Tectonic Landform of Quaternary Lakes and Its Implications for Deformation in the Northern Qinghai‐Tibet Plateau   总被引：1，自引：1，他引：0  

WANG An  WANG Guocan  LI Dewei  XIE Defan  LIU Demin 《《地质学报》英文版》2009,83(1):121-129

The Hohxil region in the northern Qinghai-Tibet Plateau is occupied by numerous plateau lakes, which have long been inferred as being tectonic products. However, so far little evidence has been found to support this tentative inference. Field survey and morphotectonic analysis of TM satellite images in the eastern segment of the Hohxil region revealed that Kusai Lake and Yelusu Lake are S-shaped pull-apart basins, which were dominated by left strike-slip master faults trending WNW–ESE. The pull-apart distances of the two lakes are analyzed to be <15-20 km and 15 km respectively. Based on studies of the faulting rate, the initiation ages of the pull-apart basins are suggested to be approximately in the Early Pleistocene. The pull-apart basin tectonics is further regarded as a common mechanism for the widely distributed large lake basins in the northern Qinghai-Tibet Plateau. Regional distribution of these pull-apart basins and their substantial intra-block slip suggest that a sinistral shear stress, which is independent of the distinguished strike-slip faults, has been imposed on across the northern Qinghai-Tibet Plateau. Thus, the intra-block slip may be an important expression of the eastward extrusion of the Plateau crustal material in accommodating the ongoing continent–continent convergence between India and Eurasia. The revelation of pull-apart tectonics within the Plateau hinterland provides field evidence and a possible style of deformation for the newly proposed continuous deformation by the global positioning system (GPS) measurement across the northern Qinghai-Tibet Plateau. A model, with respect to systematic tectonic landform development, for pull-apart basins is finally proposed.  相似文献   

燕家台碎裂岩质边坡变形体变形规律研究   总被引：1，自引：0，他引：1  

王成  陈昌彦  杨素春  魏云杰 《地质灾害与环境保护》2010,21(2):37-39

燕家台碎裂岩质边坡是区域地质构造多次反复作用而形成的,其复杂多变的工程地质条件给工程设计和施工带来了极大的困难。通过对大量的边坡监测资料分析,选取具有代表性的断面进行研究,人为扰动和降雨是边坡位移的主要控制因素。将边坡变形演化分5个阶段,分析了滑体的变形规律并提出支护建议,为公路边坡的设计和施工提供了依据。  相似文献   

中、下地壳中长石的塑性变形机制及其证据——长石的显微构造研究综述     

王国灿 《地质科技情报》1993,12(3):18-24

综述了有关长石的碎裂流动、位错蠕变、扩散蠕变、颗粒边界滑动及超塑性流动的特点及有关现象,并指出了长石塑性变形机制研究的重要意义。  相似文献   

控制长石塑性变形机制转换的主要环境因素     

王国灿 《地质科技情报》1994,13(2):17-22

根据近年来有关长石的实验变形和自然变形研究的新成果，综述了环境因素对长石塑性变形机制转制约条件，并指出这类研究为分析中，下地壳或中，深变质岩区岩石变形环境开辟了新的途径和线索。  相似文献   

冀北崇礼—赤城大断裂的多相逆冲——兼论内蒙地轴隆升的构造制约因素   总被引：1，自引：0，他引：1  

王国灿  谭应佳  王方正 《地球科学》1992,(6)

阐述了内蒙地轴南缘崇礼—赤城东西向大断裂的多变形变质相构造岩带特征,确定并阐明了五台—吕梁期的角闪岩相韧性逆冲、海西晚期的绿片岩相脆—韧性逆冲及燕山早期的表层次脆性逆冲的多次逆冲运动。根据各期构造岩的变质温压条件,对北盘内蒙地轴在几次逆冲期的抬升幅度进行了分析,提出内蒙地轴是水平挤压体制控制下的隆起带。  相似文献   

东昆仑造山带东段清水泉高级变质岩片的变质岩石学研究   总被引：15，自引：0，他引：15       下载免费PDF全文

陈能松  朱杰  王国灿  侯光久  张克信  朱云海  拜永山 《地球科学》1999,24(2):116-120

清水泉高级变质岩片位于东昆仑造山带东段昆中多旋回俯冲碰撞构造混杂岩带内,由高角闪岩相—麻粒岩相变质的麻粒岩、斜长角闪岩、片麻岩、变粒岩和大理岩组成,地球化学特征显示为一套形成于后太古宙以来的火山－沉积岩系．顶峰期典型矿物共生组合为石榴石＋蓝晶石＋钾长石＋斜长石＋黑云母＋石英＋金红石和石榴石＋紫苏辉石＋斜长石＋石英,属中压相系,变质温度压力条件为（８５０±５０）℃和高于１．０ＧＰａ．石榴石中ｘ（Ｓｐｓ）成分剖面平坦,近边缘略为上升,ｘ（Ａｌｍ）,ｘ（Ｐｙｒ）和ｘ（Ｇｒｓ）仍保留了较好的生长环带特点．ｐ－ｔ轨迹为顺时针型,记录了古－中元古代之交或晋宁运动期间强烈的碰撞构造事件．  相似文献   

