鲜水河断裂带研究进展

鲜水河断裂作为协调藏东地区高原物质挤出的边界断裂,在青藏高原构造演化中起着很重要的作用.近年来对其几何学运动学的研究表明断裂在南缘发生构造转换,形成小江地区的盆岭地貌;在西北端可能与风火山逆冲推覆构造相连.断裂具有分散变形和围绕东构造结旋转的特征.其年代学研究揭示断裂可能有两期活动,(15～13)Ma左右断裂开始做左旋走滑活动,但其活动范围可能局限在龙门山逆冲推覆构造带后缘;在5Ma左右,断裂重新活动并切穿了龙门山断裂延伸到小江断裂带.造成断裂分期活动的原因是藏东地区下地壳流体的存在.断裂形成的机制可能是由于晚中新世以来下地壳流体向藏东地区扩散,引起藏东地区地壳的增厚和高原的隆升,当高原隆升到一定高度,周缘块体无法继续承担高原隆升造成的压力时,高原物质向周缘挤出时产生的.     

莺歌海盆地东方1-1底辟区深部热流体穿层的热应力及其效应

东方1 - 1底辟区的热流体活动相当强烈和频繁.深部热流体的穿层上涌产生热应力造成了局部的应力场状况的变化, 形成了特征性的构造和断裂系统, 水力破裂、热流体拱张形成褶皱和局部破裂等, 这些褶皱和断裂共同构成了底辟带热流体活动中垂向输导的主要通道之一.由于热流体穿层活动不仅携带了大量的烃类气和CO₂等非烃气, 而且具极强的热力作用, 引起了强烈的热异常, 导致所穿入的浅部地层中的热力学参数, 如粘土矿物的演化、储层中流体包裹体以及岩石所含有机质的镜质体反射率等发生一系列的异常变化, 致使底辟作用前后底辟体内部及其围岩的特征具有非常显著的差别.本次研究对热流体穿层所引起的热应力效应和温度异常采用Field模型进行了定量动力学模拟, 结果显示应力场和温度场的分布随着时间不断向上迁移, 使各小断裂和裂隙连通形成流体的良好的垂向运移通道, 在热流体活动的通道附近热应力的影响十分明显, 致使局部应力急剧增高      

青藏高原新生代火山活动的深部力学背景

为了研究火山形成基本要素——岩浆运移通道的形成, 基于重力异常反演的青藏高原下地壳底部的地幔对流应力场, 结合地壳破裂形成机理和对流应力场与青藏高原新生代火山分布的关系, 以及青藏高原下地幔对流演化的数值模拟结果, 分析了高原火山岩浆运移通道产生的深部力学机制.研究表明, 高原下地幔对流应力场存在两个大的拉张区, 高原中部和北部的火山岩均分布于拉张应力区.南部的林子宗火山区对应了印度板块与欧亚大陆碰撞前或碰撞早期高原下的地幔上升流.对流应力的量级为~100Ma, 这与导致地壳破裂的应力量级相当.所有这些证据表明, 青藏高原下地幔对流应力场可能是导致高原地壳破裂, 并发展为岩浆物质通道的主要力学机制之一.      

西藏中,南部壳内高导体与热结构特点

以ＩＮＤＥＰＴＨ－ＭＴ发现的西藏中，南部壳内高导体分布特征为依据，结合西藏地热学研究资料进行综合分析，探讨了喜马拉雅构造带与冈底斯构造带的地壳热结构特点。认为藏南喜马拉雅地区是以横向发育的中深层区域性热变异带迭向延深的局部热异常带为其地壳热结构特点。而藏中冈底地区则以宽阔热背景叠覆较大面积熔融或局部熔融层为地壳热结构特点。就热量来源而论，喜马拉雅地区以构造生热作用为主，而冈底斯地区则来源于炽热软流     

广西丹池盆地泥盆系浊积岩和硅质岩的特征及构造意义

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。     

新疆北部及邻区贵重、有色金属成矿历史及前景

新疆北部及邻区的地壳发展演化历史十分复杂，从太古宙至今，经历了３０亿年的长期演变，形成了独具特色的矿产资源和矿床分布格局。本文通过对该区地壳演化历史的研究，划分出４个成矿阶段，着重探讨了各阶段的构造、岩石和成矿作用特征，论述了各阶段的构造、岩石和成矿作用特征，论述了贵重、有色金属矿产在地壳发展演化过程中的分布规律，指出了新疆北部及邻区贵重、有色金属矿产的主攻类型及找矿方向。     

