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1.
辽东早元古代裂谷带内的隆滑构造是在吕梁造山前期伸展体制下的第一幕变形期间形成的。本区隆滑构造的内核隆起部位大致与中南岩基空间分布一致,由同构造侵位的二长花岗岩(辽吉花岗岩)组成,在裂谷带西区和东区,辽吉花岗岩皆顺基底与盖层之间的接合面呈席状侵位。由于辽吉花岗岩局部隆起,引起外壳内多层滑脱型韧性剪切带(简称韧变带)及流褶层的形成,在递进变形过程中流褶层会发生尖灭。因变形分解作用,在形成韧变带及流褶层的同时,也形成一些巨型透镜体,它们为弱变形域或未变形域,其内原生构造保存完整。对流褶层内流动褶皱的倒向及拉伸线理的统计,结果进一步表明中南岩基为辽河群内隆滑构造的隆起部位。现今东区和西区的穹形构造是初始席状侵位的叠加性构造,即在吕梁运动期间收缩体制下,辽吉花岗岩仍呈塑性并向背斜部位聚集,呈底辟式重就位;第三幕构造形迹横跨叠加于第二幕构造形迹之上,从而最终使辽吉花岗岩有规律地分布于穹形构造核部。  相似文献   

2.
滇西澜沧变质带变质作用和变形作用的关系   总被引:18,自引:3,他引:18  
赵靖  钟大赉 《岩石学报》1994,10(1):27-40
滇西澜沧变质带经历了两期变质变形事件,其时代分别为519Ma和280~190Ma。早期变质变形事件(M1D1)可由销长石和石榴石变斑晶的包裹体痕迹确定,形成近E-W向的变形构造格局。晚期变质变形作用(M2D2)以形成蓝片岩相矿物组合,如以蓝门石(青铝门石)+多硅白云母+绿泥石+石英等为特征,并形成近N-S向的变形构造格局.钠质问石以青铝闪石和蓝闪石为主,白云母多为3T+2M;型多硅白云母,其bo均值在9.040A以上;蓝片岩相变质作用的P、T条件估计分别为0.6~0.7GPa和300℃。晚期变质变形事件经历了二个主要阶段(M2aD2a和M2bD2b),分别伴随透入性面理(S2)和褶劈理(S3)的形成,蓝门石的40Ar-39Ar定年分别为279Ma和214Ma;M2cD2c期局部受到热的扰动,以及出现大量的膝折带或宽缓褶皱。上述变质变形演化历史代表了澜沧变质带的隆升及剥蚀过程。  相似文献   

3.
吕建生 《黄金地质》1999,5(3):32-36
构造层次是指在一定温度、压力条件下,由一定方式的构造力作用在岩石或岩石组合中形成一套特定的构造形迹群,不同类型、样式及组成的构造形迹群代表了不同温度、压力条件下构造变形产物。与此相应又有深部,中部及浅部层次的划分,以及居于其间的多个过渡类型。不同层次构造变形的代表性物质组成是变晶糜棱岩带(构造片麻岩带)、糜棱岩带,构造片岩和破裂岩等。据此提出深层次构造变形与变晶糜棱岩型金矿有关、中、深层次构造变莆  相似文献   

4.
磨坪-维摩寺、下浦池-郭沟和三道岗-小罗沟三条韧性剪切带的形成与活动,影响并决定了它们所分隔的四个构造变形域和变形带的构造变形,导致地壳压缩,最终奠定了复杂的构造格局,并形成脆裂剪切、弯曲滑动、固态流变和柔流或熔融四种构造变形相。  相似文献   

5.
八卦庙金矿床的控矿构造为脆-韧性剪切带,其变形从早至晚经历了变形分解阶段、构造挤出阶段与倾竖褶皱阶段。在变形分解阶段,剪切带内形成线性强变形带与透镜状弱变形域,并在强变形带中发育一系列"顺层"石英脉,且递进剪切为一系列A型褶曲;在构造挤出阶段,剪切带产状由缓变陡,构造体制逐渐由非共轴剪切转变为近共轴挤压,形成挤出构造控制的构造蚀变岩型成矿构造;在倾竖褶皱阶段,剪切带叠加了顺层非共轴右行剪切,形成八卦庙倾竖褶皱,并在挤出构造体中形成一组NE向剪裂控制的构造脉型成矿构造。挤出构造主要包括:剪切带边部呈叠瓦状分布的内倾弧形逆冲断层系;剪切带内条带状构造大理岩与构造千枚岩间的滑动构造;构造千枚岩带中发育一系列呈倒水滴状、平面上呈不对称"鱼状"的挤出构造体;挤出构造体中含炭泥砾-角砾岩脉。蚀变岩型金矿体发育于挤出构造体中,其空间排布规律及挤出构造结构完全受控于构造挤出时的动力学机制。单个蚀变岩型金矿体向西侧伏,侧伏角约65°;而南、中、北矿带则整体向东侧伏,侧伏角约25°。  相似文献   

