乌伦古坳陷东南部中生代早期断裂构造生长指数分析

发布时间：2018-01-25 18:11

本文关键词： 生长指数构造迁移乌伦古坳陷中生代　出处：《河南理工大学学报(自然科学版)》2017年01期 　论文类型：期刊论文

【摘要】：为确定乌伦古坳陷东南部中生代早期断裂构造的活动规律和控制因素,在确定同沉积逆断层引起的断展褶皱轴面和组成的基础上,对乌伦古坳陷东南部由红岩断阶带和陆梁隆起所夹持的三角区域内中生代早期断裂构造生长指数进行分析。在上三叠统白碱滩组(T_3b)沉积阶段,乌东断裂生长指数一般在1.5左右,红盆断裂多小于1.3,喀拉萨依断裂多小于1.2;下侏罗统八道湾组至中侏罗统西山窑组(J_1b-J_2x)沉积阶段,乌东断裂在下侏罗统八道湾组(J_1b)沉积时期具有最大的生长指数,红盆断裂在中侏罗统三工河组(J_1s)沉积时期具有最大的生长指数,喀拉萨依断裂在中侏罗统西山窑组(J_2x)沉积时期具有最大的生长指数。在断裂走向方向上,红盆和喀拉萨依断裂具有最南东端(或东端)生长指数较小,并接近于1,然后向北西(或西)方向生长指数逐渐增大,然后又逐渐减小至生长指数等于1的变化规律;乌伦古坳陷东南部乌东断裂、红盆断裂和喀拉萨依断裂在上三叠统白碱滩组(T_3b)沉积阶段和下侏罗统八道湾组至中侏罗统西山窑组(J_1b-J_2x)沉积阶段均具有从北东向南西方向的前展式迁移特征,说明当时的构造动力是从北东方向发起的。在断裂走向上生长指数的变化规律既与断裂构造的不同归属有关,又与不同方向断裂之间的距离有关。喀拉萨依断裂的生长指数沿走向表现出更大的变化特点,这与其他方向断裂构造的叠加所造成的活动性增强有关。
[Abstract]:In order to determine the active regularity and controlling factors of the early Mesozoic fault structures in the southeastern Wulungu depression, the axial plane and composition of the fault-spreading folds caused by the synsedimentary reverse faults are determined. The structural growth index of the early Mesozoic faults in the triangular region of the southeastern Wulungu depression, which is held by the Hongyan fault terrace and the Luliang uplift, is analyzed. The sedimentary stage of the Upper Triassic Baijiatan formation is T ~ 3b). The growth index of Wudong fault is about 1.5, the red basin fault is less than 1.3, and the Karasayi fault is less than 1.2. In the depositional stage of the lower Jurassic Badaowan formation to the Xishanyao formation of the Middle Jurassic Xishanyao formation, the Wudong fault has the largest growth index during the lower Jurassic Badaowan formation J1b) sedimentary period. The red basin fault has the largest growth index during the deposition period of the Sangonghe formation of the Middle Jurassic. The Karasayi fault has the largest growth index during the deposition period of the Xishanyao formation of the Middle Jurassic and the strike direction of the fault. The red basin and Karasayi faults have a smaller growth index of the southernmost eastern end (or the eastern end) and are close to 1, then the growth index increases gradually in the north west (or west) direction. Then it decreases to the law of growth index equal to 1. Wudong fault in southeastern Wulungu depression. Red basin fault and Karasayi fault in the Upper Triassic Baiyatan formation (T3b) sedimentary stage and the Lower Jurassic Badaowan formation to the Middle Jurassic Xishanyao formation J1b-J2x). The sedimentary stage has the characteristics of pre-spreading migration from NNE to NW. It shows that the tectonic dynamics at that time were initiated from the north to east direction. The variation of the growth index on the fault strike is related to the different attribution of the fault structure. It is also related to the distance between the faults in different directions. The growth index of the Karasayi fault shows a greater variation along the strike, which is related to the increase of activity caused by the stacking of the faults in other directions.
【作者单位】：河南理工大学资源环境学院;中原经济区煤层(页岩)气河南省协同创新中心;
【基金】：全国油气资源战略选区调查与评价项目(1211302108023-2)
【分类号】：P542.3
【正文快照】： *0引言乌伦古坳陷是准噶尔盆地东北部的一个一级构造单元,沉积有巨厚的上三叠统以来的中生界沉积盖层,暗示了影响乌伦古坳陷沉积和构造演化的主要断裂在中生代具有重要的活动性。揭示这些断裂的活动规律和控制因素不仅对于乌伦古坳陷的油气勘探,而且对整个准噶尔盆地的石油地

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