刘孜, 方维萱, 卜鹏, 唐志新, 曹经纬, 杜玉龙, 贾润幸. 新疆萨热克巴依盆地中—新生代构造变形特征及其找矿意义[J]. 地质通报, 2020, 39(11): 1858-1872.
    引用本文: 刘孜, 方维萱, 卜鹏, 唐志新, 曹经纬, 杜玉龙, 贾润幸. 新疆萨热克巴依盆地中—新生代构造变形特征及其找矿意义[J]. 地质通报, 2020, 39(11): 1858-1872.
    LIU Zi, FANG Weixuan, BU Peng, TANG Zhixin, CAO Jingwei, DU Yulong, JIA Runxing. Characteristics of Mesozoic-Cenozoic structural deformation in the Sarekebayi basin, Xinjiang, and its prospecting significance[J]. Geological Bulletin of China, 2020, 39(11): 1858-1872.
    Citation: LIU Zi, FANG Weixuan, BU Peng, TANG Zhixin, CAO Jingwei, DU Yulong, JIA Runxing. Characteristics of Mesozoic-Cenozoic structural deformation in the Sarekebayi basin, Xinjiang, and its prospecting significance[J]. Geological Bulletin of China, 2020, 39(11): 1858-1872.

    新疆萨热克巴依盆地中—新生代构造变形特征及其找矿意义

    Characteristics of Mesozoic-Cenozoic structural deformation in the Sarekebayi basin, Xinjiang, and its prospecting significance

    • 摘要: 基于野外地质调查和构造测量工作,系统解析了萨热克巴依盆地边缘及内部的断裂-褶皱构造的几何学、运动学和动力学特征,重建盆地演化过程,探究控矿规律,促进深部找矿预测。研究表明:①盆地经历了早—中侏罗世拉分盆地发育、中侏罗世末—晚侏罗世初构造隆升剥蚀、晚侏罗世沉降、晚侏罗世末—早白垩世初构造隆升剥蚀、早白垩世早期沉降、早白垩世中晚期—古近纪隆升剥蚀、中新世压剪性构造变形、上新世—第四纪挤压收缩变形8个构造演化阶段,其中前6个阶段表现为沉降-抬升垂直运动,后2个阶段(新近纪—第四纪)表现为挤压收缩水平运动。②盆地叠加有2期挤压收缩构造变形,早期形成规模不大的北(西)西—南(东)东向宽缓向背斜构造;后期形成一系列北东东—南西西向褶皱-断层构造,表现为盆地边缘南北边界断层(ST、NT)朝盆地内对冲,导致在断层附近下盘形成的伴生褶皱趋于紧闭,而在远离断层的复式向斜(Sf)核部的次级褶皱多呈开阔宽缓状。③盆地构造控矿可以分为2个阶段:在成矿期阶段(早侏罗世—早白垩世),由盆地沉降、隆升形成的正断层、反转断层及伴生断裂-节理-裂隙为重要的导矿构造,上侏罗统库孜贡苏组砂砾岩层内发育的顺层裂隙为萨热克铜矿重要的储矿构造,导矿构造与储矿构造交汇部位成为矿液富集成矿的最佳部位;在成矿后阶段,由后期(上新世—第四纪)北北西—南南东向区域挤压应力作用形成的收缩构造变形,明显控制了矿体的空间展布形态,造成矿体卷入褶皱变形,以及被断裂-裂隙带切穿或错断。④在30勘探线以东一带,南矿带深部隐伏的库孜贡苏组上段(J3k2)为铜(锌)矿(化)体的有利赋存层位,具有良好的找矿前景。

       

      Abstract: Based on field geological survey and structural geological survey, the authors systematically analyzed the geometry, kinematics and dynamics characteristics of the faults and folds which are at the edge and in the interior of the Sarekebayi basin, and reconstructed the evolution process of the basin so as to explore the ore-controlling rules and promote prospecting prediction at the depth. The results are as follows: ① The basin has experienced eight stages of structural evolution. i.e., the development of pull-apart basin (J1-J2), the tectonic uplift and denudation (J2-J3), the subsidence (J3), the tectonic uplift and denudation (J3-K1), the subsidence (K1), the tectonic uplift and denudation (K1-E), the compressive-shear structural deformation (N1), and the compressive structural deformation (N2-Q). There existed vertical movement of subsidence and uplift in the first six stages (J1-E) and horizontal movement of compression in the last two stages (N-Q). ② There are two stages of superimposed compressive structural deformation in the basin. In the early stage, the N(W)W-S(E)E-trending open fold with small scale was formed. In the late stage, a series of NEE-SWW trending folds and faults were formed, which showed that southern boundary fault and northern boundary fault on the margin of the basin were thrusting towards the basin, and the associated folds formed in the footwall near the faults (NF, SF) tended to be closed tightly, while the secondary folds in the core of compound syncline (Sf) far away from the faults (NF, SF) were mostly open and wide. ③ Structural ore-control of the basin can be divided into two stages. In the mineralization stage (J1-K1), the normal fault, reverse fault and associated fault-joint-crack formed by basin subsidence and uplift were the important ore-passing structures, the bedding fissures developed in the sandy conglomerate layer of Kuzigongsu Formation of Upper Jurassic were the important ore-storage structures, and the intersectional parts of ore-passing structures and ore storage structures were the best location for ore fluid enrichment and mineralization. In the post mineralization stage, the compressive structural deformation formed by the late (N2-Q) NNW-SSE regional compression obviously controlled the spatial distribution of the orebody, resulting in the involvement of the orebody in the fold deformation as well as it being cut through or staggered by the fault-crack zone. ④ In the east zone of the 30th prospecting line, Cu or Zn orebodies or mineralization bodies probably occurred in the second lithologic section of Kuzigongsu Formation, which was concealed in the depth of southern ore zone, and it has great potential for prospecting.

       

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