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西藏洞中拉铅锌矿床S,Pb,Sr同位素组成对成矿物质来源的示踪 总被引：2，自引：0，他引：2
洞中拉铅锌矿床位于西藏冈底斯东段念青唐古拉山地区扎雪—金达成矿带内,为印度—亚洲大陆主碰撞期形成的矿床.在分析该矿床成矿地质条件的基础上,对该矿床的主要金属硫化物的S,Pb,Sr同位素组成进行分析,并对成矿物质来源进行示踪讨论.研究表明:矿石硫化物的δ34S组成变化范围较窄,变化范围为3.0‰～5.7‰,多数集中于4.0‰～6.0‰之间,具有塔式分布效应,估算的总硫同位素值δ34 S∑s为4.7‰,具有岩浆硫的特征.矿石铅同位素组成稳定,矿石的206Pb/204Pb,207Pb/204Pb,208Pb/204Pb的变化范围分别为:18.628～18.746,15.698～15.802,39.077～39.430,与矿区岩浆岩的铅同位素组成一致,为正常普通铅,矿石铅来源于早白垩世上地壳物质部分熔融形成的岩浆.矿石锶同位素的初始值(87 Sr/86 Sr)i较高,介于0.717 32～0.727 67之间,成矿物质来源于地壳. 相似文献
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西藏蒙亚啊铅锌矿床S、Pb同位素组成及对成矿物质来源的示踪 总被引：11，自引：3，他引：8
西藏蒙亚啊铅锌矿床位于冈底斯成矿带东段,矿体主要赋存于上石炭统—下二叠统来姑组碳酸盐岩内的矽卡岩和矽卡岩化大理岩中,近东西向似层状产出。在分析该矿床成矿地质条件的基础上,系统地研究了矿石硫、铅同位素组成特征,探讨了成矿物质来源。研究表明,矿石硫化物的硫同位素组成变化范围较窄,具塔式分布效应,估算得到成矿热液系统的总硫同位素值3δ4S∑S约为5.2‰,具有岩浆硫的特征;矿石铅同位素组成稳定,为正常普通铅,矿石铅来源于早白垩世上地壳物质部分熔融形成的岩浆。 相似文献
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铜厂沟斑岩型铜钼矿床位于格咱岛弧成矿带南缘,是西南三江地区近年来新发现的大型斑岩型铜钼多金属矿床。本文通过硫、铅同位素的示踪研究,探讨了成矿物质的来源。测试结果表明,矿石中硫化物的δ34S值变化于-0.7‰~+3.8‰,平均为0.79‰,变化范围很小,表明硫同位素来源单一,显示岩浆源硫同位素组成的特征。矿石矿物的铅同位素组成,206Pb/204Pb为18.3325~18.694,207Pb/204Pb为15.588~15.663,208Pb/204Pb为38.454~39.008,铅同位素组成较为稳定,显示正常铅的特征。铅同位素组成与特征参数(△β与△γ、V1与V2)之间具有明显的正相关性,依据铅构造模式判别和成因分类的综合分析,铜厂沟斑岩型铜钼矿床的铅主要来源于深部,并显示壳幔混合来源的特征。矿床的成矿作用与燕山期岩浆侵入岩活动存在较密切的关系,但地层源的成矿物质对矿床的形成有一定的物质贡献。 相似文献
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加多捕勒铁铜矿床位于念青唐古拉成矿带西段。综合研究围岩、岩体与矿石的硫、铅同位素组成,发现其矿石硫化物的δ~(34)S值变化范围为-2.1‰～6.2‰,δ~(34)S_(ΣS)值为2.16‰,总体具有岩浆硫的特征。矿石硫化物的δ~(34)S值与石英闪长岩、板岩中硫化物的δ~(34)S值相近,表明矿石的硫源可能部分由板岩与石英闪长岩提供。矿石铅同位素组成比较均一,~(206)Pb/~(204)Pb、~(207)Pb/~(204)Pb和~(208)Pb/~(204)Pb的变化范围分别为18.27～18.842、15.653～15.899和38.793～39.703,与冈底斯成矿带北亚带矿床矿石硫化物的铅同位素组成相近,具有上地壳铅源的特征。矿石铅同位素组成与黑云母二长花岗岩、大理岩的铅同位素组成一致,显示铅可能主要来源于黑云母二长花岗岩和大理岩。综合分析表明,加多捕勒铁铜矿床硫、铅同位素的研究显示其成矿物质可能主要来源于黑云母二长花岗岩,部分来源于中二叠统下拉组岩石,少量由石英闪长岩提供,它们为深入研究该矿床的成矿模式提供了资料。 相似文献
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西藏墨竹工卡县洞中拉铅锌矿床S、Pb同位素组成及成矿物质来源 总被引：1，自引：0，他引：1
为了探讨西藏墨竹工卡县洞中拉铅锌矿的成矿物质来源,研究矿床成矿机制,对该矿床的矿石样品进行了硫和铅同位素分析,并对其变化规律和成因意义进行讨论。研究结果表明,6件金属硫化物样品(闪锌矿、黄铜矿、方铅矿)的δ34S值变化于2.2‰～4.8‰之间,显示硫同位素组成比较稳定。根据共生硫化物对所确定的温度,该矿床属中低温热液矿床。6件金属硫化物样品206Pb/204Pb、207Pb/204Pb和208Pb/204Pb变化范围分别为18.628 0～18.629 6、15.698 0～15.699 9、39.077 5～39.082 4,平均值分别为18.628 70、15.699 02和39.079 37。硫和铅同位素研究结果表明,洞中拉铅锌矿床的硫主要来自沉积围岩,主要为无机还原成因,有少量硫来自本地区燕山晚期花岗岩;洞中拉铅锌矿床矿石铅主要来自上地壳物质。 相似文献
