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1.
甲岗雪山W-Mo多金属矿床位于西藏自治区申扎县境内,地处冈底斯北部,成矿时代为中新世。矿床与矿区内的二长花岗岩体时空关系紧密,矿区内的围岩蚀变普遍见云英岩化,并且云英岩化强烈的地方多伴随强烈的钨钼矿化;矿体的类型以云英岩型为主,还有少量石英脉型,矿石又多呈细脉状或浸染状赋存于云英岩或云英岩化二长花岗岩体内部,证实了矿床的成因类型为云英岩型。依据野外见到的矿物共生组合、脉体穿切关系等,可将成矿期划分为硅酸盐-氧化物阶段和硫化物阶段。流体包裹体研究表明,甲岗雪山W-Mo多金属矿床主成矿期的成矿流体为中-高温、中-低盐度的流体,从主成矿期的硅酸盐-氧化物阶段演化到硫化物阶段,成矿流体的温度下降明显,盐度也有所下降。  相似文献   

2.
白干湖钨锡矿田位于东昆仑祁漫塔格西段新疆维吾尔自治区若羌县境内.笔者通过对柯可卡尔德、白干湖、巴什尔希和阿瓦尔4处矿床实地剖析,认为这些矿床已构成一个集矽卡岩型、云英岩化花岗岩微细网脉浸染型和石英脉型交代、充填叠加复合的具超大型远景规模的钨锡矿田.矿田内矿化类型显示出一定的分布规律或分带性:即产于花岗岩边部外接触带的矽卡岩型白钨矿矿体,呈透镜状或似层状分布在金水口群浅变质岩系大理岩内;产于花岗岩小突起内侧及其顶部外接触带伸枝脉岩的云英岩化花岗岩微细网脉浸染型钨锡矿体,前者呈厚板状透镜体面型分布,后者则呈脉状线型分布于围岩地层中;产于隐伏花岗岩突起上部外接触带的石英脉充填交代型锡石黑钨矿矿体,其因受区域NE向白干湖深大断裂构造限制,多呈低缓角度的平行脉状充填于金水口群浅变质岩系的绢云石英片岩中.根据矿石矿物组合等特征,矿田内的矿化蚀变可划分为3种:即矽卡岩化、云英岩化(包括钠长石化、电气石化等)和硅化.研究表明,矿田内矽卡岩型白钨矿化、云英岩化花岗岩微细网脉浸染型钨锡矿化和石英脉充填交代型锡石黑钨矿化构成一个与加里东期中细粒(似斑状)二长花岗岩侵入活动有成因联系的矿田成矿系列,属于岩浆期后高温-气化热液交代和中低温热液充填交代形成的产物.  相似文献   

3.
大义山岩体内云英岩化电气石化的找矿意义   总被引:1,自引:0,他引:1  
李惠纯 《湖南地质》2000,19(4):233-236
大义山复式岩体内发育的云英岩脉和电英岩脉,锡矿化较强。而鳞云母黄玉云英岩、电气石云英岩、白云母云英岩、电英岩、蚀变细粒花岗岩、云英岩-似伟晶岩,亦与锡多金属矿密切有关。显而易见,云英岩化和电气石化是大义山岩体内锡矿的最佳找矿标志。  相似文献   

4.
通过总结福建省南靖县南坑钼矿床的地质特征,认为该钼矿床为斑岩型钼矿床,钼矿体主要赋存于燕山早期花岗岩与文宾山组接触带,主要产在燕山早期花岗岩体内,受缓倾斜的石英脉和网脉状石英细脉控制,矿石类型为石英粗脉型和石英细脉型。该钼矿床具有弱磁异常,原生晕、次生晕异常发育,钼次生晕异常在深部见矿效果较好;与钼矿体关系密切的蚀变主要有云英岩化和硅化,找矿标志主要为燕山早期花岗岩、白楼—下楼断裂带、晚三叠世文宾山组、云英岩化、硅化及物化探异常,以上认识对区域寻找类似钼矿床具有参考价值。  相似文献   

