湖南骑田岭白腊水锡矿围岩蚀变与矿化关系浅析

白腊水锡矿是骑田岭芙蓉矿田的重要组成部分,与锡矿化有关的围岩蚀变有钠长石化、绿泥石化、矽卡岩化、云英岩化、黑（绿）鳞云母化、萤石化等.以野外观观察和镜下分析为基础,结合矿体中石英包裹体的化学成分研究和绿泥石的电子探针分析结果,认为钠长石化、绿泥石化、复杂矽卡岩化和云英岩化与区内锡的成矿关系最为密切,蚀变强度与矿化强度呈正相关关系.     

三维地质建模的用途、现状、问题、趋势与建议

文章论述了三维地质建模技术的用途、现状、存在问题、发展趋势和几点建议。笔者认为三维地质建模的用途是:1真三维的立体场景;2精准的储量计算;3平、剖面构造形态相容并联动编辑;4多源、异构数据的集成与同化;5各种三维空间分析与过程模拟;6便于向客户与领导介绍复杂的地质条件。从行业应用和国内软件发展两个方面论述了当前三维地质建模的应用现状,该技术应用中存在的问题:1软件操作太复杂,难以为基层广大地质作图人员所掌握;2三维建模约束条件太严苛,编辑工作量巨大;3没有三维地质模型数据标准,模型数据难以交换与共享;4勘探规范没有要求,地质队积极性不高;5三维地质模型的建模成本由谁支付。三维地质建模的发展趋势:1软件将更加成熟、稳定、易用;2由早期的注重形态建模向形态与属性建模并重的方向发展;3与地震、测井等物探数据结合更加紧密;4与矿藏描述、成藏模拟、沉积环境分析、构造演化分析、构造演化模拟等专业应用结合更加紧密;5融入大数据、云计算、物联网等IT主流技术。向国家相关主管部门、企业用户和软件开发商提出了几点建议:1国家应继续支持三维地质建模领域;2三维地质建模要与专业应用紧密结合;3加强相关标准的制定与维护;4逐步在勘探规范中增加对三维建模的要求;5软件开发者设法降低软件的操作复杂度,提高容错能力。     

西秦岭天水范家山夕卡岩型铜金矿床地质特征及成因探讨

范家山铜金矿位于西秦岭北成矿亚带,温泉复式花岗岩天水斑岩夕卡岩钼铜金矿带的核心位置。矿床地质特征表明：范家山铜金矿体主要受岩体与围岩接触带以及岩体附近的断裂破碎带的控制,以金铜矿化为主,围岩蚀变为夕卡岩化、角岩化及硅化、绢英岩化等。范家山铜金矿床主矿脉包裹体温度、盐度及H-O同位素研究显示,主成矿流体的盐度(S)为2.0%～11.0%(w(NaCl)eq),均一温度为120～345 ℃,主要集中在150～280 ℃范围,具有中温和中低盐度的特征,为岩浆水和大气降水的混合。成矿花岗斑岩锆石U-Pb年龄为(248.3±1.9) Ma(MSWD=0.67, N=9),表明成矿活动发生在印支早期。结合区域构造背景,范家山铜金矿为印支期早期陆陆碰撞导致地壳加厚背景下的夕卡岩型矿床,深部具有斑岩型成矿的潜力。     

江西城门山矿田块状硫化物型矿体矿化分带特征

通过城门山矿田矿床地质、矿体走向及倾向上的厚度及品位变化情况总结其矿化特征,根据成矿温度及地球化学成矿条件研究该矿体矿化富集规律的控制因素,并从矿化特征方面佐证讨论该类矿床的成因及外围找矿方向。研究表明,矿体矿化沿水平及垂向上均具有分带特征,大致表现为沿热液中心向外为Mo、Cu、Zn、Pb、Ag、Au元素的分带,从地表向下为TFe、Au、Ag、Pb、Zn、Cu元素的分带。除此之外,矿化还具有差异特征,表现为走向上矿体两端发育的不一致性、倾向上的局部豆荚状发育特征。本次工作厘定的分带性及差异性分别佐证了矿床的热液成因与沉积成因,并预测外围具有较好的多金属找矿前景,且东段好于西段。      

