秦岭勉县-略阳地区的构造混杂岩及其意义

Characteristics and implication of the tectonic melanges in Mianxian-Lueyang area, Qinling orogenic belt.

秦岭造山带勉县长坝和略阳横现河地区发现的混杂岩均由不同性质的构造岩块和基质组成 ,混杂岩基质为受到不同变质作用的泥质岩或砂岩 ,属泥沙质混杂岩 ;构造岩块包括原地岩块和外来岩块两种基本类型 ,岩块大小不一 ,成分和形态复杂 ,在混杂岩中分布无序。两地区混杂岩普遍受到不同程度的褶皱变形和剪切作用 ,并且与两侧岩层以剪切带接触。综合研究表明长坝、横现河混杂岩明显区别于沉积成因的滑塌堆积 ,具典型构造混杂岩的性质特点 。

The Changba and Hengxianhe melange distributed in Mianlue area are both composed of matrix and various blocks. The matrix is composed of sandstones and mudstones that underwent different metamorphism. The blocks in two melanges can be subdivided into local and exotic blocks, They are different in size, lithological composition and distributed disorderly in melange. The boundary of the two melanges with surrounding stratigraphic units are shear zones. That's distingushed tectonic melange from deformed conglomerates. The identification of Changba and Hengxianbe melanges is one of important evidences for the Mianlue suture zone.