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1.
刘训  傅德荣 《地球物理学报》1995,38(A02):114-129
将格尔木-额济纳旗地学断面走廊及其邻区划分为14个地体,分属扬子-华南、华北-柴达木、塔里木和哈萨克斯坦-准噶尔4个板块,其间为规模不等的洋盆所分隔,从中元古代以来,上述板块经历了开理解到碰撞、拼合的复杂过程。  相似文献   

2.
格尔木——额济纳旗地学断面地体构造的古地磁学研究   总被引:4,自引:0,他引:4  
给出了格尔木-额济纳旗地学断面及其邻区的23个古地磁新数据,为该区地体构造的划分提供了古地磁证据。提出北山北部地体属于哈萨克斯坦板块的东延部分,探讨了该板块晚古生代的逆时针旋转运动,分析了塔里木板块的演化特点,该板块大约于泥盆纪通过顺时针旋转运动与哈萨克斯坦板块对接拼合,应用多个参考点古纬度资料研究板块运行特征的方法,分析了断面域及其区地体构造的演化过程。研究发现了北祁连地体的古生代南向位移事件,  相似文献   

3.
新疆准噶尔二台地区晚古生代古极点位置与塔里木、哈萨克斯坦地块同时代极点位置无显著差别。实测古纬度更接近于用哈萨克斯坦极点计算得到的预期古纬度。因此,晚古生代准噶尔地块与哈萨克斯坦地块已是统一的整体。泥盆纪准噶尔地块内的准噶尔洋盆于晚石炭世闭合于乌伦古河一带。西伯利亚板块、塔里木、哈萨克斯坦地块等组成东部劳亚大陆的块体,尽管其运动演化有所差异,但都遵循了以西伯利亚板块为主体大致相同的总的运动演化过程,即晚古生代至中生代早期,由低纬度向高纬度的NW向运动和侏罗纪以来的SEE向运动  相似文献   

4.
华南中生代构造-岩浆活动研究:现状与前景   总被引:10,自引:0,他引:10  
华南陆块是由华夏地块和扬子克拉通在新元古代早期碰撞拼贴形成,在古生代时期其北侧、西侧和南侧受到古特提斯洋消失的影响,在晚古生代末期在南、北两侧分别与印支陆块和华北陆块发生碰撞形成现今中国大陆东部的基本格架,自中生代起受到太平洋板块向西俯冲的影响.因此,华南陆块经历了三大构造体系的作用,产生了叠加复合型构造样式.华南与周边地区有关中生代地质的对比研究表明,尽管华南陆块中生代紧邻西太平洋俯冲带,但东缘尚未发现有新生的弧型地壳,华南中生代地质特征主体表现为吉大陆边缘再造至陆内构造,缺乏洋岛玄武岩和大陆弧安山岩.研究华南中生代构造.岩浆活动的重点,是确定华南中生代岩浆岩的时空展布和构造演化.本文通过总结华南具有挤压.伸展构造转换的三条结合带的岩浆岩记录,结合构造变形和深部地球物理资料,试图推动华南地质研究,使其成为发展板块构造理论的典型靶区.  相似文献   

5.
华北克拉通在形成和演化中经历的最重要的地质事件发生在 2 600~2 400和2 000-1700 Ma期间(简称 25亿年地质事件和 18亿年地质事件).提出这两个事件的实质是:古老的微陆块以规模较小的板块构造形式拼合成超大陆,以及超大陆受古地幔柱构造的影响再裂解成不同的陆块.  相似文献   

