首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到19条相似文献,搜索用时 125 毫秒
1.
欧亚北极东部地区资源丰富,但由于区域地质构造复杂,勘探程度低,盆地分布及其发育的构造背景仍存在很大的争议.在大量收集整理区域地质文献的基础上编制了该区构造简图,并对区域地质构造及其演化进行梳理.该区主要构造单元包括:上扬斯克-科雷马造山带、北极阿拉斯加-楚科塔微板块、科雷马-奥莫隆复合超地体、南阿纽伊缝合带等.早侏罗世至早白垩世,随着美亚海盆的张开,北极阿拉斯加-楚科塔微板块裂离加拿大北部陆缘,并随着Anui-Anvil洋的关闭,与科雷马-奥莫隆超地体及亚洲大陆北缘碰撞,形成新西伯利亚-楚科奇造山带-布鲁克斯造山带及南阿纽伊缝合带.上扬斯克-科雷马造山带是晚侏罗世-早白垩世科雷马-奥莫隆超地体与西伯利亚克拉通边缘的碰撞结果.   相似文献   

2.
新疆古生代构造—生物古地理   总被引:4,自引:0,他引:4  
郭福祥 《新疆地质》2001,19(1):20-26
通过6幅图表达了新疆古生代板块的构造-生物古地理区系。早古生代,包括劳伦,波罗的、西伯利亚和哈萨克斯坦4陆块的亚帕特斯古陆(Iapetusa)群,与由其余陆块构成的冈瓦纳古陆群隔原特提斯洋相对峙。石炭-二叠纪,欧美、安加拉、太平洋和冈瓦纳4古陆共存并立。西伯利亚和哈萨克斯担板块经历了早古生代亚伯特斯古陆、晚古生代安加拉古陆和早二叠世晚期以来欧亚大陆3个发展阶段。塔里木、中朝、华南-东南亚板块经历了早古生代冈瓦纳古陆、晚古生代太平洋古陆和早二叠世晚期以来欧亚大陆3个发展阶段。指出在中晚寒武世和晚奥陶世哈萨克斯坦板块靠近塔里木、中朝和华南-东南亚板块;在早古生代其余时期它接近西伯利亚板块。伊犁和托克逊-雅满苏地体是在中泥盆世之前裂解自塔里木板块,尔后在早二叠世晚期接近安加拉古陆。塔里木板块北东缘北山地区在早二叠世早期首先靠近安加拉古陆。塔里木与西伯利亚-哈萨克斯坦板块之间缝合时代大抵上和土耳其-中伊朗-冈底斯与华南-东南亚板块之间缝合时代一致。缝合事件发生在早二叠世早期,而相应的构造运动出现在早晚二叠世之交。  相似文献   

3.
南天山:晚古生代还是三叠纪碰撞造山带?   总被引:56,自引:42,他引:56  
伊犁-哈萨克斯坦板块和塔里木-卡拉库姆板块之间的南天山造山带是‘中亚型造山带’的典型代表之一,经历了复杂的构造演化与地壳增生过程。传统上,它被视为华力西期褶皱带或晚古生代碰撞造山带。但近年来,部分学者提出它可能为三叠纪碰撞造山带。本文在综述南天山造山带的蛇绿岩、高压变质岩、花岗岩类等方面研究成果的基础上,讨论了其碰撞造山的时限。我国境内南天山西段碰撞造山可能开始于早石炭世(345Ma),结束于晚石炭世末(300Ma左右)。二叠纪时期,南天山至整个中亚地区进入后碰撞演化阶段。现有资料证实南天山为一晚古生代碰撞造山带,并非一三叠纪碰撞造山带。  相似文献   

4.
西天山造山带区域构造演化及其大陆动力学解析   总被引:1,自引:0,他引:1  
西天山位于哈萨克斯坦-准噶尔板块与塔里木-华北板块两大板块之间,在漫长的构造演化过程中历经前震旦纪基底形成演化阶段(D1)、震旦纪至早奥陶世稳定陆壳发展阶段(D2)、中奥陶世至石炭纪末板块裂解与再拼合阶段(D3)、二叠纪陆陆叠覆造山阶段(D4)和中新生代盆山耦合阶段(D5)等5个大的发展阶段,其古生代时期中奥陶世至石炭纪末板块裂解与再拼合阶段(D3)又可细化为4个次级演化阶段:中奥陶世至晚志留世早古南天山洋盆形成阶段(D31)、晚志留世至晚泥盆世俯冲造山阶段(D32)、晚泥盆世至早石炭世初陆陆碰撞造山阶段(D33)和早石炭世至晚石炭世后碰撞阶段(D34)。西天山造山带自中新元古代以来历经俯冲造山、陆陆碰撞造山、陆陆叠覆造山和陆内再生造山等多机制多旋回的造山作用,终成为横亘于中亚地区的宏伟的复合型造山带。  相似文献   

