新疆多拉纳萨依金矿区构造特征与成矿关系

多拉纳萨依金矿发现于20世纪80年代末,近年研究确认该矿与韧性剪切带关系密切,但对于韧性剪切带如何控制金矿床的形成并未进行深入研究.笔者从地质背景、矿床地质,以及控矿构造分析了多拉纳萨依金矿矿床特征及其成矿机理;明确了矿床产于泥盆系托克萨雷组第三岩性段的灰岩-浅变质-硅质岩系,受控于多拉纳萨依韧性剪切带;控矿构造具有二次韧性剪切变形、矿化和多期次脉体矿化的特征,显示出构造活动的多期次性与复杂性,阐明了构造期次与矿化之间的关系.     

秦岭地区类卡林型金矿成矿特征和找矿方向

秦岭金矿床产于浅变质沉积岩区,韧-脆性剪切带和大型断裂带控制金矿和成矿带的分布,矿床地质特征与美国卡林金矿类似,故称类卡林型金矿.秦岭地区金矿分为南带和北带,在阐述各带大中型矿床成矿特点的基础上,提出了进一步的找矿方向和找矿标志.     

赵家堡子金矿I号脉成矿特征及找矿标志

赵家堡子金矿Ⅰ号脉为受王家崴子韧-脆性剪切带控制的金矿床，位于王家崴子金矿北西，是王家崴子金矿向北西的延伸。文章介绍了控矿韧-脆性剪切带控矿特征，阐述了金矿床的地质特征，总结出成矿规律，指出了找矿标志。     

广东河台金矿成因探讨——来自氢氧同位素与稀土元素的证据

<正>韧性剪切带型金矿在我国占有十分重要的工业地位,每年大约有30%的黄金产量来自这种类型的矿床,而广东河台金矿床即为这类矿床的典型。河台金矿床是一个受吴川-四会断裂和广宁-罗定断裂共同控制产出的韧性剪切带型金矿床,自矿床发现以来,对其成因的研究已有许多,最早出现的是曾捷[1]叙述了该矿床的地质特征,初步探讨了矿床的成因,认为河台金矿具有许多自身独特的特点,并称其为"河台式金矿",随后王鹤年等[2]、陆建军等[3]、涂绍雄等[4]和周永章等[5,6]通过研究矿体包裹体     

排山楼金矿床的发现及其地质特征

排山楼金矿床是在辽宁西部首次发现的大型韧性剪切带型金矿,矿体严格受近东西向排山楼—马家荒韧性剪切带控制。此类型矿床矿化范围广,产状稳定,连续性好,矿化均匀,但品位偏低,它的发现和勘探为今后东北地区开展韧性剪带中金矿找矿工作提供了地质依据。     

粤西黄泥坑金矿床地质地球化学特征和成矿时代

粤西黄泥坑金矿是近年来新发现的一个中-大型金矿床。其成矿作用分为石英-黄铁矿阶段、石英-多金属硫化物阶段和石英-碳酸盐阶段。其中,石英-黄铁矿阶段为金的主成矿阶段。对含金石英脉进行了流体包裹体Rb-Sr同位素定年,获得等时线年龄为(233.4±8.6)Ma(MSWD=2.3,n=5),表明黄泥坑金矿形成于印支期。对矿区花岗闪长岩进行了锆石LA-ICP-MS U-Pb定年,获得的206Pb/238U加权平均年龄为(451.1±2.7)Ma(MSWD=2.1,n=21),表明其形成于加里东期。综合分析花岗闪长岩和矿石的微量元素分析数据及已有的研究成果显示,黄泥坑金矿床中金的来源并非加里东期花岗闪长岩,可能来自于寒武系及隐伏的晚期岩浆岩。矿床的形成主要受罗定-广宁推覆构造控制,挤压推覆后拉张剪切作用形成的剪切破碎带及其热液蚀变作用与成矿密切相关。     

新疆西南天山金矿床主要类型、特征及成矿作用

文章在总结前人研究成果的基础上,综合论述了西南天山金矿的成矿地质背景、金矿床的时空分布和基本特征。根据矿床地质特征和控矿因素,将西南天山的金矿划分为与剪切带有关的金矿床、与侵入岩有关的金矿床(包括斑岩型)、石英-重晶石脉型金矿床、与火山岩有关的金矿床和矽卡岩型金矿床5类,其中与剪切带有关的金矿床是最重要的矿床类型。探讨了西南天山金矿的成矿时代、成矿物质和成矿流体来源,以及成矿地球动力学机制。提出与剪切带有关的金矿床成矿物质主要来源于岩浆和海相碳酸盐岩,成矿流体主要来源于岩浆水或主要来自大气降水,混合少量岩浆水。石英-重晶石脉型金矿床成矿物质来自容矿地层,成矿流体主要来源于沉积建造水。与剪切带有关的金矿、与侵入岩有关的金矿、石英重晶石脉型金矿和矽卡岩型金矿成矿时代主要集中在二叠纪—三叠纪,形成于后碰撞构造演化阶段。斑岩型和浅成低温热液型金矿床形成于岛弧挤压环境。     

萨瓦亚尔顿金（锑）矿床地质地球化学特征与成矿机理探讨

新疆萨瓦亚尔顿金（锑）矿床是９０年代初在我国南天山西段发现的大型金矿,其成矿地质背景、矿床地质特征与乌兹别克斯坦穆龙套金矿床具有类似的特点。通过对该矿床地质地球化学特征进行研究分析,指出成矿与含碳浊积岩有关,矿体受一组早期为韧性、中晚期为脆性的剪切带控制。成矿与深部的热源的驱动有关,成矿流体成分具有深部来源与浅部来源混合特点,主成矿期为海西晚期－印支期。     

广宁-罗定金矿带金矿成矿条件及预测

广宁-罗定断裂带隶属于粤西地区云开加里东褶皱系云开隆起,是广宁-罗定金矿带的控矿断裂带,前人曾把它称为断裂带、断褶带、断裂变质带、推覆构造带.目前,该矿带内已发现金矿床（点）120余处.自1983年以来,发现了河台等一系列大中型金矿,引起了对此矿带基础地质和成矿条件研究工作的重视.从目前的研究看,广宁-罗定金矿带内的一系列金矿床（点）均赋存于广宁-罗定韧性剪切带内,严格受剪切带内强变形糜棱岩-初糜棱岩带控制.河台金矿床、塔岗金矿点均为河台型金矿床,产于含炭细碎屑岩系中的韧性剪切带内.金矿床形成于韧性剪切构造活动的晚期构造扩容阶段,与印支期伍村单元花岗质岩石的侵入有明显的成因联系.通过对金矿带内金矿成矿条件研究及河台金矿典型矿床研究,成功地圈定出塔岗地区为广宁-罗定金矿带内的又一个最具找矿远景的预测靶区.进一步的工程验证,求得F级金矿储量8234kg.     

甘肃枣子沟金矿床地质特征及成因分析

枣子沟金矿为近年发现的大型金矿。矿床产于秦岭造山带三叠系浅变质细碎屑岩中,为一受岩脉、断裂、蚀变带控制的构造蚀变岩型金矿床,矿体严格受断裂破碎带控制。矿床地质和地球化学研究表明,成矿物质主要来源于岩浆期后中—低温热液。岩浆活动为成矿提供热动力和物质来源。     

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