6.
中国主要古陆与联合大陆的形成——综述与展望   总被引:5,自引:0,他引:5  
中国主要的古老陆块有华北、华南和塔里木,这些古陆在前寒武纪有各自独立的构造演化历史.华北陆块的前寒武纪构造演化记录最复杂也最完整,从古陆核的形成、巨量陆壳的生长和克拉通化,继而经历了古元古代裂谷.岛弧.碰撞构造事件和大氧化事件,中.晚元古代的裂谷事件代表了华北克拉通的地台属性的演化史.塔里木盆地的基底包括太古宙和古元古代的变质岩系以及新元古代地层,确定有三期冰川作用造成的新元古代冰躜岩.华南古陆是由扬子和华夏克拉通在新元古代拼接而成的.扬子克拉通经历了早前寒武纪的陆壳生长,而后发生了10~9亿年的和8-6亿年的两期变质与岩浆事件,此外,新元古代的两次冰川作用可与全球雪球事件对比.华夏古陆由18亿年、10—9亿年和约8亿年的古老花岗(片麻)岩以及变质岩组成,说明广泛的古老基底存在.华夏与扬子克拉通有统一的新元古代沉积盖层表明华南大陆至少形成在约10~9亿年后,并构成Rodinia超大陆的组成部分.中央造山系的高压.超高压变质作用研究支持了上述古陆块在三叠纪全球Pangea造山作用时期拼合在一起,形成中国大陆的主体.  相似文献   

7.
华北克拉通基底构造单元特征及早元古代拼合   总被引:58,自引:2,他引:58  
华北克拉通基底可分为东部陆块、西部陆块和中部带. 西部陆块是由其南部的鄂尔多斯陆块和北部的阴山陆块沿华北西部孔兹岩带在早元古代(~1.9 Ga)碰撞对接而成. 在~1.85 Ga, 西部陆块与东部陆块沿中部带发生碰撞拼合而形成现今的华北克拉通统一结晶基底.  相似文献   

8.
据地层及其时代,岩相古地理,基性-眼基性岩及蛇绿岩套,花岗岩类,古生物地理区系,古地磁,地球物理,遥感影像及韧性变形变质带等系统分析研究,表明康古尔塔格-黄山深断裂带为晚古生代双向俯冲对接碰撞带。其南为塔里木板块,早古生代为库都克奇克-沙泉子俯冲带;泥盆纪北移至康古尔塔格-黄山一带,经泥盆-石炭纪拉张,双向俯冲、对接碰撞,二叠纪固结-裂解演化,两者间为觉罗塔格岛弧增生带,其北为哈萨克斯坦-准噶尔板块南缘大南湖岛弧带,有基性-超基性岩、火山岩和中酸性斑(玢)岩及铜镍、金和铜钼矿分布,中酸性斑(玢)岩及铜钼矿呈对称分布,进而建立区域构造-造浆-成矿模式,进行战略性和战术性成矿预测,千万吨资源量的赤湖-土屋斑岩型Cu,Mo(Ag)矿的发现,验证了这种模式和预测的正确性,对地质构造研究及找矿有重要意义。  相似文献   

9.
中国三大地块的碰撞拼合与古欧亚大陆的重建   总被引:26,自引:4,他引:26  
根据最新取得的华北地块的古地磁数据,并与目前收集到的按一定判据经过筛选的华南地块、塔里木地块、蒙古褶皱带与中亚褶皱带、西伯利亚板块以及稳定欧亚大陆的数据对比分析,对中国三大地块--华北、华南、塔里木地块的碰撞、拼合及其与北邻的西伯利亚板块的构造关系,进行了初步的讨论,并尝试作了古欧亚大陆的重建.  相似文献   

