太行山带造山带岩浆活动特征及其造山过程反演

太行山造山带被大多数学才称为构造岩浆带，被认为是中生代环太平洋岩浆弧的组成部分，立足于太行山地区燕山期侵入岩类的研究和对比，以岩浆演化的最新理论作为基础和主线，大宏观－微观－宏观的分析对比手法，对不同时期、不同区段侵入岩类的岩石化学、地球化学特征及其反映的成因信息作了详细对比，从而提出了“太行山型”造山带的概念及其形成模式，认为太行山造山一步富集带属于一种新的造山带类型，受控于板缘俯冲作用的远距离     

龙门山断裂带隆起造山独特性探讨

龙门山断裂带位于四川盆地西缘;青藏高原东部;为四川盆地与松潘—甘孜地块的接触构造边界。龙门山地区海拔从东侧100 km外四川盆地的500 m突升至3 000 m高度;明显地标注了青藏高原的东部边界;其隆升机制也引起了国内外地质工作者的广泛兴趣;并且提出了多种隆升机制模型。在本次研究中;我们利用SinoProbe-02深反射地震剖面数据对龙门山地区的隆升机制进行研究;从而进一步探讨龙门山地区隆起造山的独特性;并讨论其与传统意义中的造山带的区别;认为龙门山断裂造山带为板块内部构造活动引起岩石圈隆起所形成的。本文的研究结果将使我们更深刻地了解龙门山地区的构造活动特点;并且有助于了解青藏高原东缘对印度—欧亚板块碰撞的构造响应。     

五台山早前寒武纪碰撞造山带中的韧性剪切带及其大地构造意义

在五台山早前寒武纪碰撞造山带中存在两种类型韧性剪切带，即逆冲型和伸展型剪切带。除变质程度不同外，南部和北部构造片体中的角闪岩相逆冲型韧性剪切带与中部构造片体中的绿片岩相逆冲型韧性剪切带具有相同的变形特征，它们形成于同一变形过程中，是造山作用早期地壳拼合阶段的产物。伸展型韧性剪切带在整个造山带都有分布，与造山作用晚期显著增厚的地壳发生大规模纵向伸展作用相联系     

东天山-北山造山带中大型韧性剪切带属性及形成演化时限与过程

塔里木盆地北缘的东天山-北山造山带中发育多条近E-W走向的大型韧性剪切带,它们构成了造山带中不同地体单元的主要边界,是碰撞造山及造山后的产物。本文在野外调查基础上,通过微观/宏观构造、几何学/运动学/动力学/年代学相结合的研究、厘定了东天山北山造山带中的7条大型韧性剪切带,阐述了剪切带的延伸、规模、剪切变形特征、变形条件以及形成与演化时限。并讨论了这7条不同类型韧性剪切带的形成过程以及东天山和北山古生代造山过程中所起的重要作用。     

郯庐断裂带肥东韧性剪切带的变形规律同位素年龄及其构造意义

郯庐断裂带肥东韧性剪切带的几何学形态为一正花状左行平移断裂带，目前出露的为该韧性剪切带的根部，具有典型的深层次左行走滑变形特征，肥东韧性剪切带中糜棱岩，超糜棱岩测得的^40Ar/^39Ar全岩年龄分别为120.48Ma和118.75Ma，说明郯庐断裂带的大规模左行平移时代为早白垩世，对该带构造变形和构造叠加的研究表明，肥东浮槎山一带是被郯庐断裂带截切，牵引，叠加，改造的印支期大别一胶南造山带的残块，郯庐断裂带与大别-胶南造山带是不同时期，不同构造系统的产物，前者属于滨太平洋构造系统，后者属于特提斯构造系统。     

西天山造山带的古生代造山过程

古生代时期，西天山位于塔里木板块、伊犁－中天山板块和准噶尔板块之间，为古亚洲洋演化史上一个重要的构造域，曾经历了“古准噶尔洋（奥陶纪为主）”，“早古南天山洋（志留纪为主）”，“晚古南天山洋（中泥盆－早石炭世）”和“晚古北天山裂陷槽（晚泥盆世－早石炭世）”４个古洋盆演化时期，早石炭世末，天山及邻区的古洋壳已被完全消减掉，塔里木伊犁中天山和准噶尔板块与欧亚大陆拼合，中晚石炭世，天山地区接受陆表海（残余     

