共查询到18条相似文献，搜索用时 202 毫秒
1.
Eastern Iran has great potential for the discovery of different types of mineralization. The study area encompasses Tertiary magmatism in the northern Lut block located in northern Khur, South Khorasan, eastern Iran and is mostly covered by volcanic rocks, which are intruded by porphyritic subvolcanic intrusions in some places. Application of the spectral angle mapper (SAM) technique to Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) images detected sericitic, argillic, and propylitic alterations, silicification, and secondary iron oxides. The alteration is linear and associated within vein-type mineralization. Twelve prospective areas are selected for detailed exploration and based on our processing results, in addition to NW-SE faults, which are associated with Cu mineralization indications, NE-SW faults are also shown to be important. Based on the presence of subvolcanic rocks and numerous Cu ± Pb-Zn vein-type mineralizations, extensive alteration, high anomaly of Cu and Zn (up to 100 ppm), the age (43.6 to 31.4 Ma) and the initial 87Sr/86Sr ratio (0.7047 to 0.7065) of the igneous rocks, and the metallogenic epoch of the Lut block (middle Eocene-lower Oligocene) for the formation of porphyry Cu and epithermal deposits, the studied area shows great potential for porphyry copper deposits. 相似文献
2.
The purpose of this study is to evaluate the Spectral Angle Mapper (SAM) classification method for determining the optimum threshold (maximum spectral angle) to unveil the hydrothermal mineral assemblages related to mineral deposits. The study area indicates good potential for Cu-Au porphyry, epithermal gold deposits and hydrothermal alteration well developed in arid and semiarid climates, which makes this region significant for Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) image processing analysis. Given that achieving an acceptable mineral mapping requires knowing the alteration patterns, petrochemistry and petrogenesis of the igneous rocks while considering the effect of weathering, overprinting of supergene alteration, overprinting of hypogene alteration and host rock spectral mixing, SAM classification was implemented for argillic, sericitic, propylitic, alunitization, silicification and iron oxide zones of six previously known mineral deposits: Maherabad, a Cu-Au porphyry system; Sheikhabad, an upper part of Cu-Au porphyry system; Khoonik, an Intrusion related Au system; Barmazid, a low sulfidation epithermal system; Khopik, a Cu-Au porphyry system; and Hanish, an epithermal Au system. Thus, the investigation showed that although the whole alteration zones are affected by mixing, it is also possible to produce a favorable hydrothermal mineral map by such complementary data as petrology, petrochemistry and alteration patterns. 相似文献
3.
斑岩铜（钼）矿成矿作用的地球化学特征 总被引：1，自引：0，他引：1
Dealt with in this paper are some geochemical characteristics of mineralization of porphyry copper deposits, especially those observed in intrusive bodies, wa11 rocks, alteration zones, ores and individual pyrites. Productive intrusions have been correlated with barre nones from such aspects as major and trace elements, copper contents of biotite and pyrite,and distribution pattern of copper. In the mineralized rocks, trace elements show apparent zoning surrounding ore bodies; major and trace dements seem to show some reguIarity of variation in the process of alteration, and as a result each alteration zone displays its own peculiar element combination. Trace dements in ores can provide information on the genesis of ore deposits, thus of great help in distinguishing ore types while those in pyrites may be indicative of mineralization, provide dues for distinguishing orebearing from barren rocks,and reflect the degree of erosion of ore bodies. 相似文献
4.