6.
关于构造带变形能的有限元法数学模拟   总被引:2,自引:0,他引:2  
王红才  吕古贤 《地球学报》1998,19(2):126-131
本文是在同一外力和边界及岩石力学性质条件下,用有限元数学模拟的方法研究不同构造变形带内部变形能的差别和分布问题。形状改变能(或称歪变能)UW比体积改变能(或称体变能)UT大将近一个数量级,UW、UT和构造变形能UB在挤压、剪切和引张变形岩带中总体依次逐步变小。UW和UB大致呈较大→大→小的变化,而UT却呈大→较大→小的趋势性变化。利用构造变形能这种规律,结合构造附加静水压力研究,进而探讨构造变形热及其影响流体运移等问题。  相似文献   

7.
在简述韧性变形带研究进展的基础上,重点讨论了韧性变形带分类,依据变形区域应力场型式,可以将韧性变形带划分出水平拉伸式、正断拉伸式、碰掸挤压式、逆冲推覆式,以及走滑式等五种基本类型。若从变形构造相色度出发,又可以将韧性变形带划分出四种类型,即构造片麻岩带、变晶糜棱岩带、(狭义)糜棱岩带和构造片岩带。  相似文献   

8.
板内造陆变形以平行不整合为标志,它是一个容易失稳的界面,后期构造变动中常常转化成拆离面。中浅构造层次形成脆性拆离断层(拆离带);中深构造层次则形成韧性剪切断层(韧性剪切带)。板内造陆变形及其后期演化改善了储集岩性能,影响了油气运移和聚集。后期转化还可以使油气重新运移,也可形成新的油气圈闭,同时深刻影响油气演化,有利于再次生油气。  相似文献   

9.
河南南召地区韧性剪切带及构造变形相   总被引:1,自引:1,他引:1  
磨坪-维摩寺、下浦池-廓沟和三道岗-小罗沟三条韧性剪切的形成与活动,影响并决定了它们所分隔的四个构造变形域和变形带的构造变形,导致地壳压缩,最终奠定了复杂的构造格局,并形成脆裂剪切,弯曲滑动,固态流变和柔流或熔融四种构造变形相。  相似文献   

10.
彭松柏  彭少梅 《广东地质》1995,10(2):17-24,T001
地云开地区不同变形期次岩石的显微-超显微变形研究,提出:(1)云开地块中的条带状混合岩一片麻状花岗岩-眼球状花岗岩(侵入花岗岩)岩石组合序列,是晋宁期、加里东期中深层次流变剪切作稆部分熔融的产物。(2)海西-印支期桂东南地体与云开地体碰撞拼贴,形成由NNW→SSE逆冲推覆构造系统,并在其根据带形成同碰撞期花岗岩,发生韧-脆性变形。(3)燕山期以平移剪切为主,在断裂带中形成对称分布的超糜棱岩(中心)  相似文献   

11.
Pant-y-ffynnon Quarry in South Wales yielded a rich cache of fossils in the early 1950s, including articulated specimens of new species (the small sauropodomorph dinosaur Pantydraco caducus and the crocodylomorph Terrestrisuchus gracilis), but no substantial study of the wider fauna of the Pant-y-ffynnon fissure systems has been published. Here, our overview of existing specimens, a few described but mostly undescribed, as well as freshly processed material, provides a comprehensive picture of the Pant-y-ffynnon palaeo-island of the Late Triassic. This was an island with a relatively impoverished fauna dominated by small clevosaurs (rhynchocephalians), including a new species, Clevosaurus cambrica, described here from a partially articulated specimen and isolated bones. The new species has a dental morphology that is intermediate between the Late Triassic Clevosaurus hudsoni, from Cromhall Quarry to the east, and the younger C. convallis from Pant Quarry to the west, suggesting adaptive radiation of clevosaurs in the palaeo-archipelago. The larger reptiles on the palaeo-island do not exceed 1.5?m in length, including a small carnivorous crocodylomorph, Terrestrisuchus, and a possible example of insular dwarfism in the basal dinosaur Pantydraco.  相似文献   