华北大陆边缘造山过程与成矿研究的重要进展和问题

本文简要总结了国家973计划项目"华北大陆边缘造山过程与成矿"前4年取得的重要进展,包括提出了镁铁质岩石容矿的热液铜镍一贵金属矿床、浅成作用的概念,将热液成矿系统分为岩浆热液、变质热液和浅成热液三大系列;基于一批造山型银、铅锌、铜、钼等矿床的发现或识别,将造山金矿的概念和成矿分带模式拓展为造山型矿床;确定华北克拉通南缘和北缘均发生了印支期成矿事件,尤其是浆控高温热液型钼矿床;发现大陆内部浆控高温热液成矿系统以富CO_2、富钾、富氟为特征,不同于岛弧区同类矿床;挤压造山带的卡林型-类卡林型金矿成矿系统也以含CO_2-H_2O包裹体而区别于弧后盆岭省的同类成矿系统;发现中央造山带和中亚造山带在成矿类型、优势矿种等方面差异显著,缘于它们分别经历了弱增生-强碰撞和强增生-弱碰撞的造山作用;确定华北陆块及其陆缘造山带东部在燕山期大规模成矿,自西向东成矿年龄梯级变新,优势成矿类型和矿种不同,缘于太平洋板块作用叠合于造山带自身的演化;发现碰撞前的热液成矿系统均或多或少地遭受改造,甚至活化、再就位成另类矿床;在秦岭造山带新发现了1.9Ga和1.75Ga浆控热液钼矿床以及430Ma的造山型银金钼矿床,在兴蒙造山带新发现了泥盆纪造山型铜金矿床,据此预测了前中生代矿床的找矿潜力;提出矿床是地球动力学研究的探针,厘定秦岭-大别-苏鲁造山带在120Ma之后的隆升剥蚀幅度总体小于10km,平均每年0.04mm,快速隆升剥蚀只能发生在130Ma之前;初步厘定古亚洲洋沿索伦-延吉缝合带自西向东闭合于260～250Ma,古特提斯洋北支最终闭合于220Ma;揭示华北克拉通对于Kenor、Columbia、Rodinia、Gondwana和Pangea超大陆事件均有响应,发现了拉马甘迪(Lomagundi)事件的碳同位素正向漂移现象,确定孔兹岩系主要形成于2.3Ga以后.提出急需加强研究的重要科学问题是大陆碰撞造山事件的起止时限和标志,前中生代成矿系统的识别和预测,燕山期大规模成矿的区域规律性和差异性,构造域叠合-转化过程的细节和机理.     

碰撞后的造山过程及造山带巨量花岗岩的成因

传统上认为造山作用是板块碰撞的结果，即近水平碰撞挤压引起物质的垂向加厚。事实上，许多山脉却是碰撞后“造山”隆升的。     

祁连山东南段加里东造山期构造变形年代的精确限定及其意义

祁连山东南段呈北西-南东向展布着加里东期中祁连造山带和拉脊山造山带, 其基底为前加里东变质岩系, 在该变质结晶基底岩系中发育着菱形网格状韧性剪切带, 共轭韧性剪切带面对缩短方向的夹角为104°~114°, 其最大主应力方位为SW210°左右.在中祁连地块金沙峡和化隆地块科却两处韧性剪切带中的糜棱岩化岩石, 获取变质矿物白云母40Ar-39Ar坪年龄分别为(405.1±2.4) Ma和(418.3±2.8) Ma.这一年代学结果不仅确定了加里东基底变质岩系中韧性剪切带是加里东造山作用过程中形成, 更重要的是通过对基底韧性剪切带中变质变形岩石的年代学研究, 精确地限定了祁连山东南段的早古生代火山盆地(或岛弧盆地)、拉脊山小洋盆关闭的构造年代.这为造山带构造演化过程中盆地关闭时间的确定开辟了新的途径.      

