中国银矿的资源特征及成矿规律概要

中国银矿资源丰富,成矿地质条件优越,主要以共伴生为主,近年来独立银矿找矿也取得一些进展。本文系统搜集了国内外银矿数量与规模、储量和分布等内容,梳理了中国银矿资源分布及储量分布规律,总结了中国银矿资源特点。在对全国490处银矿矿产地资料系统梳理的基础上,深入总结了中国银矿的成矿规律,划分了海相火山沉积型、陆相火山次火山岩型、矽卡岩型、热液型(脉型和层控型)、沉积变质型、沉积型和新生风化淋积型等7个银矿预测类型,其中前4个应该作为重点预测类型,并划分出32个成银带,编制了"中国成银带分布图",为中国银矿资源潜力评价和勘查部署提供了理论依据。     

福建省东部火山岩地区银矿成矿地质条件及找矿方向

通过对该区银矿床地质特征、成矿地质条件和成矿规律的研究，将区内银矿按成因、成矿作用、矿床地质特征等划分为三类六型。指出了火山－次火山热液型银矿是本区银矿的重要类型。总结了银矿的找矿标志，提出了本区银矿的主攻类型和主攻地区。     

湖南省银矿资源概况及成矿规律

【研究目的】银是现代国防、尖端科技不可缺少的材料,也是人民群众用于装饰美化生活的贵金属之一。【研究方法】本文系统收集了湖南银矿床储量和分布等内容,在对全省93处银矿床资料系统梳理的基础上,综合分析湖南银矿床成因类型、主要预测类型及地层、构造、岩浆岩、地球化学异常、重砂异常等成矿控制因素,总结了湖南银矿的时空分布规律。【研究结果】至2018年,湖南省发现银矿床93处,累计查明资源储量1.55万t,占中国查明银矿比例4.71%,郴州、衡阳、永州三市,占全省总查明量的89.40%。银主要与铅锌、金、铜、钨等共伴生,以伴生矿床为主、共生矿床及主要矿床为辅。对各矿床划分了岩浆作用形成的矽卡岩型、岩浆热液型,含矿流体作用形成的浅成中—低温热液（MVT密西西比河谷）型,沉积作用形成的机械沉积（砂岩）型、化学沉积（页岩）型,表生作用形成的风化型等6个银矿成因类型及预测类型,其中前3个为主要成因类型及主要预测类型,编制了湖南银矿主要预测类型分布图。【结论】划分了加里东期、印支期、燕山期、喜山期共4个成矿时代,以燕山期为主;湖南银矿除洞庭湖以外均有分布,主要分布于岳阳—邵阳一线以东,资源储量主要分布于七宝...     

广东省钼矿资源潜力分析

钼矿是广东省的优势矿种之一。本文在对广东钼矿成矿特征研究的基础上,确定了各类型钼矿的预测模型,并利用地质参数体积法在MRAS资源评价系统的平台上估算了广东省钼矿的潜在资源量,进而对其资源潜力进行分析。分析结果表明,广东省钼矿资源量有望增加2倍以上;园珠顶式斑岩型钼矿、大宝山式斑岩型钼矿是广东省钼矿主要的矿床类型,也是未来找矿的主攻类型;广东省钼矿资源量主要集中于大宝山、大镇和木双地区;建议设立大宝山-大镇、木双两个勘查部署区。     

晋东北地区银矿床类型及成矿机制

银矿床类型和矿床地质特征研究表明,晋东北地区银矿王要成因类型为与火山作用有关的中低温热液银矿床(包括石英脉型银矿、火山岩型银矿、(隐)爆破角砾岩型银矿),其次为接触交代矽卡岩型银矿、层控银锰矿床(包括氧化淋滤型锰银矿和铁锰帽型银锰矿).银的主要成矿期为燕山期.在沉积作用、火山一次火山热液作用和地表氧化淋滤作用条件下形成...     