12.
Robert L. Linnen   《Lithos》2005,80(1-4):267-280
The solubilities of columbite, tantalite, wolframite, rutile, zircon and hafnon were determined as a function of the water contents in peralkaline and subaluminous granite melts. All experiments were conducted at 1035 °C and 2 kbar and the water contents of the melts ranged from nominally dry to approximately 6 wt.% H2O. Accessory phase solubilities are not affected by the water content of the peralkaline melt. By contrast, solubilities are affected by the water content of the subaluminous melt, where the solubilities of all the accessory phases examined increase with the water content of the melt, up to 2 wt.% H2O. At higher water contents, solubilities are nearly constant. It can be concluded that water is not an important control of accessory phase solubility, although the water content will affect diffusivities of components in the melt, thus whether or not accessory phases will be present as restite material. The solubility behaviour in the subaluminous and peralkaline melts supports previous spectroscopic studies, which have observed differences in the coordination of high field strength elements in dry vs. wet subaluminous granitic glasses, but not for peralkaline granitic glasses. Lastly, the fact that wolframite solubility increases with increasing water content in the subaluminous melt suggests that tungsten dissolved as a hexavalent species.  相似文献   

13.
SERIALS     
正Acta Geographica Sinica ISSN0375-5444 CN11-1856/P Acta Geologica Sichuan ISSN1006-0995 CN51-1273/P Acta Geologica Sinica ISSN0001-5717 CN11-1951/P Acta Geologica Sinica(English Edition)ISSN1000-9515 CN11-2001/P Acta Geoscientica Sinica ISSN1006-3021 CN11-3474/P Acta Micropalaeontologica Sinica ISSN1000-0674 CN32-1189/Q  相似文献   

14.
正20141864 Deng Mengchun(Institute of Exploration Technology,CAGS,Chengdu 611734,China);Huang Shenghui Rock Sample Collection and Division Technologies for Air Reverse Circulation Sampling Drilling(Exploration Engineering,ISSN1672-7428,CN11-5063/TD,40(7),2013,p.73-76,80,16 illus.,5 refs.)  相似文献   

15.
正20142366Bi Yuanqing(Institute of Geophysical and Geochemical Survey Technology of Anhui Province,Hefei 230022,China);Fang Junhua Analysis of Ore-Prospecting Potential in the Taojiaxiang Mining Site,Zongyang County(Geology of Anhui,ISSN1005-6157,CN34-1111/P,23(4),2013,p.256-260,5illus.,10refs.)  相似文献   

16.
正20140786Deng Zhenping(Institute of Karst Geology,Chinese Academy of Geological Sciences,Guilin 541004,China);Yang Wen-qiong Application of Stripping Voltammetry with a Solid Amalgam Electrode for Determination of Copper in a Tracer and Groundwater Tracing Experiment(Rock and Mineral Analy-  相似文献   

17.
正20141283 Bai Daoyuan(Hunan Institute of Geological Survey,Changsha 410016,China);Zhong Xiang Nature,Origin and Tectonic Setting of Jinzhou Basin in the South Segment of Xuefeng Orogen(Geology in China,ISSN1000-3657,CN11-1167/P,40(4),2013,p.1079-1091,10 illus.,47 refs.)Key words:foreland basins,strike-slip faults,Hunan Province  相似文献   

18.
正20141900Lan Xianhong(Key Laboratory of Marine Hydrocarbon Resources and Environmental Geology,Ministry of Land and Resources,Qingdao 266071,China);Zhang Zhixun Geochemical Characteristics of Trace Elements of Sediments from Drillhole SFK-1  相似文献   

19.
正20141074Bao Xijie(Research Institute of Exploration and Development,Daqing Oilfield Company,PetroChina,Daqing 163712,China)Gather Optimal Processing and Application Effect of Prestack AVA Instantaneous Inversion  相似文献   

20.
正1.HYDROGEOLOGY20142452Chang Chengcao(Institute of Coalfield Geological Survey and Design of Jilin Province,Changchun 130062,China)Hydrogeological Type Division of Coal Mine No.2Mine in Yitong Manchu Autonomous County,Jilin Province(Jilin Geology,ISSN1001-2427,CN22-1099/P,32(4),2013,p.129-131,3refs.)  相似文献   

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