燕山板内造山带中生代逆冲构造样式及形成过程

逆冲推覆构造是燕山板内造山带的重要构造形迹之一,我们曾对其总体特征进行了研究并同前陆褶冲带逆冲推覆构造作了比较。      

桐柏—大别造山带内与脆性—韧性剪切带共生的假玄武玻璃的发现及意义

在桐柏—大别造山带大河镇剪切带中首次发现与碎裂岩和糜棱岩共生的两种不同类型的假玄武玻璃。野外产状及显微结构的研究表明与碎裂岩共生的假玄武玻璃产出于以脆性破裂为主的断层浅部(<15km),而与糜棱岩共生的假玄武玻璃则产出于以韧性变形为主的断层深部(>15 km)。这两种类型的假玄武玻璃均含有熔解起源的自形微晶体,圆形或港湾状的碎片,流动结构和部分玻璃质基质。假玄武玻璃与碎裂岩和糜棱岩共生的现象说明在桐柏—大别造山带形成和隆起过程中同一断层剪切带内大地震重复发生。大河镇假玄武玻璃的研究可对大陆型大地震的发震机制及地壳浅部的脆性变形领域到深部的塑性变形领域的地震断层的破裂过程和力学性质的研究提供重要信息。     

敦煌北部岩浆-变质杂岩构造环境初步探讨:对中亚造山带南缘扩展方式的启示

中亚造山带南缘如何向南扩展,对深入理解增生型造山作用和大陆地壳生长机制以及中亚构造域与特提斯构造域的衔接具有重要科学意义.作为中亚造山带南缘的关键构造单元,敦煌构造带大地构造属性长期备受关注且颇有争议.传统观点认为敦煌构造带是古亚洲洋南侧的前寒武纪稳定大陆地块,以刚性块体的形式参与了中亚造山带南缘的最终拼贴过程.然而,...     

中亚造山带东段岩石圈电性结构特征及其构造涵义

中亚造山带东段内蒙古中部地区一直是地球内部动力学和全球变化研究的热点地区。鉴于该地区的构造在理解中亚造山带的形成过程中起着重要作用,因此对该地区构造的研究具有重要意义。本文收集了中亚造山带东段一条长364 km的大地电磁测深(MT)剖面数据,该剖面西北起于内蒙古东乌旗内的国境线附近,向东南延伸,穿过北部造山带、索伦缝合带、南部造山带,在内蒙古翁牛特旗以西约30 km附近终止。根据数据的分析结果,对该剖面进行了二维反演。结果表明,剖面区段内岩石圈电性结构沿南北方向上整体表现为横向分块的特征。其中,北部造山带整体上以低阻为主要特征;索伦缝合带是整个剖面电性特征从低阻到高阻的过渡区;南部造山带整体上以高阻为主要特征。北部造山带的低阻特征表明该区域是不稳定的,可能是由古亚洲洋闭合后残留洋壳或者软流圈上升流引起的。索伦缝合带的电性结构特征表明该区域可能在缝合之后还发生了新的构造事件。南部造山带的高阻特征表明该区域基底是稳定的、“冷”的,且流体含量很低,电性结构的几何特征反映了该区域增厚的岩石圈。剖面所经过区域的电性结构特征表明,在西伯利亚板块与华北板块碰撞缝合之后研究区内可能还发生了诸如软流圈流...     

Continental crustal growth and the supercontinental cycle: evidence from the Central Asian Orogenic Belt

Studies of supercontinental cycle are mainly concentrated on the assembly, breakup and dispersal of supercontinents, and studies of continental crustal growth largely on the growth and loss (recycling) of the crust. These two problems have long been studied separately from each other. The Paleozoic–Mesozoic granites in the Central Asian Orogenic Belt have commonly positive Nd values, implying large-scale continental crustal growth in the Phanerozoic. They coincided temporally and spatially with the Phanerozoic Pangea supercontinental cycle, and overlapped in space with the P-wave high-V anomalies and calculated positions of subducted slabs for the last 180 Ma, all this suggests that the Phanerozoic Laurasia supercontinental assembly was accompanied by large-scale continental crustal growth in central Asia. Based on these observations, this paper proposes that there may be close and original correlations between a supercontinental cycle, continental crustal growth and catastrophic slab avalanches in the mantle. In this model we suggest that rapid continental crustal growth occurred during supercontinent assembly, whereas during supercontinental breakup and dispersal new additions of the crust were balanced by losses, resulting in a steady state system. Supercontinental cycle and continental crustal growth are both governed by changing patterns of mantle convection.     

