地体构造对研究地台和地盾区域成矿规律的重要性   总被引：3，自引：0，他引：3  

胡受奚  赵懿英  徐兵  陈衍景 《地学前缘》1994,(4)

３０年前板块构造理论的建立引起所有相关的地球科学的革命，其中包括区域成矿学。然而随着地球科学理论的发展，板块构造理论对于解释地壳，特别是早前寒武的地盾、地台和克拉通区的复杂构造现象显得不完备，因此，近２０年来地体构造理论的发展补充了板块构造理论的不足。近年来，各国地质学家相继发现世界上各地盾、地台和克拉通区，如华北地台、乌克兰地盾、阿尔丹地盾、加拿大地盾、非洲地台、澳大利亚耶尔冈克拉通等是由多个地体所组成。每一个地体是一个独立的和基本的地质构造单元，彼此间由地缝合线或深断裂隔开。由于每个地体的地质特征、构造环境和成矿作用各不相同，因而地体构造成为区域成矿学的一个重要组成部分。  相似文献   

广西丹池盆地泥盆系浊积岩和硅质岩的特征及构造意义     

廖宗廷  陈跃昆 《上海国土资源》1994,(3)

对广西丹池地区泥盆系浊积岩和硅质岩的沉积特征、岩石化学成分和形成机制的研究表明,它们是在受同生断裂控制的深水拗陷盆地中,由浊流和热水沉积而形成的沉积岩石。相同类型岩石的分布特征表现南盘江晚古生代沉积盆地呈浅海“台地”和深海“槽沟”相间排列的构造格局,其形成和演化与滇黔桂地体和云开地体的碰撞拼贴造山作用以及造山后地壳的蠕散拉伸作用有关。  相似文献   

吉黑东部中生代两种机制的碰撞构造     

Liu Xifanwen  Shen Ninhua  Ge Xiaohong 《吉林大学学报(地球科学版)》1994,(4)

吉林、黑龙江东部地区中生代存在两种机制的碰撞构造，即由南北陆块碰撞（华北古板块与张广才—佳木斯地块）所形成的近东西走向的构造（古洞河—富尔河碰撞带）和东部地体向陆缘增生挤压所产生的南北走向的褶皱—推覆构造。前者由早期构造杂岩带及叠加于其上的印支期韧性剪切带和推覆构造所代表，后者是在印支期的褶皱和糜棱岩化带之上发育的推覆构造。两种碰撞构造的主要发育时期为晚中生代（Ｊ＿３—Ｋ）。  相似文献   

江南古岛弧浙赣段基底地壳演化     

凌洪飞  章邦桐 《大地构造与成矿学》1993,17(2):147-152

双溪坞群、双桥山群等为江南古岛弧浙赣段的前寒武纪基底地层。依据基底地层建造的差异及蛇绿岩套和碰撞花岗岩等的分布,可将浙赣段江南古岛弧沿赣东北断裂划分为怀玉地体和九岭地体。怀玉地体基底地层建造以火山岩占主导,10—13亿年是该地体的重要成壳时期。九岭地体基底地层建造以浊流复理石占主导,14—16亿年为该地体的重要成壳时期。距今9亿年左右两地体相互碰撞拼接,与此同时,华夏古陆向江南古岛弧碰撞,至～8亿年、完成碰撞对接,开始震旦系盖层沉积。  相似文献   

扬子板块北缘碧口群火山岩的地球化学特征及其构造环境   总被引：26，自引：1，他引：26  

闫全人  Andrew D.Hanson  王宗起  闫臻  Peter A.Druschke  王涛  刘敦一  宋彪  姜春发 《岩石矿物学杂志》2004,23(1):1-11

碧口群火山岩系中部的基性熔岩以拉斑系列为主 ,基性火山岩的Sr同位素初始比值和Nd同位素初始比值较低 ,分别为 0 .70 12 4 8～ 0 .70 4 4 13和 0 .5 110 80～ 0 .5 12 341,大部分样品的εNd(t) >0 ,表明母岩浆主要来自地幔源区。岩石显示明显的富2 0 7Pb及2 0 8Pb特征。在以部分熔融作用为主的演化过程中岩浆发生了一定程度的分异 ,LREE、大离子亲石元素等表现了从亏损到富集的变化特点。基性熔岩的稀土与微量元素表现出与俯冲碰撞型的弧区玄武岩相同的特点。分析表明 :碧口群火山岩系形成于岛弧环境 ,它与横丹群浊积岩系在扬子板块西北缘构筑了一个弧盆系统 ,其时代为新元古代。  相似文献   

The Crustal Structure and Assembly of Terranes in the Qaidam-Qilian-Beishan Area, Western China   总被引：2，自引：0，他引：2  

LIU Xun  GAO RuiInstitute of Geology  Chinese Academy of Geological Sciences  Baiwanzhuang Rd.  Beijing 《《地质学报》英文版》1998,72(3):243-255

Through a study of the geotransect from Golmud to Ejin Qi published recently, the tectonics of the crust beneath the area from the northern Qinghai-Tibet plateau (Qaidam and the Qilian Mountains) to the border between China and Mongolia and its structure, composition and tectonic evolution have been revealed, and abundant information about the deep structures has been provided. Based on the research into the geotransect, it is suggested that the crust in this area was formed by the assembly of the terranes in different geological stages. Following the formation of the Palaeo-Asian continent, the north part of the corridor of the transect became a part of the huge unifying continent by the end of the Early Permian. In the Mesozoic and Cenozoic, as a result of the compression mainly by the push of the Qinghai-Tibet plateau on the south, the unique crustal structure and geomorphologic features on the northern Qinghai-Tibet plateau were formed. This geotransect together with the Yadong-Golmud geotransect co  相似文献   

