四川前陆褶皱-冲断带构造样式与特征

STRUCTURAL STYLES AND CHARACTERISTICS OF FOLD-THRUST BELTS IN SICHUAN FORELAND BASIN

四川前陆褶皱-冲断带的递进冲断推覆控制了四川前陆盆地内主要构造样式的展布和发育，平面上可分为：（1）川东南隔挡式褶皱变形；（2）川中隆起低级背斜构造区；（3）川西及川东北低陡褶皱－低平格皱区，变形具有平面上的分带性。纵向上变形具有层次性，可划分为深层次、中层次和浅层次，因而呈“三明治”式结构。主要构造样式有：基底冲断推覆构造、叠瓦冲断系、飞来峰构造、双重构造、背冲隆起、三角构造带、断展褶皱、断弯褶皱及平缓褶皱。

The progressive thrusting and napping of Sichuan fold-thrust belts controlled the distribution and development of the main structural styles in the Sichuan foreland basin. In plane it can be divided into (1) ejective folded deformation belt in Chuandongnan area; (2) low and gentle anticlinal structural area in Chuanzhong uplift;and (3) low and steep-low and gentle folded belt of Chuanxibei and Chuandongbei. While it shows a zonality in plane, vertically the structural deformation appears in different levels, which can then be divided into (1 ) deepseated level; (2) middle-seated level; and (3) upper-seated level. On the whole, it is in a sandwich-like structure. The main structural types consist of basement thrust and nappe, imbricate thrust system, klippe, duplex,pop-up, triangle zone, fault-propagation fault-bend and gentle fold, etc.