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1.
大别山榴辉岩的包裹体研究   总被引:2,自引:0,他引:2  
孙先如  李院生 《矿物学报》1995,15(3):352-359,T001
本文对大别山榴辉岩流体包裹体进行了研究。包裹体成分以NaCl-H2O、H2O、NaCl-CO2-H2O为主,是在退变质的角闪岩相和绿片岩相条件下捕获的。从变质高峰期至退变质晚期,包裹体成分演化由氧化向还原转化。熔融包裹体的发现,说明榴辉岩在形成过程中伴随局部深熔作用。通过流体包裹体研究,对大别山榴辉岩抬升过程p-T-t轨迹进行了探讨,认为是一等温降压过程。  相似文献   

2.
吉林海沟金矿床成矿流体的地球化学特征   总被引:15,自引:1,他引:15  
李荫清 《地质学报》1994,68(1):48-61
海沟金矿床石英中含丰富的三相CO2-NaCl-H2O和两相富CO2包裹体,并与两相的NaCl-H2O包裹体共生。成矿流体富含CO2,并有2种类型和来源:高盐度富CO2的NaCl-H2O溶液,来源于浆热液;低盐度NaCl-H2O溶液,来自古大气降水。成矿最佳温度为220-300℃,流体静压力为4-20MPa,矿化深度为1-3km,流体盐度为2-7ω(NaCl)/10^-2,总密度为0.644g/cm  相似文献   

3.
山东沂水麻粒岩杂岩中的变质流体及地质意义   总被引:2,自引:0,他引:2  
山东沂水麻粒岩杂岩中含有大量高密度富CO_2流体包裹体,伴随有CO_2-H2O,CO_2±N_2±cH_4的包裹体。对这些包裹体的产状、分布和组成等特征进行了详细的岩相学研究,并选择有代表性样品进行了显微测温和激光拉曼探针分析。结合本区地质和岩石学研究成果确定沂水麻粒岩杂岩峰期变质温度为800℃,压力为0.75GPa。对变质流体组成、演化及其成岩意义也进行了讨论。  相似文献   

4.
粤西河台金矿床的流体包裹体及成矿流体   总被引:10,自引:0,他引:10  
周永章  卢焕章 《矿物学报》1995,15(4):411-417
河台金矿床存在三种类型流体包裹体:低盐度(约1.5 ̄6wt%NaCl)H2O-CO2包裹体、中等盐度(约6 ̄14wt%NaCl)水溶液包裹体、富CO2包裹体。它们的均一化温度范围在130℃至310℃之间,捕获时的围压大约为50 ̄170MPa。初始的成矿流体是一个低盐度的以H2O-NaCl-CO2为主的化学体系,主要源于大气水与变质建造水的混合。在演化过程中,成矿热液流体发生了CO2发泡和气液两相不  相似文献   

5.
山东半岛东部变质岩中的角闪石分为角闪岩相岩石中的和麻粒岩、榴辉岩中的,均属钙质角闪石。角闪石的Mg、Ca含量主要受寄主岩石控制,而Si、AlⅣ、AlⅥ、Ti、(Na+K)含量主要受变质温压条件控制。随变质温度的增高,AlⅣ、Ti、(Na+K)增高,Si减少,随变质压力的增高AlⅥ增高。低角闪岩相的角闪石形成于520~600℃、0.46~1.04GPa的温压条件下,高角闪岩相的角闪石形成于650~700℃、0.75~0.89GPa的温压条件下。麻粒岩和榴辉岩中退变质阶段的角闪石主要形成于中压相系角闪岩相的温压条件。  相似文献   

6.
石门超大型雄黄矿床流体包裹体丰富。包裹体液相成分中富Na+、Cl-和K+、SO2-4,气相成分中H2O占绝对优势,少量CO2,成矿流体化学类型属Cl SO4 Na K型水。雄黄、雌黄形成于低温(180~90℃)、低压(20~5MPa)、浅成(175~700m)、弱酸性(pH:4.67、4.43)和弱还原(Eh:-0.265V)条件。流体包裹体氢氧同位素研究表明,成矿流体主要为古大气降水,并混有盆地建造水,大气降水下渗、循环、加热、淋滤形成了中-低盐度[w(NaCl):16.03%~4.27%],中等密度(0.863~1.065g/cm3),含矿地下热水。  相似文献   

7.
吉林小西南岔金铜矿床流体包裹体及成矿作用研究   总被引:8,自引:1,他引:8  
李荫清  陈殿芬 《矿床地质》1995,14(2):150-173
该矿床流体包裹体丰富,为2相气液、1相液体、少数含子晶多相和含液态CO_2三相包裹体。包裹体液相中富Na ̄+、Cl ̄-和SO,气相中H_2O占优势,CO_2次之。属NaCl-H_2O体系。包裹体同位素分析表明,成矿流体为岩浆水和大气降水的混合流体。在温度高于360~400℃的中性—弱酸性热流体中,Au和Cu的络合物呈迁移状态,在温度低的弱酸—酸性的较还原环境下,围岩产生广泛的石英-绢云母化,导致Au、Cu络合物分解,沉淀出大量Au和Cu。  相似文献   

8.
胶南造山带变质作用及其演化   总被引:2,自引:1,他引:2  
宋明春 《山东地质》1997,13(1):60-66
胶南造山带曾经历过五期变质作用,早中元古代麻粒岩相变质作用,以出现紫苏辉石为标志,其变质条件为P=1.35GPa、T=787.7℃,属中高压相系,区域中高温变质作用;晋宁期榴辉岩相变质作用,以发育榴辉岩为标志,其变质条件P≥2.8GPa、T=601-1375℃,超高压变质作用,榴辉岩围岩的变质条件为P=1.1-1.6GPa、T=560-650℃;晋宁一震是于期的角闪岩相变质作用是胶南造山带最重要的  相似文献   

9.
豫西上宫构造蚀变岩型金矿成矿过程中的流体—岩石反应   总被引:31,自引:8,他引:23  
范宏瑞  谢奕汉 《岩石学报》1998,14(4):529-541
上宫金矿赋存在中元古界熊耳群安山岩和玄武岩中,矿体受断裂破碎带控制。含矿热液在迁移过程中,与围岩发生了强烈的流体-岩石反应,造成Au、Ag、As、Sb等成矿及其相关微量元素和Al2O3、TiO2、Na2O等常量元素含量增加,稀土元素及其总量急剧减少。流体-岩石反应第一阶段发生的温度和压力条件为365℃~300℃和285~200MPa,而大量金沉淀成矿时的温度和压力范围则分别为325℃~240℃和160~100MPa。成矿热液类型及其演化比较简单,从初始的低盐度(9.5%~6.3%NaCl)、XCO2为0.18~0.24的含CO2流体演化为低盐度(5.9%~1.6%NaCl)的水溶液流体。流体-岩石反应是造成上宫金矿金沉淀成矿最主要的原因  相似文献   

10.
刘晓春  谢鸿森 《地质学报》1999,73(3):250-262
在750 ̄1200℃、1.0 ̄4.5Gpa条件下对取自于大别山朱家冲的斜长角闪岩进行了重结晶实验,并对其在高压-超高压区域的相关系进行了简要讨论。结果表明,在750℃时,斜长角闪岩随压力的前进演化经历了斜长角闪岩(Ga+Amp+Ep+Bi+Pl+Qz,1.0 ̄1.5GPa)、角闪榴辉岩(Ga+Cpx+Amp+Ep+Ph+Qz,1.75 ̄2.25GPa)、石英榴辉岩(Ga+Cpx+Zo+Ph+Qz,  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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