中亚造山带东段铀、钼矿床分布与中间地块的关系

在近年来中亚造山带东段多金属矿床研究取得新进展的基础上,选择铀、钼两类矿床,结合铀、钼元素的地球化学行为探讨成矿物质来源的多样性和成矿的多阶段演化。此外,从构造研究角度,结合中亚造山带东段中大量中间地块存在的构造现象,讨论中间地块与成矿作用的关系:中间地块经历了从大陆边缘的裂解、漂移和板块碰撞造山作用,在漫长而复杂的地质过程中遭受的多次改造,有利成矿物质的反复被萃取和聚集。最后提出印支期华北克拉通北缘和北部造山带的成矿作用与底侵背景下的伸展作用密切相关。     

秦岭造山带勉略缝合带构造变形与造山过程

秦岭晚古生代以来造山过程中的构造变形研究对建立华北板块与华南板块之间的最终拼合过程尤为重要。为此，选择勉略带进行了详细的野外调查，对其物质组成，几何学结构，变形序列，运动学和动力学作了系统解剖，认为：勉略带是有一定宽度，由一定实体组成的蛇构造混杂岩带，它包括不同时代，不同构造背景，不同起源的一系列构造岩片，如：基底岩片组，洋壳岩片组，岛弧岩片组，碰撞构造沉积楔形体，大陆边缘岩片组，它们被一系列的北倾南冲的断裂分割。勉略带到－高川段的北倾南冲逆冲断裂和勉略带北部南倾北冲的逆冲断裂组合成为现今不对称的正花状几何学结构，但勉略带的北界状元碑断裂和南界 到－略阳断裂走滑特征明显。结合勉略带邻区的构造特征，分别对带内重要断裂及岩片的构造解析表明，除主造山的大地构造演化阶段外，可将勉略带构造变形序列及演化历程总体归纳为三大阶段：俯冲变形阶段，主造山碰撞变形阶段的陆内造山调整变形阶段，并对不同变表阶段的时限，变形特征，运动学和动力学分别作了描述；最后针对该区复杂的楔入，挤出（逃逸）走滑，逆冲过程，提出了一个统一的动力学演化模式。     

东天山觉罗塔格造山带康古尔塔格断裂带构造特征及边界属性研究

东天山觉罗塔格造山带是塔里木板块和古亚洲洋碰撞对接的关键部位,为中亚造山带的重要组成部分,而其大地构造属性一直存在着争议。康古尔塔格断裂带作为觉罗塔格造山带的边界断裂,其构造特征的研究对区内大地构造演化有重要的启示作用。通过对康古尔塔格断裂带的地质特征、火山沉积建造及演化过程等方面的研究,发现康古尔塔格断裂带为韧性兼走滑特征深层次的剪切带;区内石炭系火山岩具有典型的沟-弧-盆体系火山-沉积建造特征;康古尔塔格断裂带到阿其克库都克断裂带之间的区域为准噶尔板块与塔里木板块之间的碰撞缝合带;早石炭-晚二叠世,康古尔大洋发生了颇具规模的南北双向俯冲,形成了康-阿缝合带,而康古尔塔格断裂带为康-阿缝合带的北部边界。     

Carboniferous Highly Fractionated I‐type Granites from the Kalamaili Fault Zone,Eastern Xinjiang,NW China: Petrogenesis and Tectonic Implications

Carboniferous magmatism is one of the most important tectonothermal events in the Central Asian Orogenic Belt(CAOB). However, the final closure time of the Kalamaili Ocean between East Junggar and Harlik Mountain is still debated. Early Carboniferous(332 Ma) and late Carboniferous(307–298 Ma) granitic magmatism from Kalamaili fault zone have been recognized by LA-ICP-MS zircon U-Pb dating. They are both metaluminous highly fractionated I-type and belong to the high-K calc-alkaline. The granitoids for early Carboniferous have zircon ε_(Hf)(t) values of-5.1 to +8.5 with Hf model ages(T_(DM2)) of 1.78–0.83 Ga, suggesting a mixed magma source of juvenile material with old continental crust. Furthermore, those for late Carboniferous have much younger heterogeneous zircon ε_(Hf)(t) values(+5.1 to +13.6) with Hf model ages(T_(DM2)=1.03–0.45 Ga) that are also indicative of juvenile components with a small involvement of old continental crust. Based on whole-rock geochemical and zircon isotopic features, these high-K granitoids were derived from melting of heterogeneous crustal sources or through mixing of old continental crust with juvenile components and minor AFC(assimilation and fractional crystallization). The juvenile components probably originated from underplated basaltic magmas in response to asthenospheric upwelling. These Carboniferous highly fractionated granites in the Kalamaili fault zone were probably emplaced in a post-collisional extensional setting and suggested vertical continental crustal growth in the southern CAOB, which is the same or like most granitoids in CAOB. This study provides new evidence for determining the post-accretionary evolution of the southern CAOB. In combination with data from other granitoids in these two terranes, the Early Carboniferous Heiguniangshan pluton represents the initial record of post-collisional environment, suggesting that the final collision between the East Junggar and Harlik Mountain might have occurred before 332 Ma.     

