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1.
秦岭造山带内的山阳-柞水古生代弧前盆地中出露有池沟、小河口、冷水沟、园子街、下官坊及双元沟等CuMo、CuFe(Au)矿床,与这些矿床具有成因联系的岩体为形成于150~140Ma的高钾钙碱性和钾玄岩系列花岗岩,为华北和扬子大陆碰撞后伸展阶段壳、幔混合岩浆的产物。矿化主要发生在岩体与泥盆、石炭纪地层中碳酸盐岩的接触带附近,主要类型为矽卡岩型,少量为斑岩型,部分矿床具有统一的矽卡岩-斑岩型成矿系统,矿化组合主要为CuMo、CuFe(Au)和Cu矿化。外接触带主要发育有矽卡岩和角岩化蚀变,内接触带主要为岩体内部的硅化、钾化、绢云母化、绿泥石化及粘土化,内矽卡岩不发育。矽卡岩矿物主要有石榴石、透辉石、绿帘石、透闪石,阳起石等,其中石榴子石主要为钙铁榴石和钙铝榴石,透辉石是辉石的主体,早期形成的石榴石和透辉石等无水矿物组合常被后期的绿帘石、透闪石和阳起石等含水矿物及石英、方解石等所交代。金属矿物比较简单,最主要的含铜矿物为黄铜矿和斑铜矿,铁矿化主要为磁铁矿和镜铁矿。尽管这些矿床以矽卡岩型矿化为主,但部分矿床中已发现有斑岩型矿化和蚀变特征,这可能暗示了该区可能具有统一的矽卡岩-斑岩型成矿系统,进而表明山阳-柞水矿集区深部具有寻找斑岩型矿床的巨大潜力。  相似文献   

2.
Abstract: The Fengshan porphyry-skarn copper–molybdenum (Cu–Mo) deposit is located in the south-eastern Hubei Province in east China. Cu–Mo mineralization is hosted in the Fengshan granodiorite porphyry stock that intruded the Triassic Daye Formation carbonate rocks in the early Cretaceous (~140 Ma), as well as the contact zone between granodiorite porphyry stock and carbonate rocks, forming the porphyry-type and skarn-type association. The Fengshan granodiorite stock and the immediate country rocks are strongly fractured and intensely altered by hydrothermal fluids. In addition to intense skarn alteration, the prominent alteration types are potassic, phyllic, and propylitic, whereas argillation is less common. Mineralization occurs as veins, stock works, and disseminations, and the main ore minerals are chalcopyrite, pyrite, molybdenite, bornite, and magnetite. The contents of palladium, platinum and gold (Pd, Pt and Au) are determined in nine samples from fresh and mineralized granodiorite and different types of altered rocks. The results show that the Pd content is systematically higher than Pt, which is typical for porphyry ore deposits worldwide. The Pt content ranges from 0.037 to1.765 ppb, and the Pd content ranges between 0.165 and 17.979 ppb. Pd and Pt are more concentrated in porphyry mineralization than skarn mineralization, and have negative correlations with Au. The reconnaissance study presented here confirms the existence of Pd and Pt in the Fengshan porphyry-skarn Cu–Mo deposit. When compared with intracontinent and island arc geotectonic settings, the Pd, Pt, and Au contents in the Fengshan porphyry Cu–Mo deposit in the intracontinent is lower than the continental margin types and island are types. A combination of available data indicates that Pd and Pt were derived from oxidized alkaline magmas generated by the partial melting of an enriched mantle source.  相似文献   

3.
The Tongling ore district is one of the most economically important ore areas in the Middle–Lower Yangtze River Metallogenic Belt, eastern China. It contains hundreds of polymetallic copper–gold deposits and occurrences. Those deposits are mainly clustered(from west to east) within the Tongguanshan, Shizishan, Xinqiao, Fenghuangshan, and Shatanjiao orefields. Until recently, the majority of these deposits were thought to be skarn-or porphyry–skarn-type deposits; however there have been recent discoveries of numerous vein-type Au, Ag, and Pb-Zn deposits that do not fall into either of these categories. This indicates that there is some uncertainty over this classification. Here, we present the results of several systematic geological studies of representative deposits in the Tongling ore district. From investigation of the ore-controlling structures, lithology of the host rock, mineral assemblages, and the characteristics of the mineralization and alteration within these deposits, three genetic types of deposits(skarn-, porphyry-, and vein-type deposits) have been identified. The spatial and temporal relationships between the orebodies and Yanshanian intrusions combined with the sources of the ore-forming fluids and metals, as well as the geodynamic setting of this ore district, indicate that all three deposit types are genetically related each other and constitute a magmatic–hydrothermal system. This study outlines a model that relates the polymetallic copper–gold porphyry-, skarn-, and vein-type deposits within the Tongling ore district. This model provides a theoretical basis to guide exploration for deep-seated and concealed porphyry-type Cu(–Mo, –Au) deposits as well as shallow vein-type Au, Ag, and Pb–Zn deposits in this area and elsewhere.  相似文献   

