柴西地区柴中断裂的分布特征——来自地球物理的证据

The Distribution Characteristics of Fracture in Western Qaidam Basin——from Geophysical Evidence

柴达木盆地中部横亘着一条近东西向的隐伏断裂——柴中断裂,大致沿甘森—德令哈一线展布,对盆地基底与后期演化起着显著的控制作用,前人对此认识比较统一。受复杂构造背景和巨厚的中、新生界覆盖影响,柴中断裂的分布特征仍未明确。通过对最新取得的区域重力及以往的地震、航磁数据处理研究,笔者发现柴西地区不存在东西走向的大断裂,而新推断的北西西向阿拉尔—甘森断裂从性质、对盆地基底的控制等方面看应是柴中断裂的一部分。这一新的发现有可能对柴达木盆地的形成、演化和油气富集研究产生一定的影响。

The central part of Qaidam basin is covered with a east-west concealed fault - middle fracture of Qaidam basin roughly along a line distribution from GanSen to Delingha,which has a significant control effect on basin basement and late evolution. Due to the complex tectonic back- ground and the huge thickness of Meso Cenozoic cover,the distribution characteristics 〇 ￡ the mid- die Qaidam fault are not clear. Based on the latest regional gravity and previous study of seismic, aeromagnetic data processing, the east-west fault in western qaidam basin doesn＇t exist, and the newly inferred north-west fault from Aral to Gansen should be a part of the fracture in the mid-dle part of Qaidam Basin from the aspect of properties and control of the basin basement. A new study may have an impact on the formation and evolution of the Qaidam basin and the research of oil and gas enrichment.