大地构造环境对世界主要类型银矿的控制作用

不同大地构造环境控制了不同类型的银矿床。火山弧和岛弧控制了浅成低温热液型和黑矿型银矿床。裂谷带的地垒之上产出有浅成低温热液银矿床、中深中温次火山热液银矿床、斑岩型银矿床和矽卡岩型银矿床。裂谷带的地堑之中产出有五元素矿床、碱性火山岩中的块状硫化物型银矿床、沉积岩中的块状硫化物型银矿床、砂岩型铜银矿床。     

湖南省伴生银矿床类型及其主要地质特征

我省尚未找到单独的或共生的银矿床,已知的银矿主要与铅、锌、铜矿伴生。伴生银矿床类型的划分,根据主要金属元素产出特点和成因类型可分为“三类”、“七型”:即伴生银矿铅锌矿床类、伴生银矿铜矿床类、其他伴生银矿床类;热液充填型、热液交代型、矽卡岩型、沉积再造型、沉积砂岩型、铁锰黑土型、黑色页岩型。根据其成矿的围岩、岩浆岩、构造等条件、以及矿体形态、蚀变、矿物共生组合、银的赋存特征等方面,略述了各类型伴生银矿床的主要地质特征。最后,据我省以往银矿的地质工作情况,以及国家目前对银的需求程度,提出了要加强银矿地质工作的几点意见。     

特大型银矿床地质特征及找矿方向

特大型银矿床在资源占有量上占举足轻重的地位,使之已经成为近年来重要的研究课题之一.从已知的国内外特大型银矿床入手,在成矿时间、空间以及成矿特征方面进行了深入的研究.提出了特大型银矿床的主要成矿地质特征、矿床类型划分方案及在我国的找矿方向.概括如下:(1)已知特大型银矿床均分布于环太平洋成矿带内,主要受控于中生代、新生代的火山岩带和裂谷带之中,多数矿床与中酸性-酸性岩浆活动有关;(2)特大型银矿床以成矿系列为主要线索,划分为浅成低温热液型、斑岩型、矽卡岩型和5元素型;(3)中国在中新生代火山岩及裂谷发育地区,如大兴安岭-太行山带等,具有特大型银矿床的成矿潜力.     

特大型银矿床地质特征及找矿方向

特大型银矿床在资源占有量上占举足轻重的地位,使之已经成为近年来重要的研究课题之一,从已知的国内外特大型银矿床入手,在成矿时间,空间以及成矿特征方面进行了深入的研究,提出了特大型银矿床的主要成矿地质特征,矿床类型划分方案及在我国的找矿方向,概括如下：（1）已知特大型银矿床均分布于环太平洋成矿带内,主要受控于中生代,新生代的火山岩带和裂谷带之中,多数矿床与中酸性一酸性岩浆活动有关,（2）特大型银矿床以成矿系列为主要线索,划分为浅成低温热液型,斑岩型,矽卡岩型和5元素型,（3）中国在中新生代火山岩及裂谷发育地区,如大兴安岭－太行山带等,具有特大型银矿床的成矿潜力。     

世界银矿资源及主要银矿床特征

世界银矿资源主要分布在苏联、墨西哥、加拿大、美国、澳大利亚和秘鲁等国,重要银矿床类型是与中一新生代火山岩、次火山岩有关的浅成热液脉状银矿床,斑岩银矿床,火山岩中的含银块状硫化物矿床,沉积型银多金属矿床,碳酸盐岩中的沉积一改造型含银多金属矿床.     

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.     

Définition d'une limite multicritère ; stratigraphie du passage Campanien–Maastrichtien du site géologique de Tercis (Landes,SW France)Definition of a multi-criteria boundary; stratigraphy of the Campanian–Maastrichtian interval of the geological site at Tercis (Landes,SW France)

Lithostratigraphy, physicochemical stratigraphy, biostratigraphy, and geochronology of the 77–70 Ma old series bracketing the Campanian–Maastrichtian boundary have been investigated by 70 experts. For the first time, direct relationships between macro- and microfossils have been established, as well as direct and indirect relationships between chemo-physical and biostratigraphical tools. A combination of criteria for selecting the boundary level, duration estimates, uncertainties on durations and on the location of biohorizons have been considered; new chronostratigraphic units are proposed. The geological site at Tercis is accepted by the Commission on Stratigraphy as the international reference for the stratigraphy of the studied interval. To cite this article: G.S. Odin, C. R. Geoscience 334 (2002) 409–414.     