4.
《Resource Geology》2018,68(3):258-274
The Dabaoshan deposit in Northern Guangdong Province, South China, is a Cu–Mo–W–Pb–Zn polymetallic deposit, located in the southern part of the Qin–Hang porphyry–skarn Cu–Mo ore belt. The deposit mainly comprises porphyry Mo and stratiform skarn Cu ore deposits. The genesis of the Cu ore deposit has been ascribed to a typical skarn ore deposit formed by the metasomatism of Devonian carbonate rock layers or to a volcanic rock‐hosted massive sulfide deposit formed by marine exhalation. In this paper, we report on the homogenization temperatures and salinities of fluid inclusions and C, H, O, S, and Pb isotopic compositions of fluids and minerals in this deposit. Homogenization temperatures and salinities of fluid inclusions in garnet, diopside, quartz, and calcite provide information on the skarnification, mineralization, and postmineralization stages. The data show that ore‐forming fluids experienced a continuous transition from high temperatures and salinities to low temperatures and salinities over the entire period of mineralization. C, H, and O isotopic compositions indicate that ore‐forming fluids were derived mainly from magmatic water. O isotopic compositions indicate that ore‐forming fluids mingled with atmospheric water during the last stage of mineralization. Sulfur in the ore came mainly from deep magmatic sources. Pb isotopic compositions in the orebody show that almost all the lead in the ore was derived from magma with a crustal source. Combined geological, geophysical, and geochemical data were achieved before we proposed that the Dabaoshan porphyry–skarn Cu–Mo–W–Pb–Zn deposit, as one member of the Qin–Hang porphyry–skarn Cu–Mo ore belt, formed during the Jurassic subduction of the paleo‐Pacific plate beneath the Eurasian continent at quite low angle. NE‐ and EW‐trending structures controlled the emplacement of magmatic rocks in the South China region. In the mining area, the Xiangguanping Fault and its branches were the main conduits for magmatic crystallization and mineralization. The many subfaults, folds, and interlayer fracture zones on both sides of the main fault provided the requisite space for the ore and, together, were the controlling structures of the orebody.  相似文献   

5.
SUPRA SUBDUCSEDIMENTARY, MAGMATIC AND TECTONIC CONSTRAINTS ON THE FORMATION OF THE YULONG SUPPER0-LARGE PORPHYRY COPPER POLYMETAL DEPOSIT, EAST TIBET  相似文献   

6.
The Middle–Lower Yangtze Region (MLYR) is one of the most important metallogenic belts in China that hosts numerous Cu–Fe–Au–S deposits. The Hucunnan deposit in the central part of MLYR is a newly discovered porphyry–skarn‐type copper–molybdenum deposit during recent drilling exploration. Laser ablation ICP–MS analysis carried out in this study yields U–Pb isotopic ages of 137.5 ± 1.2 Ma for the Cu–Mo bearing granodiorite rock and 125.0 ± 1.5 Ma for the Cu‐bearing quartz diorites. The Re–Os isotopic dating of seven molybdenite samples gave an isochron age of 139.5 ± 1.1 Ma, suggesting a syn‐magma mineralization of molybdenite in the Hucunnan deposit. Since porphyry‐type molybdenum deposits are rare in central MLYR, the discovery of the Hucunnan deposit suggests possible molybdenite mineralizations in the deep places of the Cu–Mo bearing granitoids. In addition, the U–Pb isotopic age of 125 Ma for the Cu‐bearing quartz diorites implies a new Cu mineralization period for the MLYR that was rarely reported by previous studies.  相似文献   

