准噶尔盆地西北缘三期走滑构造及其油气意义

准噶尔盆地西北缘的红浅-车排子、克拉玛依-百口泉以及乌尔禾-夏子街断裂带是影响和控制油气成藏的关键要素之一，但目前对准噶尔盆地西北缘断裂带的属性与时限仍存在较大分歧。通过区域构造背景分析，以区域地质资料为基础，结合前人的研究成果，讨论准噶尔盆地西北缘的构造属性问题。研究发现，由于处于特殊的大地构造位置，西准噶尔地区在不同的演化阶段，以发育北东向展布的走滑构造为显著特征，主要存在3期：第一期是晚石炭世造成白碱滩和达拉布特蛇绿混杂岩带就位的左行走滑断裂带；第二期是晚二叠世—中晚三叠世之间，由于准噶尔地块和西准噶尔相对于成吉斯弧的反时针旋转，进而形成的克拉玛依-百口泉、乌尔禾-夏子街右行走滑逆冲带，它们伴生的构造圈闭，是油气成藏的关键；第三期是指形成于新生代的达拉布特左行走滑断裂，对盆地北缘有一定的改造，但是总体变形分布范围较窄，在实际分析中应当和中生代走滑构造注意区分。

Three-stage strike-slip fault systems at northwestern margin of Junggar Basin and their implications for hydrocarbon exploration

The Hongqian-Chepaizi,Karamay-Baikouquan,and Wuerhe-Xiazijiefaultzones faulted zones,developed at the northwestern margin of the Junggar Basin,are considered to be key controls on the development of hydrocarbon reservoirs in the area.However,the timing and span of the fault zones' evolution,and their characteristics are still under intensive debate.Our purpose here is to determine the structure attributes of the northwestern margin of Junggar Basin based on analysis of regional tectonic setting as well as previous studies.The result shows that West Junggar is dominated by NE-trending strike-slip fault systems caused by the Paleozoic-Cenozoic tectonic evolution of the basin.Three main stages of NE-trending strike-slip fault systems have been distinguished.The first stage is the Late Carboniferous sinistral strike slip fault belt that resulted in the emplacement of the Baijiantan and Darbut ophiolitic belts.The following second stage is the dextral strike-slip fault system that was expressed by the development of the Late Permian-Mid-late Triassic Karamay-Baikouquan and Wuerhe-Xiazijie dextral strike-slip fault belts.These two fault belts were resulted from the Late Permian-Triassic counterclockwise rotation of the Junggar Plate and the West Junggar relative to the western part of the Chingiz Range.The faulted noses,blocks and en echelon anticlines derived from the relevant thrust faulting and folding may account for the development of main structural traps in the West Junggar.The third stage is characterized by the development of the Cenozoic Darbut sinistral strike-slip fault,resulting in limited deformation confined in the north margin of the Basin.In field analyses,this younger imprint shall be distinguished from the Mesozoic strike-slip faults.