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哀牢山—红河构造带哀牢山段可划分为东部高级变质带和西部低级变质带。构造分析表明:该构造带由3个不同变形域组成,可能代表其经历的3期左行走滑。第1期走滑发生在整个高级变质带,为拉张性左行走滑,形成角闪岩相L型构造岩。第2期走滑形成高级变质带中的高应变带,变形体制接近简单剪切,形成绿片岩相L-S型糜棱岩。第3期主要发生在低级变质带,为挤压性走滑,形成左行逆冲构造格局,并形成低绿片岩相千糜岩。地质年代学数据证明,3期左行走滑的形成时代分别是:距今58~56Ma、27~22Ma和13~12Ma±。哀牢山—红河构造带第1期左行走滑可能对应于印度与欧亚大陆距今60Ma左右的初始碰撞;第2期变形与青藏高原最强的挤压隆升期一致;第3期事件可能代表距今16~13Ma开始的青藏高原物质进一步东挤。哀牢山—红河构造带的3期主要左行走滑均发生在新生代印度与欧亚大陆的汇聚过程中。 相似文献
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澜沧江断裂带的新生代走滑运动学特点 总被引：10，自引：1，他引：9
通过对澜沧江断裂带北、中、南段新生代构造形迹的运动学解析,结合前人工作,论证了澜沧江断裂在新生代早期(古新世-中始新世末)、中期(晚始新世-渐新世末)、晚期(中新世-第四纪)的走滑运动序列为：中、南段,右行→左行→右行;北段,左行→左行→右行。研究表明,澜沧江断裂带早期主要表现为中、南段的右行逆冲和北段的左行逆冲,与同期发生的昌都-思茅地体颈缩事件相对应,其地球动力学背景与太平洋板块向西推挤作用以及扬子-华南板块与印度板块发生的强烈东西向碰撞挤压有关;中期,整个断裂发生左行逆冲,其地球动力学背景与南海盆地的扩张作用及其扬子-华南板块相对于印度板块北移所致的左行扭动相适应：晚期,整个断裂右行走滑,与太平洋构造域的南海盆地扩张终止,昌都思茅地体整体向南东逃逸相适应。 相似文献
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哀牢山-红河剪切带中段多阶段新生代花岗岩脉:同位素年代学及对于剪切应变型式转变时间的约束 总被引：1，自引：1，他引：0
哀牢山-红河剪切带是新生代印度板块与欧亚板块碰撞过程中发育的大规模走滑型剪切带,其发育对于碰撞过程中印支地块的南东向逃逸以及藏东南地区构造格局的形成具有重要的贡献。与剪切带演化相关,伴随发育多阶段花岗岩脉就位,它们为限定剪切变形时限、阐明剪切作用属性提供了重要证据。本文在野外观察基础上,应用显微构造和EBSD石英c-轴组构分析查明花岗岩脉的构造特点与应变型式,同时采用锆石LA-ICP-MS测年方法获得岩脉侵位与结晶年龄。年龄分析结果表明,岩脉年龄分别为27.09±0.48Ma、25.17±0.23Ma和25.16±0.50Ma,其中年龄为27.09±0.48Ma的花岗岩脉具有糜棱岩化现象,其变形特征体现为中温变形后叠加低温变形,且剪切变形形式由一般剪切转换为简单剪切;年龄为25.17±0.23Ma的花岗岩脉表现出同剪切晚期构造特征,且具有较低温度简单剪切变形特点;25.16±0.50Ma的切穿糜棱叶理,矿物未见变形,可能代表剪切期后岩脉。结合区域构造,推测剪切方式由纯剪为主的剪切向由单剪为主的剪切转换发生在27Ma和25Ma之间,哀牢山-红河剪切带中段在约25Ma走滑运动结束。 相似文献
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与时俱进,发展中国大地构造学 总被引：38，自引：1，他引：38
