胶东台上金矿成矿机制模拟实验研究

模拟实验研究表明，台上金矿床的成矿机制为：胶东群地层重熔形成滦家河花岗岩岩浆时，初始浆为几乎均匀的熔体相；随着结晶成岩作用的进行，由于局部岩浆结晶分异作用，产生富Ｋ＾＋，Ｎａ＾２＾＋，Ｃａ＾２＾＋，Ｍｇ＾２＾＋，Ｆ＾－，Ｃｌ＾－，Ｓ＾２＾－，ＣＯ３＾２＾－及挥发份ＣＯ２，ＣＯ，Ｈ２Ｏ等的流体相，并不断从已结晶矿物及残熔体中，以［Ａｕ（ＨＳ）２］＾－，［Ａｕ（ＨＳ）Ｓ］＾２＾－，ＡｕＣｌ４］＾－等络     

361铀矿床热液地球化学特征及成矿物理化学条件

文章研究了３６１矿床热液地球化学特征，并进行了热力学模拟计算，认为矿床热液是大气降水与深源流体混合而成。深源流体是与基性岩脉同源的富含Ｎａ＾＋，Ｃｌ＾－和ＣＯ２等挥发组分的流体，它沿深大断裂上升，对地壳表层的大气降水加热、混合。混合热液运移时把花岗岩中的活化铀浸出，并主要以［ＵＯ２（ＣＯ３）３］＾４－，［ＵＯ２（ＣＯ３）２·２Ｈ２Ｏ］＾２－和ＵＯ＾２＋２等形式迁移至断裂附近的破碎部位富集成矿。     

东坪金矿床的围岩蚀变和流体特征

东坪金矿床围岩蚀变特征、流体包裹体特征与氢氧同位素特征研究表明，成矿流体富集Ｋ＾＋，Ｎａ＾＋，Ａｕ＾＋，Ｃｌ＾－和ＣＯ２、Ｈ２Ｓ成矿溶液以岩浆热液为主，但有天水的混合。金在溶液中以Ａｕ（ＨＳ）＾－２和ＡｕＣｌ＾－２形式存在，构造活动引起的压力突变和流岩反应是引起金沉淀的主要因素。     

恒山鹿沟金矿形成的物理化学条件及同位素地球化学

本文对恒山东段鹿沟金矿形成的温度，压力，ｆＣＯ２，ｆＯ２，成矿溶液的成分，盐度，ｐＨ值，Ｅｈ值进行了系统的论述。同时利用硫、铅、氧、氢、锶同位素资料，对成矿时代、物质来源进行了论证，得出成矿物质主要来自围岩，成矿溶液以变质水为主的结论。溶液性质属Ｎａ＾＋－Ｃａ＾２＋－ＣＩ＾－ －ＳＯ＾２－４型，富ＣＯ２，高盐度，偏酸性。成矿时代与区域变质年龄一致，为２２１４．５±６４．１Ｍａ。燕山期岩浆活动对其有     

3110矿床成矿流体地球化学特征

通过对３１１０矿床不同成矿阶段石英流体包裹体成分的研究,阐述了该矿床成矿的物理化学环境。该矿床成矿流体来源于改造围岩的构造热液和大气降水混合。成矿流体中铀的迁移形式,矿前期为ＵＯ２（ＣＯ３）３＾４－（７７．４％）和ＵＯ２（ＣＯ３）２＾２－（２２．５％）;成矿期为ＵＯ２（ＣＯ３）２＾２－（９９．９％）;矿后期ＵＯ２（ＣＯ３）３＾４－（５４．４％）和ＵＯ２（ＣＯ３）２＾２－（４２．０％）。矿化是在混合     

韩国中生代花岗岩氧同位素组成

韩国中生代花岗质岩，根据其时代、产状、岩石化学特征，分为早侏罗－早白垩世的大宝花岗岩和晚白垩－早第三的佛国侍花岗岩。大宝花岗岩的δ＾１８Ｏ值为＋５．０－＋１０．０‰（平均值为８．２‰），佛国寺花岗岩的δ＾１８Ｏ值为＋２．４－４９．１‰（平均值为＋７．０‰）。δ＾１８Ｏ值的大范围变化，表明了在岩浆期后蚀变作用过程中，花岗岩中进入了＾１８Ｏ亏损的天水。可用石英δ＾１８Ｏ、ＳｉＯ２、ＴｉＯ２和Ｓｒ的含量     