Time scale of an early to mid-Paleozoic orogenic cycle of the long-lived Central Asian Orogenic Belt, Inner Mongolia of China: Implications for continental growth

We present a detailed, new time scale for an orogenic cycle (oceanic accretion–subduction–collision) that provides significant insights into Paleozoic continental growth processes in the southeastern segment of the long-lived Central Asian Orogenic Belt (CAOB). The most prominent tectonic feature in Inner Mongolia is the association of paired orogens. A southern orogen forms a typical arc-trench complex, in which a supra-subduction zone ophiolite records successive phases during its life cycle: birth (ca. 497–477 Ma), when the ocean floor of the ophiolite was formed; (2) youth (ca. 473–470 Ma), characterized by mantle wedge magmatism; (3) shortly after maturity (ca. 461–450 Ma), high-Mg adakite and adakite were produced by slab melting and subsequent interaction of the melt with the mantle wedge; (4) death, caused by subduction of a ridge crest (ca. 451–434 Ma) and by ridge collision with the ophiolite (ca. 428–423 Ma). The evolution of the magmatic arc exhibits three major coherent phases: arc volcanism (ca. 488–444 Ma); adakite plutonism (ca. 448–438 Ma) and collision (ca. 419–415 Ma) of the arc with a passive continental margin. The northern orogen, a product of ridge-trench interaction, evolved progressively from coeval generation of near-trench plutons (ca. 498–461 Ma) and juvenile arc crust (ca. 484–469 Ma), to ridge subduction (ca. 440–434 Ma), microcontinent accretion (ca. 430–420 Ma), and finally to forearc formation. The paired orogens followed a consistent progression from ocean floor subduction/arc formation (ca. 500–438 Ma), ridge subduction (ca. 451–434 Ma) to microcontinent accretion/collision (ca. 430–415 Ma); ridge subduction records the turning point that transformed oceanic lithosphere into continental crust. The recognition of this orogenic cycle followed by Permian–early Triassic terminal collision of the CAOB provides compelling evidence for episodic continental growth.     

Late Paleozoic Element Migration and Accumulation under Intracontinental Sinistral Strike-slip Faulting in the West Junggar Orogenic Belt, NW China

The migration, accumulation and dispersion of elements caused by tectonic dynamics have always been a focus of attention, and become the basis of tectono-geochemistry. However, the effects of faulting, especially strike-slip faulting, on the adjustment of geochemical element distribution, are still not clear. In this paper, we select the West Junggar Orogenic Belt (WJOB), NW China, as a case study to test the migration behavior of elements under tectonic dynamics. The WJOB is dominated by NE-trending large-scale sinistral strike-slip faults such as the Darabut Fault, the Mayile Fault, and the Baerluke Fault, which formed during the intracontinental adjustment under N–S compression during ocean-continental conversion in the Late Paleozoic. Geochemical maps of 13 elements, Al, W, Sn, Mo, Cu, Pb, Zn, As, Sb, Hg, Fe, Ni, and Au, are analyzed for the effects of faulting and folding on element distribution at the regional scale. The results show that the element distribution in the WJOB is controlled mainly by two mechanisms during tectonic deformation: first is the material transporting mechanism, where the movement of geological units is consistent with the direction of tectonic movement; second is the diffusion mechanism, especially by tectonic pressure dissolution driven by tectonic dynamics, where the migration of elements is approximately perpendicular or opposite to the direction of tectonic movement. We conclude that the adjustment of element distributions has been determined by the combined actions of transporting and diffusion mechanisms, and that the diffusion mechanism plays an important role in the formation of geochemical Au blocks in the WJOB.