郯庐断裂带的起源时间与型式仍然存在着很大的分歧。最近在大别山东缘早白垩世左旋走滑韧性剪切带中 ,发现了早期左旋走滑韧性剪切带。其中三处早期糜棱岩中白云母分别给出了( 188.7± 0 .7)Ma、( 189.7± 0 .6 )Ma、( 192 .5± 0 .7)Ma的40 Ar/ 3 9Ar坪年龄 ,指示了同造山走滑热事件。前陆沉积与变形构造也表明该断裂带在华北与华南板块碰撞中就发生了活动。郯庐断裂带内的造山期构造及旁侧的前陆沉积与变形构造特征 ,指示断裂带同造山运动为转换断层型式 ,并将大别—苏鲁造山带左行错移了约 35 0km ,同时苏鲁造山带发生逆时针旋转。在早白垩世滨太平洋构造活动中 ,该断裂进一步向北延伸 ,发生了约 2 0 0km的左行平移。因而 ,该断裂带起源于华北与华南板块的碰撞之中 ,其同造山运动与这两大板块的碰撞过程相伴生 相似文献
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构造分析表明,哀牢山-红河构造带哀牢山段由3个不同变形域组成,它们可能代表该构造带所经历的3期左行走滑。第一期左行走滑发生于构造带的整个东部高级带,变形体制为拉张性走滑,并形成角闪岩相L型构造岩。第二期走滑形成东部高级带的强变形带,变形体制接近简单剪切并形成绿片岩相L-S型糜棱岩。第三期左行走滑主要发生于西部低级带,变形体制为挤压性走滑,形成一左行逆冲的整体构造格局,并在变形带上形成千糜岩。地质年代学数据证明,三期左行走滑的形成时代分别是:58～56Ma以前、27Ma到22Ma、13～12Ma左右。哀牢山-红河构造带第一期走滑可… 相似文献
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郯庐断裂带肥东段早白垩世中期走滑运动的年代学证据 总被引：3，自引：0，他引：3
郯庐断裂带肥东段西韦地区和桃花源地区出露了大规模的北北东向韧性剪切带。桃花源地区韧性剪切带显示出2期构造变形的叠加。野外构造和显微构造分析皆指示为左行走滑韧性剪切带。糜棱岩中石英与长石的变形行为指示其变形温度分别为400~450℃和500℃。通过对这两处走滑剪切带内糜棱岩化花岗岩脉的锆石LA-ICP-MS定年,获得了3个样品的侵位年龄分别为(133.2±1.9)Ma,(131.3±2.0)Ma,(130.3±2.0)Ma。再结合已有的研究成果,认为在128~124Ma(早白垩世中期)郯庐断裂带发生过左行走滑活动。综合分析表明,郯庐断裂带在晚侏罗世和早白垩世中期分别经历了2期左行走滑活动,而期间和之后的早白垩世则处于伸展活动之中。伸展活动持续较长,控制发育了西侧的合肥盆地及断裂带内一系列岩浆活动;而区域挤压背景下出现的走滑活动则相对短暂。这些演化规律显示该断裂带在晚侏罗世—早白垩世呈现为交替式的走滑和伸展活动。新发现的早白垩世中期走滑活动,与太平洋区伊泽纳崎板块板块运动方向的调整相对应,是大洋板块运动方向短暂调整的构造响应。 相似文献
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大兴安岭北段地壳左行走滑运动的时代及其对中国东北及邻区中生代以来地壳构造演化重建的制约 总被引：59，自引：0，他引：59
中国东北及邻区 ,在中生代期间是否经历了大规模走滑运动而发生向东的逃逸和地壳加厚 ,是该区乃至碰撞造山带后碰撞地壳构造演化的一个重要问题。在对已有资料的综合分析基础上 ,大兴安岭北段中生代以来的构造变形可以划分为四期 :( 1 )可能发生在侏罗纪晚期的向南逆冲推覆运动 ;( 2 )平行蒙古—鄂霍茨克造山带的左行韧性走滑剪切作用 ;( 3)切割上述韧性走滑剪切带和蒙古—鄂霍茨克造山带的向南东的逆冲断裂作用 ;( 4)新生代北北东走向的正断作用。根据时空展布和运动学特征 ,推测前两期变形与蒙古—鄂霍茨克造山带的形成演化有关 ,第三期变形与古太平洋板块在亚洲大陆下的俯冲有关 ,第四期变形与现今太平洋板块的俯冲有关。