5.
全球早古生代造山带(Ⅳ):板块重建与Carolina超大陆   总被引:2,自引:0,他引:2  
古元古代与显生宙的板块构造特征和旋回演化过程具有明显区别,反映出地质记录为两种不同的板块构造体制。早古生代为这两个时期的过渡阶段,其构造过程研究与板块重建是地球板块构造旋回机制和周期分析的关键。本文采用综合集成的方法,在总结对比罗迪尼亚超大陆裂解以来全球早古生代主要碰撞造山带的地质事件基础上,分析早古生代碰撞造山带的演化特征,总结出与冈瓦纳大陆拼合、劳俄大陆拼合、古中华陆块群增生相关的7期碰撞-增生造山事件群:Brasiliano、东非、Kuunga、东亚与原特提斯洋和古亚洲洋演化相关的的加里东期造山事件、经典加里东造山、中欧加里东造山、Appalachian造山。再在这7期造山事件群基础上,结合古地磁、古生物、古地理等资料,重建了新元古代-早古生代末全球板块的拼合过程:罗迪尼亚超大陆从新元古代的~950 Ma开始经历了3个阶段裂解,此时存在泛大洋、莫桑比克洋和古太平洋3个大洋,随后615~560 Ma Iapetus洋打开,~560 Ma波罗的陆块与西冈瓦纳裂离导致狭窄的Ran洋打开;~540 Ma南半球Brasiliano、东非和Kuunga造山运动导致冈瓦纳大陆分阶段最终完成拼贴;~500 Ma冈瓦纳大陆北缘西段的微陆块群局部向北裂离,导致Rheic洋和Tornquist洋打开,并于~420 Ma随经典加里东造山带和中欧缝合带形成导致Iapetus洋闭合,此时斯瓦尔巴特和英国可能位于格陵兰地盾东南缘,同时冈瓦纳大陆北缘东段华北为代表的微陆块基本拼合在冈瓦纳大陆北缘;此外,虽然425 Ma西伯利亚板块有远离聚合了的劳俄大陆的趋势,但晚奥陶世-早泥盆世南美和北美板块靠近,北美板块与环冈瓦纳北缘西段的地体拼合碰撞。在大约400 Ma时,南、北美洲的混合生物群和古地理重建显示两者非常接近,因此,推测此时存在一个初始的逐步稳定的超大陆的可能,本文称为Carolina超大陆,因为Carolina造山带是这个超大陆最终拼合的地带。并据此判断超大陆旋回为7亿年。  相似文献   

6.
北极地区区域地质及美亚海盆的演化   总被引:1,自引:0,他引:1  
北冰洋是世界四大洋之一,受自然条件的限制,其地质调查和研究程度还很低。美亚海盆的形成演化,更是众说纷纭,且很少得到地质地球物理资料的支持。笔者在充分调研的基础上,试图对北极地区区域地质及美亚海盆的扩张进行综述。北冰洋张开之前,北极地区主体是北极克拉通,周边为不同时期形成的造山带,包括晚新元古代贝加尔造山带、中古生代加里东造山带、二叠纪—三叠纪海西造山带及早白垩世晚基末利造山带。美亚海盆中的阿尔法海岭、门捷列夫海岭以及楚科奇高地、Northwind脊均为陆壳,是北极克拉通的一部分。美亚海盆应是中—晚侏罗世伴随着泛大陆的裂解开始形成,但海盆的扩张方式及时间有多种不同的观点,包括晚侏罗世门捷列夫海岭从加拿大陆缘裂离及门捷列夫海岭从罗蒙诺索夫海岭裂离等。这些观点均难以解释美亚海盆的外形与地理特征。平行四边形模式,虽能较好地解释美亚海盆演化的外形特征,但其地球动力系统复杂,尚需地质地球物理资料的支持。  相似文献   

7.
中古生代秦岭造山带是原特提斯大洋中华夏陆块群的一部分.晚加里东—早海西期扬子板块、秦岭微板块和华北板块具反Z型的构造格局.三者的碰撞造山过程为斜向碰撞和不规则边缘碰撞,其中北秦岭的碰撞为由西向东,南秦岭洋闭合为由东向西.南秦岭呈现碰撞闭合不造山的特征,而北秦岭表现为造山不成熟的特征.因此晚加里东—早海西期古秦岭造山带为一发育不成熟的造山带  相似文献   

