构造综合分析法判定瓦乌斯矿区电法推断的断层

Analysis and judgment of the faults inferred by resistivity method in Wawusi mining area

瓦乌斯矿区(盆地)是一个NW走向、南北均为断层边界的断陷含煤盆地,通过电法工作,发现该矿区煤层露头附近视电阻率等值线密集,推断存在走向断层DF2,但该断层究竟存在与否?产状如何?争议很大。文章基于岩体变形破坏的摩尔强度原理,应用节理应力场分析、赤平投影和断裂共生组合的构造分析方法,判断DF2断层是矿区断裂共生组合中第2序次断裂中的一支,并确定了该断层的产状,结合DF2附近的岩层厚度及变形等特征综合判定了DF2断层的存在。该研究结果对中新生代断陷含煤盆地的构造分析和该矿区煤炭普查工作有积极的指导意义。

Wawusi mining area (coal-bearing basin) is a faulted depressed coal-bearing basin of NW strike with faults as boundary in both the south and the north. By resistivity method, we discovered that the contour line of apparent resistivity is the densest around the outcrops of coal seams in the mining area, and we inferred the direc-tional fault (DF2). However, two questions are very controversial: whether the fault exists, and how the occurrence of the fault is. In this paper based on Mohr strength theory of rock mass deformation and failure, we made use of joint stress field analysis, hemispherical projection method and fault assemblage analysis to infer that the fault(DF2) is a part of the second fault, and determined the occurrence of the fault (DF2). Also, we took advantage of thickness of strum and deformation features and so on around the fault (DF2) to judge the existence of the fault (DF2). The result has a positive guiding significance for structural analysis in coal-bearing faulted basin of middle Cenozoic and the general coal reconnaissance in the mining area.