盆地演化与地球动力学旋回   总被引：7，自引：0，他引：7  

刘和甫 《地学前缘》1997,(Z2)

盆地演化受地球演化节律所制约，节律由多层次构成。地球动力学旋回主要有３个级序：（１）超级大陆旋回，主要由羽柱构造的地幔对流动力学所控制，产生超级大陆的裂解和拼合，形成全球性同步隆升与沉降的克拉通盆地；（２）地槽旋回或造山旋回，主要由板块构造的岩石圈运动学所控制，按威尔逊旋回进展，发育各类盆地和造山带，形成“区域性”穿时开合与“非对称”互补；（３）褶皱幕或裂陷幕，主要由地体构造与拆层作用几何学所控制，产生盆地内各种构造样式和沉积样式，形成地方性的穿时递进变形，发育幕式变形和幕式沉积作用等。  相似文献   

Research on the Terrane Tectonics in China     

郭令智  舒良树等 《中国地球化学学报》1996,15(3):193-202

This paper summarizes the latest advances in research on the terrane tectonics of China.The terranes of China distributed around various plates may be divided into four terrane belts of different ages and sizes.i.e.,the East China,Northwest China,Southwest China and Qilling-Dabie terrane belts.Among them,the East China belt may be subdivided into three composite terrane groups;each terrane proup is composed of several terranes that were formed roughly at the same time and have distince geologic histories.The accretion of China‘s terranes involver three types;the collision type,the flake-thrusting type,and the docking type.The results of the lates study in the five widening fields and some advances in the methods of research on the terrane tectonics in China are presented in the present paper.  相似文献   

The Allochthony of the Argentine Precordillera Ten Years Later (1993–2003): A New Paleobiogeographic Test of the Microcontinental Model     

Juan L. Benedetto   《Gondwana Research》2004,7(4):1027-1039

Recent and new faunal data from the Cambrian to Silurian rocks of the Precordillera, Famatina and Northwest Argentina basins are used to discriminate between different paleogeographic models, and especially to establish to what extent they are compatible with a previous conclusion that the Precordillera is a Laurentian-derived microcontinent. There is no paleontological evidence to support a para-autochthonous Gondwanan origin of the Precordillera. The strong differences in the Cambrian trilobite faunas and lithologic successions preclude a common origin of the Precordillera terrane, eastern Antarctica and South Africa. Recent discoveries of brachiopods and organisms of the Phylum Agmata strengthened Laurentian affinities during the Cambrian. The latest Cambrian-early Ordovician faunas that inhabited the autochthonous Northwest Argentina basin, including the western Puna volcaniclastic successions, are mostly peri-Gondwanan. The early Ordovician brachiopods, ostracods and trilobites display mixed Laurentian, Baltic and Avalonian biogeographical links supporting a drifting of the Precordillera across the Iapetus Ocean. Increasing Gondwanan elements during the Llanvirn, along with varied geological evidence, indicate that the first stages of collision may have begun at that time, involving a major change in the plate kinematics. The distribution of facies and faunas, basin development, and timing of deformation are interpreted as resulting from a north to south diachronous closing of the remnant basin during the last phases of convergence and oblique collision of the Precordillera terrane with the Gondwana margin. The high level of endemism of Caradoc faunas may be a consequence of the rearrangement and partial isolation of sedimentary areas during the strike-slip movement of the colliding Precordillera plate with respect to the Gondwana margin. Suggested relationships between facies distribution, geographic barriers and faunal migrations before and during the collision are depicted in a series of schematic reconstructions at five time slices from late Cambrian to Silurian.  相似文献   

苏鲁地体超高压和退变质时代的厘定:来自片麻岩锆石微区SHRIMP U-Pb定年的证据   总被引：31，自引：16，他引：31       下载免费PDF全文

刘福来  许志琴  宋彪 《地质学报》2003,77(2):229-237

锆石微区矿物包体的激光拉曼和阴极发光测试以及相应的SHRIMP U-Pb定年结果表明,苏鲁地体片麻岩锆石微区记录了十分复杂的年代学信息。其中副片麻岩锆石核部记录了345～743 Ma的继承性锆石年龄,标志着原岩碎屑锆石来源的复杂性;含柯石英的锆石微区记录了220～234 Ma的超高压变质年龄;而含石英包体的边部则记录了202～219 Ma的退变质年龄。正片麻岩继承性锆石核部所记录的年龄为574～680 Ma,表明原岩锆石曾经历了部分Pb丢失,原岩的形成年龄应大于680 Ma;含柯石英锆石微区所记录的超高压变质年龄为224～242 Ma;而锆石边部所记录的退变质年龄为209～219 Ma。两类片麻岩锆石微区所隐藏的超高压变质和退变质年龄信息十分相近,平均值分别为229±4Ma和211±4Ma,标志着苏鲁地体超高压变质时代应为印支期,相应的构造抬升速率约5.6 km/Ma。该项成果不仅确定了苏鲁地体超高压变质和退变质时代,而且对于深入探讨苏鲁地体快速折返过程中的动力学机制有着重要的科学意义。  相似文献