10.
北祁连加里东造山带位于华北板块与柴达木微板块之间, 是柴达木微板块与华北板块碰撞形成的造山带. 北祁连加里东期造山带是在晚元古代Rodinia联合大陆基础上裂解, 经由寒武纪裂谷盆地、奥陶纪多岛洋盆、志留纪-早泥盆、中泥盆世碰撞造山而成的. 北祁连甘露池、向前山、石青洞寒武纪黑茨沟组硅质岩(除热液影响的样品)的常量元素Al/(Al+Fe+Mn)值平均为0.794, Al/(Al+Fe)值平均为0.627, δCe值平均为1.114, Lan/Ybn值平均为0.994, Lan/Cen平均为1.034. 天祝向前山的硅质岩以北美页岩标准化的稀土元素配分模式呈重稀土富集的配分特征, 接近于大洋盆地的重稀土富集的配分模式. 甘露池、石青洞两地稀土元素配分模式呈平坦状, 即不同于大陆边缘的明显轻稀土元素富集的配分模式, 也不同于开放洋盆的重富集的配分模式. 这些稀土元素特征特征反映寒武纪硅质岩形成于靠近或远离陆源的大陆边缘裂谷盆地的构造背景. 北祁连大克岔、黑茨沟、边马沟、大岔大坂、九个泉、百泉门、肮脏沟、石灰沟、老虎山、毛毛山、崔家墩等地奥陶纪硅质岩(除热液影响的样品)Al/(Al+Fe+Mn)值平均为0.72, Al/(Al+Fe)值平均为0.58, δCe值平均为0.99, Lan/Ybn值平均为1.09, Lan/Cen平均为0.96. 北祁连奥陶纪大部分硅质岩以北美页岩标准化的稀土元素配分模式呈平坦状或略左倾的重稀土元素. 个别硅质岩的稀土元素配分模式呈略右倾的轻稀土富集的配分模式. 沉积地球化学特征结合早古生代沉积特征与构造演化分析, 认为北祁连寒武纪-奥陶纪与裂谷、洋壳、岛弧、弧后盆地火山岩共生的硅质岩的构造背景不是典型的远洋盆地和洋中脊, 而是部分靠近、部分远离陆源的大陆边缘深水盆地的多岛洋背景. 北祁连及相邻的柴达木微板块周缘地区存在的多条早古生代的蛇绿岩带说明该区处于原特提斯洋东侧的多岛洋背景.  相似文献   

11.
扬子板块北缘壳(慢)岩石圈结构与古生代盆地   总被引:1,自引:0,他引:1  
“七·五”计划期间,在扬子板块北缘地带所作地震测深(DSS)和大地电磁测深(MTS)成果揭示了该地带壳(慢)岩石圈结构,提供了分析古生代盆地形成演化的深部地质依据。本文据深部地球物理资料探讨古生代盆地的深部地质结构与其所处大地构造背景之内涵。早古生代扬子板块北缘秦巴地区为被动边缘型盆地,江南大别区为陆内裂谷;晚古生代,秦岭大巴地区为前陆盆地,江南大别地区为陆表海盆。  相似文献   

12.
中国及其邻区地球三维结构初始模型的建立   总被引:53,自引:9,他引:53       下载免费PDF全文
对人工地震测深及天然地震面波体波三维层折反演数据进行统一处理,建立了中国及其邻区地球三维结构初始模型.此模型图像表明,中国及其邻区地球各圈层横向变化明显.岩石圈及软流圈内速度分布主要反映这一区域自古生代以来板块及地块拼合模式.各主要板块或地块(塔里木、扬子、中朝、青藏、哈萨克斯坦、印度、印度支那)岩石圈增厚或有很深的地慢根,板块或地块间的造山带岩石圈减薄,软流圈速度降低。下地幔底部及核幔边界D″层出现高速异常,表明古太平洋及古特提斯洋俯冲板块因重力坍塌已进入地球深层,形成亚洲超级下降地幔柱。这一下降地幔柱引起地球表层物质向中亚、东亚地区集中,印度半岛、青藏高原、新疆、蒙古至贝加尔一带,成为全球岩石圈最大的汇聚场所.  相似文献   

13.
The Shan-Thai Block, regarded traditionally as awhole geotectonic unit by the geologists engaged inthe study of geotectonic evolution of Southeast Asia, issituated to the west of the Ailaoshan and Nan-UttaraditSutures and to the east of the Shan Boundary Faults,and covers southwestern Yunnan, eastern Myanmar,most of Thailand, northwestern Laos, western Malay-sia, and Sumatra[1,2] (fig. 1). However, recent researchshows that it consists of two continental terranes fromGondwana and Cathay…  相似文献   