Platinum-group elements （PGE） in PGE-rich porphyry copper （gold） deposits are mainly Pt and Pd, whereas the concentrations of other PGE （Ru, Rh, Os, Ir） are significantly low. Moreover, Pt and Pd mainly exist in sulfides in the forms of crystal lattice or tiny platinum-group mineral （PGM） inclusions. The present data show that there is a positive relationship between Pt and Pd concentrations and Cu （Au） in porphyry copper （gold） deposits. The comparison of chondrite-normalized PGE distribution patterns between the ore-bearing porphyry intrusions and ore-barren porphyry intrusions in arc setting, 187^Os/188^Os, 87^Sr/86^Sr and S isotopes for porphyry copper （gold） deposits shows that PGEs were mainly derived from the mantle, and fluids from subduction zones devoted trivial PGE to the magma. The porphyry copper （gold） deposits associated with subducted events are most probably enriched in PGE, whereas those related to crustal thickening, lithospheric delamination or underplating rarely concentrate PGE. The osmium isotopic compositions in porphyry copper （gold） deposits reveal that （187^Os/188^Os）i values are highly variable and not lower than those of primitive upper mantle （PUM） and mantle peridotite, however, osmium concentrations are commonly lower than mantle peridotite, suggesting that parental magmas of some porphyry intrusions had experienced crustal contamination during magma evolution. Experimental investigations have proved that PGE exist in the forms of Cl^- and HS^- complexes during transportation and migration of the oreforming fluids. This paper summarizes previous studies including crucial controlling factors and mechanisms for PGE enrichment, and points out that the mantle-derived magmas parental to porphyry intrusions are the prerequisite for PGE enrichment in porphyry copper （gold） deposits. Favorable physical and chemical conditions （including salinity, temperature, pressure, pH, and oxygen fugacity） in hydrothermal fluids crucially control the 相似文献
5.
The Yinyan porphyry tin deposit is a blind deposit associated with a small granite porphyry stock.The petrology and geochemistry of the Yinyan granite porphyry suggest that it is genetically of the transfor-mation type,emplaced at the late stage of fractional crystallization within a high-level magma chamber.Ore-forming fluids are derived predominantly from the granitic magma and they interact with the wall rocks intensely when finding their way upwards through the granite porphyry.From the lower part of the porphyry upwards the following alteration zones can be distinguished(a)slightly altered granite porphyry (with weak potash feldspathization),(b)protolithionite-quartz greisenization zone,(c)to-paz-quartz greisenization zone,(d)senicite-quartz sericitization zone,and （e）silicification zone (quartz core at the surface).Tin mineralization is related to greisenization,especially to topaz-quartz greisenization.Rock and ore-forming temperatures and oxygen fugacities are estimated,respectively.There are significant differences in many aspects between the Yinyan porphyry tin deposit and volcan-ic-subvolcanic porphyry tin deposits. 相似文献
6.
阳储岭斑岩钨钼矿床地质地球化学特征及其成因探讨 总被引：5，自引：0，他引：5
The Yangchuling porphyry W-Mo-deposit is a new-type tungsten deposit discovered recently in southern China. Being of certain economic significance, this type of deposits promises some new prospects for the availability of increasing tungsten resource. The ore-bearing rock mess, intermediate to acid in composition, is a composite rock body resulted from comagmatic, multiple-stage intrusion during Middle-Late Yanshan Period. Spatially, the rock mass is controlled by the Guangji-Anqing-Nanjing deep fault. As a typical porphyry deposit, the ore-bearing rocks (granodiorite porphyry,mozonitic granite porphyry, and camouflage breccia) belong to sub-volcanic facies characteristic of near-surface environment. The rocks have suffered, strong hydrothermal alteration which is closely related to mineralization. The deposit is classified as mesoepithermal deposit and our study shows that W and Mo come from the granodiorite,granodiorite porphyry and mozonitie granodiorite porphyry, which are believed to be derived through remelting from some W-rich basement roeks contaminated with minor amounts of upper mantle material. 相似文献
7.
WangXueping WeiMin YangLipei ZhaoJingnmn 《中国地质大学学报(英文版)》2003,14(3):274-277
A grade-tonnage model is established according to the analysis of 72 porphyry copper deposits recorded in “The Mineral Resources Data Base of China“. Based on the analysis of frequency histogram, the cumulative frequency distributing graph and the theoretical model with double logarithmic coordinated of copper deposits, the typical mathematical characteristics of grade-tonnage model of porphyry copper deposits are clarified. 相似文献
8.