7.
劣布铜矿为火山沉积喷流层控型铜矿床;矿体受比马组第四岩性段层位和角砾岩筒控制,容矿岩石为角岩、层夕卡岩和角砾岩,矿物组合简单,流体包裹体测试表明夕卡岩铜矿化形成深度小于典型的斑岩铜钼矿,显示矿床的剥蚀程度较低,对寻找斑岩型铜矿是有利的。  相似文献   

8.
西藏劣布铜矿的基本特征及成因初探   总被引:1,自引:0,他引:1       下载免费PDF全文
劣布铜矿为火山沉积喷流层控型铜矿床;矿体受比马组第四岩性段层位和角砾岩筒控制,容矿岩石为角岩、层夕卡岩和角砾岩,矿物组合简单,流体包裹体测试表明夕卡岩铜矿化形成深度小于典型的斑岩铜钼矿,显示矿床的剥蚀程度较低,对寻找斑岩型铜矿是有利的.  相似文献   

9.
克鲁-冲木达矿集区位于西藏南部扎囊-桑日之间,累计估算铜金属资源量达200多万t.文章从"景"、"场"、"相"、"床"金属成矿省等级体制出发,阐述了该矿集区在印-亚陆陆碰撞"陆内汇聚-地壳分层加厚-重力均衡调整"的高原隆升过程中的成矿地质背景,指出区内存在着与碰撞挤压流体迁移汇聚有关的层控铜矿床、碰撞后伸展环境中夕卡岩铜矿床、斑岩型铜矿床3种矿床类型.利用"成矿构造聚敛场"观点分析成矿资源潜力,并指明了找矿方向.  相似文献   

10.
冬瓜山铜矿床是铜陵矿集区狮子山矿田中的主要矿床,对于该矿床中斑岩型成矿作用的研究缺乏。本文对冬瓜山矿床深部是否存在斑岩型矿体、斑岩型矿化特征及其与层状矽卡岩型矿化的关系等问题开展研究。冬瓜山矿床深部具有斑岩型矿化的蚀变类型和蚀变分带特征,矿化可分为钾硅酸盐阶段和石英硫化物阶段两个成矿阶段,斑岩型蚀变分带在空间上向外与矽卡岩化带过渡。斑岩型矿化的石英闪长岩形成年龄为140 Ma,与上部层状矽卡岩型矿化相关的石英/辉石二长闪长岩应为同期闪长质岩浆形成。深部斑岩型矿化的成矿流体具有由高温向中温演化的特点,与浅部层状矽卡岩型矿化的成矿流体具有相似的演化趋势,二者的成矿流体应该为一个热液系统,深部岩体内部流体演化形成斑岩型矿化,而接触带部位流体演化形成矽卡岩型矿化。  相似文献   

11.
Mesozoic ore deposits in Zhejiang Province, Southeast China, are divided into the northwestern and southeastern Zhejiang metallogenic belts along the Jiangshan–Shaoxing Fault. The metal ore deposits found in these belts are epithermal Au–Ag deposits, hydrothermal‐vein Ag–Pb–Zn deposits, porphyry–skarn Mo (Fe) deposits, and vein‐type Mo deposits. There is a close spatial–temporal relationship between the Mesozoic ore deposits and Mesozoic volcanic–intrusive complexes. Zircon U–Pb dating of the ore‐related intrusive rocks and molybdenite Re–Os dating from two typical deposits (Tongcun Mo deposit and Zhilingtou Au–Ag deposit) in the two metallogenic belts show the early and late Yanshanian ages for mineralization. SIMS U–Pb data of zircons from the Tongcun Mo deposit and Zhilingtou Au–Ag deposit indicate that the host granitoids crystallized at 169.7 ± 9.7 Ma (2σ) and 113.6 ± 1 Ma (2σ), respectively. Re–Os analysis of six molybdenite samples from the Tongcun Mo deposit yields an isochron age of 163.9 ± 1.9 Ma (2σ). Re–Os analyses of five molybdenite samples from the porphyry Mo orebodies of the Zhilingtou Au‐Ag deposit yield an isochron age of 110.1 ± 1.8 Ma (2σ). Our results suggest that the metal mineralization in the Zhejiang Province, southeast China formed during at least two stages, i.e., Middle Jurassic and Early Cretaceous, coeval with the granitic magmatism.  相似文献   

