准噶尔盆地石英滩凸起正反转构造及成因机制

构造反转是沉积盆地构造演化的关键基础过程之一,其形成演化受到多因素的控制,对研究油气圈闭的形成具有重要价值。陆梁隆起是准噶尔地区石炭纪多岛弧构造体系的重要组成之一,石炭纪裂陷背景下发育的断陷结构在二叠纪以来经历了多期次构造作用的叠加和改造。本文针对陆梁隆起北部石英滩凸起开展精细构造建模,依据不整合面、生长地层约束构造演化时空格架,正演、反演相结合建立构造演化模式。研究结果表明：1）石英滩凸起反转构造受控于3条主要断裂,石西断裂（Fsx）、石英滩南断裂（Fssyt）、石英滩北断裂（Fnsyt）,控制石西凹陷—石英滩凸起石炭系非对称地堑结构。2）石英滩凸起及邻区构造演化历经早石炭世断陷伸展期,早-晚石炭世之间弱断陷—坳陷过渡期,晚石炭世伸展—挤压转换期,早二叠世弱伸展期,中二叠世—中三叠世挤压以及中、晚侏罗世—早白垩世挤压6期重要构造事件,其中反转构造活跃于晚石炭世末期和中-晚侏罗世—早白垩世。3）正、反演结果表明石西断裂（Fsx）、石英滩南断裂（Fssyt）控制石炭纪断陷结构,后期的改造作用主要激活了石英滩南断裂（Fssyt）,断陷的发育与反转构造可能受控于多期次构造变形中最大构造主应力的优势方向转变。

Positive inversion structure and formation mechanism of Shiyingtan Uplift in Junggar Basin

Inversion structure is one of the key basic processes of tectonic evolution in sedimentary basins. Its formation and evolution are controlled by many factors, which is of great value to study the formation of oil and gas traps. The Luliang Uplift is one of the important components of the Carboniferous island arc tectonic system in the Junggar area. The rift structure developed in the Carboniferous rift background has undergone multi-stage tectonic superposition and transformation since the Permian. In this paper, the fine structural modeling is carried out for the Shiyingtan Uplift in the north of Luliang Uplift. According to the time-space framework of unconformity surface and growth strata, the structural evolution model is established by combining forward modeling and inversion. The results show that: 1) The inverted structure of Shiyingtan Uplift is controlled by three main faults: Shixi fault(Fsx), south Shiyingtan fault (Fssyt) and north Shiyingtan fault(Fnsyt). 2) The tectonic evolution of the Shiyingtan Uplift and its adjacent areas has gone through six important tectonic events: the Early Carboniferous fault extension period, the Early-Late Carboniferous weak fault-depression transition period, the Late Carboniferous extension-compression conversion period, the Early Permian weak extension period, the Middle Permian-Middle Triassic compression and the Middle-Late Jurassic-Early Cretaceous compression. The inversion structure is active in the Late Carboniferous and the Middle-Late Jurassic-Early Cretaceous. 3) The results of forward and inversion show that Shixi fault(Fsx) and south Shiyingtan fault(Fssyt) control the structure of Carboniferous fault depression, and the later reformation mainly activates south Shiyingtan fault (Fssyt). The development and inversion structure of fault depression may be controlled by the maximum structure in multi-stage tectonic deformation.