Ore and Skarn Mineralogy of the Yamato Mine,Yamaguchi Prefecture,Japan, with Emphasis on Silver‐, Bismuth‐, Cobalt‐, and Tin‐bearing Sulfides

Assemblages and chemical compositions of ore minerals from the Yamato mine, Yamaguchi Prefecture, Japan, were investigated in detail to clarify its characteristics as a skarn deposit. Special attention was paid to silver‐, bismuth‐, cobalt‐, and tin‐bearing sulfide minerals and native gold at the mine, which are described here for the first time. Samples of arsenopyrite‐dominant massive ore, and garnet‐rich, clinopyroxene‐garnet‐rich, and wollastonite‐bearing skarn ores were collected from the mine dump. Arsenopyrite is the most abundant ore mineral (>80 vol.%) in the massive ore, in association with both As‐poor/free and As‐bearing pyrite. The major ore minerals in the skarn specimens are pyrite, pyrrhotite, arsenopyrite, chalcopyrite, galena, and sphalerite, along with minor argentite, Ag‐Pb‐Bi sulfate, matildite, bismuthinite, native bismuth, molybdenite, scheelite, stannite, stannoidite, cassiterite, cobaltite, gersdorffite, and Co‐rich violarite. In addition, native gold is observed in the interstices of gangue minerals. Based on the mineral assemblages and textures of the specimens examined, the major ore minerals formed in the early stage of mineralization, and the Bi‐, Ag‐, Co‐, Ni‐, As‐ and Sn‐mineralization occurred in the middle stage. Native gold was deposited in the late stage. The estimated formation temperature of the middle mineralization stage was 312±5 °C, according to iron and zinc partitioning between stannite and coexisting sphalerite. The mineralogical properties and mineralization process of the Yamato mine are consistent with those of common skarn‐ and vein‐type ore deposits associated with ilmenite‐series granitoids in the San‐yo and San‐in districts.     

南美洲圭亚那地盾北部绿岩带地质特征、典型金矿床及金成矿作用

圭亚那地盾位于南美洲亚马孙克拉通的北部,其北部广泛发育太古宙典型的花岗岩-绿岩带,主要岩石组成为花岗岩、片麻岩和英云闪长岩,古元古代变质超基性-基性火山岩-侵入岩、其他变质火山岩等。由于独特的地质构造位置和复杂的构造演化历史,形成了良好的绿岩型金成矿地质背景,产生了大量的金矿床。通过总结圭亚那地盾北部绿岩带的岩石特征、成岩时代和构造演化历史,对委内瑞拉埃尔卡劳金矿、圭亚那欧迈金矿和苏里南罗瑟贝尔金矿进行典型矿床剖析,系统研究了该区绿岩带型金矿的成矿地质背景、成矿流体及成矿年代学特征,建立了区域绿岩带型金矿成矿模型,并在分析找矿要素的基础上,提出圭亚那地盾北部的金矿找矿方向。     

广西大厂X矿体数字化研究及其意义

以计算机为辅助工具,将GIS技术与矿床数学模型软件包相结合,完成对广西大厂X矿体的数字化研究.研究的第一步是建立矿体原始资料数据库,该数据库包括矿体所有探矿工程的品位数据、岩性数据以及空间坐标;第二步是建立矿体的矿体数学模型,科学地估算出矿体各点的品位值;第三步是根据建立好的矿体品位模型,结合GIS技术,建立矿体矿化强度模型.该矿体的数字化研究在实现矿山动态管理和进行找矿预测等很多方面具有重要的意义.     

新疆和静县查岗诺尔铁矿床FeⅠ矿体围岩蚀变特征

新疆和静县查岗诺尔铁矿床位于伊犁微板块北缘之博洛科努早古生代岛弧带,属于阿吾拉勒金、铜、铅、锌、铁成矿带东段。矿区出露地层主要为下石炭统大哈拉军山组火山岩和上石炭统伊什基里克组火山岩,两者为断层接触关系。由于成矿矿浆的多期次活动,查岗诺尔铁矿广泛发育围岩蚀变,形成沿断裂带分布的带状蚀变带。通过研究发现,矿床主矿体FeⅠ号主矿体的围岩蚀变情况,按不同蚀变矿物组合,自东向西可分出石榴石带、绿帘石-阳起石带、阳起石-磁铁矿带、蚀变大理岩带和阳起石带,对应三期蚀变作用。各阶段的矿物共生组合分别为：磁铁矿＋透辉石＋石榴石、磁铁矿＋阳起石＋绿帘石、磁铁矿-石榴石-阳起石-绿帘石-石英-碳酸盐。矿区蚀变是由高、中温火山热液交代中酸性火山碎屑岩而形成。     

