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1.
煌斑岩在玲珑金矿田形成过程中的地质意义   总被引:5,自引:0,他引:5  
玲珑金矿田发育的金矿脉以黄铁石英脉为主.发育的含金石英脉在时空及成因方面与煌斑岩脉有密切联系.在空间上,煌斑岩脉与黄铁石英矿脉呈小角度相交,且大都错断矿脉.在时间上,同位素测年显示,煌斑岩脉的形成时间范围较大,一般为80~132Ma,而石英脉的形成主要集中在100~110Ma.通过煌斑岩中金含量测定及高温高压实验,煌斑岩并非是金元素的来源,金元素与煌斑岩在高温高压条件下不相溶,在成因方面,形成矿脉的大部分金元素与煌斑岩脉应同属于地幔物质;地幔岩浆含大量的地幔流体,根据金的化学性质,金易和地幔流体中的Cl-、OH-结合形成络合物,在地幔岩浆上侵过程中随地幔流体上升到地壳上部,并在适当的位置聚集形成含金石英矿脉,而煌斑岩浆从上侵的基性岩浆中分离出来,充填于构造裂隙中,形成煌斑岩脉.  相似文献   

2.
矿体呈脉状、扁豆状、透镜状平行脉群,产于陕东南寒武-奥陶系涧河群第四层泥质千枚岩(南矿带)及震旦系耀岭河群第二层绿泥钠长千枚岩或绿泥绢云千枚岩中.矿脉走向北西-南东,倾向北西,倾角28~72°,与围岩产状一致.金红石矿脉赋存于变质的基性岩脉——"绿钙岩"(含  相似文献   

3.
破碎蚀变岩型金矿与裂隙充填石英脉型金矿是栖霞地区主要金矿化类型,破碎蚀变岩型金矿分布于郭家岭超单元西石硼单元或玲珑超单元郭家店单元二长花岗岩体内外接触带附近;而裂隙充填石英脉型金矿主要分布于栖霞-桃村一带的古老基底构造轴部附近,且集中分布于该地区南北宽不超过20km的范围内。而大部分含金矿脉其附近往往发育有成群成带的中基性岩脉,中基性岩脉特别是煌斑岩为该区找金的一个间接标志。  相似文献   

4.
安徽省枞阳县柳峰山地区金铜矿点地质特征及找矿方向   总被引:1,自引:0,他引:1  
安徽省枞阳县柳峰山地区金铜矿是热液充填形成的脉状矿床.矿体严格受断裂带控制、矿脉的力学性质以扭压性为主、矿脉铜金矿与岩脉关系极为密切、主要的铜金矿脉均有岩脉相伴.火山口的外围断裂构造中,岩脉的发育的地区,断裂构造的交汇部位是今后找矿的重点部位.  相似文献   

5.
论夹皮沟地区金矿床的花岗岩浆热液成因   总被引:3,自引:0,他引:3  
夹皮沟地区金矿床已有三十余年的研究历史,但关于金矿床的成因问题依然是众说纷纭。笔者利用大量的地质地球化学标志,论证了金矿脉与岩脉及岩脉与海西期花岗岩间的同源性,建立起夹皮沟地区海西期岩浆岩脉与金矿脉的形成演化序列。根据金矿脉与花岗岩之间明显的地球化学相似性,进而直接地证明了夹皮沟地区金矿床属花岗岩浆热液成因。  相似文献   

6.
在对川西北壤塘金成矿带内中-基性岩脉(闪长岩、闪长玢岩、煌斑岩)时空分布及岩相学特征调查的基础上,结合典型矿床成矿地质条件、成矿规律的研究,表明壤塘金成矿带内的中-基性岩脉与金成矿作用在时间、空间及成因上具有十分密切的关系,中-基性岩脉为金成矿作用提供了成矿物质及赋矿空间。  相似文献   

7.
采用石墨炉原子吸收光度计对金厂峪金矿区4条典型矿脉的金、银化学相态含量进行测定,分析了金、银的化学相态的含量分布特征及相关关系。实验结果表明:各条矿脉围岩中金、银含量相近,矿石中金的含量高低依次为Ⅳ矿脉、Ⅲ矿脉、Ⅱ矿脉、Ⅴ矿脉,银的含量高低依次为Ⅱ矿脉、Ⅳ矿脉、Ⅲ矿脉、Ⅴ矿脉;金在围岩、矿石中的主要化学相态分别为硅酸盐态、游离自然金,银在围岩和矿石中的主要化学相态为硅酸盐态;金的游离自然金、碳酸盐态为金的成矿有利相态,银的氯化银态、自然银态对成矿具有指示意义;岩石中金的化学相态特征可指导地球化学找矿,为岩石地球化学的异常评价提供依据。  相似文献   

8.
在综述了脉岩与热液型脉状金矿关系的基础上,认为中基性脉岩、煌斑岩脉不仅在空间上与脉状金矿相伴生,形成时间祁近,而且在物源和成因上有着密切的关联。脉岩是脉状金矿床成因系列的组成部分。据此提出中基性岩浆在某种动力作用下,诱导上覆花岗质岩石(包括古老变质岩)熔融,并发生混染,在地壳脉动作用下,脉岩与含矿流体多期次多阶段侵位,在相应的部位形成脉岩与矿脉共存的金矿区带。  相似文献   

9.
小秦岭金矿田已发现的石英脉有1200条以上,但目前查明的金矿脉不到总数的15%,为了加速该区含金石英脉的评价工作,我们以金硐岔9号矿脉为典型,进行了原生晕和包体方面的研究。本文是在小秦岭课题组1985年工作基础上着重探讨矿脉原生晕水平分带和三晕异常带特征,提出矿脉评价指标,供地质找矿工作参考。  相似文献   

10.
托库孜巴依矿床和金坝矿床位于中国阿尔泰南缘西段,是中亚成矿域的重要组成部分。矿区内广泛分布闪长岩脉,与金矿脉具有密切的空间关系,但其与金成矿是否具有成因关系尚不清楚。本次研究采用野外调查、显微鉴定、矿物自动分析系统、LA-ICP-MS等分析方法,对金成矿作用与闪长岩脉的关系进行探讨。实验结果表明:(1)托库孜巴依矿床和金坝矿床中闪长岩脉受金矿脉穿切,其中闪长岩脉经历了明显的构造变形,而金矿脉却未见显示;(2)金主要分布在石英脉及两侧蚀变带中,托库孜巴依矿床金矿物主要为碲金矿,金坝矿床则以自然金、碲金银矿为主;(3)托库孜巴依矿床与金坝矿床闪长岩具有相近的锆石U-Pb加权平均年龄,分别为(382.3±0.9)Ma和(385.5±2.0)Ma,形成于中泥盆世古亚洲洋俯冲期。综合前人研究,金成矿于晚石炭世—早二叠世后碰撞期,闪长岩明显早于金矿形成,二者并不具备成因关系。金成矿可能与韧性剪切带和同期的岩浆活动有关,未来的勘查工作应聚焦于含金石英脉与同期岩浆岩体周围。  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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