14.
History and modes of Mesozoic accretion in Southeastern Russia   总被引:8,自引:1,他引:8  
Boris  Natal'in 《Island Arc》1993,2(1):15-34
Abstract The history of Mesozoic accretion and growth of the Asia eastern margin, occupied by Southeastern Russia, includes five main events; two main tectonic regimes were responsible for the growth of the continent. In the Triassic-Jurassic, Early Cretaceous and Late Cretaceous-Paleogene, the subduction of the oceanic lithosphere resulted in the formation of wide accretionary wedges of the Mongol-Okhotsk, Khingan-Okhotsk and Eastern Sikhote-Alin active continental margins, respectively. These stages of the comparatively slow growth of the continent were broken by stages of rapid growth and drastic changes in the shape of the continent, since at these stages large terranes of various tectonic nature collided with active continental margins. At the end of the Early-Middle Jurassic, the Bureya terranes collided with the Mongol-Okhotsk active margin, and at the beginning of the Late Cretaceous there was collision of the Central and Southern Sikhote-Alin terranes with the Khingan-Okhotsk active margin.
Collision-related structural styles in all cases are indicative of oblique collision and great strike-slip motions along the main sutures. The peculiarities of the terrane's geological structure show that prior to collision with the Mongol-Okhotsk and Khingan-Okhotsk active margins, they had already accreted to Asia and then migrated along its margins along the strike-slip faults. The Bureya terranes were squeezed out of the compression zone between Siberia and North China. This compression zone originated after the Paleozoic oceans which divided these cratons had closed. The Khanka terranes and Mesozoic accretionary wedge terranes of the Sikhote-Alin shifted along the strike-slip faults subparallel to the Asia Pacific margin. Strike-slip motions resulted in duplication of the primary tectonic zonation.  相似文献   

15.
The Precambrian and lower Paleozoic units of the Japanese basement such as the Hida Oki and South Kitakami terranes have geological affinities with the eastern Asia continent and particularly strong correlation with units of the South China block. There are also indications from units such as the Hitachi metamorphics of the Abukuma terrane and blocks in the Maizuru terrane that some material may have been derived from the North China block. In addition to magmatism, the Japanese region has seen substantial growth due to tectonic accretion. The accreted units dominantly consist of mudstone and sandstone derived from the continental margin with lesser amounts of basaltic rocks associated with siliceous deep ocean sediments and local limestone. Two main phases of accretionary activity and related metamorphism are recorded in the Jurassic Mino–Tanba–Ashio, Chichibu, and North Kitakami terranes and in the Cretaceous to Neogene Shimanto and Sanbagawa terranes. Other accreted material includes ophiolitic sequences, e.g. the Yakuno ophiolite of the Maizuru terrane, the Oeyama ophiolite of the Sangun terrane, and the Hayachine–Miyamori ophiolite of the South Kitakami terrane, and limestone‐capped ocean plateaus such as the Akiyoshi terrane. The ophiolitic units are likely derived from arc and back‐arc basin settings. There has been no continental collision in Japan, meaning the oceanic subduction record is more complete than in convergent orogens seen in intracontinental settings making this a good place to study the geological record of accretion. Hokkaido lacks most of the Paleozoic history recognized in Honshu, Shikoku, Kyushu, and the Ryukyu Islands to the south and its geology reflects the Cenozoic development of two convergent domains with volcanic arcs, their approach, and eventual collision. The Hidaka terrane reveals a cross section through a volcanic arc and the main accretionary complex of the convergent system is represented by the Sorachi–Yezo terrane.  相似文献   

