滇中荒田铅锌矿床Rb-Sr同位素年代学与C-O-S-Pb同位素地球化学特征

滇中荒田铅锌矿床赋存于下二叠统碳酸盐岩与上二叠统峨眉山玄武岩接触界面上,矿体主要呈似层状、透镜状产出。矿石矿物组合以闪锌矿、方铅矿为主,脉石矿物以石英、方解石、白云石为主。热液方解石C、O同位素组成表明荒田铅锌矿床成矿流体中CO_2的碳具有多元性,主要来源于幔源与海相碳酸盐岩的混合碳;硫化物硫同位素组成表明荒田铅锌矿床硫以岩浆硫为主,可能混有其他硫源(可能包括地层硫酸盐),铅同位素表明赋矿围岩、玄武岩和燕山期花岗岩均有可能为成矿提供了成矿物质,是多源混合后的产物;闪锌矿Rb-Sr同位素等时线年龄为(83.2±3.4)Ma,指示荒田铅锌矿床形成于晚燕山期,荒田铅锌矿床成矿动力学背景可能与右江褶皱带在中生代末期发生了大规模的岩石圈伸展有关。而晚二叠世海相喷发火山岩对矿区铅锌矿床的形成起了重要的盖层、赋矿层及矿化作用。综上,荒田铅锌矿床成矿流体中的不同组分来源不同,矿床类型为沉积-改造型矿床。     

冀东地区东梁金矿床地质特征及成因

东梁矿区位于冀东地区宽城凹褶束东南边缘。金矿床主要产于燕山期火成岩与中元古界长城系、蓟县系碳酸盐岩地层的接触带部位,受构造、岩浆活动控制。矿区岩(矿)石地球化学分析结果表明,成矿流体中的硫、铅主要来源于深部,与深部岩浆活动有关;氢、氧同位素分析结果显示,成矿流体主要来源于原生岩浆水;金矿床成矿温度125~305℃,成矿深度1.5km,成矿时代为燕山期火山活动晚期。认为在燕山期板块构造影响下,东梁金矿床成矿物质主要来源于深部活化变质岩系,属岩浆热液型中低温金矿床。     

山东金岭金岚沟金矿流体包裹体特征

<正>金岚沟金矿位于山东省招远市金岭镇,为金岭金矿采矿权范围内一小型金矿床。本文对金岚沟金矿主成矿阶段流体进行系统的流体包裹体研究工作,并根据结果探讨其成矿流体性质及矿床成因。1矿区矿床地质金岚沟金矿围岩以燕山早期玲珑型片麻状黑云母花岗岩为主,矿区北部出露少量似斑状中粗粒花岗闪长岩。矿区内地层为太古代胶东群变质岩,呈残留体形式分布于后期的花岗岩中。矿区内构造发     

福建香厝坑铁多金属矿床地质特征及成矿模式

通过对香厝坑铁多金属矿床区域地质背景、矿区地质特征和矿床地质特征进行研究,分析了矿床的成矿模式。结果表明:燕山早期中酸性岩浆(汤泉岩体)侵入活动是矿床形成的主导因素,为成矿提供了成矿物质、成矿流体和热能;构造是成矿的重要因素,北北东向区域性大断裂(政和—大浦断裂带)和太华—长塔复式背斜控制了岩浆的侵入,区内滑脱构造控制了矿体的形成和就位;地层是矿床形成的关键控制因素,一方面在含矿流体的运移、矿质的沉淀和矿体的定位过程中,地层成为十分重要的成矿地球化学障;另一方面地层作为矿源层,为矿床的形成提供了大量的成矿物质。矿床成因属接触交代型和风化淋滤型铁多金属矿床。     

江西银山铅锌矿床成矿流体特征

银山铅锌矿床产于前震旦系地层中 ,容矿围岩主要为千枚岩 ,矿体呈脉状受构造裂隙控制。流体包裹体及同位素研究表明金属元素及硫主要来自上地幔 ,流体主要是岩浆水。矿床属中低温岩浆热液矿床 ,为燕山期成矿     

贵州西北部江子山—蟒硐构造带两类铅锌矿床特征及其形成机制

贵州西北部江子山—蟒硐铅锌成矿带,位于扬子板块西南缘之菱形断块北东边界断裂南东段,经历了加里东—印支期裂陷作用和燕山期褶皱造山过程,以及海西—印支期、燕山期两次岩浆活动。铅锌成矿特征显示,本区矿化层位较多,根据矿化特征分析并差异分辨,矿床类型划分为受上司组和摆佐组主控的矿床、受垭都—蟒硐断裂主控的矿床2种,成矿金属主要来源于下伏D-C铁质、炭质、泥质碎屑岩类,但硫的来源有所不同,其中第一种类型形成机制差别在于赋矿的上司组和摆佐组地层沉积了成矿主要的硫源,并在印支期和燕山期发生富金属流体上行与地层中富硫酸盐热液的混合成矿和二次叠加,矿床成因类型为层控类型;第二种类型成矿过程为构造驱动富金属成矿流体上行至构造空间,与断裂穿层逆冲过程中下行之硫酸盐流体混合成矿,矿床成因类型为热液类型;两种类型的划分对深入研究本区铅锌成矿作用和找矿实践具有参考意义。     

安徽铜陵天马山矿床与大团山矿床流体成矿作用对比研究

对安徽铜陵天马山矿床和大团山矿床的成矿地质背景和成矿流体特征, 特别是流体成矿作用进行了较系统的对比研究, 在此基础上探讨了在铜陵天马山和大团山矿区分别形成层控矽卡岩型金硫矿床和层控矽卡岩型铜矿床的主要原因.研究结果表明, 在天马山矿区之所以形成金硫矿床, 主要与岩浆岩岩体本身含金高而含铜低, 围岩地层中有含有机质的赋金黄铁矿层存在, 并且主成矿阶段的成矿流体以岩浆流体为主有关; 而在大团山矿区之所以形成铜矿床, 主要原因是岩浆岩岩体本身含铜高, 成矿流体富铜, 且主成矿阶段的成矿流体以地下水流体为主.当然, 流体成分演化和物理化学条件改变方面的差异导致铜或金在流体成矿过程晚期逐步分散也是这两个矿区分别形成不同类型矿床的重要原因.      

