STRUCTURAL CHARACTERISTICS AND EXPLORATION POTENTIAL OF THE THRUST BLOCK IN LONGMENSHAN

The Longmenshan structural zone is divided into Maowen ductile shear zone,Longmenshan imbricated thrust structural zone and Longmenshan thrust nappe structural zone from west to east according to its deformation characteristics.And the Longmenshan thrust nappe structural zone can be further divi-ded into two subzones,foremountain zone and concealed zone where is idea position for hyarocarbon accumulation.As to the foremountain zone,the relativehy stable structure and good closing and capping capability are the master elements for hydrocarbon accumulation.And for the mountain front concealed zone,the master elements are the polymerzation of old and present structure,relatively active structure and where fissures develop.Thus it is predicted that,the most favorable exploration area for natural gas is the Cifengchang high part in the hanging wall of concealed fault belt in Guankou-Shuikouchang,the Gaojia-chang,Shuikouchang,Youzhatuo and Shibantan structural zones and Pingluoba in the footwall,as well as Qiongxi,Dayi and Yazibe anticlines.