8.
杜远生  殷鸿福 《地球科学》1997,22(4):401-405
中古生代秦岭造山带是原特提斯大洋中华夏陆块群的一部分,晚加里东-早海西期扬子板块,秦岭微板块和华北板块上有反Z型的构造格局,三者的碰撞造山过程为斜向碰撞和不规则边缘碰撞,其中北秦岭的碰撞为由西向东,南秦岭洋闭合为由东向西,南秦岭呈现碰撞闭剑造山的特征,而北秦岭表现为造山不成熟的特征,因此晚加里东-早海西期古秦岭造山带为一发育不成熟的造山带。  相似文献   

9.
晚加里东到早海西期,西秦岭北带存在一较大规模的造山带,泥盆纪的古地形呈北高南低的特征。持续的海侵由南向北侵进、中泥盆世由于北秦岭造山带的向南仰冲,形成同造山的前陆拗陷盆地。南秦岭裂陷槽是早古生代小洋盆的残余海槽。西秦岭造山带泥盆纪的地层层序分为海平面变化控制型层序(SC型)、基底构造控制型层序(TC型)和复合型层序(STC型)三种类型。SC型层序发育于中秦岭微板块的小型克拉通盆地,TC型层序发育于同造山盆地和相邻的前隆(反弹)带,STC型层序是造山作用和造山过程的沉积响应。秦岭造山带加里东-早海西期碰撞-造山作用过程较为复杂,北秦岭造山带是由秦岭微板块与华北板块斜向和不规则边缘碰撞形成的,是一个发育不成熟和不均一的造山带,碰撞和造山由西向东,造山作用在西秦岭表现显著;南秦岭洋盆的闭合是秦岭微板块和扬子板块的斜向碰撞形成的,具闭合不碰撞和碰撞不造山的特征,闭合和碰撞由东向西。晚海西-印支期,秦岭进入再生盆地发育阶段。再生盆地于印支-燕山期闭合并造山。  相似文献   

10.
板块碰撞远程效应的传播与地球层圈间的运动   总被引:4,自引:0,他引:4  
我国西部大地构造活动的一大特点是新生代造山作用的复活 ,特提斯洋的最终关闭———印度板块和欧亚板块碰撞的远程效应常被解释为这种构造复活的原因。比较典型的造山带复活是天山造山带 ,天山造山带原生造山发生于古生代末期 ,古天山洋闭合塔里木板块和哈萨克斯坦板块碰撞拼贴形成碰撞造山带。原生造山的主要特点是海西期沿天山造山带发生大规模的中酸性岩浆活动和古生代沉积岩系的广泛变形变质 ,沿碰撞造山带发育有晚古生代蛇绿混杂岩带。古地磁及沉积相证据分析表明原生造山作用以后 ,塔里木板块、哈萨克斯坦板块、西伯利亚和中朝板块一…  相似文献   

11.
An attempt is made to characterize an assembly of Arctic tectonic units formed before the opening of the Arctic Ocean. This assembly comprises the epi-Grenville Arctida Craton (a fragment of Rodinia) and the marginal parts of the Precambrian Laurentia, Baltica, and Siberian cratons. The cratons are amalgamated by orogenic belts (trails of formerly closed oceans). These are the Late Neoproterozoic belts (Baikalides), Middle Paleozoic belts (Caledonides), Permo-Triassic belts (Hercynides), and Early Cretaceous belts (Late Kimmerides). Arctida encompasses an area from the Svalbard Archipelago in the west to North Alaska in the east. The Svalbard, Barents, Kara, and other cratons are often considered independent Precambrian minicratons, but actually they are constituents of Arctida subsequently broken down into several blocks. The Neoproterozoic orogenic belt extends as a discontinuous tract from the Barents-Ural-Novaya Zemlya region via the Taimyr Peninsula and shelf of the East Siberian Sea to North Alaska as an arcuate framework of Arctida, which separates it from the Baltica and Siberian cratons. The Caledonian orogenic belt consisting of the Scandian and Ellesmerian segments frames Arctida on the opposite side, separating it from the Laurentian Craton. The opposite position of the Baikalian and Caledonian orogenic belts in the Arctida framework makes it possible to judge about the time when the boundaries of this craton formed as a result of its detachment from Rodinia. The Hercynian orogenic belt in the Arctic Region comprises the Novozemel’sky (Novaya Zemlya) and Taimyr segments, which initially were an ending of the Ural Hercynides subsequenly separated by a strike-slip fault. The Mid-Cretaceous (Late Kimmerian) orogenic belt as an offset of Pacific is divergent. It was formed under the effect of the opened Canada Basin and accretion and collision at the Pacific margins. The undertaken typification of pre-Late Mesozoic tectonic units, for the time being debatable in some aspects, allows reconstruction of the oceanic basins that predated the formation of the Arctic Ocean.  相似文献   

