大同火山群新生代火山岩成因相平衡实验约束

通过常压控制氧逸度熔融相平衡实验结果可探讨一些火山岩岩石学的基本问题及火山岩成因机制问题。在Ｏｌ－Ｄｉ－Ｎｅ三元相图上，不同大地构造环境中产出的碱性玄武岩的Ｏｌ＋ＣＰｘ－Ｐｌ饱和同结线不重合，相同构造环境中产出的碱性玄武岩的Ｏｌ＋ＣＰｘ＋Ｐｌ饱和同结线随ｆｏ＿２升高只是简单地朝Ｏｌ端移动。在ＬｅＢａＳ（１９８６）ＴＡＳ图内火山岩低压结晶作用硅─碱演化趋势呈正斜率并近似与ＴＡＳ图内火山岩系列分界线相近。由低压液相成分演化线与大同火山群岩石化学变异趋势对比，以及高压控制下的结晶作用特点的分析，大同火山群中更新世早期岩浆向中更新世晚期岩浆的演化不能用简单的低压结晶作用解释，而高压控制下的结晶作用可能是主要的控制因素。     

热液体系中Si的络合作用

在不同温度、ＰＨ和硅浓度条件下,实验标定了Ａｕ－ＳｉＯ以及Ｓｎ－ＳｉＯ２之间的络合反应：Ａｕ＾＋＋Ｈ３ＳｉＯ４＾－之间的络合反应：Ａｕ＾＋＋Ｈ４ＳｉＯ＝ＡｕＨ３ＳｉＯ４ ｌｇＫ＝－１．６５４３６＋９６１１．２１／Ｔ;Ｓｎ＾４＋＋４Ｈ３ＳｉＯ４＾－＝Ｓｎ（Ｈ３ＳｉＯ４）４;ｌｇＫ２００ｃ＝４２．７３。通过与Ａｕ－Ｃｌ、Ａｕ－ＨＳ以及Ｓｎ－ＯＨ络合物迁移能力的比较,表明在具地质意义的Ｐ睡ＥＨ条件下,Ａ     

加拿大苏必利尔区太古宙煌斑岩脉的成因：微量元素和Nd—Sr同位…

出露于加拿大苏必利尔罗灵河杂岩体中的含角闪石斑晶和单斜辉石斑晶的煌斑岩，具有碱性，含霞石标准矿物的玄武岩质成分（ＳｉＯ２＜５０ｗｔ％），成分变化从原始岩浆到分异岩浆［Ｍｇ／Ｍｇ＋∑Ｆｅ）＝０．６６－０．４０；Ｎｉ＝２００－３５ｐｐｍ］，岩石富含ＬＲＥＥ［Ｃｅ／Ｙｂ）ｍ＝１６－２６，Ｃｅｎ＝６０－３００；ｎ＝球粒陨石标准化］，Ｓｒ（８７０－１８００ｐｐｍ），Ｐ２Ｏ５（０．４－１．３ｗｔ％）和Ｂａ（１     

尖晶石中的Si含量及其存在形式

自然岩石及简单和复杂体系中实验合成或经重新平衡的尖晶石化学成分显示，在中－低压条件下，与橄榄石共存的尖晶石可含一定量的Ｓｉ，其含量随温度和压力的升高而增大。用最小二乘法对简单体系中 实验数据的热力学模拟发现，Ｓｉ在铬尖晶石中以硅酸盐尖晶石（Ｍｇ２ＳｉＯ４）形式存在，Ｍｇ２ＳｉＯ４组份在铬尖晶石中的活度ａＳＤＭＧ２ＳｉＯ４＝（ＮＳＰＭＧ／２）２＊（ＮＳＰＳｉ）２（ＮＳＰＳｉ代表以４个氧为基础的单位尖     