12.
俯冲、碰撞、深断裂和埃达克岩与斑岩铜矿   总被引:30,自引:2,他引:30  
无论是碰撞前的B型俯冲,还是碰撞后的A型俯冲,形成斑岩铜矿都必须要有洋壳或上地幔为主的物质参与.因此斑岩铜矿的初始锶值都小于0.708,超过0.708,则意味地壳物质的增多,将形成斑岩钼矿和斑岩钨锡矿.斑岩铜矿带常常与切穿地壳的深断裂带平行共生,并产于其上盘,在该地带往往发育壳幔混合以幔为主的深源花岗质浅成-超浅成小斑岩体.含铜斑岩和埃达克岩可能均为俯冲和交代产物,因而具有相似的特征,但到俯冲末期它们分道扬镳了.文章通过对冈底斯斑岩铜(钼、金和多金属)矿带的分析,来讨论俯冲、碰撞和深断裂带与斑岩铜矿的关系.同时也通过我国中央碰撞造山带仅发育斑岩钼矿,而缺乏斑岩铜矿,从而证明上地幔物质的加入对斑岩铜(金)矿的重要意义.  相似文献   

13.
INTRODUCTIONShoshonitesarepotassicigneousrockswhichoccurmain-lyinsubduction-relatedtectonicsettings(Morrison,1980).Theyarecom...  相似文献   

14.
The Dawan Mo–Zn–Fe deposit located in the Northern Taihang Mountains in the middle of the North China Craton (NCC) contains large Mo‐dominant deposits. The mineralization of the Dawan Mo–Zn–Fe deposit is associated with the Mesozoic Wanganzhen granitoid complex and is mainly hosted within Archean metamorphic rocks and Proterozoic–Paleozoic dolomites. Rhyolite porphyry and quartz monzonite both occur in the ore field and potassic alteration, strong silicic–phyllic alteration, and propylitic alteration occur from the center of the rhyolite porphyry outward. The Mo mineralization is spacially related to silicic and potassic alteration. The Fe orebody is mainly found in serpentinized skarn in the external contact zone between the quartz monzonite and dolomite. Six samples of molybdenite were collected for Re–Os dating. Results show that the Re–Os model ages range from 136.2 Ma to 138.1 Ma with an isochron age of 138 ± 2 Ma (MSWD = 1.2). U–Pb zircon ages determined by laser ablation inductively coupled plasma mass spectrometry yield crystallization ages of 141.2 ± 0.7 (MSWD = 0.38) and 130.7 ± 0.6 Ma (MSWD = 0.73) for the rhyolite porphyry and quartz monzonite, respectively. The ore‐bearing rhyolite porphyry shows higher K2O/Na2O ratios, ranging from 58.0 to 68.7 (wt%), than those of quartz monzonite. All of the rock samples are classified in the shoshonitic series and characterized by enrichment in large ion lithophile elements; depletion in Mg, Fe, Ta, Ni, P, and Y; enrichment in light rare earth elements with high (La/Yb)n ratios. Geochronology results indicate that skarn‐type Fe mineralization associated with quartz monzonite (130.7 ± 0.6 Ma) formed eight million years later than Mo and Zn mineralization (138 ± 2 Ma) in the Dawan deposit. From Re concentrations in molybdenite and previously presented Pb and S isotope data, we conclude that the ore‐forming material of the deposit was derived from a crust‐mantle mixed source. The porphyry‐skarn type Cu–Mo–Zn mineralization around the Wanganzhen complex is related to the primary magmatic activity, and the skarn‐type Fe mineralization is formed at the late period magmatism. The Dawan Mo–Zn–Fe porphyry‐skarn ores are related to the magmatism that was associated with lithospheric thinning in the NCC.  相似文献   

15.
黑龙江省嫩江县三矿沟含金铁铜矿床地质特征   总被引:11,自引:0,他引:11  
三矿沟含金铁铜矿床属典型的夕卡岩型矿床.它产在华力西期花岗岩体外接触带上,经夕卡岩化及热液硫化物矿化,形成众多黄铜矿矿体、含金黄铜矿矿体、磁铁矿矿体,矿石矿物主要有黄铜矿、斑铜矿、磁铁矿、银金矿,并伴生硒、碲、镓、铟等有益组分.三矿沟花岗岩体-断裂破碎带及接触带-多宝山组地层三者控制着矿床的形成.在三矿沟-多宝山一带存在寻找同类矿床的极大可能性.  相似文献   

