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利用最新的钻井、地震资料,对东非凯瑞巴斯盆地(Kerimbas Basin)进行构造–地层解释和构造演化过程恢复。结果显示,凯瑞巴斯盆地共发育了4期构造变形:(1)二叠纪–早侏罗世晚期的冈瓦纳陆内裂谷活动,全区发生伸展构造变形;(2)早侏罗世晚期–早白垩世晚期马达加斯加向南漂移,全区发生右行走滑变形;(3)新发现晚白垩世局部伸展构造变形;(4)中新世–第四纪的东非裂谷海域分支活动,导致研究区发生第三期伸展构造变形,形成凯瑞巴斯盆地现今地堑形态。三期伸展构造变形的应力方向均为近E-W向,断层展布方向均为近S-N向。每一期构造变形的范围,强度及对沉积地层的控制作用差异显著。凯瑞巴斯盆地控坳断层活动具有继承性。基于研究结果,建立凯瑞巴斯盆地构造成因模式。冈瓦纳陆内裂谷活动有利于二叠系–下侏罗统构造圈闭的形成,并沟通了烃源岩和储层,有利深层油气的聚集;东非裂谷海域分支裂谷活动沟通了前新生界烃源岩和西部陆坡古近系储层,但同时也破坏了盆地内及东部的圈闭。断层不发育的西部陆坡为主要油气聚集区。 相似文献
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关于大别运动的新认识 总被引：4，自引：0，他引：4
本文依据红安群（宿松群）和大别山杂岩在岩石建造和变形、变质改造等方面的重大差异以及其间残存的角度不整合面，进一步肯定了大别运动的存在。大别运动主要发生时间为２５００Ｍａ左右，区域上大致可与华北地台阜平运动对比，是大别山地区原始硅铝质陆壳形成和韧性再造的变革运动。初步将大别旋回划分出早期伸展、中期挤压和晚期走滑剪切３个变形幕。指出了大别运动界面是大别山上部地壳极其重要的滑脱界面和层圈构造，沿袭这一古老构造薄弱面曾先后发生了韧性滑覆、脆－韧性逆冲推覆和脆性剥离等变形事件。 相似文献
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辽西医巫闾山地区中生代两期韧性变形的研究 总被引：3，自引：0，他引：3
医巫闾山地区的韧性剪切构造是中生代两期韧性变形作用的产物。早期韧性变形中a线理发育,线理走向和糜棱面理走向基本一致,线理在xy面上的侧伏角绝大多数<30°;该期韧性变形是以左行走滑运动为主。晚期韧性变形中a线理发育,线理倾伏向和糜棱岩中糜棱面理倾向相近,线理在xy面上侧伏角主要在45°～90°之间;该期韧性变形是伸展作用的产物。医巫闾山中生代两期韧性剪切变形作用表明,在侏罗纪至早白垩世期间辽西地区不仅发生了强烈挤压推覆作用和伸展作用,也发生了大规模左行走滑作用。该韧性变形作用的发现对进一步研究辽西中生代的构造演化序列、期次和构造格架转换等问题有重要意义。 相似文献
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新疆东准噶尔卡拉麦里构造带多期变形和金叠加成矿 总被引：1，自引：0，他引：1
卡拉麦里韧-脆性剪切构造带形成于华力西中晚期,分属碰撞造山挤压和伸展造山走滑-伸展2个构造变形期,历经逆冲推覆、左行走滑、右行走滑和伸展4个主要演化阶段,金成矿空间上分布于碰撞期逆冲推覆型韧性剪切带中,成矿发生在转换造山及伸展造山时期,属C2-P(290～260Ma)走滑伸展阶段成矿事件。构造变形对金成矿的控制作用在空间上表现为深部构造层次韧性变形与其之上的中浅构造层次的韧脆性和脆性变形存在地质间断,金成矿与韧脆性、脆性变形同步且与韧性变形呈明显叠加复合关系,赋矿韧脆性和脆性构造统一于右行走滑剪切-伸展成矿体系中,具有不同的构造变形层次、变形特征和矿化特征。构造与金成矿空间叠加关系,有相应的两期成矿年龄响应和多阶段、多物质复合成矿的记录,代表一种时间有早晚、空间有重叠、物质来源多成因的叠加复合成矿关系。构造带韧-脆性变形转换与金成矿活动是区域构造背景发生明显转换过程中的多期变形和叠加成矿的形成机制,(成矿)动力学背景分别代表了碰撞造山期的逆冲推覆韧性变形、碰撞造山-伸展造山转变期的右行走滑韧脆性变形和金初始成矿、伸展造山期的脆性变形和金主成矿活动。与周围地质体的时间、物质关系探讨表明,金成矿受火山质围岩矿源层、构造生成演化及华力西晚期碱性花岗质岩浆侵位活动三大因素控制。 相似文献
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依据大兴安岭呼中地区中浅变质岩系构造变形特征，对其划分了5个构造岩片，其经历了两期构造变形作用的改造，早期伸展构造改变了原始地层的基本结构，晚期收缩体制下强烈的推覆挤压又造成了构造岩片的移位和叠置，从而使地层广泛非史密斯化，根据不同岩石组合变形特征，划分了8个构造地层类型，在此基础上，结合建造组合特征，建立了构造地层单位—吉祥沟岩组和大网子岩组，两岩组并称为倭勒根岩群。 相似文献
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金山金矿田构造变形特征及其模拟实验 总被引：2，自引：1，他引：2
金山金矿田岩石遭受了三期不同性质的构造变形，这三期的造变形对金矿体的形成起着决定作用。其中第二刖期韧性剪切变形阶段形成了矿田主要的控矿，容矿构造，晚期脆性剪切变形阶段金矿体在韧性剪切带中定位。 相似文献
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辽吉古裂谷内带顺层构造片岩的变形构造与变形机制 总被引：5，自引：0，他引：5
本文从变形构造,尤其是变形显微构造研究入手,探讨了广泛发育于辽吉古裂谷内带的泥质构造片岩的形成与演化。对石榴石、石英和黑云母的变形亚结构及岩石变形构造分析揭示出,构造片岩的形成主要包含了伸展环境下出现的剪切作用、挤压作用以及扩散蠕变过程。同时还应用变形轨迹图展示了构造片岩的形成及形成后的改造过程。 相似文献
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东天山北部哈尔里克晚古生代推覆构造与岩浆作用研究 总被引：9，自引：1，他引：9
东天山北部哈尔里地荀晚古生代火山弧，石炭纪末发生区域性逆冲推覆作用，研究表明，在晚石炭世碰撞造山过程中，哈尔里克地区国三个不同阶段屿性质的构造变形，变民岩浆作用；即３４６－３１２Ｍａ从南向北的推覆作用，对应于这期从北向南的俯冲事件；３１２－２６０Ｍａ从北向南的推覆作用，对应于晚石炭世的陆－陆碰撞陆内变形事件：２６０－２３０Ｍａ洞东西方向的右旋走滑作用，对应于造山期末发生在边界断裂附近的变形事件，大 相似文献