16.
Northward subduction of the Cenozoic Tethys ocean caused the convergence and collision of Eurasia-Indian Plates, resulting in the lower crust thickening, the upper crust thrusting, and the Qinghai-Tibet uplifting, and forming the plateau landscape. In company with uplifting and northward extruding of the Tibetan plateau, the contractional tectonic deformations persistently spread outward, building a gigantic basin-range system around the Tibetan plateau. This system is herein termed as the Circum-Tibetan Plateau Basin-Range System, in which the global largest diffuse and the most energetic intra-continental deformations were involved, and populations of inheritance foreland basins or thrust belts were developed along the margins of ancient cratonic plates due to the effects of the cratonic amalgamation, crust differentiation, orogen rejuvenation, and basin subsidence. There are three primary tectonic units in the Circum-Tibet Plateau Basin-Range System, which are the reactivated ancient orogens, the foreland thrust belts, and the miniature cratonic basins. The Circum-Tibetan Plateau Basin-Range System is a gigantic deformation system and particular Himalayan tectonic domain in central-western China and is comparable to the Tibetan Plateau. In this system, northward and eastward developments of thrust deformations exhibit an arc-shaped area along the Kunlun-Altyn-Qilian-Longmenshan mountain belts, and further expand outward to the Altai-Yinshan-Luliangshan-Huayingshan mountain belts during the Late Cenozoic sustained collision of Indo-Asia. Intense intra-continental deformations lead ancient orogens to rejuvenate, young foreland basins to form in-between orogens and cratons, and thrusts to propagate from orogens to cratons in successive order. Driven by the Eurasia-Indian collision and its far field effects, both deformation and basin-range couplings in the arc-shaped area decrease from south to north. When a single basin-range unit is focused on, deformations become younger and younger together with more and more simple structural styles from piedmonts to craton interiors. In the Circum-Tibetan Plateau Basin-Range System, it presents three segmented tectonic deformational patterns: propagating in the west, growth-overthrusting in the middle, and slip-uplifting in the east. For natural gas exploration, two tectonic units, both the Paleozoic cratonic basins and the Cenozoic foreland thrust belts, are important because hydrocarbon in central-western China is preserved mainly in the Paleozoic cratonic paleo-highs and the Meso-Cenozoic foreland thrust belts, together with characteristics of multiphrase hydrocarbon generation but late accumulation and enrichment.  相似文献   

17.
红河断裂带白垩纪古地磁及青藏高原地质构造演化   总被引:5,自引:0,他引:5       下载免费PDF全文
红河断裂带两侧古地磁结果表明,羌塘地体与扬子地台至少从早白垩世以来已连接为一个整体。青藏高原是由四个发育历史不同的地体组成的大地构造复合体,在晚古生代它们分别是劳亚古陆、华夏复合古陆和冈瓦纳古陆的组成部分。拉萨地体与羌塘地体碰撞拼合形成欧亚板块构造格局。喜玛拉雅地体、印度板块与欧亚板块碰撞拼合、推挤,使青藏高原隆起,并使欧亚板块的块体沿已存在的断层产生左行走滑,这种作用至今仍在继续  相似文献   

18.
塔里木周缘的新元古代地层中均记录了涉及Rodinia聚合和裂解的构造热事件,但塔里木在Rodinia超大陆中位置尚存争议.本文综合地层对比以及古地磁的研究方法,将塔里木陆块在Rodinia超大陆中置于澳洲板块的西北缘,并且塔里木的西南缘(现今位置)和澳洲的西北缘(现今位置)相连.基于塔里木周缘的构造热事件和塔里木、澳洲运动学特征分析,认为塔里木陆块周缘在约800~700 Ma中发生了强烈的裂谷事件,导致塔里木从Rodinia超大陆中裂解,但塔里木并没有完全从澳洲裂离,而是随澳洲一起,加入冈瓦纳大陆.在约450 Ma左右,塔里木与澳洲发生分离,其原因为古特提斯洋的扩张.  相似文献   

19.
基于观测应力场的大华北地区动力学机制探讨   总被引:8,自引:0,他引:8       下载免费PDF全文
采用伪三维有限元方法, 利用观测应力场应力取向和应力状态作为主要约束, 对华北地区的构造应力场进行了数值模拟. 结果显示, 华北地区应力场主要受到来自太平洋板块和青藏高原挤压作用的控制. 太平洋板块的北西西向的挤压作用对这一地区, 尤其是华北平原地区构造应力场的影响更大. 同时, 上涌地幔沿盆地边缘法线方向的引张, 对这一地区的应力场的形成也起到一定的作用.   相似文献   

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