对采自第二期构造变形带内的同构造变质矿物黑云母的Ar Ar定年 ,获得了 1 2 7～ 1 30Ma的坪年龄和等时线年龄 ,据此确定该区地壳左行走滑运动的主要活动时期为白垩纪初期。这一研究成果与中国东北南部燕山地区走滑运动资料的结合 ,揭示出在白垩纪初期 ,中国东北及邻区地壳被向东挤出加厚。根据已有的区域地质资料 ,中国东北中生代以来地壳构造演化可以划分为 4个阶段 :( 1 )三叠纪期间与古亚洲洋关闭和杭盖—肯特洋及古太平洋收缩有关的地壳挤压与伸展变动 ;( 2 )侏罗纪至白垩纪初 相似文献
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红河断裂带莺歌海段地质构造特征 总被引：3，自引：0，他引：3
红河入海后的地质构造特征研究是当前红河断裂带研究的薄弱环节.结合莺歌海地区重力和地震资料解释与前人研究成果,系统总结了红河断裂带莺歌海盆地内的几何学、运动学特征,并根据莺歌海盆地沉积中心迁移规律获得了红河断裂带的年代学数据.研究认为:红河断裂带在入海口附近分叉,其中Tien Lang断层折向NE,呈马尾状展布;在莺歌海盆地内红河断裂带分支为A(Ⅰ号断层)、B、C和D(莺西断层)4条断层,其中A断层是最主要的一条分支断层.莺歌海盆地内的分支断层均呈近NW-SE走向,延伸420～500km,其地震解释剖面上发育的典型花状构造和马尾状Tien Lang断层共同指示该断层具有走滑运动性质;红河断裂带对莺歌海盆地的沉积具有明显的控制作用,盆地沉积中心变化规律揭示红河断裂带在30～15.5Ma期间具有左行走滑运动性质,15.5～5.5Ma期间为左行向右行转换阶段,发生了强烈的构造反转作用,5.5Ma以来具有右行走滑运动特征. 相似文献
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本文系统论述了西南三江地区那邦、高黎贡山、崇山-澜沧江、点苍山-哀牢山-红河剪切走滑带、区域性伸展与变质核杂岩、新生代盆地及走滑过程中的碱性岩浆活动等特征,认为西南三江地区经历了挤压收缩变形(60~40Ma)、走滑伸展热隆(40~38Ma)、走滑剪切深熔(38~23Ma)、走滑剪切伸展(23~11Ma)、走滑剥蚀隆升(11~5Ma)5个时空演化阶段,并对应5种运动机制及动力学机制:碰撞挤压、走滑拉张热隆(岩浆)、走滑剪切深熔、剪切伸展、走滑垮塌,主要表现为走滑造山。西南三江造山带是印度板块向欧亚板块斜向俯冲形成的多条巨型顺时针走滑剪切带,其间的块体向南逸出并顺时针旋转。走滑断层系起了位移量调节和构造变换的作用,西南三江造山带为典型的走滑造山带。 相似文献
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CENOZOIC LARGE-SCALE STRIKE-SLIP FAULT IN WEST YUNNAN, CHINA1 ZhongDalaiTapponnierP ,WuHaiwei,etal.Large scalesstrikeslipfault:themajorstructureofintracontinentaldeformationaftercollision[J] .ChineseScienceBulletin ,1990 ,35:77～ 97.
2 TapponnierP ,LacassinR ,LeloupPH ,etal.TheAilaoShan/RedRivermetamorphicbelt:tertiaryleft lateralshearbetweenIndochinaandSouthChina[J] .Nature,1990 ,343:4 31～ 4 37.