5.
湘源锡矿床的特征及其成因探讨   总被引:4,自引:0,他引:4  
湘源锡矿床产于燕山中晚期的金鸡岭S型含锡花岗岩基内部.矿床类型有Sn-Li-Rb云英斑岩型和Sn-W云英岩-石英脉型.它们是由岩浆液态分异产生的富成矿元素的似云英岩相熔浆进一步演化而成.  相似文献   

6.
与交代型酸性花崗岩有关的稀有金属矿床主要是指与鈉长石化—云英岩化花崗岩有关的稀有金属矿床。与鈉长石化—云英岩化有关的主要矿床类型有:①含鈮鉄、烧綠石和水鋯石的鈉长石化花崗岩;②含綠柱石的鈉长石化—云英岩化花崗岩;③含鉄鋰云母鉭—鈮鉄矿和細晶石的鈉长石化—云英岩化  相似文献   

7.
甲岗雪山钨钼矿床位于西藏自治区申扎县境内,是西藏首例云英岩型钨矿床,关于该矿床的研究对探讨区域成矿机制和指导找矿都具有重要意义.成矿作用与矿区内的二长花岗岩紧密相关,矿体主要产于岩体内部和紧邻岩体的围岩中.矿体的类型包括云英岩型和石英脉型,矿石多呈细脉状或者浸染状产在云英岩或云英岩化二长花岗岩体内部,少量呈大脉状产于围岩地层中.为了研究该矿床成矿流体及成矿物质的来源,挑选云英岩型矿体和石英脉型矿体中的黑钨矿、石英进行H、O同位素测试,挑选金属硫化物进行S、Pb同位素测试.结果显示,黑钨矿δ18OV-SMOW(‰)值集中在3.7~4.7;石英的δ18O水值为2.0‰~4.3‰,δD值为-131‰^-84‰,表明成矿流体主要来源于脱气后的岩浆水,可能混入了极少量大气降水.矿石硫化物δ34S的值为+2.2‰^+5.3‰,表明硫来自岩浆;硫化物的206Pb/204Pb、207Pb/204Pb、208Pb/204Pb值分别为18.582 2~18.797 1、15.671 7~15.760 6、39.462 5~39.501 2,进一步表明成矿物质铅主要来源于中拉萨地体前寒武纪变质基底部分熔融产生的岩浆,可能有少量来自围岩地层.  相似文献   

8.
苍希格钨矿床位于蒙古国西部阿尔泰钨-钼-铜-铅-锌-银多金属成矿带内.矿体围岩为中-上奥陶统巴赫留克组火山沉积岩及早泥盆世陶伊陶古什杂岩体,矿体呈脉状、似脉状、透镜状产出.围岩蚀变主要有硅化、云英岩化、萤石化、钠长石化、绿泥石化和碳酸盐化,其中硅化、云英岩化及萤石化与钨矿化关系密切.金属矿物主要为黑钨矿、白钨矿、磁黄铁矿、黄铜矿、黄铁矿、辉钼矿、辉铋矿、闪锌矿,矿物组合在水平和垂向上均具有一定的分带.初步分析认为,苍希格钨矿床为与海西期中酸性岩浆侵入有关的中高温热液石英脉型钨矿床.  相似文献   

9.
云南景洪陆拉锡矿是近年来新发现的锡矿点,锡矿体呈脉状、似层状主要赋存在印支期花岗岩与、新元古界澜沧岩群接触带之云英岩(带)中,矿体形态严格受岩体与地层的界面控制。陆拉锡矿类型为典型的云英岩型锡矿床,区内印支期花岗岩体与围岩的接触带是重要的找矿部位,云英岩化、电气石化是最直接的找矿标志。  相似文献   

