渝东南地区铝土矿找矿标志初探

含铝岩系分布于渝东南陷褶束中的一系列穹褶束、凹褶束之中,矿床类型属古风化壳沉积改造型.铝土矿赋存于上古生界二叠系下统梁山组,控矿构造为近平行展布的北北东向向斜褶皱.矿体多呈层状、似层状于向斜两翼及转折端产出,产状平缓,矿石主要矿物成分为一水硬铝石,软水铝石、胶铝石次之.主要找矿标志是向斜构造的两翼及转折端;上覆地层栖霞组厚层含沥青质灰岩,及其抬升突起部位形成的陡崖周边;下伏地层韩家店组黄灰、灰绿、偶夹紫色的粉砂岩与页岩及其互层;梁山组中段深灰色、灰绿色豆状、(鱼雨)状铝土(黏土)岩.     

全椒县范水洼金矿区控矿构造初步研究

研究区主要构造活动可分为3期：早期，发育以透入性的剪切劈理为特征的复式褶皱及倒转翼的逆冲剪切减薄拉断作用；中期，伸展作用；后期，脆性的挤压剪切破碎作用。通过详细地质构造剖面测制。建立了区内的主要构造格架：总体为一复式向斜一汪洼向斜，以杨柳岗组中上段为两翼，以琅琊山组为核，二级褶皱总体表现为向斜开阔，背斜紧闭，向南东倒伏的特征；二级褶皱的转折端为主要的控矿容矿构造，矿(化)体主要赋存于复式向斜的核部、背斜转折端。二级褶皱背斜转折端的拉张垮塌破碎角砾岩及翼部特别是近倒转翼的剪切破碎带是最重要的控矿容矿构造。     

重庆玉峡锶矿床中分散元素锶的超常富集机制

重庆玉峡锶矿床位于华蓥山构造带的南段。含矿岩系为下三叠统嘉陵江组二段一亚段的含藻含膏白云岩,含矿层位自下而上有三个矿层。矿层呈似层状、透镜状赋存于西山背斜北段的背斜转折端及相邻两翼的层间虚脱部位。矿石矿物有天青石、菱锶矿、钡天青石,脉石矿物为白云石、...     

吉林省白山市木通沟铁矿地质特征与找矿预测

木通沟铁矿均赋存于太古界杨家店组上段含铁角闪岩中,处于板石沟复式向斜西部起翘转折端,板石沟所处的区域构造位置决定该矿床矿体产状变化不稳定性,同时也决定了该矿床与板石沟铁矿南北两条成矿带的连续性。转折端出露南北向薄层矿体是受三期褶皱改造叠加变形作用影响,矿区所含矿体呈北东倾没,南东倾斜的多层斜列宽缓向形盲矿体群,东部被F201逆断层破坏,断层倾向北东东,预测深部矿体主要分布在F201断层的下盘,木通沟向斜横跨板石沟复式向斜两翼,与板石沟向斜两翼具备连续性赋矿因素。     

鲁奎山铁矿逆冲推覆系与成矿

对鲁奎山向斜东西两翼构造变形、赋矿特征、成矿规律、控矿因素的分析，及在东翼开展地质物探综合找矿中发现，早期鲁奎山裂陷槽中、昆明群大龙口组的含菱铁质矿源层。卷入构造变形变质后已经历不同层间剥滑构造多次错移或碾碎。后期次生淋漓富集，含矿热液交代蚀变和层间滑剥构造再次叠加改造，改变原来沉积变质含菱铁质矿源层或贫矿体的属性，形成类似于原生沉积、又具有热液交代蚀变和构造岩特征的层状富铁矿体。经坑道进一步揭露证实，沿鲁奎山向斜东西两翼断续分布、已经二次富集成矿的各矿床(点)，实际上是在具层间构造性质的环形断裂带控制下所形成的沉积变质后生矿床类型。表～浅部脆性断裂形成的热液交代与充填脉状矿体，局部叠加在沿环形断裂带内“层状”矿体之上，增加了找寻厚大巢状矿体的可能性。这一新的成矿与控矿规律，为重新认识原“鲁奎山式沉积变质铁矿床”提供了实践基础，同时也为在该区域找矿指明方向。     

