Abstract:

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(ANT₃);depression period after regional uplift(T₃);compresso-uplift period(J₁₊₂);fault-subsidence period in tenso-shear condition(J₃+K₁¹);overthrust-nappe period(K₁²);extensional fault-subsidence period(K₂+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.