16.
安徽桂林郑钼钨矿床位于江南钨矿带北部,是目前区内唯一钼储量达到大型的钼钨矿床。本文在对该矿床地质特征和已有成果总结基础上,详细观察了各代表性矿化蚀变样品的岩相学特征,提出该矿床具镁质矽卡岩矿床特征,是桂林郑花岗斑岩熔体与奥陶系白云质灰岩地层交代的产物。矿石类型可分为靠近岩体(100m)浸染状矿石和远离岩体( 100m)的条带状矿石,分别赋存在接触交代矽卡岩和层控矽卡岩中。桂林郑矿床的矿石矿物为富钼白钨矿(钼钙矿-白钨矿系列),可分为三个世代,分别形成于无水矽卡岩阶段(Sch-Ⅰ)和含水矽卡岩-氧化物阶段(Sch-Ⅱ和Sch-Ⅲ),辉钼矿仅在浸染状矿石富钼白钨矿(Sch-Ⅲ)边部少量发育。不同矿石类型、不同世代富钼白钨矿的电子探针成分分析显示,富钼白钨矿的钼含量(MoO_3%)在5.75%~71.02%之间,均值为46.00%(n=224),总体具有超常富钼的特点;从无水矽卡岩阶段到含水矽卡岩-氧化物阶段(早→晚)、从浅部的条带状矿石到深部的浸染状矿石(浅→深),富钼白钨矿MoO_3含量有降低趋势。桂林郑钼钨矿床是首个以富钼白钨矿为主要矿石矿物的钼-多金属矿床,这一特殊钼钨矿床的发现深化了矽卡岩钼钨矿床的成因认识,同时对江南钨矿带内区域成矿规律与找矿勘探工作的推进提供了依据。  相似文献   

17.
18.
Classic porphyry Cu–Mo deposits are mostly characterized by close temporal and spatial relationships between Cu and Mo mineralization. The northern Dabate Cu–Mo deposit is a newly discovered porphyry Cu–Mo polymetallic deposit in western Tianshan, northwest China. The Cu mineralization postdates the Mo mineralization and is located in shallower levels in the deposit, which is different from most classic porphyry Cu–Mo deposits. Detailed field investigations, together with microthermometry, laser Raman spectroscopy, and O‐isotope studies of fluid inclusions, were conducted to investigate the origin and evolution of ore‐forming fluids from the main Mo to main Cu stage of mineralization in the deposit. The results show that the ore‐forming fluids of the main Mo stage belonged to an NaCl + H2O system of medium to high temperatures (280–310°C) and low salinities (2–4 wt% NaCl equivalent (eq.)), whereas that of the main Cu stage belonged to an F‐rich NaCl + CO2 + H2O system of medium to high temperatures (230–260°C) and medium to low salinities (4–10 wt% NaCl eq.). The δ18O values of the ore‐forming fluids decrease from 3.7–7.8‰ in the main Mo stage to ?7.5 to ?2.9‰ in the main Cu stage. These data indicate that the separation of Cu and Mo was closely related to a large‐scale vapor–brine separation of the early ore‐forming fluids, which produced the Mo‐bearing and Cu‐bearing fluids. Subsequently, the relatively reducing (CH4‐rich) Mo‐bearing, ore‐forming fluids, dominantly of magmatic origin, caused mineralization in the rhyolite porphyry due to fluid boiling, whereas the relatively oxidizing (CO2‐rich) Cu‐bearing, ore‐forming fluids mixed with meteoric water and precipitated chalcopyrite within the crushed zone at the contact between rhyolite porphyry and wall rock. We suggest that the separation of Cu and Mo in the deposit may be attributed to differences in the chemical properties of Cu and Mo, large‐scale vapor–brine separation of early ore‐forming fluids, and changes in oxygen fugacity.  相似文献   

19.
哈赞布拉克金铜矿位于博罗科努金铜钼铅锌成矿带.矿化产于华力西中期中酸性侵入岩体内及与围岩接触带内,主要蚀变为围岩地层中的角岩化,闪长岩中的钾化、绢云母化、青盤岩化及含矿岩石中的硅化、碳酸盐化等,矿区发现Ⅰ、Ⅱ、Ⅲ号三个矿化带,以Ⅱ号矿化带规模最大,矿床为铜、金共生矿化,矿化成因类型为石英脉型、矽卡岩型、斑岩型,以石英脉型矿化为主,矿化主要受岩浆岩和构造控制,矿床为先期斑岩型矿化,伴矽卡岩型矿化,经后期热液改造叠加的石英脉型矿床.  相似文献   

20.
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