滇西北地区第三纪的逆冲－推覆构造

滇西北地区始新－渐新世的逆冲断裂系走向南北，向西倾，向东变晚，受新特提斯闭合和碰憧控制；中新世晚期－上新世早期的逆冲断裂系走向东西，朝北倾，与青藏高原的隆升有关，见于高原边缘。它们构成前导叠瓦扇，局部有反冲现象，以推覆距离小、影响深度浅为特征，控制了磨拉石盆地、浅成斑岩和膏盐底辟体的发育，在其西和其北分别发育与之对称的逆冲断裂系，构成科伯构造。     

山东东部早白垩世青山期穿地壳岩浆系统与热隆滑脱成盆

穿地壳岩浆系统模型是近年新提出的一个全新的岩浆系统概念.聚焦山东东部早白垩世青山期穿地壳岩浆系统,在野外地质踏勘的基础上,结合火成岩年代学、断裂体系分布、大地构造学与地球化学的相关研究成果,系统探讨了不同性质火山岩浆的时空演化与分布特征.首先,在时间序列上,早白垩世青山期穿地壳岩浆系统,表现为酸性岩浆侵位-基性岩浆侵入-中性岩浆喷发的特征;其次,在不同的地壳深度,穿地壳岩浆系统有不同的表现,由深到浅,呈现岩基/岩株-岩脉岩墙-火山机构的变化;空间分布上,酸性岩体多位于古隆起区,火山机构沿深大断裂呈现串珠状分布.穿地壳岩浆系统的发育特征指示了青山期岩石圈的构造特征:岩体自身近E-W向展布,说明岩体侵入时的中上地壳的断裂体系主要为近E-W向,而岩体整体上沿着NE-SW向分布,说明了更深部断裂体系主要为NE-SW向,控制了整个区域构造的发育.早白垩世早期（莱阳期）区域发育的浅层构造断裂系统为早白垩世晚期（青山期）的穿地壳岩浆系统的发育提供了通道.早白垩世青山期穿地壳岩浆系统的发育伴随着区域热隆-伸展-滑脱作用,在此过程中山东东部青山期盆地格局形成.花岗岩抬升速率初步计算的结果表明山东东部地区早白垩世青山期的热隆速率略快于2.7~4.1 mm/a,强烈的"热隆-伸展-滑脱"作用是同期沉积盆地形成的主要动力学机制.      

燕山期构造—热事件演化与小秦岭金矿床的形成

本文以小秦岭金矿床的基本地质特征为基础，分析了燕山期构造－热事件的演化规律及其与花岗岩、韧性剪切带和金矿床的关系。认为花岗岩是构造－热事件高峰期地壳深部物质部分熔融的产物，区域性热异常的出现则导致地壳浅部形成了韧性剪切带。构造－热事件晚期，随着热异常的衰减，剪切带的变形性质发生转化并有序叠加，金矿床便是在这一变形性质转化与叠加过程中，在成矿流体演化的晚期形成的。花岗岩侵位在局部造成横向上显著的物理     

造山带蠕动应力场格局与后造山伸展作用

在理解岩石圈内部流变分层性和造山带热异常形成与演化多控制因素的基础上，建立了造山带热－应力作用数值模型，研究了不同参数下造山带不同部位蠕动应力场的格局及其演化。其研究结果表明，碰撞终止后岩石圈内部应力调整或热松驰控制了造山带内部不同层次构造样式。在造山带中心，加厚岩石圈在碰撞附加力终止后40Ma，岩石圈应力强度明显减少，可诱发科迪勒拉式后造山伸展作用；在地壳中下层次或岩石圈深部（约40～60km、120～150km）可发生拆沉作用，但非岩石圈地幔的整体拆沉，其动力源自岩石圈套内部相应层位的应力引张；在40Ma以内或在拆沉作用发生前，岩石圈地幔根部及地壳中下层次作为热的应变软化区段，相应控制着Moho面形态及中上地壳构造样式；缝合带及造山带前缘作为应力挤压区，在10Ma可出现局部应力引张，孕育喜马拉雅式伸展。但在宽度巨大的造山带（1000km以上），后造山伸展作用的发生则与带内其它大规模构造活化有关。     

Spatial and temporal distribution of peraluminous granites in Tibet and their tectonic significance

