青海滩间山金矿床地质特征和控矿因素分析   总被引：7，自引：5，他引：2  

于风池  马国良  魏刚锋  王永祥  梅安静 《矿床地质》1998,17(1):47-56

滩间山金矿床产于中元古界万洞沟群碳质糜棱片岩和华力西晚期侵入岩中。矿床是在热水沉积、区域变质和热变质的预富集基础上,与区域进变质型绿片岩相韧性剪切带的退化演化同步,经历了脆韧性、韧脆性和脆性剪切变形成矿阶段的演化,并遭受华力西晚期侵入岩浆活动相伴的热液成矿作用的叠加改造形成的。不同时期、不同成矿作用的叠加和多种有利因素的结合控制了滩间山金矿床的形成。经生产实践证实,具有形成大型金矿床的多种有利成矿地质条件  相似文献   

青藏高原东部及邻区富碱侵入岩中的角闪石和辉石   总被引：8，自引：0，他引：8  

谢应雯  张玉泉 《矿物学报》1998,(1)

本文研究了青藏高原东部及邻区两种富碱侵入岩中的角门石和辉石的矿物化学特征及成团演化,划分了矿物的种属和组合。钠质富碱侵入岩的暗色造岩矿物组合;辉石类（霓石为主,霓辉石次之）、碱性问石（钠门石为主,亚铁钠闪石次之）和富铁黑云母。钾质富碱侵人岩的暗色选岩矿物组合：Ca辉石组（透辉石为主）、Ca闪石组（浅门石为主,次为浅闪石角门石）和富镁黑云母。  相似文献   

Engineering geological evaluation of geological barrier rocks at landfills and repositories   总被引：1，自引：0，他引：1  

M. Langer 《Environmental Geology》1998,35(1):19-27

 A site specific evaluation of geological barriers is required for landfills and waste repositories. The waste-repository-rock system has to be taken into consideration for this. Since the geotechnical barrier in conjunction with geological barriers contributes considerably to long-term isolation of the harmful substances from the biosphere, it is absolutely necessary to use engineering geology and hydrogeological methods for a quantitative assessment of the barrier effect of the host rock and the geological environment. For a waste disposal mine, the load-bearing capacity of the rock, the protective properties of the surrounding rock formations and the geological stability of the area are important factors in a safety analysis, of which the geotechnical stability analysis is an important part. Such an analysis comprises an engineering geological study of the site, laboratory and in situ experiments and model calculations, long-term monitoring, and special geological and geochemical investigations. Existing geomechanical modelling techniques provide a useful tool to perform barrier integrity calculations and to design an underground disposal mine. As an example, the barrier performance of the rock salt of the Gorleben salt dome is demonstrated using various safety indicators. Received: 3 January 1997 · Accepted: 29 January 1997  相似文献   

Mesozoic doming extensional tectonics of Wugongshan, South China   总被引：4，自引：0，他引：4  

Liangshu Shu  Yan Sun  Dezi Wang  M. Faure  P. Monie  J. Charvet 《中国科学D辑(英文版)》1998,41(6):601-608

Wugongshan in Jiangxi Province, China was a Mesozoic granitic dome-type extensional tectonics that is composed of metamorphic core complexes, ductile and brittle shear-deformed zones distributed around Mesozoic granites. Within it, the foliation defines an E-W elliptical shape and bears S-N stretching lineations. The axial part is located in Hongjiang-Wanlongshan area and occupied by oriented granites with coaxial symmetric shear fabrics. The southem and northern flanks, including rocks in the Anfu Basin to the south and the Pingxiang Basin to the north, display top-to-south and top-to-north motions, respectively. The ductile and brittle structures indicate a geometric and kinematic consistency. The extensional tectonics is developed on a Caledonian metamorphic basement and is unconformably covered by Late Cretaceous red beds. Isotopic ages on muscovite, biotite and whole rock by⁴⁰Ar-³⁹Ar, K-Ar and Rb-Sr suggest that the Wugongshan extensional doming began from the Triassic and ended in the Late Cretaceous. A geodynamic model is discussed. Project supported by the National Natural Science Foundation of China (Grant Nos. 49632080, 49572141)  相似文献   

秦岭造山带佛坪基底杂岩的地质特征   总被引：7，自引：1，他引：7  

王居里 《西北地质》2002,35(2):1-8

综合研究表明，佛坪基底杂岩是由普遍遭受多期强烈变形变质作用和混合岩化作用的变质火山－沉积岩系和中酸性侵入岩构成的结晶杂岩系，结晶杂岩的形成年龄为22－18亿年，受强烈构造热事件改造的年龄为2亿年左右；佛坪基底杂岩经历了基底杂岩形成时期，主造山期和主造山期后3个不同演化时期的构造变形的叠加，改造，主造山期最主要的变形是在早期盖层沿其与基底的界面发生逆冲推覆构造的基础上发生热穹窿叠加变形。  相似文献   

