留山、马市坪盆地构造特征及其形成演化

TECTONIC CHARACTERISTICS AND EVOLUTION OF LIUSHAN AND MASHIPING BASINS

王定一 王立宝

Wang Dingyi Wang Libao

留山、马市坪盆地是秦岭-大别构造带北秦岭褶皱带上两个中生代沉积盆地。前者为晚三叠世坳陷型湖盆,后者是晚侏罗-早白垩世早期断陷型湖盆。由于燕山中晚期运动自北而南的逆冲推覆作用的改造,使二者均具压扭型盆地面貌。它们是华北板块与扬子板块于中生代作陆-陆碰撞过程中不同阶段的产物。

Liushan and Mashiping Basins are located in Western Henan Frovince,North Qinling Belt.Their basements are Precambrian-Lower Paleozoie rocks,and the covering series are Upper Triassic,Upper Jurassic-Lower Cretaceous respectively.Liushan Basin is a complex syncline composed of two syncline and an anticline belts.The major faults are NWW-strike thrusts which do not control the distribution of strata.A complex syncline was also identified in Mashiping Basin.Its axis trend varied from NWW to NE-NNE direction,and was cut by boundary fault of the basin;its eastern section was almost completely destroyed by a southward thrust.The Meso-Cenozoic tec-tonic evolution can be divided into seven stages:regional uplift period(ANT);depression period after regional uplift(T);compresso-uplift period(J);fault-subsidence period in tenso-shear condition(J+K);overthrust-nappe period(K);extensional fault-subsidence period(K+E?)and regional compresso-uplift period(N+Q).The prototype of Liushan Basin was a compressional basin,and that of Mashiping was an extensional one.Both of them were reformed by large scale southward overthrust-wrenching during late Yenshanian movement and became compresso-shear basins during the continent-continental collision between Yangtze and North China Plates.

10.11743/ogg19930107