伊通盆地新近纪差异构造反转与油气成藏

Neogene differential structural inversion and hydrocarbon accumulation in the Yitong Basin, East China

结合最新的地震、钻井等资料，系统研究伊通盆地新近纪反转构造的差异改造特征、成因演化、变形规律及动力学背景，分析差异构造反转与油气成藏的关系。伊通盆地西北缘反转构造以右旋走滑冲断为主，可划分为高隆翻转冲断型、中隆斜列冲断型和低隆破裂冲断型，形成沿盆地西北缘平行展布的宽约2～4km的断褶带，油气成藏条件良好；而在盆地东南缘，反转构造则以相对较弱的右旋压扭和隆升掀斜为主，且在尖山、万昌、搜登等构造带顶部还发育了拱张性断裂，对早期油气藏起破坏作用。反转构造成因主要为太平洋板块向西俯冲产生弧后扩张而使中国东北大陆遭受挤压隆升，同时还受印度板块与欧亚板块碰撞所产生的远程挤压效应影响，此外还与盆缘隆起的发育位置和隆升强度密切相关。

Based on the latest seismic and drilling data, this paper analyzes the differential transformation features, evolution/ deformation rules and kinetic background of the Neogene inversion structures in the Yitong basin, East China aiming to find the relation of differential structure inversion and hydrocarbon accumulation. At the northwestern edge of the basin, inversion structures are dominated by right-lateral strike-slip thrusts, which can be divided into three types： high-swelling overturn thrust, moderate-swelling echelon thrust and low-swelling rupture thrust - all of them formed a fault-fold belt 2 to 4 km wide along the northwestern, providing good conditions for hydrocarbon accumulation. At the southeastern edge, inversion structures are mainly composed of right-lateral compresso-shear and uplifting tilts, and also arch-tension faults at the tops of Jianshan, Wanchang, Soudeng and other structural belts, which destructed the pre-existed reservoirs. These structures originated as a result of the compression and uplifting of the northeastern China continent which occurred due to the back-arc spreading after the westward subduction of the Pacific plate, and also the long-distance compression caused by the collision between the Indian plate and the Eurasian plate. In addition, their origin is related to the position and intensity of uplifts at the edges of the Yitong basin.