靖西县新圩铝土矿地质特征及控矿因素

根据多年的实际工柞经验，论述了靖西新圩铝土矿床的地质特征及控矿因素。     

幂律度与成矿预测

分形理论的引入极大地促进了现代定量地学的发展。在成矿预测的科研和实践中，人们曾先后建立了多种分形预测模型，并取得较好的效果。作者另辟蹊径，通过引入新的分形变量——幂律度(power—law)，建立地质一分形联合预测模型，在理论上进行了初步探索；并以云南省宁蒗—永胜地区铜矿成矿预测为例，圈定A级找矿靶区1处、C级找矿靶区2处，已知矿点的误判率较单一地质预测模型明显降低，体现了幂律度这一分形变量在成矿预测中的优越性。     

西藏冈底斯成矿带矿产资源远景评价与展望

西藏冈底斯成矿带是中国西部地质工作程度极低的地区之一,但成矿条件有利.综合近年地质大调查工作的最新成果,在对冈底斯成矿带的成矿地质背景、成矿条件进行分析和研究的基础上,认为冈底斯是一个找矿潜力巨大的铜、铁、多金属成矿带.根据成矿作用类型将冈底斯主要的矿床类型分为与斑岩、弧火山岩、中酸性侵入岩和蛇绿混杂岩等有关的铜、铁、金、银多金属矿床;并根据其资源找矿潜力,在冈底斯成矿带中划分5个找矿远景区,指出铜矿、富铁矿、富银铅锌矿及金矿是冈底斯成矿带的优势矿种,斑岩铜矿、火山岩型铜矿是冈底斯成矿带中2个最重要的矿床类型.     

西南天山金锑成矿带成矿远景

中国新疆西南天山是中亚南天山金和有色金属成矿带的东延部分,成矿潜力巨大.分析了区域成矿背景,总结了金、锑成矿规律,划分了6个成矿带和15个金、锑成矿区,对4个重点成矿区的成矿远景进行了分析.指出萨瓦亚尔顿河上游、乌兰赛尔-萨恨托亥、乌什北山、哈尔克成矿带的西北部、查汗萨拉、卡拉脚古牙应作为首批重点研究和找矿靶区.提出穆龙套型金矿应作为主攻类型,对于锑矿应重视碳酸盐岩与碎屑岩接触部位的破碎带,并注意锑与其他金属的共生规律.     

云南普朗超大型斑岩铜矿特征及成矿模型

普朗斑岩铜矿床位于义敦岛弧带南端,是中国目前可以确定的印支期斑岩铜矿床的典型代表.矿床产于由石英闪长玢岩、石英二长斑岩小岩株组成的复式岩体中,通过野外观察和典型地质体的辉钼矿Re-Os年龄、黑云母Ar/Ar年龄和K-Ar年龄测定,确定成矿年龄为(213±3.8)～(216.0±1) Ma,为晚三叠世诺利期,表明普朗斑岩铜矿床的成矿作用在印支期完成.含矿岩体蚀变分带明显,由中心向外发育强硅化带(局部)→钾长石、黑云母化带→石英、绢云母化带→青磐岩化带(局部发育伊利石-碳酸岩化带).工业矿体主要产于石英二长斑岩中的钾长石、黑云母化带和石英、绢云母化带.矿床具有斑岩铜矿中下部细粒状浸染、中上部细网脉状浸染和顶部围岩中产出大脉状矿体的"三层楼"模式.其斑岩体、元素组合及矿化特征与蒙古的欧玉·陶勒盖斑岩铜矿可以对比,资源潜力巨大.     

Molybdenum isotopic composition as a tracer for low-medium temperature hydrothermal ore-forming systems: A case study on the Dajiangping pyrite deposit,western Guangdong Province,China