古新世—中新世以来青藏高原北缘隆升的特征——来自可可西里盆地的报告   总被引：2，自引：0，他引：2  

蔡雄飞  刘德民  魏启荣  顾延生  袁晏明  李德威  王国灿  罗中杰 《地质学报》2008,82(2):194-203

关于青藏高原隆升的时间有45 Ma、32 Ma、14 Ma等见解,一直存在争议。本文以青藏高原腹地最大的红色盆地可可西里为例,从古新世—中新世时期的沉积、生物、火山岩的特征等诸多方面,阐述青藏高原显著开始隆升的时间、表现特点和作用,并认为中新世初期,青藏高原有一次强烈的降温事件;在物质组分上,以钙质粘土、埃达克（Adakitic）火山岩为主;生物上以寒冷、干旱标志的裸子植物为主的植硅体;中新世中期之后青藏高原全面抬升。  相似文献   

Geochronology Constraints on Transformation Age from Ductile to Brittle Deformation of the Shangma Fault and Its Tectonic Significance, Dabieshan, Central China     

王国灿  王朴  刘超  王岸  叶润清 《中国地质大学学报(英文版)》2008,19(2):97-109

By a detailed investigation of geometry and kinematics of the Shangma (商麻) fault in Dabieshan (大别山),three different crust levels of extension movement have been recognized in sequence from the deep to the shallow:① low-angle ductile detachment shearing with top to the NW; ② low-angle normal fault with top to the NW or NWW in brittle or brittle-ductile transition domain; ③high-angle brittle normal fault with top to the W or NWW. Two samples were chosen for zircon U-Pb age dating to constrain the activity age of the Shangma fault. A bedding intrusive granitoid pegmatite vein that is parallel to the foliation of the low-angle ductile detachment shear zone of the country rock exhibits a lotus-joint type of boudinage deformation,showing syn-tectonic emplacing at the end of the ductile deformation period and deformation in the brittle-ductile transition domain. The zircon U-Pb dating of this granitoid pegmatite vein gives an age of (125.9±4.2) Ma,which expresses the extension in the brittle-ductile transition domain of the Shangma fault. The other sample,which is collected from a granite pluton cutting the foliation of the low-angle ductile detachment shear zone, gives a zircon U-Pb age of (118.8±4.1) Ma,constraining the end of the ductile detachment shearing. Then the transformation age from ductile to brittle deformation can be constrained between 126-119 Ma.Combined with the previous researches,the formation of the Luotian (罗田) dome,which is located to the east of the Shangma fault,can beconstrained during 150-126 Ma. This study gives a new time constraint to the evolution of the Dabie orogenic belt.  相似文献   

A Comparison about Metamorphism among the Oldest-Rock Units from Orogenic Belts of Dabie, Eastern Qinling and Eastern Kunlun of Central Mountain Ranges, China     

Chen Nengsong Zhang Kexin Wang Guocan Hou Guangjiu Zhu Yunhai Faculty of Earth Sciences  China University of Geosciences  Wuhan 《中国地质大学学报(英文版)》1998,9(3)

ＴｈｅＣｅｎｔｒａｌＭｏｕｎｔａｉｎＲａｎｇｅｓｏｆＣｈｉｎａ,ｗｈｉｃｈｏｃｕｐｙｔｈｅｃｅｎｔｒａｌｐａｒｔｏｆＣｈｉｎａ,ｃｏｍｐｒｉｓｅｍａｉｎｌｙｔｈｅＤａｂｉｅＭｏｕｎ－ｔａｉｎｓｉｎｔｈｅｅａｓｔ,ｔｈｅＱｉｎｌｉｎｇＭｏｕｎｔａｉｎｓ...  相似文献   

微重力法与可控源音频大地电磁法组合在豫西寻找隐伏铝土矿中的应用   总被引：2，自引：0，他引：2  

刘国印  燕长海  赵建敏  王纪中  李中明 《地质通报》2008,27(5):641-648

通过方法试验,在豫西地区已知铝土矿区的外围开展了1：5万高精度重力测量,发现绝大多数矿床点位于较平缓的重力梯度带上。：基底相对稳定的地段可作为铝土矿的找矿靶区;采用CSAMT（可按源音频大地电磁）法测深剖面,卡尼亚电阻率一频率曲线拐点可直接反映出新生界覆盖层和奥陶系灰岩层的埋藏深度,进而推断石炭系本溪组（铝土矿）的埋深。经10余个钻孔验证,见矿率达80％以上。试验结果证明,在地质研究的基础上,微重力法加上CSAMT法测深是寻找隐伏铝土矿的有效的方法组合。  相似文献