3 LiKang ,ZhongDalai.Themicrostructurecharacteristicso… 相似文献
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青藏高原新生代形成演化的整合模型——来自火成岩的约束 总被引：28，自引：8，他引：28
深部过程是青藏高原演化的主导因素,其他地质过程都可以看作是对深部过程的响应。因此,一个构造旋回(阶段)的地球动力学事件链可以概括为深部地质过程—幔源岩浆活动—壳源岩浆活动—陆壳增厚—地表隆升—表层剥蚀与沉积,其中幔源岩浆活动的研究成为追索青藏高原演化历史的关键环节。据此,青藏高原演化的关键性时间坐标为80、45、27、17、9和4Ma。青藏高原新生代火成岩具有三种展布形式:与雅鲁藏布缝合带平行的岩浆带、沿深大断裂展布的岩浆带和藏北离散性岩浆分布区,它们分别受控于大陆碰撞、大规模走滑和岩石圈拆沉构造体制,且都受控于印度—亚洲软流圈汇聚过程。据此,文中提出了一个描述青藏高原演化的整合模型:南北向地幔对流汇聚控制了岩石圈块体的相对运动,并最终导致印度—亚洲大陆的碰撞和沿碰撞带的大规模岩浆活动;碰撞之初(白垩纪末期),大陆岩石圈块体的刚性属性有利于应力的远程传递和块体旋转,沿块体边界分布的大型走滑断裂控制了岩浆活动的发生;随着挤压过程的持续进行,岩石圈块体的受热和变形,高原岩石圈的重力不稳定性增加,最终导致拆沉作用和软流圈物质的大规模上涌以及藏北高原的离散性岩浆活动。在高原演化中,岩石圈拆沉作用具有重要意义,许多地质事件的发生都与此有关。同时,软流圈的汇聚还导致软流圈物质的向东挤出,并因此造成青藏高原岩石圈的向东挤出和晚新生代的伸展构造。 相似文献
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《Gondwana Research》2014,26(4):1644-1659
The formation of a series of intermountain basins is likely to indicate a geodynamic transition, especially in the case of such basins within the central South China Block (CSCB). Determining whether or not these numerous intermountain basins represent a division of the Cretaceous Pan-Yangtze Basin by exhumation of Xuefeng Mountains, is key to understanding the late Mesozoic to early Cenozoic tectonics of the South China Block (SCB). Here we present apatite fission track (AFT) data and time–temperature modeling in order to reconstruct the evolution history of the Pan-Yangtze Basin. Fourteen rock samples were taken from a NE–SW-trending mountain–basin system within the CSCB, including, from west to east, the Wuling Mountains (Wuling Shan), the south and north Mayang basins, the Xuefeng Mountains (Xuefeng Shan) and the Hengyang Basin. Cretaceous lacustrine sequences are well preserved in the south and north Mayang and Hengyang basins, and sporadically crop out in the Xuefeng Mountains, whereas Paleogene piedmont proluvial–lacustrine sequences are only found in the south Mayang and Hengyang basins. AFT results indicate that the Wuling and Xuefeng mountains underwent rapid denudation post-84 Ma, whereas the south and north Mayang basins were more slowly uplifted from 67 and 84 Ma, respectively. Following a quiescent period from 32 to 19 Ma, both the mountains and basins have been rapidly denuded since 19 Ma. Both the AFT data and sedimentary facies changes suggest that the Cretaceous deposits that cover the south–north Mayang and Hengyang basins through to the Xuefeng Mountains define the Cretaceous Pan-Yangtze Basin. Integrating our results with tectonic background for the SCB, we propose that rollback subduction of the paleo-Pacific Plate produced the Pan-Yangtze Basin, which was divided into the south–north Mayang and Hengyang basins by the abrupt uplift and exhumation of the Xuefeng Mountains from 84 Ma to present, apart from