东濮盆地蒸发岩的成因

东濮盆地第三纪蒸发岩含大量芒硝、钙芒硝等矿物；石盐岩具有低的溴含量，都低于30ppm，部分接近或低于10ppm；硬石膏岩硫同位素的δ34S的范围从+3.31到+37.5,大大超过现代及第三纪海洋硫酸盐的数值。上述资料表明，东濮盆地第三纪蒸发岩可能为非海相成因。     

四川盆地三叠纪蒸发岩地层硫同位素的分布

四川盆地三叠系蒸发岩发育,硫同位素δ34S的变化幅度为14.5-34.9‰。其中以雷口坡组第四段最低约16.5‰,与现代海洋硫酸盐硫同位素值接近;雷一段至嘉四段26.1-29.5‰;嘉二段出现硫同位素的高异常值（32.4-34.9‰）,可用以修改世界流行的δ34S变化曲线.硫同位素的分布也表明了区内三叠纪属浅水盐湖环境。     

思茅盆地下白垩统蒸发岩硫同位素地球化学特征及其钾盐成矿意义

关于思茅盆地下白垩统勐野井组蒸发岩主要物源为海水的认识争议很少,但是关于其成矿时代和成矿模式的认识还有争议,关于陆源淡水对蒸发岩物质成分的影响还缺乏探讨。本文主要通过分析盆地内L2井27件蒸发岩样品的化学成分和硫同位素地球化学特征,结合邻区已发表的硫同位素数据,探讨了蒸发岩的物质来源、陆源淡水对蒸发岩物质成分的影响、成盐时代以及可能的钾盐成矿模式。结果表明:(1)思茅盆地蒸发岩受陆源淡水和火山热液补给,其中陆源淡水补给使蒸发岩硫同位素明显低于同一地质时期的其他海相样品;(2)海水可能自现今盆地北西方向补给,一级周期上海水补给存在两次,二级周期上海水补给至少存在七次;(3)物源海水的时代为中侏罗世,沉积析盐的时代为早白垩世晚期,可能的钾盐成矿模式为中侏罗世海水侧向迁移成矿。这些结果对解释思茅盆地及邻区海相蒸发岩异常低的硫同位素值、高硫同位素值与中侏罗世海水相当以及钾盐成矿缺失"碳酸盐岩相和硫酸盐岩相"有重要的意义。     

TSR成因H2S的硫同位素分馏特征与机制

热化学硫酸盐还原反应(TSR)是深层碳酸盐岩油气藏中硫化氢的主要成因机制,目前已在全球发现了50多个TSR成因的大中型含硫化氢天然气田。通过对中国四川盆地含硫化氢气田硫化物的采集与同位素分析,结合全球含硫化氢天然气田硫同位素分析数据,研究了TSR过程中硫同位素的地球化学行为和分馏特征。研究发现,TSR成因的高含硫化氢天然气中,硫化氢与硫酸盐的硫同位素分馏值小于15‰,主要分布范围为2.5‰~13.82‰,平均在10‰。四川盆地海相层系膏岩的硫同位素值分布较宽,并呈现阶梯状变化,而硫化氢的硫同位素则呈现出相似的分布规律,表明各主要含硫化氢气田硫化氢中的硫来自于本层系的硫酸盐,TSR主要发生在各自的储集层中。四川盆地各气田TSR发生的温度条件相似,硫同位素分馏比较接近。TSR过程中硫同位素的分馏过程与硫酸盐本身硫同位素值的高低无关,而与TSR反应程度有关。TSR反应程度越高,硫化氢的硫同位素值与地层硫酸盐的硫同位素越相近。通过系统分析整理全球含硫化氢气田的硫化物硫同位素数据,并结合四川盆地地质条件和油气演化过程,揭示了TSR过程中硫同位素的分馏特征,并绘制出四川盆地和全球各时代硫化氢和石膏的硫同位素分布曲线图,为研究含油气盆地蒸发岩沉积演化和硫化氢成因提供了参考。     

三叠纪海的硫同位素

前言自Ault和Kulp(1959)发表第一批海相硫酸盐岩的硫同位素分析数据以来,海相硫酸盐岩(石膏、硬石膏)的硫同位素研究工作已进行了二十余年。     

四川盆地三叠纪海水的硫同位素分布特点及其地质意义

四川盆地海相三叠系地层发育齐全。通过盆地海相三叠系各层段众多的硫酸盐（ 石膏、硬石膏） 和盐卤水硫同位素分析样的系统整理和研究,可见同一层段的硫同位素（δ３４Ｓ）组成稳定,而沿剖面由下而上δ３４Ｓ呈阶梯状递减轻化趋势,与已知全球海相三叠硫酸盐δ３４Ｓ的研究的结果有明显差异,这对全球海相三叠系硫酸盐δ３４Ｓ的研究是一个重要的补充和贡献。对地层划分对比、盐卤水产层和成因、蒸发岩形成环境、咸化发展方向及成钾预测等方面的研究,也有重要意义。     

