盆地腹地隆起带内高角度变形带构造样式新解

在总结岩石变形理论和砂箱模拟实验研究进展基础上, 通过构造物理模拟实验和地震剖面的地质解释, 对塔里木盆地腹地巴楚隆起区的高角度变形带的构造属性进行了全新的分析和解释, 认为形成隆起的部分高角度构造为大型膝褶带。巴楚隆起内的膝褶带在地震剖面上表现为低反射、低信噪比, 且地震信息模糊带具有一定的宽度, 这是由于膝褶带内地层发生陡倾斜所致。根据最大有效力矩准则, 一定宽度的低反射带、近于平行的低反射带边界、低反射带与地层呈高角度及其钝角角分线对着挤压方向的几何学特征均表明塔里木盆地腹地巴楚隆起带内部存在膝褶带构造。

A New Insight into the High-Angle Deformation Bands in the Central Region of Basin

Based on the review of rock mechanics theory and recent simulated experiment results,as well as sand-box simulation and seismic profile interpretation,the new interpretation explains that some uplifts/folds with high-angle deformation bands in the Tarim basin to be composed of folds flanked by megascopic-scale kink bands.The low-reflectivity,low-signal-tonoise zones seen in seismic profiles across the Bachu fold belt are poorly imaged sections of the folds that result from steeply dipping bedding in the kink bands.These fuzzy seismic zones show a substantial width in the seismic profile.According to the Maximum Effective of Moment Criterion(MEMC),the substantial width of these low reflectivity zones,their subparallel edges in cross section,and their orientation at a high angle to layering,as well as their organized spacing and the obtuse angle in the contraction direction of conjugate kink-bands,indicate that there are kink-band structures and kink-related folds in the Bachu uplift.