The Jiujiang-Ruichang area in northwestern Jiangxi extends along the western part of the minerogenic belt of the middle-lower Yangtze Valley in a terrain of sediments ranging from Ordovician to Triassic in age with NEE-folda,and NW-compressive,NNW-tensile and NEE-compressive-shearing faults as the major structures .Igneous rocks are mostly intermediate-acid epizonal intrusive bodies.Typical copper mineralizations in this area include the skarn-type and stratiform Cu-bearing pyrite-type deposits at Wushan and the porphyry and breccia-pipe type copper-molybdenum deposits at Chengmenshan.Silurian strata,with a great thickness and an average copper content of 51 ppm,are considered to be the source bed of copper mineralization,as is evidenced,among other things,by the presence of an envelope which is notably impoverished in Cu aroud most of the deposits.Magmatic rocks which intruded into the Silurian strata often have relatively high alkali contents and K2O/Na2O ratios ,with extensive potash alteration.Magmatic rocks in the area are of co-melting type or mixed type.The magma assimilated a large quanity of country rocks while ascending.They are characterized by high REE contents,absence of Eu anomalies and high LREE/HREE ratios.Ancient lead and strontium isotopes were detected in feldspar megaphenocrysts from the granodiorite porphyry.Hydrothermal convective circulation systems of magmatic water of magmatic water and supergenic water was extensively developed in the magmatic and country rocks,in which copper,potassium and other ore-forming components were extracted from the country rocks and concentrated through heating,boiling and evaporating.When the ore-forming fluids found their way into the skarn zone or the unconformity between the Wutong Formation and the Huanglong Formation,ore precipitation would have occurred as a result of changing media,If the concentration of KCl exceeded 9%,copper and other ore-forming components might have been deposited in magmatic rocks,forming the porphyry-type ore deposits. 相似文献
9.
中亚造山带中斑岩铜钼矿的Re，Pt，Pd和Au含量 总被引：1，自引：1，他引：1
Anita N．Berzina Alexander F．Korobeinikov 《岩石学报》2007,23(8):1957-1972
Precious metal(Pt,Pd and Au)and Re contents in rocks,ores and flotation concentrates of Siberian(Russia)andMongolian porphyry Cu-Mo and Mo-Cu deposits were studied.The following deposits are discussed:Early Devonian porphyry Mo-CuSora deposit(Kuznetsk Alatau Mountains,Russia)and porphyry Cu-Mo Aksug deposit,(northeastern Tuva,Russia);Triassicporphyry Cu-Mo Erdenetiin Ovoo deposit(northern Mongolia).The samples analyzed include unaltered host rocks of plutons,porphyryrocks of ore-bearing series,different types of altered rocks,mineral separate analyses of molybdenite,chalcopyrite and magnetite,aswell as flotation concentrates.Pt,Pd,Au and Re contents were determined using ICP/MS,AAS and inversion voltammetric analysis.PGE abundances in rocks and poorly mineralized samples span a large range from below detection limit to 65 ppb Pt and 74 ppbPd.Re concentrations in whole rock samples range from below detection limit to 89 ppb.Molybdenite has been shown to be the majorhost phase for Re.The results presented show that Aksug deposit reveals elevated PGE and Au contents in ore minerals and flotationconcentrates.High Pd contents in ores of the Aksug deposit are in accordance with the presence of palladium mineralization in the formof palladium telluride merenskyite(Pd,Pt)Te_2.The variety of precious metals and Re contents in the studied deposits could be caused by a complex interplay of several factors,including importance of primary metal concentrations derived from the source,transport of metals to the deposition area,physicochemical properties of the fluid(fo_2,pH,fs,T,P),and depositional conditions.Higher Re contents in molybdenite andchalcopyrite separates are typical for copper-rich Aksug and Erdenetiin Ovoo deposits.Rhenium concentration in sulfides frommolybdenum-rich Sora deposit is significantly lower.Highly oxidized,Cl-rich fluid style at Aksug and Erdenetiin Ovoo was favorable forhigh rhenium solubility and transport to depositional area.The occurrence of significant precious metals contents at Aksug were likelydue to:1)PGE and Au enriched source,2)favorable fluid style(high fo_2,high Cl-activity),promoting high solubility andtransportation of precious metals in ore-forming fluid as chloride complexes;3)moderately reducing depositional conditions from PGE-bearing solutions containing As and Te,facilitating PGM deposition.As for the porphyry systems at the Sora and Erdenetiin Ovoodeposits,they were probably devoid of precursors favorable for the enrichment in PGE and Au or the role of such precursors wasinsignificant. 相似文献
10.