12.
The Verkhoyansk–Kolyma belt (VK) forms the western part of the Verkhoyansk–Chukotka Mesozoic orogen (NE Asia) and lies between the Siberian craton on the western side, the Mesozoic–Cenozoic Koryak–Kamchatka accretionary orogen on the eastern side, and the Arctic Alaskan craton to the north. The VK results from the collision of the Siberian craton and the Kolyma–Omolon composite terrane (KO), which acted as an indentor resulting the Kolyma orocline. The KO is made up of ophiolite and olistostromal and schistose units that were amalgamated during the Middle–Late Jurassic by thrust and nappe tectonics under greenschist facies metamorphism. This was followed in Latest Jurassic by thrusting and strike-slip faulting related to the collision of the KO composite terrane with the Siberian craton. This collision also produced the Verkhoyansk fold-and-thrust belt in the Siberian continental margin. In the earliest Cretaceous, collision of the Alaskan and Siberian margins resulted in further thrust and strike-slip tectonism.  相似文献   

13.
Previous models for the tectonic evolution of northeastern Siberia have proposed the existence of a Kolyma plate composed of the Kolyma and Omolon massifs of presumed Precambrian age. Lithologic similarities between the Siberian platform and the Cherskiy Mountains and the presence of oceanic and island arc type deposits in the Kolyma-Indigirka interfluve suggest that no such plate exists. The eastern margin of the Siberian plate is suggested to lie along a line between the Ulakhan Sis Range, the Alazeya uplift and the Arga Tas Range; the Cherskiy Mountains and the Verkhoyansk fold belt are parts of the Siberian plate. The Paleozoic deposits of the Omolon massif are unlike those found in the Cherskiys or Siberia. Paleomagnetic data from the Omolon massif are discordant from data from Siberia. It is suggested that the Omolon massif represents a microplate which accreted onto Siberia in the Jurassic. Ophiolites in central Chukotka are of the same emplacement age as in the western Brooks Range and may have been emplaced at the initiation of the rotation of Arctic Alaska. Geometric and limited stratigraphic data suggest that the East Siberian Sea may be floored by oceanic crust left by an incomplete closure between Arctic Alaska, Siberia and Omolon. The tectonic position of the Prikolymsk massif remains ambiguous.  相似文献   

14.
INTRODUCTIONANDBRIEFGEOLOGICALDESCRIP┐TIONSTheUpperOrdovicianmarinevolcanicrocksonthenorthmarginofQaidamhavebeenrepeatedlydis...  相似文献   

15.
沉积大地构造相是反映陆块区、洋区、洋与陆块之间的陆缘区(活动和被动陆缘)形成演变过程中, 在各个演化阶段及其特定的大地构造环境中形成的沉积盆地及其充填序列, 是表达大陆岩石圈板块在离散、汇聚、碰撞、走滑等动力学过程中形成的不同类型沉积盆地及其综合产物, 具有恢复陆块区和造山系形成演化的功能.为从大地构造环境和沉积盆地分析角度系统剖析中国大陆新元古代以来纷繁复杂的大陆增生历程, 根据中国大陆形成演化特点, 提出一套沉积大地构造相(沉积盆地类型)划分方案, 并简述其大地构造环境鉴别标志.该划分方案分4级(相系、大相、相和亚相): 一级为陆块区(含地块)相系和造山系相系.陆块区按构造古地理位置和区域构造应力场进一步划分出二级和三级单元.造山系由弧盆系、叠接带和对接带大相构成, 是岩石圈板块大规模水平运动, 在洋陆转换过程中岛弧增生、弧-弧碰撞、弧-陆碰撞、陆-陆碰撞和陆内俯冲的产物, 常表现为复杂岩石组成、复杂褶皱和断裂构造的巨大山系; 叠接带大相主要由弧-弧碰撞和弧-陆碰撞时, 在陆缘形成的洋-陆转化增生带, 是软碰撞产物; 对接带大相由陆-陆碰撞形成, 是硬碰撞产物.在造山系的弧盆系、叠接带和对接带大相之下, 按洋盆演化-洋陆转化历程所产生的系列构造古地理环境和建造, 进一步划分出洋盆、弧前盆地、弧间盆地、弧后盆地、残余海盆、周缘前陆盆地、弧后前陆盆地等大地构造相单元.   相似文献   

