塔里木盆地色力布亚断裂带变形特征和演化史

色力布亚断裂带为塔里木盆地麦盖提斜坡与巴楚隆起两个构造单元间的边界断裂带,其构造样式和构造演化与巴楚地区及柯坪地区的形成演化具有一定的相关性。结合最新的钻井、测井以及二维地震资料解释,提出了原来的色力布亚断裂带可分为两个断裂带。剖面上主要表现为基底卷入高角度逆冲挤压断裂样式和正花状走滑断裂样式,与柯坪隆起上的皮羌断裂早期共同构成了皮羌-色力布亚断裂带;而亚松迪断裂属于叠加型逆冲断裂,剖面上表现为浅层倾向南西的盖层滑脱型逆冲断层和深层倾向北东的基底卷入型逆冲断层的相互叠加。平面上呈现出分段性,主要分为北段和南段。断裂带整体表现为深层高角度逆冲断裂和正花状构造样式,而南段向上切入新近系和第四系,且新近系和第四系发生微弱的褶皱变形,并且伴有局部的沿古近系的盖层滑脱。结合巴楚地区和柯坪地区的区域演化,认为色力布亚断裂带的构造演化主要经历了加里东晚期断裂形成阶段、海西晚期(二叠纪晚期)、喜马拉雅早-中期(古近纪—中新世)及喜马拉雅晚期(上新世—第四纪)4个阶段。

Deformation and tectonic evolution of the Selibuya fault zone in Tarim Basin

The Selibuya fault zone separates the Maigaiti Slop and the Bach Uplift in the Tarim Basin,and its structural styles and tectonic evolution Fault zoneis related to some extent with the evolution of Bachu and Keping.Referring to the latest data of drilling,logging and 2D-seismic interpretation,we proposed that the previous defined Selibuya Fault zone be divided into two fault zones including Selibuya and Yasongdi.On sectional view,the former mainly features in basement-involved high-angle thrust extrusion and consists,together with the early Piqiang fault on Keping uplift,Piqiang-Selibuya fault zone,while the later is a superimposed thrust fault resulted from the superimposition of the SW-dipping shallow thrust fault of cap rock slipping type and the NE-dipping deep basement-involved thrust fault.On plane view,the Selibuya fault zone recognized in this paper can be divided into a north segment and a south segment.The whole Selibuya fault zone are characterized by high-angle deep thrust and positive flower structures.The south segment of this fault zone cuts upward into the Neogene and Quaternary,leading to the weak folding of the Neogene and Quaternary and the associated local decollement along the Paleogene cap rock.Combined with the evolution of Selibuya and the regional evolution of Bachu and Keping,it is believed that Selibuya fault zone went through mainly four main stages:the Late Caledonian,the Late Hercynian,the Early-Middle Hymalayan,and Late Hymalayan.