The distribution of peraluminous granites in Tibet is treated on the basis of the tectonic zones in which they occur, their spatial and temporal distribution, the peak of magmatic activity and the volume of magma intruded. Magmatic activity, with the intrusion of peraluminous granites, was initiated during the Early Jurassic and culminated in the middle Miocene, especially between 20 and 10 Ma. Rock types include tourmaline, muscovite and two-mica granites. Magmatic activity in the Gangdise Belt migrated from the east to west and from the south to the north. Episodes of tectonic evolution for the lithosphere of the Qinghai–Xizang (Tibet) Plateau, deduced from peraluminous granite intrusion are: (1) Latest Triassic to Early Jurassic (208–157 Ma), representing the subduction phase of the Bangong Co–Nu Jiang oceanic zone; (2) Late Jurassic to Early Cretaceous (157–97 Ma), representing the subduction and collision phases of the Bangong–Nu Jiang oceanic zone; (3) Late Cretaceous to early Paleocene (97–65 Ma), representing the subduction and initial collision phases of the Yarlung Zangbo oceanic zone ; (4) Paleocene to Eocene (65–40 Ma), representing the major collisional stage of the Yarlung Zangbo Oceanic zone and the formation of crust-derived granites; and (5) Oligocene to Recent, representing an intense intracontinental convergence phase.     

大陆板内盆山耦合及盆山成因——以青藏高原及周边盆地为例

摘要：大陆造山带与沉积盆地之间具有十分密切的内在联系,空间上相互依存,物质上相互补偿,构造上相互作用,时间上同步演化。这些内在联系体现在统一的形成机制上:大陆造山带和沉积盆地是在大陆边缘俯冲板片脱水熔融和大陆内部地幔柱(枝)上隆的热动力作用下,地壳由盆向山侧向流动,导致盆山地壳物质发生循环运动。青藏高原与周边盆地的耦合作用十分典型。青藏高原不是印度板块与欧亚板块碰撞的结果,而是形成于下地壳流动驱动的板内盆山作用。青藏高原板内盆山耦合可分为两个阶段:(1)板内造山成盆阶段,表现为180～120 Ma→65～30 Ma→23～7 Ma从青藏高原北部和东部盆山系统→青藏高原中部盆山系统→青藏高原南部盆山系统有序迁移,以构造隆升、水平运动、地质作用和大规模板内金属成矿为特征;(2)均衡成山成盆阶段,表现为从36 Ma开始,青藏高原整体快速隆升和周边沉积盆地边缘坳陷带巨厚的磨拉石沉积,以36 Ma B.P.、25 Ma B.P.、18~12 Ma B.P.、 08 Ma B.P.和015 Ma B.P.等一系列脉动式快速隆升、垂直运动、地理作用和水系 环境变化为特征。大陆板内盆山构造演化经历从伸展构造向挤压构造的转换,伴随盆地主动作用转变成造山带主动作用。大陆下地壳流动和盆山耦合形成非安德森式的低角度拆离断层、波状起伏逆冲断层和异常共轭关系走滑断层。     

THE NUMERICAL SIMULATE OF THE UPLIFT PROCESS OF THE QINGHAI—TIBET PLATEAU

THE NUMERICAL SIMULATE OF THE UPLIFT PROCESS OF THE QINGHAI—TIBET PLATEAU     

The Characteristics of the Indosinian Pacific-Type Ancient Continental Margin in the Qinghai-Xizang (Tibet)-Sichuan-Yunnan Region1

Abstract The Qinghai- Xizang (Tibet) Plateau and the “Sanjiang” area², where are extensively developed the Tethys-type marine Triassic sequences with Indosinian tectonic disturbance and magmatism, provide an important region for the study of the tectonic evolution and the Indosinian movement of China as well as for the study of the boundary between Gondwana and Laurasia and the characteristics of the time-space distribution of the Tethys oceanic crust within the territory of China. Over a long period of time in the past, quite a number of scholars made substantial studies and discussions from various viewpoints on the geotectonic and regional geological evolution of this region. Based on some new data obtained recently and the field observations by the author, and by using the plate tectonic theory, the author considers that there developed a Pacific-type (active type) ancient continental margin bordering the Palaeo-Tethys ocean (or North Tethys ocean) in the south in Late Permian to Triassic times in the region of south-central Qinghai, northeastern Xizang (Tibet), western and southwestern Sichuan, and western Yunnan. Its characteristics basically represent the Indosinian tectonic evolution of this region.     

Sedimentary Evolution of the Qinghai–Tibet Plateau in Cenozoic and its Response to the Uplift of the Plateau