新疆哈图金矿成矿流体地球化学

新疆哈图金矿床赋存在石炭系基性火山岩－火山碎屑岩中,矿体受古火山口断裂系控制。矿脉内流体包裹体较为丰富,主要为气液相ＮａＣｌ－Ｈ２Ｏ包裹体和少量的ＮａＣｌ－ＣＯ２－Ｈ２Ｏ包裹体。成矿热液中富含ＣＯ２、Ｎ２、Ｎａ＋、Ｋ＋、Ｃｌ－和ＳＯ２－４,而所含的成矿元素以Ａｕ－Ａｓ－Ａｇ－Ｓｂ组合为特征。成矿热液为低盐度流体,主成矿阶段的盐度为４．１ｗｔ％～６．３ｗｔ％ＮａＣｌ,密度为０．８８～０．８０ｇ／ｃｍ３,ｆＯ２为１０－３５～１０－３１Ｐａ,Ｅｈ为０．６０～０．８０ｅＶ,为还原环境。金沉淀成矿的最佳温度为２３０～２６０℃。哈图金矿成矿热液不是典型的岩浆热液,而是受到了古大气水混入的火山晚期热液。流体不混溶、水－岩反应及古大气水的混入是造成本区金沉淀成矿的主要因素。     

灵宝大湖金矿地质特征及成矿规律初析

矿床赋存于太古代太华群绿岩系地层中，受近东西向韧性剪切带中缓于轴面的一组张性断裂控制，呈斜切形式产出，沿北方方向富集成矿规律性强，为中低温岩浆热液矿床，成矿物质来源于上地幔或地壳深部，成矿介质为富含ＣＯ２、ＣＨ４、ＨＣＯ３＾－，Ｃｌ＾－、Ｆ＾－等成分的热水溶液，据成矿规律对矿床远景提出预测。     

河南前河金矿床地球化学特征

对前河金矿微量元素、稳定同位素、流体包裹体研究表明,矿石中金与砷、钨、钼相关性较强,矿体在垂向上微量元素分带性明显。成矿流体以岩浆水为主,并有大所降水的混合。成矿物质主要由深源岩浆提供,并有浅部物质参与。成矿流体属Ｎａ＾＋－Ｋ＾＋－Ｃｌ＾－－ＳＯ４＾２－型,而且气相成分中ＣＯ２含量较高。     

栖霞金矿床成矿流体地球化学研究

栖霞金矿床是胶东地区产在变质岩中的石英脉型金矿床较典型的代表。该矿床属中低温热液矿床，成矿流体的盐度较低，气相成分以Ｈ２Ｏ，ＣＯ２为主；液相成分中Ｎａ＾＋，Ｃａ＾２＋和Ｃｌ＾－的含量料高，相对贫Ｋ＾＋和Ｆ＾－，流体的成分与大气降水热液的相类似。     

The terrestrial fauna of the Late Triassic Pant-y-ffynnon Quarry fissures,South Wales,UK and a new species of Clevosaurus (Lepidosauria: Rhynchocephalia)

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.     

Définition d'une limite multicritère ; stratigraphie du passage Campanien–Maastrichtien du site géologique de Tercis (Landes,SW France)Definition of a multi-criteria boundary; stratigraphy of the Campanian–Maastrichtian interval of the geological site at Tercis (Landes,SW France)

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.     

The effect of water on accessory phase solubility in subaluminous and peralkaline granitic melts

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.     

Quaternary stresses revealed by calcite twinning inversion: insights from observations in the Savonnières underground quarry (eastern France)

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).     

HYDROGEOLOGY

正20141756 Chen Ruige(Mathematical College,China University of Geosciences,Beijing100083,China);Zhou Xun Numerical Simulation of Groundwater Level Fluctuation in a Coastal Confined Aquifer with Sloping Initial Groundwater Level Induced by the Tide(Geological Bulletin of China,ISSN1671-2552,CN11-4648/P,32(7),2013,p.1099-1104,6 illus.,16 refs.) Key words:confined water,groundwater level     

METAMORPHIC PETROLOGY

正20141408 Cai Jia(Institute of Geology,Chinese Academy of Geological Sciences,Beijing100037,China);Liu Fulai Petrogenesis and Metamorphic P-T Conditions of Garnet-Spinel-Biotitebearing Paragneiss in Danangou Area,Daqingshan-Wulashan Metamorphic Complex Belt(Acta Petrologica Sinica,ISSN1000-0569,CN11-1922/P,29(7),     

SERIALS

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GEOPHYSICAL EXPLORATION

正20142386An Guoying(China Aero Geophysical Survey and Remote Sensing Center for Land and Resources,Beijing 100083,China)Application of Satellite Remote Sensing in Regional Hydrogeological Investigation:Taking Cenozoic Strata in Wenquan Sheet(1∶250 000)of Karakoram Range as an Example(Geosci-     

QUATERNARY GEOLOGY & GEOMORPHOLOGY

正20141016An Chengbang(Key Laboratory of Western China’s Environmental Systems,Ministry of Education,Lanzhou University,Lanzhou 730000,China);Zhao Yongtao Lake Records during the Last Glacial Maximum from Xinjiang,NW China and Their Climatic Impli-     

PETROLEUM GEOLOGY

正20141538 Cao Qing(School of Earth Sciences and Engineering,Xi’an Petroleum University,Xi’an 710065,China);Zhao Jingzhou Characteristics and Significance of Fluid Inclusions from Majiagou Formation,Yichuan Huangling Area,Ordos Basin(Advances in Earth Science,ISSN1001-8166,CN62-1091/P,28(7),2013,p.819-828,7 illus.,3 tables,43 refs.)