湖北长阳半峡背斜岩层应变分析

利用核部Ｍ型小褶皱、层间小褶皱、方解石脉及劈理等地质标志体，对半峡背斜进行了系统的线应变测量；在此基础上，运用长短轴法，Ｆｒｇ法及Ｒｆ／Φ法对南津关组、分乡组鲕粒灰岩的鲕粒应变进行测量、统计与分析。应变分析结果表明：半峡背斜岩层发生过两次明显的变形。第一次在半峡背斜形成之前，岩层在成岩作用或构造作用下形成的变形。第二次是在半峡背斜形成过程中发生的变形，半峡背斜不同构造部位、不同岩性的应变值与褶皱弯滑作用形成的应变协调一致。

A STUDY ON THE STRAIN OF BANXIA ANTICLINE

With geological markings such as small M - type fold, interformational fold, calcite vein and cleavage, the linear strain of Banxia anticline was systematically measured. And through three statistical methods, the plane strains in ooidal limestone were measured, counted and analyzed. The results show that the strata in Banxia anticline have been deformed twice. The first deformation took pIace before the formation of Banxia anticline. The second deformation took pIace during the formation of Banxia anticline. And the strain at different localities of Banxia anticline was concordant with the strain which formed in buckle folding.