^40 Ar/^39 Ar Dating of the Shaxi Porphyry Cu-Au Deposit in the Southern Tan-Lu Fault Zone, Anhui Province 
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下载免费PDF全文 YANG Xiaoyong ZHENG Yongfei XIAO Yilin DU Jianguo SUN Weidong 《《地质学报》英文版》2007,81(3):477-487
Four samples of plagioclase and biotite from the Shaxi porphyry in the lower part of the Yangtze metallogenic belt were analyzed for age determination with the 40Ar/39Ar method. The results yield reproducible ages of 126 Ma to 135 Ma with a high level of confidence according to the agreement between isochron and plateau ages. The four Ar-Ar ages are relatively consistent within the analytical error. These ages are also consistent with, but more precise than, previous K-Ar and Rb-Sr ages and thus provide better constraints on the time of porphyry formation and associated Cu-Au mineralization along the middle to lower part of the Yangtze metaliogenic belt. The ages of 126 to 135 Ma are interpreted to represent the intrusive time of the Shaxi porphyry, so that the Cu-Au mineralization should have occurred later due to the post-magmatic hydrothermal event. 相似文献
11.
文章基于ASTER和Landsat-8OLI两种多光谱遥感数据,采用高光谱遥感技术混合调谐滤波(MTMF)、多光谱遥感技术相对吸收深度(RBD)、波段比值(BR)等方法提取了西藏多龙矿集区地堡那木岗斑岩型铜金矿床地表的蚀变矿物组合。其结果表明,基于ASTER数据的MTMF技术可将Al—OH矿物划分为白云母+高岭石/蒙脱石和地开石+蒙脱石+累托石两种组合,进一步可细分出斑岩型矿床多光谱遥感地表蚀变矿物组合并呈现出良好的分带特征:地堡那木岗铜金矿床自内而外依次为白云母+高岭石/蒙脱石→地开石+蒙脱石+累托石→Mg—OH类矿物组合,分别对应于前人野外调查所勘测到的的绢英岩化带+泥化带→泥化带→青磐岩化带,Fe3+矿物叠加于绢英岩化带、泥化带及其两带的叠合部位。所提取的多光谱遥感蚀变矿物组合分带特征对该区斑岩型铜金矿床的勘查工作提供了重要的遥感线索,对定位找矿靶区具有指导意义。 相似文献
12.