吉林磐石石咀—官马地区建造构造与成矿探讨

本文系统的总结了石咀—官马地区火山建造、侵入岩建造、沉积建造、变质建造的特征,以石咀铜矿、头道川金矿、吉昌铁矿的控矿因素和矿床形成机制为切入点,探讨了区域建造构造与成矿的关系。     

巴布亚新几内亚利希尔岛拉多拉姆(Ladolam)金矿矿床地质特征及找矿标志

巴布亚新几内亚利希尔岛拉多拉姆金矿处于太平洋板块与印澳板块的板块边界部位,为西南太平洋地区最大的碱性侵入岩有关的低硫型浅成低温热液型金矿。矿床赋存在Luise火山内,成矿与更新世碱性二长闪长岩侵入体有关,该岩体形成于俯冲带环境下被流体交代的上地幔的部分熔融。矿床的矿化可分为三个阶段,在岩体侵入后形成斑岩铜矿化,并在之后逐渐过渡为浅成低温热液型金矿化。该类矿床在成矿过程和矿体的分布明显受到区域性构造、蚀变带和成矿有关角砾岩等成矿结构面的控制,在找矿标志上具有特定的物化探和地质特征,具有较好的找矿远景。     

河南省栾川县罗村钼矿成矿特征及找矿

通过对河南省栾川县罗村钼矿区域地质背景、矿床地质特征与南泥湖、三道庄及东沟超大型钼矿的综合对比、分析、研究,总结归纳了矿区NWW构造形迹、小岩体与钼矿成矿关系、围岩对成矿的控制作用、围岩蚀变与成矿的关系、地球化学异常与钼矿床的关系等成矿特征.根据罗村钼矿的成矿特征,初步指出今后的找矿方向.     

Gold mineralization in the Mazowe area, Harare-Bindura-Shamva greenstone belt, Zimbabwe: II. Genetic relationships deduced from mineralogical, fluid inclusion and stable isotope studies, and the Sm-Nd isotopic composition of scheelites

In the Mazowe area some 40 km NW of Harare in Zimbabwe, gold mineralization is hosted in a variety of lithologies of the Archean Harare-Bindura-Shamva greenstone belt, in structures related to the late Archean regional D2/3 event. Conspicuous mineralzogical differences exist between the mines; the mainly granodiorite-hosted workings at Mazowe mine are on pyrite-rich reefs, mines of the Bernheim group have metabasalt host rocks and are characterized by arsenopyrite-rich ores, and Stori's Golden Shaft and Alice mine, both in metabasalts, work sulfide-poor quartz veins. In contrast to the mineralogical diversity, near-identical fluid inventories were found at the different mines. Both H₂O-CO₂-CH₄ fluids of low salinity, and highly saline fluids are present and are regarded to indicate fluid mixing during the formation of the deposits. Notably, these fluid compositions in the Mazowe gold field markedly contrast to ore fluids “typical” of Archean mesothermal gold deposits on other cratons. Stable isotope compositions of quartz from the various deposits (δ¹⁸O=10.8 to 13.2‰ SMOW), calcite (δ¹⁸O=9.5 to 11.9‰ SMOW and δ¹³C=−3.2 to −8.0‰ PDB), inclusion water (δD=−28 to −40‰ SMOW) and sulfides (δ³⁴S=1.3 to 3.2‰ CDT) are uniform within the range typical for Archean lode gold deposits worldwide. The fluid and stable isotope compositions support the statement that the mineralization in the Mazowe gold field formed from relatively reduced fluids with a “metamorphic” signature during a single event of gold mineralization. Microthermometric data further indicate that the deposits formed in the PT range of 1.65–2.3 kbar and 250–380 °C. Ages obtained by using the Sm/Nd and Rb/Sr isotope systems on scheelites are 2604 ± 84 Ma for the mineralization at Stori's Golden Shaft mine, and 2.40 ± 0.20 Ga for Mazowe mine. The Archean age at Stori's is regarded as close to the true age of gold mineralization in the area, whereas the Proterozoic age at Mazowe mine probably reflects later resetting. Received: 30 September 1998 / Accepted: 17 August 1999     

