东川运动及其对东川矿区褶皱构造的影响

DONGCHUAN MOVEMENT AND ITS INFLUENCE ON FOLDING STRUCTURES IN DONGCHUAN MINING DISTRICT

分析了当前东川运动的各种认识,通过上下地层的特征、构造、变质作用、火山-岩浆活动、形成背景以及汤丹、落雪和拖布卡3个典型剖面的研究,确定该运动是一次大规模的构造运动。东川运动是南北向挤压运动,在东川矿区下(昆阳)亚群形成东西向褶皱构造,被后期小黑箐和晋宁运动叠加改造后,其构造形迹变得模糊和复杂,但经仔细研究分辨出了10个较大的褶皱构造。

The various understandings about Dongchuan Movement were analyzed.Researches on characteristics of the strata in Kunyang Group,metamorphism,volcano-magma activities,and typical profiles as Tangdan,Luoxue and Tuobuka show that Dongchuan Movement is a large-scale tectonic movement.Dongchuan Movement is SN-trend compressional movement.In Dongchuan mining district,EW-trend fold structures formed in the lower Kunyang subgroup.These EW-trend fold structures were reformed and transformed by later Xiaoheijing Movement and Jinning Movement.The structural features became indistinct and complex.But after a careful study,the 10 larger fold structures were distinguished in Dongchuan mining district.