Little is known about the range or controls on the molybdenum isotopic composition of low-medium temperature hydrothermal ore-forming systems. We present molybdenum isotope data from 12 hydrothermal syndepositional silicalite and carbonaceous slate samples from the Dajiangping pyrite deposit in western Guangdong Province, South China. The δ ^97/95 Mo values from Orebody III range from −0.02‰ to 0.29‰, with an average of 0.18‰. In contrast, the composition values from Orebody IV display a larger variation from −0.70‰ to 0.62‰. However, the five samples from the main ore bed all show strong negative values. This indicates that the significant variation in molybdenum isotopic composition supports different hydrothermal ore-forming metallogenesis and a metallogenic environment between the two orebodies. Orebody III is likely to have been deposited from submarine exhalative hydrothermal fluids under a relatively strong reducing environment and Orebody IV may have also been influenced by hydrothermal superimposition in a more oxidized disequilibrium condition. In addition, the δ ^97/95 Mo values of Orebody IV are clearly negative, together with the values increasing stratigraphically upward in the ore beds, suggesting that the metallogenic environment of Orebody IV is different from the open oceanic systems. There might be dynamic fractionation in this restricted environment. Therefore, the molybdenum isotope can be used as an effective tracer for the ore-forming fluid and metallogenic environment.     

相山矿田居隆庵铀矿床成矿物理化学条件分析

目的了解相山矿田居隆庵铀矿床成矿物理化学性质及其背景。方法应用岩石化学及铷、锶、硫、氧等同位素地质及包裹体研究方法。结果含矿主岩碎斑熔岩岩石形成的初始岩浆起源于上地幔,在上升过程中混染并重熔了地壳组分;成矿热液起源于深部岩浆热液,在沿构造上升过程中混合了浅部地下水溶液,形成了一种混合热液。结论成矿热液物理化学性质为弱酸、弱还原性的中低温热液,成岩成矿物质既来源于深部(上地幔),又有浅部物质的混合。     

新疆西天山西段金铜成矿带——中亚成矿域东延

新疆西天山西段位于哈萨克斯坦 -伊犁板块的东南部边缘 ,包括伊犁石炭纪裂谷、那拉提地块、哈尔克早古生代被动陆缘褶皱带。主要已知矿床 (点 )按其容矿围岩可分为镁铁 -超镁铁岩型、斑岩型、花岗岩型、矽卡岩型、陆相火山岩型、陆相沉积岩型、浅变质含碳碎屑岩型。根据区内成矿地质条件、矿化特征 ,区内以找金矿主 ,兼顾铜镍矿等。金矿以穆龙套型和火山岩型金矿为主 ,同时注意卡林型和中 -酸性侵入岩内外接触带型 ;铜矿以镁铁 -超镁铁岩型和火山岩型为主。地质与成矿条件与中亚成矿域具有可比性 ,因此 ,新疆西天山西段金铜成矿带应为中亚成矿域东延部分     

新疆昭苏水磨沟铜金矿特征

新疆西天山下石炭统大哈拉军山组地层中产有众多的金矿体。通过对昭苏水磨沟铜金矿床矿化特征的研究 ,总结出这类矿床的成矿规律是 :下石炭统大哈拉军山组中酸性火山岩是矿源层 ;区域性大断裂是矿质运移通道 ,其中的低级别、低序次构造为容矿空间 ;华力西期钾长花岗岩是形成铜金矿的能量来源 ;绿片岩相以下的动力变质作用是矿化富集的条件。矿床成因应属构造破碎蚀变岩型铜金矿床     

Metallogenic epoch and genesis of the gold deposits in Jiaodong Peninsula, Eastern China: a regional review

Gold deposits are characterized by multi-sources, superimposition, large scale and temporal-spatial concentration in Jiaodong Peninsula, Eastern China. In this paper, we review the history and the development of the study on metallogenic chronology and genesis of gold deposits, summarize the main features of superimposed metallogenesis, provide evidence of the Mesozoic complex metallogenic system, and point out some problems for further research of Jiaodong gold deposit cluster from a regional view. Although gold deposits are different in genetic types, ore-forming materials and geological settings, our research indicates that the accumulation and emplacement of the ore-forming materials are temporally-spatially concentrated on a large scale, and the main metallogenic epoch of Jiaodong gold deposits was concentrated in Mesozoic. Metallogenic chronology and geological-geochemical data indicate that there are two periods of gold mineralizations occurred in 130-110 Ma and 90-80 Ma respectively in Jiaodong ore cluster. The gold deposit cluster results from the superimposition of the polygenetic mineralization, and further study is needed to investigate the formation and evolution of the Mesozoic complex metallogenic system.