巴基斯坦盐岭东部薄皮构造特征及演化过程浅析  

Characteristics and Its Evolution of Thin-Skinned Deformation in Eastern Salt Range,Pakistan

作　　者：杜芳鹏 吕录仕[3] 杨创[3] 李聪聪[3] 谭富荣[3] Du Fangpeng;Lu Lushi;Yang Chuang;Li Congcong;Tan Furong(State Key Laboratory for Continental Dynamics;3. Department of Geology, Northwest University, Xi＇an 710069, Chin;2. Aerophotogrammetry ＆ Remote Sensing Bureau, China National Administration of Coal Geology, Xi＇an 710199, Chin)

机构地区：[1]西北大学大陆动力学国家重点实验室,西安710069 [2]西北大学地质学系,西安710069 [3]中国煤炭地质总局航测遥感局,西安710199

出　　处：《地质科技情报》2018年第3期51-58,共8页Geological Science and Technology Information

摘　　要：薄皮构造是前陆盆地向前陆冲断带转化过程中常出现的一种构造样式,不仅是造山带研究的重要内容,对于前陆盆地、破裂前陆盆地以及前陆冲断带油气的富集也有着重要的影响。巴基斯坦盐岭位于印度板块北缘,是由沉积盖层沿前寒武系盐岭组盐岩层发生韧性滑脱、向南逆冲而形成的,属于典型的薄皮构造。盐岭及周邻的这一变形过程发生在第四纪,较好地保留了内部的次级构造变形。为了厘清薄皮构造内部的次级构造特征及变形过程,在盐岭东部以高精度SPOT遥感影像为指导,结合野外工作,对各级断层进行了细致调查,详细描述记录了其特征。经综合对比分析认为,盐岭东部断层(组合)类型主要包括背斜顶部局部正断层组、高角度逆断层及大型走滑断层,走滑断层周边偶见小型低角度逆冲推覆构造。这些断层的演化过程大致为:第四纪以来,在印度-欧亚板块强烈碰撞背景下,印度板块北部南北向挤压应力场导致了薄皮构造的形成;其后,南北向挤压使得薄皮构造整体发生波浪式连续褶皱,宽缓褶皱顶部形成了局部拉张应力,导致倾向相反的局部正断层组的形成,随着挤压的持续,部分正断层被迫发生反转,形成高角度逆断层,随着挤压进一步加剧,形成了北西向、北东向走滑断层,切割了南北向构造线,形成盐岭东部现今典型的"倒三角形"地貌。Salt Range in Pakistan is built up by sedimentary cover thrusting southward along the salt layer in the formation,and therefore,the whole Salt Range is a typical thin-skinned deformation.To clarify the deformation process of secondary structures in thin-skinned,we investigated and recorded the main faults in its eastern Salt Range.After mutidisciplinary analysis,we find out that types of faults in eastern Salt Range include normal fault,high angle abnormal fault and strike slip fault.The process of these faults could be thatunder the north to south crushing stress,the thin-skinned layers folded gradually and a partly tensional environment formed at the top of anticlines,causing the creation of these garben like normal faults.With the continuing pressing,some normal faults reversed into high angle abnormal faults.Finally,the northwestward and northeastward strike slip faults were formed under the intense press.These faults cut eastwest lineament,forming the inverted striangle surface features.

关 键 词：盐岭东部 薄皮构造 断层 印度板块北缘 遥感影像 第四纪 

分 类 号：P546[天文地球—构造地质学]