内蒙古安乐锡多金属矿床特征及成矿模式

安乐锡多金属矿床产于地球构造变异带幔洼区,主矿体赋存在压性构造透镜体外缘断裂中,呈复合脉产出。矿区次火山岩和侵入角砾岩发育。锡石稀土元素特征与基性—超基性岩中镍矿有相似之处。矿床可能是含锡多金属的上地幔（或硅—镁层）物质部分熔融的流体多期次喷贯到断裂中成矿。构造变异带幔洼区中多期次活动的断裂,次火山岩和侵入角砾岩发育地段的锡多金属异常,复杂矿物组合的地质体为其找矿标志。     

滇西北衙金多金属矿床成矿作用特征标志

文章通过对北衙金多金属矿床成矿作用特征标志的系统总结,认为从岩体内部到外接触带,矿化样式以"脉-块体-层-脉"的内外多元结构模式产出:岩体内部Au-Fe(Cu)矿体呈透镜状脉、平行脉沿断层破碎带陡倾斜产出;岩体接触带附近的矽卡岩带围绕岩体呈环状分布,Au-Fe-Cu矿体以大透镜状、块体状在矽卡岩带中断续产出;外带Au-Fe、Pb-Ag矿体呈似层状、透镜状,沿层间破碎带产出;远程带Au-Fe矿体呈小透镜状脉、平行脉沿断层破碎带陡倾斜产出。矿体对应的矿物组合、成矿元素和蚀变分带具有自高温到低温的分布规律和矽卡岩型矿床的特征。矿床的热液成矿作用阶段可划分为早矽卡岩、晚矽卡岩、磁铁矿、石英硫化物以及碳酸盐五个热液阶段,各阶段流体包裹体划分为富液相包裹体、富气相包裹体、含子晶矿物包裹体、富含CO_2三相包裹体等四类。成矿年龄为36.46 Ma—39.44 Ma,与石英正长斑岩的成岩年龄35.00 Ma—36.72 Ma基本一致。矿床成矿深度范围为0.7~2.2km。矿床类型为斑岩-矽卡岩型金多金属矿床。北衙组碳酸盐岩(T_2b)+多期断裂构造系统(接触带构造、岩性界面及层间破碎带、断裂裂隙、不整合面构造)+喜马拉雅期富碱斑岩侵位构成了"三位一体"的成矿系统和成矿模式。     

个旧矿区发现一种富锡矿类型——花岗岩锡矿体

１９９５年在老厂－１００ｍ中段花岗岩中发现并圈定了锡工业矿体，平均锡品位１％，锡矿体赋存于花岗岩体中４０３３突起的盆状的构造中，即隐性构造带中，菱铁矿为矿体产出标志的特征矿物，花岗岩锡矿的矿石为硫化物锡石型，属中一低温阶段形成。     

腾冲大松坡云英岩型锡矿矿床地质

大松坡锡矿是滇西云英岩型锡矿的典型代表。矿体产于燕山晚期花岗岩体内的次级NNW向构造裂隙带中，呈脉状成群产出。共圈出含锡云英岩脉60余条，但主矿体却只有少数几条。矿体沿走向具有分枝、复合、尖灭再现或尖灭侧现的特点。矿石类型为云英岩型锡矿石。矿床成因属气成高温热液云英岩型锡矿床。根据矿体特征及近年开采实践，对主矿体连接对比标志进行探讨。     

牦牛坪稀土矿床地质构造特征及其控矿意义

与碱性花岗岩破碎带有关的碱性伟晶岩、碳酸岩脉型轻稀土矿床,明显受岩性和构造控制。运用地质力学方法,进行区域构造分析,论证了控矿裂隙在矿区呈多字型构造体系,成矿有利的岩性和构造条件。指出两种不同岩性地质体接触带附近,变形大的碱性花岗岩一侧是成矿裂隙发育的有利地段;接触界线突变部位是厚大矿体产出的部位。     

江西遂川草林金矿床地质特征及找矿标志

草林金矿属石英脉型金矿床。矿床(体)赋存于加里东期花岗闪长岩体内外接触带中,沿NW向横店复向斜两翼分布。金矿化与岩石中发育的NW向蚀变破碎带石英脉关系密切,矿体成组成群分布,矿体长度20~70m,厚0.12~1.39m。金成矿年龄测定为燕山期。矿体富集与多金属硫化物复脉充填和NE向、EW向裂隙构造复合处有关。矿体富集于氧化-还原界面附近。地球化学异常和蚀变破碎带石英脉是主要找矿标志。     

滇西云龙锡矿带花岗岩及其成矿

对云龙锡矿带锡矿床有花岗岩成矿与混合岩成矿两种不同的观点,笔者参与了1:5万地质填图后认为是花岗岩成矿。华力西晚期花岗岩沿断裂带侵入的特征清楚,明显区别于崇山群深变质的片麻岩与混合岩。锡矿床产于含锡黑云母花岗岩体的边部、顶部、上盘内外接触带以及邻近的花岗岩脉中。系花岗岩浆所携带的含锡热液沿着花岗岩体内的冷凝张裂隙及围岩的裂隙、层理发育而成矿。     

江西崇义老庵里破碎带蚀变岩型锡钨多金属矿床地质特征

江西崇义老庵里锡多金属矿床产于南岭成矿带赣南段天门山岩体西缘外接触带,矿化地质体受破碎带与灰岩层控制,沿破碎带发育矽卡岩化、绿泥石化、碳酸盐化和与之相伴的锡石—硫化物—白钨矿化,矿与矿化界线靠样品圈定,矿体呈似层状、扁透镜状,金属矿物主要是锡石、黄锡矿、方铅矿、闪锌矿、锡黝铜矿及白钨矿,往深部白钨矿增多.矿床成因应属与...     

关于层控式矽卡岩型矿床——以安徽省内下扬子坳陷中一些矿床为例

矽卡岩型矿床是矿床学上的一个重要成因类型。它在我国(特别是东部成矿域)已知矿产资源中占有突出的地位,在成矿作用和富集规律的研究方面也获得了许多有意义的成果,构成我国矿床理论和实践上的一大特色。根据矽卡岩型矿床的成矿控制因素,矿体与岩体和容矿岩层的关系,可把这类矿床归纳为几个“式”:(1)接触式(矿体就位于岩体接触带包括捕虏体接触带上);(2)层控式(矿体沿一定层位在外接触带作单层或多层产出);(3)裂隙充填式(脉状含矿矽卡岩沿裂隙充     

龙头山金矿构造控矿作用及找矿方向

龙头山金矿的主要矿体受火山机构构造、断裂构造和雏形断裂构造三种成矿构造控制。火山机构构造控制了产于火山与围岩的接触带部位的火山岩型金矿,该类金矿以Ⅸ号矿体最为典型,表现为矿体围绕火山机构引起的塌陷式断裂产出,矿体的形态和品位变化受火山机构构造发育程度的影响;断裂构造控制了产于泥盆系砂岩中的断裂裂隙充填型金矿,以Ⅰ号矿体最为典型,表现为矿体沿NW向断裂分布,其产状与断裂一致,向SE方向侧伏明显;雏形断裂控制了矿区南部含金富矿体的就位,表现为矿区花岗斑岩南部的富矿体沿近EW向断续展布。矿体的形成与定位都离不开这三种控矿构造,因此在靠近火山机构一定范围内,向SE方向的深部及在已知富矿体的东西两侧具有较好的找矿前景。     

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