sedimentary facies types are recognized,there are coastal facies,neritic facies,bathyal-abyssal facies and abysmal-ocean basin facies.The tectono-lithofacies-palaeogeography maps of the Cambrian in the area are drawn on the basis of the above work.The tectono-lithofacies-palaeogeography inherited the Sinian pattern.The depositional area mainly distribute in the middle of old land and the margin of the old land.The region with different structural backgrounds presents different depositional environment.The sediments preserved in the area were all marine sediments.更多还原