川东南—黔西北桐湾Ⅲ幕岩溶古地貌恢复

发布时间：2018-01-20 16:46

  本文关键词： 古岩溶标志 桐湾运动 岩溶古地貌 灯影组 麦地坪组 川东南—黔西北　出处：《地质论评》2017年05期 　论文类型：期刊论文

【摘要】：通过对川东南—黔西北灯影组露头、钻井岩芯的详细观察分析,认为灯影组中上部发育一系列的古岩溶标志,包括岩溶角砾岩、充填的溶洞溶缝、含铁质古风化壳等。在结合前人对上扬子桐湾运动研究的基础上,认为川东南—黔西北大部分地区由Ⅲ幕和Ⅱ幕叠加形成了寒武系与震旦系之间的平行不整合面。采用"印模法"恢复桐湾Ⅲ幕岩溶古地貌,"印模"为下寒武统"牛蹄塘组+明心寺组+金顶山组";"印模"如果包括麦地坪组,"印模"底界将具明显穿时性。根据"印模"地层分布及古地貌指示,研究区岩溶古地貌主体呈南北向展布,具有东高西低的特征,东部发育岩溶高地,西侧为岩溶洼地,中部则发育岩溶斜坡。岩溶高地和岩溶斜坡可以进一步划分为残丘、平台以及上斜坡、下斜坡等次级岩溶古地貌单元。
[Abstract]:Through the detailed observation and analysis of outcrop and drilling core of Dengying formation in southeastern Sichuan and northwestern Guizhou, it is considered that a series of paleokarst markers, including karst breccia and karst cavern dissolved fracture, are developed in the middle and upper part of Dengying formation. Iron bearing paleo-weathering crust and so on. Based on the previous studies on the movement of the Upper Yangtze Gulf. It is considered that the parallel unconformities between Cambrian and Sinian systems were formed in most areas of southeast Sichuan and northwest Guizhou by the superposition of acts 鈪，

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