a period of tectonic inactivity from 32 to 19 Ma. This late Late Cretaceous to Paleogene denudation resulted from movement on the Ziluo strike–slip fault, which formed due to intra-continental compression most likely associated with the Eurasia–Indian plate subduction and collision. Sinistral transpression along the Ailao Shan–Red River Fault at 34–17 Ma probably transformed this compression to the extrusion of the Indochina Block, and produced the quiescent window period from 32 to 19 Ma for the mountain–basin system in the CSCB. Therefore, the initiation of exhumation of the Xuefeng Mountains at 84 Ma indicates a switch in tectonic regime from Cretaceous extension to late Late Cretaceous and Cenozoic compression. 相似文献
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通过在红河两侧（大姚、景谷、江城、勐腊剖面）的早第三纪古地磁样品的研究，进一步证实了红河两侧由白垩纪古地磁研究所揭示的印支地块相对于华南地块存在的左旋相对运动。这一结果说明了印度支那地块在印度板块的挤压下，于早第三纪至中新世沿红河大断裂发生向南侧向滑移达1000km左右，它不仅使青藏高原的巨大构造缩短得到调整，而且在北部湾地区形成伸展构造，并引起南中国海的张开。印度支那地块北部各地区的差异性旋转和红河断裂共轭的剪切断裂系的发育，以及红河大断裂早第三纪至中新世左旋剪切作用密切相关。 相似文献
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It seems to be progressively recognized that the stress of the India-Asia convergent front can be transferred rapidly through the southern and central Tibetan lithosphere to the northern Tibet, hence leading to the crustal thickening deformation there during or immediately after the onset of the India-Asia collision(ca.55 Ma).This study focuses on the late Cenozoic deformation and tectonic uplift of the northern Tibet and Tian Shan area.Detailed compilations of a variety of proxy data from sediments and bedrocks suggest that the northern Tibet and Tian Shan area underwent one stage of approximately synchronous widespread contractile deformation since 25–20 Ma, which seemed to decrease at circa 18 Ma as revealed by low-temperature thermochronological data.The latest Oligocene-early Miocene was also significant basin-forming episodes when many intermontane subbasins began to receive syntectonic sedimentation in the northeastern Tibet.Subsequently, the other phase of compressional deformation began to encroach more widely into the northern Tibet and Tian Shan area in episodic steps or continuously from 16–12 Ma to present. 相似文献
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青藏高原的新生代火山作用是印度-亚洲大陆碰撞的火山响应,它显示了系统的时、空变化。随着印度-亚洲大陆碰撞从~65 Ma的接触-碰撞(即"软碰撞")转变到~45 Ma的全面碰撞(即"硬碰撞"),火山作用也逐渐从钠质+钾质变为钾质-超钾质+埃达克质。65~40 Ma的钾质和钠质熔岩主要分布于藏南的拉萨地块,少量分布于藏中的羌塘地块。从45~26 Ma,在藏中的羌塘地块中广泛发育钾质-超钾质熔岩和少量埃达克岩。随后的碰撞后火山作用向南迁移,在拉萨地块中产生~26~10 Ma间的同时代超钾质和埃达克质熔岩。尔后,从~18 Ma始,钾质和少量埃达克质火山作用重新向北,在西羌塘和松潘-甘孜地块中呈广泛和半连续状分布。此种时-空变异对形成青藏高原的深部地球动力学过程提供了重要约束。该过程包括:已消减的新特提斯大洋板片的回转、断离及随后增厚拉萨岩石圈根的去根作用,及因此而造成的印度岩石圈向北下插。青藏高原的隆升是自南向北穿时发生的。高原南部被创建于渐新世晚期,并保持至今;直到中新世中期,由于下插印度岩石圈的持续向北推挤,西羌塘和松潘-甘孜岩石圈的下部开始塌陷和拆离,高原北部才达到其现今的高度和规模。 相似文献
18.