10.
粤北红岭钨矿为产于热水复式岩体之中的大型钨多金属矿床,矿化类型为石英脉型黑钨矿化和岩体蚀变岩型白钨矿化。红岭岩体蚀变岩型白钨矿赋存于燕山期云英岩化白云母花岗岩中,围岩蚀变主要有钾长石化、钠长石化、云英岩化、硅化和绿泥石化,一些蚀变在空间分布上经常相互重迭,其中云英岩化与矿化关系最为密切。红岭钨矿床存在富液相气液两相包裹体及富CO_2包裹体。石英脉型钨矿及岩体蚀变岩型钨矿成矿流体为中低温中等密度流体。石英脉型钨矿成矿流体的气相成分主要为H_2O,还含有CO_2、N_2、H_2等;包裹体流体成分主要为H_2O,含有CaSO_4、KCl、NaCl等。石英脉型钨矿中石英δ~(18)O值为11.0‰~13.4‰,δD值为-92.3‰~-60.4‰,结合流体包裹体温度及前人研究成果表明:成矿流体在演化过程中发生了沸腾作用,且石英脉型钨矿有大气降水参与,岩体蚀变岩型钨矿基本未受大气降水影响,而是受到岩浆热液系统的控制。  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.
Lithostratigraphy, physicochemical stratigraphy, biostratigraphy, and geochronology of the 77–70 Ma old series bracketing the Campanian–Maastrichtian boundary have been investigated by 70 experts. For the first time, direct relationships between macro- and microfossils have been established, as well as direct and indirect relationships between chemo-physical and biostratigraphical tools. A combination of criteria for selecting the boundary level, duration estimates, uncertainties on durations and on the location of biohorizons have been considered; new chronostratigraphic units are proposed. The geological site at Tercis is accepted by the Commission on Stratigraphy as the international reference for the stratigraphy of the studied interval. To cite this article: G.S. Odin, C. R. Geoscience 334 (2002) 409–414.  相似文献   

13.
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   

14.
15.
Calcite samples were extracted both from the rock matrix and the superficial coating of a karstified fault plane of an underground quarry, located in the eastern border of the Paris basin. The karstification is dated as Quaternary. Analysis of mechanical calcite twinning reveals that only the calcite matrix has also undergone a compression trending WNW that can be attributed to the Mio-Pliocene alpine collision. Both coating and matrix have undergone a strike-slip regime with σ1 roughly trending north–south, that could correspond to the regional present-day state of stress, a strike-slip compression rather trending NNW, modified by local phenomena. To cite this article: M. Rocher et al., C. R. Geoscience 335 (2003).  相似文献   

16.
正20141520 Bo Ying(Key Laboratory of Metallogeny and Mineral Assessment,MLR,Beijing 100037,China);Liu Chenglin Saline Spring Hydrochemical Characteristics and Indicators for Potassium Exploration in Southwestern and Northern Tarim Basin,Xinjiang(Acta Geoscientica Sinica,ISSN1006-3021,CN11-3474/P,34(5),2013,p.594-602,5 illus.,3 tables,28 refs.)  相似文献   

17.
正20141243Chen Ge(Hangzhou Research Institute of Petroleum Geology,PetroChina,Hangzhou 310023,China);Si Chunsong Study on Sedimentary Numerical Simulation Method of Fan Delta Sand Body(Journal of Geology,  相似文献   

18.
正20142599Chen Sanming(Guangxi Key Laboratory of Concealed Deposits Exploration,Guilin University of Technology,Guilin541004,China);He Yuzhou Block Model and Reserves Estimation of Panzhihua Iron Deposit Based on 3D Geological Modeling(Journal of Guilin University of Technology,ISSN1674-9057,CN45-1375/N,33(4),2013,p.610-615,9illus.,1table,15refs.)  相似文献   

19.
正20140594 Bai Daoyuan(Hunan Institute of Geology Survey,Changsha 410016,China);Zhong Xiang Faults in the Jingzhou Basin and Their Tectonic Settings(Geotectonica et Metallogenia,ISSN1001-1552,CN44-1595/P,37(2),2013,p.173-183,6illus.,59refs.)Key words:basin evolution,tectonic setting,South China In the Upper Paleozoic and Jurassic se-  相似文献   

20.
正20141912Cao Hui(State Key Laboratory for Continental Tectonics and Dynamics,Institute of Geology,Chinese Academy of Geological Sciences,Beijing 100037,China)Gravitational Collapse and Folding during Orogenesis:A Comparative Study of FIA Trends and Fold Axial Plane Traces(Geology in China,ISSN1000-3657,CN11-1167/P,40(6),2013,p.1818-1828,9illus.,35refs.,with  相似文献   

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