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江西金山金矿床成矿物质来源的铅和硫同位素示踪 总被引：10，自引：3，他引：10
江西金山金矿床赋存于浅变质的中元古界双桥山群上亚群 ,该建造明显富Au ,Au平均丰度达 2 5 5× 10 -9。矿石铅同位素组成出现明显的线性关系表明 ,区域构造活动 成矿作用中存在着铅同位素的混合机制。大部分矿石铅Doe单阶段模式年龄与该矿床的Rb Sr年龄值十分接近 ,可能反映了区域变质的成矿意义。矿石铅 μ值介于 9 2 9～ 9 86之间 ,2 3 2 Th/ 2 3 8U比值变化于 3 88～ 4 0 9,揭示了成矿物质的壳源特征。Zartman图解和△γ △ β图解表明 ,双桥山群是矿石铅的主要源区。该矿床硫同位素组成特征与外围双桥山群上亚群中硫化物的硫同位素极为相似 ,成矿流体的硫主要来源于双桥山群含矿建造。对比研究表明 ,虽然不同金矿床的硫同位素组成特征不尽相同 ,但金山金矿床的层控特征与江南金成矿带中其他金矿极为相似。金山金矿床的铅、硫同位素地球化学特征揭示 ,该矿床的成矿物质主要来自浅变质的中元古界双桥山群含金建造 ,燕山期岩浆热液活动为该矿床的后期富集提供了部分成矿物质。 相似文献
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《地质通报》2020,(4)
滇西金厂河铁铜铅锌多金属矿床位于保山地块北部,是"三江"多金属成矿带内典型矿床之一。对该矿床开展硫铅同位素示踪研究,探讨成矿物质来源,并结合构造背景和成矿时代分析了矿床成矿机制。样品测试结果表明,矿石中硫化物的δ~(34)S值为+2.5‰～+11.1‰,平均值为+5.65‰,硫同位素来源为深部幔源岩浆和岩浆上侵混染壳源物质形成的多种硫源同位素组合;矿石矿物铅同位素组成中~(206)Pb/~(204)Pb为18.167～18.497,~(207)Pb/~(204)Pb为15.668～15.779,~(208)Pb/~(204)Pb为38.554～38.997,铅同位素总体较稳定,显示壳幔混染特征,以上地壳铅为主,可能来源有深部侵入岩浆及赋矿围岩。由矿床成矿物质来源表现出的多源、深源-浅源的特征推测,与成矿有关的中酸性岩体隐伏在区域深部。 相似文献
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三矿沟Cu-Fe-Mo矿床是大兴安岭地区三矿沟—多宝山构造-成矿带中一个比较典型的矽卡岩型矿床,矿体形成与三矿沟复式英云闪长岩体侵入关系密切。在分析该矿床成矿地质条件的基础上,对矿石硫、铅同位素组成特征和锆石U-Pb测年数据进行了研究,探讨了成矿物质来源和成矿成岩年代。研究表明,硫同位素组成变化范围较大,显示塔式分布效应,估算得到成矿热液系统的总硫同位素值约为-1.5‰,反映成矿过程中硫主要来源于深源岩浆,极少量可能来自于地层;矿石铅同位素具有壳幔混合铅的特征,反映了该矿床成矿物质主要为壳幔混合来源,与岩浆作用密切相关;锆石206Pb/238U加权平均年龄范围为（168.18±0.96）200±1Ma,代表了英云闪长岩的侵位时间,表明三矿沟矽卡岩型Cu-Fe-Mo矿床的成岩成矿年代为早侏罗世。 相似文献
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多宝山铅锌矿床地质特征及地球化学研究 总被引：1，自引：0，他引：1
新疆和田县多宝山是西昆仑地区新发现的一处重要铅锌矿床,矿体呈似层状、不规则囊状、脉状,产于白垩系铁隆滩组碳酸盐岩岩溶角砾岩、生物碎屑灰岩中,围岩蚀变主要有碳酸盐化、白云石化、硅化及泥化等.矿石为块状、细脉状、浸染状、角砾状等构造.矿石矿物与脉石矿物中具极相似的微量元素组构,矿石中铅、锌硫化物δ34SV-CDT=-10.55‰～-1.01‰,矿石Pb同位素组成206Pb/204Pb=18.739 8～18.743 3,207Pb/204Pb=15.702 5～15.7040,208Pb/204Pb=39.092 9～39.097 1,成矿物质来源于白垩系铁隆滩组碳酸盐岩.矿石中方解石δ13CPDB=3.44‰～5.09‰,18OSMOW=23.09‰～26.79‰,热液中CO2来自海相碳酸盐岩去碳酸作用.流体包裹体均一温度为207℃～262℃,盐度为6.30%～7.73%,说明成矿流体来源于海水热卤水,矿床具MVT铅锌成矿特点. 相似文献
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云南芦子园铅锌矿床地球化学、流体包裹体及稳定同位素特征 总被引：8，自引：0，他引：8