We have studied the evolution of the tectonic lithofacies paleogeography of Paleocene–Eocene, Oligocene, Miocene, and Pliocene of the Qinghai–Tibet Plateau by compiling data regarding the type, tectonic setting, and lithostratigraphic sequence of 98 remnant basins in the plateau area. Our results can be summarized as follows. (1) The Paleocene to Eocene is characterized by uplift and erosion in the Songpan–Garzê and Gangdisê belts, depression (lakes and pluvial plains) in eastern Tarim, Qaidam, Qiangtang, and Hoh Xil, and the Neo-Tethys Sea in the western and southern Qinghai–Tibet Plateau. (2) The Oligocene is characterized by uplift in the Gangdisê–Himalaya and Karakorum regions (marked by the absence of sedimentation), fluvial transport (originating eastward and flowing westward) in the Brahmaputra region (marked by the deposition of Dazhuka conglomerate), uplift and erosion in western Kunlun and Songpan–Garzê, and depression (lakes) in the Tarim, Qaidam, Qiangtang, and Hoh Xil. The Oligocene is further characterized by depressional littoral and neritic basins in southwestern Tarim, with marine facies deposition ceasing at the end of the Oligocene. (3) For the Miocene, a widespread regional unconformity (ca. 23 Ma) in and adjacent to the plateau indicates comprehensive uplift of the plateau. This period is characterized by depressions (lakes) in the Tarim, Qaidam, Xining–Nanzhou, Qiangtang, and Hoh Xil. Lacustrine facies deposition expanded to peak in and adjacent to the plateau ca. 18–13 Ma, and north–south fault basins formed in southern Tibet ca. 13–10 Ma. All of these features indicate that the plateau uplifted to its peak and began to collapse. (4) Uplift and erosion occurred during the Pliocene in most parts of the plateau, except in the Hoh Xil–Qiangtang, Tarim, and Qaidam.     

Intracontinental Orogenic Igneous Rocks and Orogenic Processes in Qinghai-Xizang-Himalaya

Based on the discussion on the intracontinental orogenic igneous rocks formed after India- Asia collision (40 or 45 Ma ),the intracontinemal orogenic processes of Qinghai-Xizang (Tibet)-Himalaya are traced . Muscovite/two mica granite is considered as a petrological record of intracontinental subduction. Volcanic rocks of shoshonite series are believed to be the products of the orogenic and outside cratonic lithosphere convergence . The intracontinental orogenic igneous rocks are developed only on the margins of the orogenic belt. The pairing phenomenon of the igneous rock zones is regarded as one of the best signs to recognize the special range of orogenic belt . The stage of magmatic activity is a representation and indicator of orogenic episode . Three pairs of the igneous events in Oligocene , Miocene and Pleistocene and their space distribution indicate three corresponding orogenic episodes and the horizontal expansion across the orogenic belt , respectively , On the northern and southern margins of     

青藏高原递进式隆升的力学模式

根据青藏高原现代构造变形的GPS速度场、高原区喜马拉雅山等五大山脉之间的几何关系,及其在地貌构造上的褶皱结构特点、岩石圈的分层特征,提出在印度板块的推挤作用下,青藏高原具有递进式隆升特征的观点。在此基础上,建立了地壳层递进式弯曲隆升的力学模型,并利用FLAC有限差分法数值模拟软件,近似采用平面应变条件,模拟了在水平推力作用下,地壳层递进式挤压弯曲隆升的过程。根据所建立的力学模型和数值模拟结果认为,青藏高原隆升的主要动力源是印度板块北北东方向的推挤力,地壳层依照自南而北的次序逐步产生一系列弯曲隆起,从平面、剖面上均具有密切的时序因果关系;高原隆升与活动构造的发育、分布具有密切关系,断裂活动强度自南向北递进式扩展。     

CENOZOIC BASIN EVOLUTION, STRUCTURAL STYLES OF THE QAIDAM AND AN ESTIMATE OF DENUDATION IN ADJACENT MOUNTAIN SYSTEMS, NORTHEAST QINGHAI—TIBETAN PLATEAU

CENOZOIC BASIN EVOLUTION, STRUCTURAL STYLES OF THE QAIDAM AND AN ESTIMATE OF DENUDATION IN ADJACENT MOUNTAIN SYSTEMS, NORTHEAST QINGHAI—TIBETAN PLATEAU     

柴达木盆地第四纪环境演变、构造变形与青藏高原隆升的关系

青藏高原北部柴达木盆地发育了巨厚的第四纪河湖相沉积。盆内沉积地层强烈的构造变形以及湖盆环境突变进一步证实了青藏高原经历了多期挤压隆升运动。沉积环境、介形虫和植物孢粉化石及磁性地层研究表明,自距今 2.5Ma以来,青藏高原共经历了距今2.52～2.28Ma,1.94～1.66Ma,1.38～1.1Ma,0.71～0.5Ma和 0.24～0.09Ma 5次强烈的隆升阶段,分别对应于青藏运动B幕和C幕、昆黄运动A幕和B幕以及共和运动。高原内、外 9个盆地的构造—沉积记录对比研究也进一步揭示了青藏高原隆起的整体性和阶段性。     

On Tectonogeomorphology of China

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