【作者】 朱卫平；

【导师】 王果胜；

【作者基本信息】 中国地质大学（北京） ， 构造地质学， 2007， 硕士

【摘要】 研究区位于华北板块北部陆缘增生带槽台界线附近,构造复杂。区内出露主要地层原白乃庙群的时代归属问题一直争议较大,主要原因是未找到古生物化石和合适的年龄依据。因此,笔者选择白音希勒地区作为自己的论文研究区。对该区构造特征及其演化的研究有助于工作区地层构造格架的建立和白乃庙群时代归属的确定。论文主要以野外工作为基础,分析了包尔汉图群的褶皱构造变形特征及区内其它构造特征,并结合区域资料建立研究区的构造演化史,最后探讨了白乃庙群的时代归属问题。并取得以下主要认识:1.包尔汉图群的褶皱构造经历了多期叠加变形作用,大致可分为三期即早期层内无根勾状褶皱;主期北西西紧闭褶皱和同斜褶皱;晚期南北向宽缓叠加褶皱。2.区内发育的徐尼乌苏断层,确认其断层面向南倾斜且是由南往北推覆的逆冲构造,推测其逆冲时间为晚侏罗世。3.研究区中部发育的韧性剪切带,与徐尼乌苏逆冲断层可能是同一构造体系的根带,属于较深构造层次。该带上出露基性岩块,可能代表地槽与地台界线通过的位置,并得到地球物理资料的验证。4.包尔汉图群一段发育软沉积变形,反映了包尔汉图群形成早期处于一种动荡的大陆边缘地壳抬升的拉张构造环境,可能受板块俯冲作用的的影响。5.研究区的构造演化可划分为六个阶段:(1)奥陶纪及以前-----陆缘裂解增生阶段;(2)晚泥盆世-晚二叠世——早期褶皱构造变形和板块碰撞阶段;(3)早三叠世-中三叠世——岩浆侵入及韧性剪切带形成阶段;(4)晚三叠世-晚侏罗世——主期褶皱和自南向北逆冲阶段;(5)晚侏罗世末-早白垩世——晚期褶皱变形阶段;(6)中白垩世-新近系——南西-北东向挤压及火山岩喷发阶段。同时研究区在中生代可能发生了一次造山作用,使得地壳抬升超过3.5km。6.原白乃庙群包括白乃庙组的含铜绿片岩(将底部的斜长角闪岩段删除)、徐尼乌苏组和西别河组,时代定于早寒武世-晚志留世;原白乃庙群三、四、五段置于白云鄂博群上部岩段,时代定于早奥陶世-早志留世。更多还原

【Abstract】 The study area is nearby the boundary of Geosyncline and plateform, lies in the epicontinental aggradational belt in the northern margin of the North China Plate, the structure is complex. Divergent views still exist as to the chronocorrelation of the Pre- Bainaimiao Group ,the majaor stratum of this area, the main reason is that the evidence of the Palaeobiological fossil and the appropriate age were not been found. Therefore, the author takes the Baiyixile area as his own research area. It is helpful to establish the strata-tectonic framework of work area and solve the chronochorizone of Bainaimiao Group through studying the structure characteristics and its evolution in this area.The research is mainly base on the field work, this paper analyzed the fold structure features of Baoerhantu Group and other structures in the area, and established the structure evolution history with the analysis of regional data, and also discussed the chronocorrelation of the Pre- Bainaimiao Group .The main comprehensions are as follow:1. The Baoerhantu Group has been undergone by several tectonizations. Based on the structural features. There are three types of the fold structure of Baoerhantu Group can be recognized: the rootless folding; NWW-SEE-face or near EW-face folds ; near S-N-face folds.2. Xuniwusu fault developed in area, whose fault tilting facing the south and is from pushing going against covering rushing structure, guessing its forming in late Jurassic.3. In the middle of the research area, the ductile shear zone was developed; it was possibly the identical structural system root belt with Xuniwusu fault, which belonged to the deeper tectonic level. Basic clod appears on this belt possibly represents the boundary of geosyncline and platform; it obtains the confirmation where the geophysics material results in.4. The Soft-sediment Deformational Structures exit in the first section of Baoerhantu Group, which had showed Baoerhantu Group formed in turbulent continental margin and the crustal uplifting and tesensional tectonic setting in the early time, possibly influenced by the seismic activity in the region.5. On the basis of the tectonic features, the tectonic evolution of the Baiyinxile region has been distinguished as the follow six stages: (1) epicontinental rifting and aggradational in the Preordovician; (2) the early fold structure deformation and the collision between the North China plate and the Siberia plate during the late Devonian to the late Permian; (3) the magmatic intrusion and the ductile shear zone forming during the early triassic to the middle Triassic; (4) the mail fold deformation and thrusting from the south to the during the late Triassic to the late Jurassic; (5) the later fold deformation during the late Jurassic to the early Cretaceous ;(6) the compression from southwest to northeast and the volcanic rock eruption during the middle Cretaceous to Neogene. In the Baiyinxile region, there may be an orogeny in the Mesozoic era, caused the lithosphere uplifting over 3.5km.6. The Pre-Bainaimiao Group consists of Bainaimiao Formation whose lithology is cupreous green-schists (amphibolite at the bottom is excluded), Xuniwusu Formation and Xibiehe Formation .The time is from early Cambrian to late Silurian. The third section to the fifth section of Pre-Bainaimiao Group should be setted on top of the Baiyunebo Group. The time of these three sections is from early Ordovician to early Silurian.更多还原