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.     

Late Wuchiapingian (Late Dzhulfian,early Late Permian) limestone olistolites within the Tertiary flysch of Glypia Unit (Mount Parnon,central–eastern Peloponnesus,Greece)

Some olistolites reworked in a Tertiary flysch of Mount Parnon (Peloponnesus, Greece) exhibit a Late Permian assemblage, dominated by Paradunbarula (Shindella) shindensis, Hemigordiopsis cf. luquensis and Colaniella aff. minima. This association corresponds to the Late Wuchiapingian (=Late Dzhulfian), a substage whose algae and foraminifera are generally little known. Contemporaneous limestones crop out in the middle part of the Episkopi Formation in Hydra, but they are rather commonly reworked in Mesozoic and Cainozoic sequences. The palaeobiogeographical affinities shared by the foraminiferal markers of Greece, southeastern Pamir, and southern China, are very strong (up to the specific level), and are congruent with the Pangea B reconstructions. To cite this article: E. Skourtsos et al., C. R. Geoscience 334 (2002) 925–931.     

PALEONTOLOGY

正20141596 Liu Yunhuan(School of Earth Sciences and Resources,Chang’an University,Xi’an 710054,China);Shao Tiequan Early Cambrian Quadrapyrgites Fossils of Xixiang Boita in Southern Shaanxi Province(Journal of Earth Sciences and Environment,ISSN1672-6561,CN61-1423/P,35(3),2013,p.39-43,3 illus.,20 refs.)     

GEOCHEMICAL EXPLORATION

正20141719 Chen Zhijun(State Key Laboratory of Geological Processes and Mineral Resources,China University of Geosciences,Wuhan 430074,China);Chen Jianguo Automated Batch Mapping Solution for Serial Maps:A Case Study of Exploration Geochemistry Maps(Journal of Geology,ISSN1674-3636,CN32-1796/P,37(3),2013,p.456-464,2 illus.,2 tables,10 refs.)     

MICROPALAEONTOLOGY

正20140962 Chen Fenning(Xi’an Institute of Geology and Mineral Resources,Xi’an710054,China);Chen Ruiming Late Miocene-Early Pleistocene Ostracoda Fauna of Gyirong Basin,Southern Tibet(Acta Geologica Sinica,ISSN0001-5717,CN11-1951/P,87(6),2013,p.872-886,6illus.,56refs.)     

PETROLOGY

正1.IGNEOUS PETROLOGY20142008Cai Jinhui(Wuhan Center,China Geological Survey,Wuhan 430205,China);Liu Wei Zircon U-Pb Geochronology and Mineralization Significance of Granodiorites from Fuzichong Pb-Zn Deposit,Guangxi,South China(Geology and Mineral Resources of South China,ISSN1007-3701,CN42-1417/P,29(4),2013,p.271-281,7illus.,     

ENVIRONMENTAL GEOLOGY

正20141205Cheng Weiming(State Key Laboratory of Resources and Environmental Information System,Institute of Geographic Sciences and Natural Resources Research,CAS,Beijing 100101,China);Xia Yao Regional Hazard Assessment of Disaster Environment for Debris Flows:Taking Jundu Mountain,Beijing as an     

PROSPECTING EXPLORATION

正20141266Fan Chaoyan(Guangdong Provincial Key Laboratory of Mineral Resources and Geological Processes,Guangzhou 510275,China);Wang Zhenghai On Error Analysis and Correction Method of Measured Strata Section with Wire Projection Method(Journal of