西昆仑-塔西南坳陷晚古生代以来的沉积构造演化

自柯克亚深层油气勘探取得突破以来,塔西南坳陷一直受到各类地质学家的广泛关注,有关该盆地的形成和演化历史及其油气资源评价近年来更是成为人们的研究热点.本文在总结前人资料的基础上,探讨塔西南和西昆仑地区自晚古生代以来所经历的构造及沉积格架的演变过程,对塔西南坳陷性质及其演化阶段划分所存在的争议进行了归纳,分析了塔西南-西昆仑这一盆山体系形成和演化中的构造变形和沉积记录.总体来说,根据现有沉积和构造变形资料,中生代之前西昆仑和塔西南坳陷分别处于同一构造背景下的不同沉积单元;二者之间盆山体系的形成主要自晚侏罗世-早白垩世,中-上新世是造盆造山作用机制发生重大转折的时期,或者说早更新世末的构造运动基本上奠定了西昆仑.塔里木盆地南缘现今的盆-山构造格架.

Sedimentary tectonic evolution of the southwestern Tarim Basin and west Kunlun orogen since Late Paleozoic

After the finding of the deep buried oil in Kekeya in 1970' s, the west Tarim depression has become one of the most attractive area in Tarim Basin, which has been extensively studied by geologists around the world, and the formation and evolution of this basin and its oil-gas evaluation are becoming the hottest research subjects. Based on different kinds of data from lithological, sedimentary and structural geology in this area, sedimentary tectonic evolutionary history of the west Kunlun orogenic belt and Tarim Basin system were reviewed. Generally, according to current data from sedimentary strata and structural deformations in west Kunlun and southwestern depression of Tarim Basin, the coupled orogenesis and basin system was formed during Late Jurassic to Early Cretaceous, while the geodynamic change from basin-formation to orogen-formation happened during Middle to Late Pliocene, i. e. , the current framework of this region was built by the Early Pleistocene tectonic movements due to the continuous subduction of the Indian plate underneath the Eurasian plate.