向斜构造的地震作图法

向斜构造是主要含煤构造之一。本文从几何地震学的观点出发,利用射线原理,将向斜构造剖面分解成两翼为直线,轴部为双曲线等易于逼近的线段,并用近似方法将向斜构造正确归位。文中详细介绍了有回转波和没有回转波时向斜剖面的地震作图法,最后对作图误差进行了分析。     

辽宁省大石桥—吉洞峪—带辽河岩群变质地层的对比研究

辽宁省大石桥－吉洞峪－带出露的主要为古元古代的变质层状岩、由云母片岩，长英质粒岩和大理岩组成。区域上形成一大型北东向的复式向斜构造，复向斜南北两翼变质地层对比问题是辽吉东部辽河岩群研究的主要内容之一。作者根据五年来在大石桥－吉洞峪－带进行１：５万区调所获得的新资料，从标志层及组合标志层岩，岩相学特征，主要标志层的岩石化学和稀土地球化学特征，变质作用泻化等方面的研究入手，讨论了复向斜两翼变质地层对比     

贵州大方-金沙地区九架炉组含铝岩系地质地球化学特征与沉积环境探讨

含铝岩系主要产于石炭系九架炉组中上部,呈似层状、层状产出,受黔中隆起影响,产于寒武系娄山关组白云岩之上、二叠系梁山组炭质粘土岩之下。针对九架炉组开展剖面测量、工程揭露、样品测试等工作,对地球化学元素分析显示,微量元素中锆、锶、钒、镓、钪等元素含量相对较高,而钽、铯、钍等其他微量元素含量相对较低。样品测试结果Sr/Ba表明含铝岩系形成于海相、海陆过渡沉积环境;同时对环境敏感元素Th统计分析,表明含铝岩系形成于海陆过渡沉积环境;Th/U表明含铝岩系处于还原环境。综合本次成果研究,九架炉组铝质岩系形成于还原的半咸水—陆相沉积环境。古喀斯特特地貌控制了九架炉组的含铝岩系的规模,古喀斯特岩溶盆地为铝质粘土岩的沉积提供了良好场所,结合地球化学特征、沉积环境和古气候等进行分析,为后续的矿产调查、勘查及综合评价提供科学依据。     

河南淅川寨沟钒矿床地质特征与矿床成因研究

首次对寨沟钒矿成矿地质背景、矿体特征、矿石特征及矿床成因进行了系统研究,研究结果表明,该矿床产于寒武系水沟口组硅质岩、泥岩中,空间分布严格受地层及背斜构造双重控制,矿体呈隐伏—半隐伏状态,呈现鞍状、层状分布于背斜的转折端及两翼;成矿时间为寒武纪早期,钒主要来源于前寒武系地层,矿床形成于滨海至浅海环境中,矿床属滨海至浅海沉积型层控矿床。     

新晃县贡溪重晶石矿床地质特征及形成条件

新晃县贡溪重晶石矿床是一个浅海盆地边缘相化学沉积型矿床,是目前国内外为数不多的特大型重晶石矿床之一。矿体出露于湘黔边境复式背斜南东翼的贡溪复式向斜两翼。主要含矿层位为寒武系下统牛蹄塘组,属盆地边缘相;次要含矿层位为震旦系上统陡山沱组,属半封闭台地相的泻湖相。矿体呈层状、似层状和透镜状。矿石的有用矿物为重晶石,脉石矿物主要有方解石、含炭的粘土矿物和石英(含玉髓)等。矿石的主要结构是镶嵌粒状变晶结构;主要构造是块状和条纹状构造。矿床的形成严格受古构造、古地理、层位和沉积岩相的控制。钡物质的来源与陆源和海底火山喷发、水下含矿(钡)热卤水有关,且以后者为主。     

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