四川盆地威远背斜的形成时代及形成机制

FORMATION TIME AND FORMATION MECHANISM OF THE WEIYUAN ANTICLINE IN SICHUAN BASIN

四川盆地威远背斜形成于喜马拉雅期。喜马拉雅运动 幕 (渐新世末 ) ,NW- SE向挤压力使中生代乐山 -龙女寺下古生界古隆起南东坡上犍为 -安岳基底断层反转活动形成断层传播型的老龙坝 -威远背斜。喜马拉雅运动 ～ 幕 (早更新世始与末 ) ,SW- NE向挤压力使NW向的沐川 -荥经基底断层和雅安 -宜宾基底断层反转活动将上述背斜截成老龙坝背斜和威远背斜。从构造观点看 ,乐山

The Weiyuan anticline formed in Cenozoic. At the end of Oligocene, NW SE direction compression made the Qianwei Anyue basement fault in the southeast slope of the Leshan Longnusi paleo anticline move inversely so as to form the Laolongba Weiyuan fault propagation type anticline. At the beginning and the end of Pleistocene, SW NE direction compression made the Muchuan Yongjin and Yaan Yibin basement fault move inversely to cut the above anticline into the Laolongba anticline and Weiyuan anticline. From the point of view of tectonic trap, prospecting for gas should aim at the anticline nearby in which moderate faults develop.