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HOUMingjin TANGJiafu LIHuaikun WUYuedong 《大地构造与成矿学(英文版)》2003,27(1):33-54
Multistage superimposed deformation has been discussed systematically based on the progress of the stratigraphic sequences of the northeastern margin of Yangtze Block. The new-discovered first stage deformation of those sequences occurred from the middle Triassic to the end of early Jurassic together with development of regional folding, which was resulted from the deep detachment shearing tending toward NW-WNW. The folds dip to east and fall down toward west, and were superimposed by the main stage folding. Thereafter, a series of folds were developed with axes trending toward northeast. Consequently normal folds occurred on the normal limbs while overturned fold on the overturned limbs during the first stage folding. The detachment or thrust was form edfrom late Jurassic to early Cretaceous. Due to the uplifting of Dabie and the Wannan Mountains in the north and south sides, the bi-directional thrusting belt was formed by gravity flowing from the Mountains toward the center of the basin along the north side of Xuancheng and south side of Guichi. The deformation geodynamics was discussed simply based on the newly recognized information about the tectonic evolution. 相似文献
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龙门山冲断带北段前锋带新生代构造变形 总被引：3，自引：0，他引：3
龙门山北段前锋构造的地震剖面解释和前缘盆地内沉积地层的磁组构研究表明前锋构造中发育两期构造挤压作用,即整体强烈的晚三叠世变形和由北向南逐渐减弱的弱新生代构造变形。受这两期构造挤压作用的控制,龙门山北段前锋构造中发育上、下两套构造层,地表构造为晚三叠世时期形成,而深部隐伏构造则形成于新生代。北部的矿山梁和天井山构造几何学上表现为一个双重构造,浅层是一个晚三叠世形成的断层转折褶皱;深层是新生代形成的多个逆冲岩片叠置所构成的隐伏堆垛背斜;南部的青林口和中坝构造主体表现为叠瓦状逆冲,前锋构造是断层转折褶皱和断层传播褶皱。新生代构造冲断位移量以及造成早期构造抬升由北向南逐渐减小,反映新生代变形强度由北向南的减弱。磁组构研究表明新生代变形从龙门山冲断带边缘到盆地内部,磁组构从铅笔状磁组构到初始变形磁组构并逐渐过渡到沉积磁组构。由南向北磁组构由初始变形磁组构转变为铅笔状磁组构,说明应变越来越强,从而进一步证明了龙门山前锋新生代构造的弱变形作用和变形强度的北强南弱分布特征。 相似文献
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贺兰山北段结晶基底中保留有不同程度的韧性变形剪切带.通过详细的野外考察和室内显微构造研究,明确贺兰山北段的古元古代基底经历了4期韧性剪切变形:(1)早期顺层剪切带表现出中下部地壳层次的变形样式,运动学特征一致反映了近南北向的伸展;(2)麻粒岩相变质的糜棱片麻岩剪切带为南北向挤压的产物,导致经历高温高压变质的孔兹岩系从下地壳向中部地壳抬升;(3)高级糜棱岩(低角闪岩相-高绿片岩相)剪切带涉及的2次伸展运动(北西-南东向伸展和北东-南西向伸展)使得基底进一步向中部地壳抬升,可能发生在形成孔兹岩系的同一造山运动的晚期伸展垮塌过程中;(4)北东-近东西向左行逆冲绿片岩相糜棱岩剪切带则将结晶基底抬升到中上部地壳层次,其运动学特征与高级糜棱岩剪切带明显不同,可能是另一造山运动的产物.贺兰山北段与大青山-乌拉山地区有相似的韧性剪切带和构造变形,表明华北克拉通西部北缘存在一致的近东西走向的古元古代碰撞造山运动以及随后另一造山运动的改造. 相似文献
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兴地断裂发生在中元古代末期，使中元古巨厚的沉积岩发生了强烈褶皱和隆起，并伴有大量岩浆侵入和区域变质作用。在兴地断裂形成的同时，发生了第一期构造变形，其特点以韧性变形为主，由三个变形幕构成，形成了本区主要构造骨架；晚元古代本区进入晋宁期发展阶段，团结的塔里木地台基底局部裂开，形成一系列近东西向的断陷盆地，发生了第二期变形，形成以塑性变形为主的板劈理和千枚理为其特征。该期变形结束了塔里木基底发展，进入了稳定盖层沉积发展阶段；进入早古生代，兴地断裂控制了该时期的沉积作用，之后发生第三期变形，以脆性变形为主，形成一系列碎裂岩和脆性变形组构，使兴地断裂形成几十米乃至上百米宽的破碎带，从而改造了早期的糜棱岩；至中、新生代，兴地断裂再次活动，形成断裂两侧南升北降的扭动形迹。通过对兴地断裂的深入探讨，笔者认为：该断裂具有线性特征明显，活动时间漫长，构造变形复杂，是塔里木盆地北缘规模巨大的复活大断裂。 相似文献
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《China Geology》2018,1(4):466-476
