六盘山弧形冲断体系构造新探

New Advances in Study of Liupanshan Arc Thrust System

六盘山弧形冲断体系处于秦祁地槽系和华北地台两大构造单元的结合部，大地构造位置特殊。本文通过多种资料综合分析．认为六盘山弧形冲断体系、桌子山一贺兰山冲断体系是互为独立的冲断推覆构造。明确指出六盘山弧形冲断体系具有独特的双层地体叠置地质结构，为祁连地体、华北陆缘地体相互拼贴的冲断推覆构造。主张将华北地台的西界移至中卫-海原-宝鸡一线。并推断六盘山盆地深部发育华北地台基底和古生界的盖层，这为在鄂尔多斯盆地以外地区勘探和鄂尔多斯盆地类似的古生界天然气赋存层系提供了线索，具有重要的理论和现实意义。

Liupanshan arc thrust system is located at the joint position of Qin-Qi geosynclinal folding belt and the North China platform, and has special geotectonic position. Based on studies of different data, we think that the Liupanshan arc thrust system and the Zhuozishan-Helanshan thrust system were two different thrust and nappe tectonic systems. The western boundary of Ordos basin should locate at the line from Zhongwei to Haiyuan, and then to Baoji. We clearly point out that the Liupanshan arc thrust system has unique two-double geological structures of suturing of terranes, and was thrust and nappe tectonic system which combined Qilian terrane and North China terrane. So we infer that there might be crystalline basement and Paleozoic caprock of North China platform under liupanshan basin. Which has provided new clues for gas exploration in Ordos basin, and have important academic and practical significances.