纳米比亚湖山铀矿地质特征、控矿因素及其成因探讨

湖山铀矿位于泛非期达马拉造山带的南部中央区带内,构造以NNE-SSW向穹窿和断裂为主。矿区内地层自老至新为艾杜西斯组、可汗组、罗辛组、楚斯组、阿兰蒂斯组、卡里比布组和卡塞布组,侵入岩为寒武纪至晚新元古代花岗岩类。晶质铀矿为主要原生矿石矿物。后期热液叠加导致了铀石、硅钙铀矿和黄硅钾铀矿等热液矿物的形成以及高岭土化、蛇纹石化、绢云母化和绿泥石化等蚀变作用。矿床的形成受矿区地层、岩浆岩和构造联合控制,矿化仅发生于D和E型花岗岩内。矿化岩体呈席状侵入于NNE-SSW向湖山背斜转折端和翼部高应力区域,赋存于罗辛组与可汗组不整合接触带及其上部的罗辛组,少量赋存于楚斯组内。矿区内构造-岩浆事件可划分为四个阶段,铀成矿作用与第四阶段构造-岩浆事件密切相关,含矿D和E型花岗岩为后造山伸展环境下富铀阿巴比斯基底重熔形成。     

宁陕县大构园沟钒矿床地质特征及矿床成因探讨

大构园沟钒矿是近年来陕西境内新发现的中型钒矿床,属于南秦岭多金属成矿带黑色岩系中带成矿的一部分。笔者从成矿地质环境、矿床地质特征、成矿作用综合信息研究入手,对大构园沟钒矿床成因进行了分析,认为寒武系水沟口组是区内钒、金的主要赋矿层位,碳泥质板岩、含碳质石英砂岩(炭硅质岩)是赋矿的有利岩性,也是找矿的直接标志。矿床成因属有机质参与的海底热水沉积(改造)型矿床。     

Numerical Modeling of the Coupled Mechanical and Hydrological Processes during Deformation and Mineralization in the Mount Isa Block, Australia

Mount Isa is a major Australian and world Pb‐Zn‐Ag mineral province. The wide varieties of mineralization in the province are believed to be closely related to the geodynamic processes of Isan Orogeny, which occurred between ca 1500 and 1620 Ma. In order to understand the geodynamic processes associated with the Isan Orogeny and the giant mineralization systems in the Mount Isa district, a series of numerical models has been constructed to simulate coupled mechanical–hydrological processes, using Fast Lagrangian Analysis of Continua (FLAC), a finite difference computer code. The numerical modeling results have demonstrated that the most probable far‐field stress orientation during the Isan Orogeny is the asymmetrical E–W shortening, which led to greater easternward tectonic movement at the west boundary of the district in comparison with westward movement at the east boundary. During the initial and early stage of the Isan Orogeny, the mechanical and hydrological conditions in the Leichardt Fault Trough of the West Fold Belt are much more favorable for fluid accumulation and mineralization than in the East Fold Belt. The Mount Isan fault zone developed as a high dilation shear zone where the fluids were focused. As the asymmetrical shortening progressed, shortening deformation and shear strain localization became intensified in the eastern part of the orogenic district. The eastern region therefore became a more favorable locality for hydrothermal mineralization. This structural development feature seems to explain why mineralization in the East Fold Belt is generally later than in the West Fold Belt. Fluid production from the Williams–Naraku granites could result in fluid over‐pressuring, and this probably contributed to the extensive brecciation and related mineralization in the East Fold Belt.     