中国大陆环境斑岩型矿床：基本地质特征、岩浆热液系统和成矿概念模型 总被引：49，自引：5，他引：44
中国大陆环境斑岩型矿床包括斑岩型Cu(-Mo、-Au)、斑岩型Mo、斑岩型Au和斑岩型Pb-Zn等矿床类型,主要产出于青藏高原大陆碰撞带、东秦岭大陆碰撞带和中国东中部燕山期陆内环境,在地球动力学背景、深部作用过程、岩浆起源演化、流体与金属来源等方面与岩浆弧环境斑岩型矿床存在重要差异.在大洋板块俯冲形成的岩浆弧,主要发育斑岩Cu-Au矿床或富金斑岩Cu矿(岛弧)和斑岩Cu-Mo及斑岩Mo矿床(陆缘弧).相比,在大陆碰撞带,晚碰撞构造转换环境发育斑岩Cu、Cu-Mo和Cu-Au矿床,矿床受斜交碰撞带的走滑断裂系统控制,后碰撞地壳伸展环境则主要发育斑岩Cu-Mo矿床,矿床受垂直于碰撞带的正断层系统控制;在陆内造山环境,早期发育斑岩Cu-Au矿床,晚期发育斑岩Pb-Zn矿床,它们主要沿古老的但再活化的岩石圈不连续带分布,受网格状断裂系统控制;在后造山(或非造山)伸展环境,则大量发育斑岩Mo矿和斑岩Au矿,它们则主要围绕大陆基底-克拉通(或地块)边缘分布,受再活化的岩石圈不连续带控制.大陆环境斑岩Cu(-Mo,-Au)矿床的含矿斑岩多为高钾钙碱性和钾玄质,以高钾为特征,显示埃达克岩地球化学特性.岩浆通常起源于加厚的新生镁铁质下地壳或拆沉的古老下地壳.上地幔通过三种可能的方式向岩浆系统供给金属Cu(和Au):①提供大批量的幔源岩浆并底垫于加厚下地壳底部,构成含Cu岩浆的源岩;②提供小批量的软流圈熔体交代和改造下地壳,并诱发其熔融;③与拆沉的下地壳岩浆熔体发生反应.大陆环境含Mo岩浆系统高SiO_2、高K_2O,岩相以花岗斑岩为主,花岗闪长斑岩次之,既不同于Climax型,又有别于石英二长斑岩型Mo矿床,岩浆起源于古老的下地壳.金属Mo主要为就地熔出,部分萃取于上部地壳.大陆环境含Pb-Zn花岗斑岩多属铝过饱和型,与S型花岗岩相当,以高δ~(18)O(>10‰)和高放射性Pb为特征,Sr-Nd-Pb同位素组成反映其来源于中下地壳的深熔作用,金属Pb-Zn主要来源于深融的壳层.大陆环境含Au岩浆系统以富B花岗闪长斑岩为主,常与矿前闪长岩密切共生.Sr-Nd-Pb同位素显示,含Au岩浆主要来源于上部地壳,但曾与幔源岩浆发生相互作用.金属Au部分来源于上地壳,部分来源于地幔岩浆.大陆环境斑岩型矿床显示各具特色的蚀变类型和蚀变分带,其中,斑岩型Cu(-Mo,-Au)矿热液蚀变遵循Lowell and Guilbert模式;斑岩型Mo矿主要发育钙硅酸盐化、钾硅酸盐化和石英-绢云母化;斑岩型Pb-Zn矿主要发育绿泥石-绢云母化和绢云母-碳酸盐化,缺乏钾硅酸盐化;斑岩型Au矿强烈发育中度泥化.斑岩型矿床的成矿流体初始为高温、高fO_2、高S、富金属的岩浆水,由浅成侵位的长英质岩浆房在应力松弛环境下出溶而来,晚期有天水不同程度地混入.Cu、Mo、Pb-Zn通常沉淀于流体分相和流体沸腾过程中,而Au则主要沉淀于岩浆-热液过渡阶段. 相似文献
13.
Paleozoic Epithermal Au and Porphyry Cu Deposits in North Xinjiang, China: Epochs, Features, Tectonic Linkage and Exploration Significance 总被引：31，自引：1，他引：31
Kezhang Qin Shu Sun Jiliang Li Tonghui Fang Shulai Wang Wei Liu 《Resource Geology》2002,52(4):291-300
Abstract. Based on field investigation of large number of ore deposits including some latest discoveries and multidiscipline comprehensive research, we demonstrated the general features of metallic deposits and we suggest that Paleozoic archipelago-type collisional orogen at North Xinjiang, northwestern China show intimate similarity with the metallogenesis of Southeast Asia Cenozoic archipelago. We briefly described the characteristics of major porphyry-type, skarn-type Cu deposits and typical high-sulfidation type (HS-type) and low-sulfidation type (LS-type) epithermal Au deposits as well as some latest discoveries. Systematic isotopic age-dating on the Tuwu-Yandong superlarge porphyry Cu deposits revealed that they formed in Late Devonian to Early Carboniferous in an accretionary arc setting. The tectonic settings of epithermal Au deposits and its linkage with porphyry Cu deposits are further discussed. The formation condition for porphyry Cu deposits is more strict than epithermal Au deposits. The distribution width for porphyry Cu deposits in the orogenic belts is more limited than epithermal Au deposits. The discovery and prospecting progress of the Kalatage HS-type Cu-Au deposit were reported. The significance in further exploration was suggested. 相似文献
14.