Understanding the pre-collisional paleogeography in the NE Tibetan plateau provides insights into the growth mechanisms of the northern portion of the plateau in the Cenozoic. We conducted sandstone petrography analysis and determined U-Pb ages for detrital zircons from Cretaceous sandstone from the Yumen Basin and the northern Qilian Shan. Cretaceous strata in the northern Yumen Basin yield a unimodal age population at 290–240 Ma that indicates primary derivation from Bei Shan. Cretaceous strata in the westernmost Yumen Basin contain zircons of 2.6–2.2 Ga, 2.1–1.7 Ga, 1.4–0.7 Ga, 440–380 Ma and 300–230 Ma, suggesting source derivation from both the Qilian Shan and Bei Shan. Within the northern Qilian Shan, Cretaceous strata yield age populations of 2.8–2.3 Ga, 2.1–1.2 Ga, 480–380 Ma and ca. 270 Ma, indicating derivation from the Qilian Shan. Sandstone composition results show that a sample from the northern Qilian Shan contains more lithic fragments and plots in the recycled orogen field of the quartz-feldspar-lithics (QFL) diagram, while samples from Yumen Basin are more quartz-rich and plot close to the continental block field of the QFL diagram. This compositional difference corresponds to source variation, consistent with the detrital zircon record. Combined with existing sedimentology and low-temperature thermochronology datasets, we suggest the presence of Cretaceous topographic relief in the Bei Shan and Qilian Shan prior to India-Asia collision. Considering >300 km post-Cretaceous left-lateral offset along the Altyn Tagh Fault (ATF) and the consistently similar detrital zircon ages spectra of the samples from the Cretaceous to late Oligocene strata in the Yumen Basin, we infer the paleogeography in the NE Tibetan plateau has been similar from the late Cretaceous to the late Oligocene with ATF termination in the western Yumen Basin instead of having been linked to strike-slip faults in the Alxa or other regions to the east since its initiation. 相似文献
19.
《地学前缘(英文版)》2020,11(4):1123-1131
Collision between the Indian and Eurasian plates formed the ～2500 km long Yarlung Zangbo Suture Zone and produced the Himalaya mountains and Tibetan plateau.Here we offer a new explanation for tectonic events leading to this collision:that the northward flight of India was caused by an Early Cretaceous episode of subduction initiation on the southern margin of Tibet.Compiled data for ophiolites along the Yarlung Zangbo Suture Zone show restricted ages between 120 Ma and 130 Ma,and their supra-subduction zone affinities are best explained by seafloor spreading in what became the forearc of a north-dipping subduction zone on the southern margin of Tibet.The subsequent evolution of this new subduction zone is revealed by integrating data for arcrelated igneous rocks of the Lhasa terrane and Xigaze forearc basin deposits.Strong slab pull from this new subduction zone triggered the rifting of India from East Gondwana in Early Cretaceous time and pulled it northward to collide with Tibet in Early Paleogene time. 相似文献
20.
Active faults and magnitudes of left-lateral displacement along the northern margin of the Tibetan Plateau 总被引：21，自引：0，他引：21
Guoyu Ding Jie Chen Qinjian Tian Xuhui Shen Chengqi Xing Kaibo Wei 《Tectonophysics》2004,380(3-4):243-260
The northern margin of the Tibetan Plateau (NMTP) is a major intracontinental Cenozoic transpressional zone that comprises a series of active strike-slip faults and thrust faults. It is important to document cumulative horizontal displacements along the NMTP in order to understand quantitatively strain partitioning in East Asia since the India–Eurasia collision. Based on an analysis of horizontal slip along major active faults, the total amount of horizontal displacements is estimated up to 700 km between the Tibetan Plateau and the Tarim Basin since the convergence of India and Eurasia. Along the western and middle segment of the Altyn Tagh fault to the northern margin of the Qaidam Basin, there are abundant evidence that show that the net displacement is 400 km since 40–35 Ma, and along the Shulenan Shan and southeast of middle Qilian Shan since 25–17 Ma, the amount of offset is 150 km. The largest horizontal slip in Qilian Shan–Hexi Corridor to the northeast of the Altyn Tagh fault is also 150 km since late Oligocene to early Miocene. It decreases to only 60 km along the Haiyuan fault (since late Miocene) and to 25 km along the Zhongwei–Tongxin fault since the Pliocene (about 5.3–3.4 Ma), at the northeast margin of the Tibetan Plateau. This clearly implies northeastward diminishing of the total horizontal displacement and temporal getting younger of the fault slip along the NMTP. However, this tendency is very complicated at different times and different segments as a result of the uplift, growth and rotation of different segments of the NMTP at different stages during the convergence of India and Eurasia. 相似文献