准噶尔盆地西北缘构造变换带及其对中生界沉积的控制

Structural Transform Zone and Its Control of Mesozoic Deposits in Northwestern Margin of Junggar Basin

准噶尔盆地西北缘前陆冲断带可以划分为西南部的红车断裂带,中部的克百断裂带和东北部的乌夏断裂带,在相邻断裂带之间发育两个具有调节断裂带间位移和应变传递作用的变换带。变换带对研究区中生界沉积的控制体现在:与断裂带主体比较而言,变换带部位发育的沉积类型更加丰富;砂岩粒度较粗,单层厚度较大,横向上分布稳定,推进距离远,砂体往往沿着传递斜坡、变换断层走向富集,可以形成规模巨大的优质储集层。

The foreland thrust zone in northwestern margin of Junggar basin could be divided into three fault zones： Hongshanzui-Chepaizi fault zone in the southwest, Karamay-Baikouquan fault zone in the central part and Wuerhe-Xiazijie fault zone in the northeast. There are two transform zones between neighboring fault zones which have the function of adjusting displacement and transferring deformation. The effects of the transform zones on Mesozoic sediments assume that compared with major fault zones, the sedimentary types developed in the transform zones are more abundant, characterized by more coarse sand grains, larger single-layer thickness, stable lateral distribution and far prograding distance. Hence, the sand bodies tend to enrichment along transfer slopes and transform faults, which could form large scale premium reservoirs.