云南省保山—镇康古生代沉积盆地的上寒武统碳酸盐岩中发育有脉状铅锌矿体, 它们均受地层和构造的双重控制. 芦子园铅锌矿是该区此类型规模最大的一个矿床, 矿体赋存于沙河厂组的大理岩及大理岩化灰岩中.其原生矿金属矿物组合为: 闪锌矿、方铅矿、黄铜矿、黄铁矿和磁铁矿.围岩蚀变有矽卡岩化、绿泥石化、硅化、黄铁矿化和大理岩化等.流体包裹体研究表明, 该地区铅锌矿化经历中低温(160~280℃) 和中高温(280~420℃) 2个主要矿化阶段.芦子园铅锌矿的硫、铅同位素组成具有变化范围窄、相对均一的特点(δ(34S)=9.23×10-3~10.17×10-3; w(206Pb)/w(204Pb)=18.224~18.338, w(207Pb)/w(204Pb) =15.715~15.849, w(208Pb)/w(204Pb)=38.381~38.874), 其矿石硫与铅同位素都反映了成矿过程曾受到岩浆活动的影响.研究表明: 镇康地区铅锌矿为与上寒武统局部层位和隐伏岩体有关的热液型铅锌多金属矿床. 相似文献
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兰坪盆地白秧坪Cu-Pb-Zn-Ag多金属矿集区元素共生分异机制及物质来源 总被引：2，自引：0，他引：2
兰坪白秧坪Cu-Ag多金属矿集区夹持于金沙江和澜沧江断裂之间,属兰坪-思茅中新生代坳陷带之兰坪盆地北部,可分东矿带和西矿带二部分。本文通过对白秧坪金属矿集区东西2个矿带的矿石矿物电子探针分析、成矿元素含量和组合分析及S同位素的讨论得出:(1)东西2个矿带矿石矿物组合类型及微量元素组合特征具明显不同,前者矿石矿物组分较为简单,西带较为复杂,不仅有Pb、Zn和Cu的独立矿物,还存在Co和Bi的矿物;(2)东矿带Ag、As、Cd、Pb、Sb和Zn的富集从南到北依次减弱,Bi的富集依次增强,Cu的富集趋势越往北越富集,亏损元素为Co、Cr、Ni和V;西矿带Ag、Pb、Zn的富集属吴底厂和李子坪矿段最富集,而Cu则在小丫口和白秧坪矿段最富集。亏损元素为Ba、Co、Cr、Ni和V,但各个矿段这些元素的亏损程度有所不同,有的矿段部分元素有稍富集趋势;(3)Co、Ni和Cr等微量元素西带高于东带,而Sr、Pb、Zn和Ba元素则东带高于西带,与各自的矿物组合类型一致,且元素的共生分异机制与构造分带存在一定的耦合关系;(4)兰坪盆地火山岩为白秧坪多金属矿集区提供了主要物源,Mo、Co和Ni等元素显示其成矿可能与隐伏基性-超基性岩浆有关的深部来源有关;S同位素特征表明东西矿带金属硫化物硫源均以幔源为主。 相似文献
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Lead Isotopic Composition and Lead Source in the Bainiuchang Ag-polymetailic Deposit,Yunnan Province,China 总被引：1，自引：1，他引：0
ZHU Chaohui 《《地质学报》英文版》2008,(4)
The Bainiuchang deposit in Yunnan Province,China,is located geographically between the Gejiu ore field and the Dulong ore field.In addition to the>7000 t Ag reserves,the deposit also boasts of large-scale Pb,Zn and Sn reserves with a lot of dispersed elements(In,Cd,Ge,Ga,etc.).We have determined systematically the Pb isotope composition of the deposit.The Pb isotope ratios of the ores that are of sea-floor exhalative sedimentary origin in the northwest of the mining district,are ~(206)Pb/~(204)Pb=17.758-18.537,~(207)pb/~(204)pb=15.175-15.862 and ~(208)pb/~(204)pb=37.289-39.424,while those of ores that are of magmatic hydrothermal superimposition origin in the southeast of the mining district, are ~(206)Pb/~(204)Pb=17.264-18.359,~(207)Pb/~(204)Pb=14.843-15.683 and ~(208)Pb/~(204)Pb=36.481-38.838, respectively.In terms of the Pb isotope composition of feldspar in magmatic rocks or magmatic whole- rock samples from the mining district,we have determined the Pb isotope composition and acquired the Pb isotope ratios as:~(206)Pb/~(204)Pb=18.224-18.700,~(207)Tpb/~(204)Pb=15.595-15.797 and ~(208)Pb/~(204)Pb= 38.193-39.608.Then,in the light of the Pb isotope