库车前陆盆地构造特征及缩短量研究──以BC95-230剖面为例

STUDY ON STRUCTURAL CHARACTERISTICS AND AMOUNT OF CROSS SECTION SHORTENING IN KUQA FORELAND BASIN: TAKING BC95 230 PROFILE AS AN EXAMPLE

库车坳陷是一种新型的前陆盆地，其构造样式以类型Ⅱ三角带为特征。复杂构造区的层面在二维平面内可看作为一条曲线，从而可运用分形几何学方法由分数维来定量描述。运用平衡剖面技术和分形方法，以ＢＣ９５－２３０ 剖面为例，进行了缩短量和剖面应变计算。分析结果表明，Ｎ１ 底界曲面的分维值为１．０４９１，缩短量达３５．２６７ ｋｍ ，表现出５０．０５％ 的应变。由于受层间滑动等多种地质因素的影响，平衡剖面技术计算结果存在较大误差。因此，要正确平衡地质剖面。

The Kuqa depression is a new type of foreland basin, and its structural styles are characterized by Type Ⅱ triangle zones. A bedded plane of a complicated structural region can be regarded as a curve at two dimensional plane. By using fractal geometry, it can be described by fractal dimension. Through utilization of the balanced cross section technique and fractal method, and taking BC95 230 profile as an example, the amount of shorting and the strain distribution of cross section are calculated. The analytic results indicates that the bedded plane of N 1 has a D =1.0491 and 35.267 km of shortening and 50.05% strain. Because of affection of many geological factors including interlayer gliding, the calculated results by the balanced cross section technique have certain errors. So proper balancing geological cross section needs analysing the strain at small scales .