江西武功山穹隆花岗岩岩石地球化学特征与成因   总被引：15，自引：1，他引：15  

楼法生  舒良树等 《地质论评》2002,48(1):80-88

江西武功山地区发育典型的穹隆花岗岩（变质核杂岩），该区中心部位出露中生代花岗岩类和花岗质片麻岩，近EW向展布的晚古生代－中生代萍乡、安福盆地分别位于其北、南两侧。武功山中生代花岗岩类以富SiO2、K2O，Rb、Th、LREE，贫Ba、Nb，且具明显Eu负异常为特点，同时花岗岩中含有夕线石、石榴子石等富铝矿物，表明属于S型花岗岩，反映陆内构造环境。与中生代花岗岩相比，山庄加里东期花岗闪长岩具有不同的岩石地球化学特点，ISr为0．7066，接近于I型，其构造背景与大陆边缘岩浆弧环境较为相似。中生代花岗岩类具有3个不同的岩相分带，岩石学与地球化学研究表明，不同岩相带具有相似的岩石学和地球化学特征，说明武功山穹隆状花岗岩经历了从三叠纪到早白垩世的演化过程，武功山变质核杂岩伸展构造发育在一个古老的加里东期变质基底之上。通过对该区花岗岩类及花岗质片麻岩的岩石学、地球化学特征分析，为揭示穹隆花岗岩构造的形成机制和地球动力学背景提供了依据。  相似文献   

某水电站右坝肩边坡的网状张裂变形     

严明  黄润秋  许模  王士天  王运生  陈剑平 《地质灾害与环境保护》2002,13(1):85-88

勘探发现，某水电站右坝肩边坡，除正常卸荷裂隙外，发育有大量的夹泥型破裂带。为了揭示其成因、发展趋势及对工程建设的影响，作者进行了大量的调查和分析，本文拟对所获研究成果进行介绍。  相似文献   

Genetic model of hanging wall syncline and central dome in extensional fault     

刘德来  丁贵明  鲁兵 《中国科学D辑(英文版)》2002,45(5):440-448

Hanging wall syncline and central dome are special extension structures, developing over the hanging wall in an extensional ramp-flat fault. Under the condition that the flat is sub-horizontal, the hanging wall syncline is separated from the half graben by the central dome. And on the dome forms an erosional surface. Both sediments in the half graben and erosional surface on the top of the central dome extended over the dome and entered into the hanging wall syncline with extension going on. Meanwhile, those having entered were overlapped by new sedimentary layers in the hanging wall syncline, so that there is a together-threaded, diachronic unconformity to form in the same epoch stratum. The layers in the hanging wall syncline also have an attribute of migrating laterally and getting tilted with extension. There is no sedimentation on the central dome. But sediments, which came from the half graben, got thicker over the dome in extension.  相似文献   

东昆仑早泥盆世碰撞造山的侵入岩证据   总被引：15，自引：0，他引：15  

赵振明  马华东  王秉璋  拜永山  李荣社  计文化 《地质论评》2008,54(1):47-56

东昆仑昆中断裂带及其附近茶德尔塔格西、阿尔格山北、塔鹤托坂日、喀雅克登塔格地区的早泥盆世侵入岩,受昆中断裂长期活动影响,岩石变形强烈,岩体在平面上呈不规则透镜状,沿昆中断裂近东西向分布。岩石地球化学特征属于亚碱性、高钾和低钾钙碱系列,介于偏铝质和过铝质之间;在R1—R2岩石类型分类图中位于闪长岩、英云闪长岩、花岗闪长岩、二长花岗岩区;在微量元素标准化图中,具有Rb、Th、Ba富集,高强场元素Nb、Ta明显亏损的特点;在稀土元素球粒陨石标准化图中,LREE富集,HREE亏损,曲线表现出明显的较为平滑的斜率相似的一组曲线,均属强烈右倾负斜率轻稀土富集型,整体分配模式具有火山弧花岗岩的特征。通过构造环境的综合判断,本文研究的东昆仑早泥盆世侵入岩属于后碰撞造山花岗岩,物质来源,壳幔相互作用的产物,从而确立了加里东晚期东昆仑碰撞造山的构造过程。  相似文献   

尧山井田韩解村小穹隆构造成因机制初探     

赵平  仲玉芳 《中国煤炭地质》2008,20(3):20-21

根据区域构造背景及井田构造特征分析,认为尧山井田韩解村小穹隆构造的成因机制为底辟式热穹隆构造。其具有中浅成的穹隆构造以及其边缘的放射状构造,同时也具备深部热源相连通的通道。由小穹隆的热液成因机制启示,在本区及附近区域会有大小不等的热穹隆构造存在。根据本区存在广厚的石灰岩沉积层之特点,在穹隆附近深部灰岩层中存在岩盐矿床的可能性很大。  相似文献