巴达铜金矿位于藏东富碱斑岩带南段,是藏东地区近年来新发现的大型铜金矿。虽然对巴达铜金矿开展了大量勘查工作,但对该矿床的成因尚未取得共识。本文基于详细的野外调研、岩心与坑道编录及系统的镜下鉴定,对巴达铜金矿床地质特征进行研究。巴达矿床主要产于石英二长斑岩中,局部产于斑岩和砂岩地层的接触带内。矿床发育的围岩蚀变主要为青磐岩化、钾化、绢英岩化,高岭土化、蛋白石化、蒙脱石化次之,蚀变分带从内向外依次为钾硅酸盐化带、绢英岩化带、青磐岩化带、高岭土化带,铜金矿体主要赋存于钾硅酸盐化和绢英岩化带内,铜矿化主要以黄铜矿形式产出,金矿化主要以银金矿形式产于白云石±石英+细粒黄铁矿±黄铜矿脉中,铜矿化与金矿化呈正相关,矿体的产出受北西向逆冲断层的控制。与典型斑岩和浅成低温热液矿床不同,巴达铜金矿化主要产于白云石±石英+黄铁矿脉中;矿床内既发育碳酸盐、伊利石、绢云母和黄铁矿、黄铜矿、方铅矿、黝铜矿、低FeS闪锌矿等一套中硫型浅成低温热液矿床的蚀变矿物组合,又发育符合碱性斑岩系统的特征矿物赤铁矿。基于以上特征判断,巴达铜金矿矿床成因类型应为与富碱斑岩有关的浅成低温热液矿床,巴达铜金矿矿床成因的厘定,为下一步找矿提供了理论指导。 相似文献
15.
长江中下游成矿带陆内斑岩型矿床的成岩成矿作用 总被引：23，自引：21，他引：2
陆内环境斑岩型矿床的发现对斑岩成矿理论的完善具有重要意义。长江中下游成矿带作为中国东部重要的陆内成矿带之一,成矿带内发育多个重要的斑岩型矿床,如铜山口Cu-Mo矿床、鸡冠嘴Cu-Au矿床、白云山Cu矿、城门山Cu-Mo矿床、武山Cu-Mo矿床、丰山洞Cu-Au矿床、丁家山Cu矿、洋鸡山Au矿、沙溪Cu-Au矿床、冬瓜山Cu-Au矿床、舒家店Cu矿床和安基山Cu矿床等。本文选取成矿带内典型的、具有代表性的斑岩型矿床,对其地质特征(地层、构造、含矿斑岩、脉体特征和围岩蚀变)、成岩成矿年代、成矿岩体的岩石化学和成岩成矿地球化学等方面的研究资料和成果进行了系统总结,讨论和试图阐明长江中下游成矿带陆内斑岩型矿床的成岩成矿作用与成矿模式。研究显示,长江中下游成矿带形成于燕山期陆内造山过程,成矿斑岩岩浆活动和成矿作用主要发生于149~105Ma之间,进一步可以分为早、中、晚三阶段:149~135Ma、133~125Ma和123~105Ma,三阶段岩浆活动和成矿作用主要发生于成矿带中的断隆区,早阶段(149~135Ma)和晚阶段(123~105Ma)多为斑岩-矽卡岩型矿化,中阶段(133~125Ma)矿化为典型的斑岩型矿化。长江中下游成矿带内斑岩型矿床的含矿斑岩为高钾钙碱性-钙碱性系列岩石,大部分具有埃达克岩的地球化学特征,可能为源自富集地幔的岩浆和加厚下地壳部分熔融的岩浆混合的产物,源自富集地幔的基性岩浆对成矿具有至关重要的作用,它的混入使得混合岩浆富水、硫和金属(Cu、Au)等。进一步通过与岩浆弧环境的斑岩型矿床对比研究发现,长江中下游成矿带斑岩型矿床一般不发育高级泥化岩帽(advanced argillic liithocaps)以及浅部的高-中硫矿化蚀变系统,含矿岩浆源区性质和成矿物质来源等与岩浆弧环境的斑岩型矿床明显不同。 相似文献