16.
The Scandinavian Caledonides represent a classical example of a deeply eroded Himalayan‐style orogen formed during Baltica–Laurentia continent collision. We propose that initial contact along continental‐margin promontories led to a drop in convergence rate, resulting in increased slab rollback along parts of the margin still undergoing oceanic subduction. Slab rollback caused extension of the overlying lithosphere with orogen‐wide emplacement of mafic layered intrusions, ophiolite formation and bimodal magmatism at 438–434 Ma, in what immediately thereafter became the upper plate (Laurentia) in the Scandian continent–continent collision. A compilation of magmatic ages provides evidence of long‐lived, Ordovician arc magmatism in units above the suture, which is essentially absent below the suture. This model provides a tight constraint on the timing of collision initiation, and provides a framework by which tectonic units comprising the Scandinavian Caledonides can be assigned a Baltican or more exotic heritage.  相似文献   

17.
初论环准噶尔斑岩铜矿带的地质构造背景与形成机制   总被引:34,自引:17,他引:17  
准噶尔地区构造-岩浆-成矿带具环准噶尔地块分布的特征,这一格局是准噶尔地区古生代大地构造演化的结果。哈萨克斯坦-准噶尔板块在北侧古亚洲洋与南侧南天山洋的俯冲下不断侧向增生,并形成与岩浆作用伴生的火山岩型铜铁多金属矿带、斑岩铜钼金矿带与浅成低温金矿带。哈萨克斯坦-准噶尔板块与西伯利亚板块和塔里木板块碰撞发生了强烈挤压-剪切变形,并导致准噶尔地块发生逆时针旋转,从而造成构造-岩浆-成矿带发生位移、呈环状分布于准噶尔地块周边。环准噶尔斑岩铜矿形成于俯冲成因的大陆岛弧、大洋岛弧与弧后盆地及后碰撞阶段板内4种构造背景,晚古生代是成矿的高峰时期。  相似文献   

18.
内蒙古狼山地区断裂构造十分复杂,主要发育有南北、东西、北东和北西走向的断裂构造.从南北向断裂的几何形态、运动性质、构造应力场特征入手进行研究,结合野外实地调查与测量,运用极射赤平投影方法,求出构造应力场的主应力轴方位,进而对本区的构造演化进行了探讨.初步认为,研究区发育的近南北向断裂至少受到过两期构造应力场的作用,第一期是在晚二叠世,由于华北克拉通向北、西伯利亚板块向南活动而形成碰撞拼贴运动所产生的近南北向近水平挤压构造应力场,此时构造应力场的主应力轴σ1为北偏东10°左右,向北倾伏,倾伏角为15°~20°.在这一期构造应力场的作用下,狼山地区发育了一套破裂系统,它们分别表现为近东西走向的挤压构造带和逆断层、近北东走向的以左行为主的走滑断层、近北西走向的以右行为主的走滑断层以及近南北走向的张性断层.这些早期的断裂系统也制约着该区域后来的构造活动,第二期构造应力场是侏罗纪以来古太平洋板块向亚洲大陆俯冲而产生的.此构造应力场的主应力轴σ1为北西-南东向,倾伏向为150°左右,倾伏角为10°~20°.第二期构造应力场的作用,使早期南北向断裂由原来的张性破裂面转为左行走滑,早期东西向断裂转为右行走滑,早期北东向左行滑动面转为压性面和褶皱轴方向,而早期的北西向破裂面则转为张性破裂性质.   相似文献   

19.
The particularities of the current tectonic structure of the Russian part of the Arctic region are discussed with the division into the Barents–Kara and Laptev–Chukchi continental margins. We demonstrate new geological data for the key structures of the Arctic, which are analyzed with consideration of new geophysical data (gravitational and magnetic), including first seismic tomography models for the Arctic. Special attention is given to the New Siberian Islands block, which includes the De Long Islands, where field work took place in 2011. Based on the analysis of the tectonic structure of key units, of new geological and geophysical information and our paleomagnetic data for these units, we considered a series of paleogeodynamic reconstructions for the arctic structures from Late Precambrian to Late Paleozoic. This paper develops the ideas of L.P. Zonenshain and L.M. Natapov on the Precambrian Arctida paleocontinent. We consider its evolution during the Late Precambrian and the entire Paleozoic and conclude that the blocks that parted in the Late Precambrian (Svalbard, Kara, New Siberian, etc.) formed a Late Paleozoic subcontinent, Arctida II, which again “sutured” the continental masses of Laurentia, Siberia, and Baltica, this time, within Pangea.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号