沉积型天青石矿床的地质特征及其成因探讨

沉积型天青石矿床和蒸发岩类 ,特别是石膏的沉积密切相关 ,含矿地层主要是纹层状叠层石或藻灰岩。天青石中硫、锶同位素值和海水硫、锶同位素值相近。在蒸发条件下海水浓缩到一定浓度时 ,产生天青石沉积 ,或是富锶的硫酸型晶间卤水和钙碳酸盐反应 ,形成交代型天青石。天青石主要分布于蒸发盐盆地的边缘部位 ,位于钙碳酸盐和钙硫酸盐沉积的过渡带     

四川盆地海相三叠系硬石膏和盐卤水的硫同位素组成及意义

四川盆地下、中三叠统硬石膏和盐卤水广布，通过对采集于不同地段不同层位各具代表性的硬石膏、石膏和盐卤水的２４４件样品的分析，可见其同层位硫同位素组成稳定，δ３４Ｓ自下而上具阶梯状递减轻化的趋势，与已知全球海相三叠系硫同位素组成有明显差异。这种硫同位素分布规律对地层划分和对比、蒸发岩形成环境的判断、研究卤水产层和成因、掌握蒸发岩咸化发展方向及预测找钾工作等的意义不容忽视。     

贵州乌江水系枯水期河水硫同位素组成研究

对枯水期乌江及其主要支流河水的硫同位素组成进行了研究。河水SO42-的δ34S值在-15.7‰～18.9‰之间,干流δ34S值介于-3.7‰～0.0‰之间。主要支流河水的SO42-浓度和δ34S值具有明显的区域性差异:上游碳酸盐岩地区支流河水SO42-浓度较高而δ34S值较低,河水中的SO24-来源于煤中还原态硫的氧化、矿床硫化物氧化和大气降水;下游碳酸盐岩夹碎屑岩地区支流河水则相反,具有较低SO24-浓度和较高δ34S值,河水中的SO24-来源于硫酸盐蒸发岩溶解、大气降水以及煤中还原态硫的氧化。干流的硫同位素组成显示枯水期河水中的硫酸盐主要来源于碳酸盐岩地区。     

蒸发岩中硫同位素的地球化学特征及其沉积学意义——以思茅盆地MZK- 3井为例

思茅盆地目前是中国唯一的含古代固体钾盐矿床的沉积盆地,其钾盐形成时代、物源特征、海侵方向等多年来一直存在争议。本文依据海相硬石膏的形成条件、存在形式、同位素分馏机理,重点分析了盆地内MZK-3井蒸发岩硫同位素的地球化学特征。结果表明:①岩盐中的硬石膏在蒸发盆地析岩盐阶段即可形成,单独成层的硬石膏是由原始沉积的石膏经历了沉积埋藏升温进而脱水而成;②岩盐中硬石膏的硫同位素值具有"双峰"特征,分别为14‰～16‰和8‰～10‰或6‰～8‰,这体现了硫酸盐的双重来源——原始海水中的硫酸盐和陆源淡水输入的硫酸盐或火山活动提供的硫源;③硬石膏层的硫同位素在区域上具有对比性,结合~(87)Sr/~(86)Sr值的特征,认为其代表了海相的沉积环境;④硬石膏层的硫同位素值平面上由南向北降低,可能反映了在此方向陆源淡水或火山活动对蒸发岩盆地的影响逐渐增强,进而说明这可能也是海侵的方向。可见对硬石膏硫同位素的研究,不仅在沉积学上能揭示物源、沉积环境、海侵方向等信息,更能对研究区钾盐矿床勘查提供有益的参考。     

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.     

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.)     

GEOCHEMISTRY

正20142002 Wei Hualing(Institute of Geophysical and Geochemical Exploration,Chinese Academy of Geological Sciences,Langfang065000,China);Zhou Guohua Element Content and Mineral Compositions in Different Sizes of Soil in Tongling Area,Anhui Province(Geological Bulletin of China,ISSN1671-2552,CN11-4648/P,32(11),2013,p.1861