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西藏改则县多不杂斑岩型铜金矿床勘查模型 总被引：16，自引：0，他引：16
西藏改则县多不杂斑岩型铜金矿床是近年来由西藏地质五队在班公湖-怒江成矿带发现的一个具超大型规模的铜金矿床,系继玉龙、驱龙、雄村、甲玛等超大型铜矿床之后的又一重大找矿突破,也是班公湖-怒江成矿带的第一个超大型斑岩铜金矿。多不杂斑岩型铜金矿产于早白垩世花岗闪长斑岩及其与早侏罗世曲色组变长石石英砂岩的接触带,区域成矿地质背景得天独厚,岩浆活动频繁,为斑岩型铜金矿的成矿提供了有利的条件。该矿床具有典型的斑岩型铜矿的蚀变分带,在斑岩体及其围岩由内向外形成钾硅化带、粘土化带、青磐岩化带、角岩化带。地球物理勘查表明,含矿斑岩区为低视电阻率、高视极化率异常区;1:1万土壤测量显示,斑岩铜矿产于高背景区,并与强度高、浓集中心明显的Cu、Au、Ag、Mo元素的化探综合异常相对应,在空间上尤其与Cu、Au异常分布高度吻合。1:5万水系沉积物测量表明,Au、Ag、As、Sb、Cu、Pb、Zn元素高异常常与激电探测异常吻合。本文通过综合研究初步总结建立了适合本区地质-地球物理-地球化学综合勘查模型。通过勘查和初步评价,在矿区外围新发现了波龙、拿顿、拿若、赛角、尕尔勤、铁格龙、地堡那木岗等斑岩矿(床)点,并最终形成多龙斑岩型铜金矿集区,对该区域找矿起到指导作用。 相似文献
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西藏冈底斯南缘雄村铜金矿床成矿斑岩厘定及其锆石U-Pb和黑云母Ar-Ar年龄分析 总被引：1，自引：0，他引：1
雄村特大型斑岩铜金矿床主要以细脉浸染状产于强烈蚀变岩石中,赋矿岩石原岩成因类型存在争议。本文对多个赋矿蚀变岩石作了系统光薄片显微鉴定,在多个蚀变较弱的矿化样品中发现赋矿岩石具斑状结构,其基质主要为钾长石,斑晶主要为斜长石、钾长石及少量石英,显示石英正长斑岩及二长斑岩(少量)矿物组成特征。结合前人工作,可以认为雄村铜金矿床赋矿岩石为正长斑岩、火山岩及少量二长斑岩。正长斑岩发育斑岩铜金矿床成矿早期常见的钾硅化蚀变及磁铁矿化蚀变,锆石具高的Ce4+/Ce3+比值(334~3084,平均值为1169),显示高氧逸度岩浆特征,和世界斑岩铜金矿床成矿岩体一致;这表明石英正长斑岩为雄村铜金矿床成矿岩体。石英正长斑岩锆石LA-ICP-MS U-Pb年龄为173.7±2.1Ma(MSWD=0.23),石英正长斑岩钾化阶段形成的黑云母40Ar/39Ar坪年龄为48.3±0.9Ma(MSWD=1.58),远小于锆石U-Pb年龄却与矿区东北部始新世花岗岩基的年龄一致,显示Ar-Ar年龄受后期地质事件影响而发生重置。通过上述研究,可以认为雄村铜金矿床为与石英正长斑岩有关的斑岩型矿床,形成时代约173Ma,和新特提斯洋洋壳向北俯冲诱发的岩浆事件有关,矿区内云母受后期地质事件影响重置,不能记录其形成时代。 相似文献