Mg—Cr^2＋橄榄石,辉石和尖晶石的晶胞参数测定及Cr^2＋在各晶体结构…

本文用Ｍｇ－Ｃｒ＾２＋橄榄石、辉石、尖晶石的粉晶Ｘ射线衍射数据，采取“整体图谱最小二乘Ｒｉｅｔｖｅｌｄ”方法计算了上述矿物的晶胞参数和摩尔体积，并对Ｃｒ＾２＋在各晶体结构中的占位情况进行了研究。结果显示，各矿物的晶胞参数随含Ｃｒ＾２＋量的增大而增大。据Ｖｅｇａｒｄ定律，推算出各端元组分铬橄榄石（ＣＦ２ＳｉＯ４）、铬辉石（Ｃｒ２ＳｉＯ２Ｏ６）及立方铬尖晶石（Ｃｒ３Ｏ４）的摩尔体积分别为４７．７，６８     

Cr^2＋在橄榄石,斜方辉石和尖晶石中溶解度的实验研究

为了研究Ｃｒ＾２＋在橄榄石、斜方辉石和尖晶石中的溶解度及其在各相间的分配，在压力为０－２．８８ＧＰａ和温度为１１００－１４５０℃的条件下，于ＭｇＯ－ＳｉＯ２－Ｃｒ－Ｏ体系中完成了一系列实验。实验起始成分由高纯度的ＭｇＯ、ＳｉＯ２、Ｃｒ２Ｏ３和Ｃｒ混合得到。通过Ｃｒ２Ｏ３和Ｃｒ等化学混合得到所需的ＣｒＯ，且加有过量（５０％）的Ｃｒ，使得实验产物和金属Ｃｒ保持平衡。此外，还加入占起始混合物重量１０％的     

晋蒙交界孔兹岩系熔体参与变质反应的结构特征及其动力学意义

晋蒙交界孔兹岩系变质反应结构与矿物相转变机制研究结果表明,在麻粒岩相变质及其与之相伴随的重熔作用过程中,存在一类特殊的有熔体参与的变质反应,即未熔矿物与熔体之间的反应。结合天然块状岩石高温高压实验,确定研究区孔兹岩系熔体参与变质反应如下：①２Ｇｔ＋（９ＳｉＯ２＋４Ａｌ２Ｏ３）熔体＝３Ｃｒｄ;②Ｇｔ＋（２ＳｉＯ２＋２Ａｌ２Ｏ３）熔体＝Ｓｐ＋Ｃｒｄ;③２Ｇｔ＋（３ＳｉＯ２）熔体＝２Ｏｐｘ＋Ｃｒｄ;④１４Ｇｔ＋（２５ＳｉＯ２＋４Ｈ２Ｏ）熔体＝４Ｃｕｍ＋７Ｃｒｄ。这类熔体参与变质反应不仅受控于温压条件,而且与寄主岩石脱水熔融、长英质矿物部分熔融存在密切成因关系。该项理论与实验研究对于深化变质反应理论、探讨孔兹岩系矿物相转变成因机制及其动力学过程有着重要的意义。     

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     

等离子体发射光谱法测定重晶石中钡铁和硅

重晶石经Ｎａ２ＣＯ３熔融,水浸取,过滤。沉淀经ＨＣｌ溶解后,用电感耦合等离子体发射光谱法同时测定主成分ＢａＳＯ４和次量成分Ｆｅ２Ｏ３以及滤液中的ＳｉＯ２,结果与部颁标准方法符合。方法精密度好,主量组分ＢａＳＯ４测定的ＲＳＤ（ｎ＝６）为０．２４％,次量组分Ｆｅ２Ｏ３和ＳｉＯ２的ＲＳＤ（ｎ＝６）分别是３．６９％和１．４５％。     

王台山地区韧性剪切带型金矿成因

五台山地区韧性剪切带型金矿分布地晚太古代碰撞造山带中，与世界许多太古宙绿岩带型金矿具有相似的特征。研究表明：成矿流体的δ＾１８ＯＨ２Ｏ＝－２．１‰－４．９‰，δＤ＝－６９－１１２‰，蚀谜面对得起盐矿物的δ＾１３ＣＰＤＢ＝－２．０－１．４‰，δ＾１８ＯＳＭＯＷ－１０．０－２０．０‰，载金黄铁矿的δ＾１４Ｓ＝－３．７－５．６‰。成矿前流体具有一高盐度，成矿期流体以富含ＣＯ２、近似海水的δ＾１８Ｏ和海相     

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