Based on the seismic data gathered in past years and the correlation between the sea and land areas of the Lower Yangtze Platform, the structural characteristics of the South Yellow Sea Basin since the Indosinian tectonic movement is studied in this paper. Three stages of structural deformation can be distinguished in the South Yellow Sea Basin since the Indosinian. The first stage, Late Indosinian to Early Yanshanian, was dominated by foreland deformation including both the uplifting and subsidence stages under an intensively compressional environment. The second stage, which is called the Huangqiao Event in the middle Yanshanian, was a change for stress fields from compression to extension. While in the third stage (the Sanduo Event) in the Late Himalayan, the basin developed a depression in the Neogene-Quaternary after rifting in the Late Cretaceous-Paleogene. The long-time evolution controlled 3 basin formation stages from a foreland basin, then a fault basin to a final depression basin. In conclusion, since the Indosinian, the South Yellow Sea Basin has experienced compressional fold and thrust, collisional orogen, compressional and tensional pulsation, strike-slip, extensional fault block and inversion structures, compression and convergence. The NE, NEE, nearly EW and NW trending structures developed in the basin. From west to east, the structural trend changed from NEE to near EW to NW. While from north to south, they changed from NEE to near EW with a strong-weak-strong zoning sequence. Vertically, the marine and terrestrial facies basins show a “seesaw” pattern with fold and thrust in the early stages, which is strong in the north and weak in the south and an extensional fault in later stages, which is strong in the north and weak in the south. In the marine facies basin, thrust deformation is more prevailing in the upper structural layer than that in the lower layer. The tectonic mechanism in the South Yellow Sea Basin is mainly affected by the collision between the Yangtze and North China Block, while the stress environment of large-scale strike-slip faults was owing to subduction of the Paleo-Pacific plate. The southern part of the Laoshan uplift is a weak deformation zone as well as a stress release zone, and the Meso-Paleozoic had been weakly reformed in later stages. The southern part of the Laoshan uplift is believed, therefore, to be a promising area for oil and gas exploration. 相似文献
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R. Valenta 《Australian Journal of Earth Sciences》2013,60(5):429-443
