齐姆根-桑株河地区构造特征及演化

齐姆根-桑株河地区可划分出铁克力克断隆和塔西南坳陷两个二级构造单元,塔西南坳陷可进一步划分出齐姆根凸起、克孜勒塔克凹陷、叶城-和田凹陷、铁克力克北缘斜坡等4个三级构造单元.主要构造样式为逆冲推覆构造,有海西末与喜山晚期两次大规模逆冲推覆,沿推覆向可划分出根带、中带、前锋带及外缘带.与其相配套的是自南向北的高陡背斜带、中背斜带和低背斜带等3排背斜构造.克孜勒塔克凹陷与叶城-和田凹陷分界断裂为20号断裂,它是一条自古生代以来长期发展的区域性大断裂,控制了南北两侧沉积和构造发展.研究区经历了基底形成、克拉通边缘裂陷盆地、克拉通内挤压绕曲盆地、克拉通内坳陷盆地、前陆盆地及统一内陆盆地等6个发展演化阶段.

STRUCTURES OF QIMUGEN-SANGZHUHE AREA

Two second-order structural units are divided in Qimugen-Sangzhuhe area, i.e., Tiekelike fault uplift and southwestern Tarim depression. Four third-order structural units are further divided in southwestern Tarim depression, including Qimugen uplift, Keziletag depression, Yecheng-Hotan depression and Tiekelike northern margin slope. The thrust-nappe structures comprise the major structural style. Two large ones formed during the end of Hercynian stage and end of Himalayan stage. Root zone, median zone, frontal zone and outer zone are further differentiated along the thrust direction of nappe. Associated with thrust-nappe structures are, from south to north, Tanmu-Qiketashi-Pusha-Yuliqun- Sangzhu steep anticline zone, Tongyouluke-Yiliyasi-Kaokuya-Artashi-Qipan-Kekeya intermediate anticline zone and Guman-Heshitake low anticline zone. The boundary fault No.20 separating Keziletage depression and Yecheng-Hotan depression is a regional-scale one initiated from the Paleozoic, which controls sedimentation on both sides. The study area underwent 6 stages of development, from basement, rift-depression basin at margins of craton, intra-craton compressional basin, intra-craton depression basin, foreland basin to unified inland basin.