贵州独山锑矿田地质地球化学特征和构造动力热液成矿

独山锑矿田位于独山箱状背斜核部近倾伏端,矿床、矿体的产出严格受断裂控制,其半坡半锑矿呈脉状产于下泥盆统、志留系碎屑岩的陡倾斜断裂中;其巴年式的锑矿呈层状产于泥盆统碎屑岩与碳酸盐岩之间的层间滑动带中。成矿温度低,矿石组分和围岩蚀变简单,锑主要还原于下伏地层,硫主要来源于赋矿地层,成矿流体主要为大气降水,构造动力成矿作用导致锑矿床的形成,矿床类型为一典型的构造动力热液矿床。     

新疆和静县巴音铜矿地质特征与找矿标志

巴音铜矿床位于新疆西南天山东段,尤路都斯山问盆地北缘.矿化体赋存于上志留统中基性火山岩及沉积岩中,矿化富集受地层、构造、侵入岩的多重控制.文章阐述了巴音铜矿床成矿地质背景,矿床(体)地质特征.研究了矿区内地层、岩石、岩浆岩中微量元素与铜成矿的密切关系,探讨了成矿流体性质、矿床成因、成矿模式及找矿标志.     

辽宁丹东四道沟金矿床流体包裹体特征及矿床成因

四道沟金矿床为辽东南地区重要的蚀变岩型矿床,其空间产出受断裂构造、盖县组变质地层及区内岩浆活动的联合制约.流体包裹体研究表明:成矿早期流体为中温、低盐度且富含CO2及CH4等挥发分的热液;主成矿阶段成矿流体为中温、高盐度的热液体系;矿区晚期阶段矿化流体具有较低的温度及盐度特征.综合分析认为:四道沟金矿床早期成矿流体与区内燕山晚期三股流花岗闪长岩体活动有关;主成矿阶段流体可能来自其后的花岗斑岩等类脉岩活动;成矿晚期阶段流体则主要来自大气降水.四道沟金矿床是燕山晚期不同来源及性质的热液先后叠加成矿作用的产物.     

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.     

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).     

NONMETALS DEPOSITS

正20141520 Bo Ying(Key Laboratory of Metallogeny and Mineral Assessment,MLR,Beijing 100037,China);Liu Chenglin Saline Spring Hydrochemical Characteristics and Indicators for Potassium Exploration in Southwestern and Northern Tarim Basin,Xinjiang(Acta Geoscientica Sinica,ISSN1006-3021,CN11-3474/P,34(5),2013,p.594-602,5 illus.,3 tables,28 refs.)     

MATHEMATICAL GEOLOGY

正20141243Chen Ge(Hangzhou Research Institute of Petroleum Geology,PetroChina,Hangzhou 310023,China);Si Chunsong Study on Sedimentary Numerical Simulation Method of Fan Delta Sand Body(Journal of Geology,     

PROSPECTING EXPLORATION

正20142599Chen Sanming(Guangxi Key Laboratory of Concealed Deposits Exploration,Guilin University of Technology,Guilin541004,China);He Yuzhou Block Model and Reserves Estimation of Panzhihua Iron Deposit Based on 3D Geological Modeling(Journal of Guilin University of Technology,ISSN1674-9057,CN45-1375/N,33(4),2013,p.610-615,9illus.,1table,15refs.)     

STRUCTURAL GEOLOGY

正20140594 Bai Daoyuan(Hunan Institute of Geology Survey,Changsha 410016,China);Zhong Xiang Faults in the Jingzhou Basin and Their Tectonic Settings(Geotectonica et Metallogenia,ISSN1001-1552,CN44-1595/P,37(2),2013,p.173-183,6illus.,59refs.)Key words:basin evolution,tectonic setting,South China In the Upper Paleozoic and Jurassic se-     

STRUCTURAL GEOLOGY

正20141912Cao Hui(State Key Laboratory for Continental Tectonics and Dynamics,Institute of Geology,Chinese Academy of Geological Sciences,Beijing 100037,China)Gravitational Collapse and Folding during Orogenesis:A Comparative Study of FIA Trends and Fold Axial Plane Traces(Geology in China,ISSN1000-3657,CN11-1167/P,40(6),2013,p.1818-1828,9illus.,35refs.,with     

PALEOZOOLOGY

正20141609 Chen Guiying(College of Earth Sciences,Guilin University of Technology,Guilin 541004,China);Han Nairen New Materials of Stylophora from the Upper Cambrian of the Jingxi Area,Guangxi,South China(Acta Palaeontologica Sinica,ISSN0001-6616,CN32-1188Q,52(3),2013,p.288-293,2 illus.,12 refs.)Key words:Stylophora,Guangxi     

GEOPHYSICS

正20140634 Cao Lingmin(Key Laboratory of Marine Geology and Environment,Institute of Oceanology,Chinese Academy of Sciences,Qingdao 266071,China);Xu Yi Finite Difference Tomography of the Crustal Velocity Structure in Tengchong,Yunnan Province(Chinese Journal of Geophysics,ISSN0001-5733,CN11-2074/P,56(4),2013,p.1159-1167,6illus.,35refs.,with English abstract)