The Hilton deposit is a deformed and metamorphosed Proterozoic stratiform Pb‐Zn‐Ag‐Cu deposit hosted by dolomitic and carbonaceous sediments of the Urquhart Shale of the Mt Isa Group. Rocks in the Hilton area show a history of folding and faulting which spans the time range recognized elsewhere in the Western Succession of the Mt Isa Inlier, though the effects of relatively late and brittle deformation are more pronounced in the Hilton area. The Hilton area shows intense faulting relative to similar rocks to the south in the Mt Isa‐Hilton belt. Faulting in the Hilton area has generally resulted in east‐west shortening and extension in both north‐south and vertical directions. This relatively intense late strain is attributed to the geometry of the Paroo Fault Zone, a major north‐trending zone that bounds the Hilton area to the west, and the Sybella Batholith, which formed a relatively rigid indenter during late deformation in the Hilton area. The structural history of the Hilton area is broadly consistent with ongoing east‐west shortening during progressive uplift from mainly ductile to more brittle conditions. Based on these observations, thinning of the Mt Isa Group which was previously attributed to synsedimentary faulting, can now be shown to be related to heterogeneous strain during late faulting. Sulphide layers show a history of folding which is similar to that of the surrounding rocks. Pyrite which is paragenetically associated with mineralization is overprinted by a bedding‐parallel foliation which predates all other structures in the area. This suggests that stratiform sulphide mineralization in the Hilton area predates deformation. Deformation has affected the Hilton orebodies at all scales. Changes in thickness and ‘fault windows’ in the orebody interval occur on the scale of the entire deposit. Mesoscopic ore thickness changes are often clearly related to extensional and contractional structures within sulphide layers. These macroscopic and mesoscopic ore‐thickness variations are spatially associated with cross‐cutting brittle faults, suggesting that strain incompatibility between brittle host rocks and more ductile ore layers played a major role in the present geometry and thickness of sulphide ores at Hilton. 相似文献
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黔西北五指山地区叠加构造变形特征对铅锌矿成矿的控制 总被引：1，自引：0，他引：1
五指山铅锌矿区位于贵州省普定县与织金县交界区域,大地构造位于扬子板块中部、江南造山带西缘。野外构造研究表明,受早古生代加里东构造运动的控制与影响,矿区内震旦系—下古生界构造变形与上古生界—中生界的构造变形明显不同。震旦系—下古生界构造线近东西向,发育近东西向平缓褶皱、南倾或北倾劈理,显示近南北向的挤压收缩变形。震旦系—下古生界区内发育两组南北、北西向陡倾断层,断层明显受限制而不穿越晚古生代之后的地层。发育在震旦系—下古生界内的层间滑动与断层活动控制着铅锌矿的分布。晚古生代之后区域构造应力场发生转变,由早期近南北向的挤压收缩转为早燕山期SEE向NWW挤压逆冲,由此对震旦纪—早古生代变形进行叠加与改造,宏观上形成以NE走向为特征的区域构造格局。后期形成的褶皱轴面主要向SEE倾斜,断层向NWW逆冲,与早期变形呈斜跨式叠加。燕山期断层活动促进了铅锌矿的迁移与聚集。 相似文献
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摘要：天山两侧山前新生代构造变形强烈,是研究盆山耦合动力学机制的理想场所。文中在综合分析前人资料基础上,结合作者的野外观测和分析,综述了天山两侧盆山转换部位不同段的新生代构造变形特征,并进行对比分析。结果显示,新生代构造变形在天山南北山前相似性和差异性共存:变形由山体向盆地扩展,时间逐渐变新;但是南侧比北侧变形起始时间早,地壳缩短量和缩短率大。在东西方向上新生代构造变形也存在明显的分段相似性特征,整体上显示出斜方对称的变形图像:东天山博格达山前为基底式逆冲推覆,南侧为走滑变形;中天山南北两侧为多排子的褶皱 逆冲推覆构造,西天山南侧也为基底式的逆冲推覆,北侧为走滑变形。综合前人研究,认为印度和亚洲大陆的碰撞及其随后陆陆汇聚作用的远程效应,是形成天山两侧山前新生代构造变形在南北方向上相似性和差异性的主要原因;而天山山体内部先存的相对刚性地块和大型断裂,则导致了新生代构造变形的东西向分段差异性和斜方对称的特征。 相似文献