Timing of mineralization and deformation,Peak Au mine,Cobar, New South Wales∗

The ⁴⁰Ar/³⁹Ar dating of alteration muscovite from the Peak Au mine in the Early Devonian Cobar Basin, New South Wales, has distinguished two major episodes of mineralization. Veined (Pb‐Zn‐Cu‐Au) mineralization was broadly synchronous with cleavage formation during the post‐inversion, shortening deformation of the basin sedimentary rocks, and replacive Ag‐Pb‐Zn mineralization significantly postdates the latter event. Veined base metals (Pb‐Zn‐Cu) and Au associated with silicification were coeval with three stages of cleavage formation (D₁, D₂ and D₃) after basin inversion. The Cu‐Au phase of mineralization at the Peak Au mine which was broadly contemporaneous with the culmination of the cleavage‐forming events (D₃) and with the local development of high‐strain zones occurred at 401.5 ± 1.0 Ma (⁴⁰Ar/³⁹Ar on muscovite). This date is essentially coeval with known fossil constraints on the age of basin formation, and indicates that basin inversion and deformation rapidly followed sedimentation. In contrast, replacive Ag‐Pb‐Zn mineralization occurred at 384.0 ± 1.4 Ma (⁴⁰Ar/³⁹Ar on muscovite) during an extended period of relaxation characterized by normal faulting (D₄) which followed the shortening deformation. This mineralization was associated with desilicification and chlorite‐muscovite replacement assemblages which cross‐cut the cleavages, and which may have been broadly contemporaneous with the deposition of part of the Mulga Downs Group which unconformably overlies the Cobar Supergroup. Rhyolite exposed in the core of the Peak Au mine largely contains inherited zircons that range in age from ～430–1500 Ma. A few euhedral zircons have an age of ～430 Ma and this is interpreted as a maximum date for the rock. Zircons from a syn‐D₃ chlorite‐muscovite replacement zone within the deposit have ²⁰⁶Pb/²³⁸U ages of ～410–650 Ma and are apparently inherited.     

济源市莲东铁矿地质特征及物探方法应用

莲东铁矿是沉积变质型铁矿,成矿母岩为太古界老变质岩,区域变质作用为成矿提供动力。通过对磁法异常分析和验证,发现两条有一定规模的矿体。矿体似层状,矿石类型以磁铁矿为主,近矿围岩蚀变主要为硅化、碳酸盐化、绿泥石化。根据矿体特征和成矿规律分析,认为在太古界老变质岩中具有较好的找矿远景。     

黑龙江大兴安岭地区HFU-09号航放异常特征及找矿意义

利用大兴安岭地区1/5万高精度航放资料,对圈定的HFU-09号航放异常开展了综合查证,采用的工作手段包括剖面、面积性查证及深部钻探验证。在钻孔中发现了低品位铀矿体、铀矿化体、铅锌矿化体及铌钽矿找矿线索。根据查证结果认为,1:5万航空物探调查圈定的航放异常与地面伽玛能谱测量圈定的U、Th异常对应性较好,异常再现性较明显。区内岩石破碎铁染发育部位一般存在矿化。在对赋存于花岗岩中的航放异常进行查证时,需结合岩石的具体矿化蚀变特征进行贵金属、有色金属矿产的评价,以期发现多金属矿床。     

新疆小热泉子铜矿区构造特征及成矿模式

新疆小热泉子铜矿区总体为一NW-SE走向的不协调短轴复背斜,后期有SN向次级褶皱叠加。区内NW向断裂发育,均为EW向大断裂之分支断裂,规模小,无推覆性质,主要矿床(Ⅰ号矿床)呈较为典型的立交桥式双层成矿模式。矿床成因类型为中温热液充填-交代型铜(锌)矿床。      

粤北梅子窝钨矿区隐伏花岗闪长岩锆石SHRIMP U-Pb年龄与~(40)Ar/~(39)Ar成矿年龄及其地质意义

梅子窝钨矿位于粤北瑶岭—梅子窝钨矿带的东部,成矿作用同期形成白云母的40Ar/39Ar年龄为(155.9±0.6)Ma,与华南中生代燕山期大规模W,Sn成矿作用的年龄一致,代表梅子窝钨矿的成矿年龄。矿床下部600m中段附近出现的隐伏黑云母花岗闪长岩体的锆石SHRIMPU-Pb年龄为(430.4±3.6)Ma,为加里东期,与成矿作用无关。因此,矿区不存在前人提出的两套叠加的"五层楼"成矿模式。成矿年龄与隐伏花岗闪长岩的年龄显示梅子窝钨矿的形成可能与更深部的隐伏燕山期花岗岩有关,矿床向深部可能延伸更大。