composition of metamorphic rock samples from the Proterozoic basement exposed in the Dulong ore field,we have determined the Pb isotope composition and obtained the isotope ratios as:~(206)Pb/~(204)Pb=18.434-19.119,~(207)Pb/~(204)Pb=15.644-15.693,and ~(208)Pb/~(204)Pb=38.514-38.832.And the Pb isotope ratios of Cambrian sedimentary rocks,which are exposed in the Bainiuchang mining district,are ~(206)Pb/~(204)Pb=18.307-19.206,~(207)Pb/~(204)Pb= 15.622-15.809,and ~(206)Pb/~(204)Pb=38.436-39.932.By comparing the two types of ores with respect to their Pb isotope compositions,it is indicated that lead in the Bainiuchang deposit was derived largely from the lower-crust granulite which is earlier than Neoproterozoic in age,but the Yanshanian magmatic hydrothermal fluids probably provided a part of ore-forming elements such as Sn for the ore blocks in the south of the mining district. 相似文献
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Nengping Shen Zhengwei Zhang Fuhua You Jiantang Peng Xiaoqing Zhu Jiafei Xiao 《中国地球化学学报》2012,31(4):362-375
The polymetallic(Pb,Zn,Cu,etc) ore belt on the southwestern margin of Tarim is one of the major regions with the greatest prospecting potential in Xinjiang.Reported in this paper are the lead isotope data for 66 sulfide samples(including 50 galena samples,15 chalcopyrite samples and 1 pyrite sample) collected from such representative deposits as Tamu,Tiekelike,Kalangu,Abalieke,etc.in this ore belt.The Pb isotopic ratios of 206 Pb/204 Pb,207 Pb/204 Pb and 208 Pb/204 Pb in the galena samples range from 17.931 to 18.176,15.609 to 15.818 and 38.197 to 38.944,with the average values of 18.017,15.684 and 38.462,respectively.Those in the chalcopyrite samples range from 17.926 to 18.144,15.598 to 15.628 and 38.171 to 38.583,with the average values of 18.020,15.606 and 38.262,respectively.The pyrite sample has the Pb isotopic ratios of 206 Pb/204 Pb,207 Pb/204 Pb and 208 Pb/204 Pb to be 17.980,15.604 and 38.145,respectively.In combination with the previous Pb isotope data for sulfides,it is found that there is only a slight variation in the Pb isotopic composition of galena,chalcopyrite,sphalerite and pyrite in the ore belt.However,there is some difference in Pb isotopic characteristics between galena and chalcopyrite,especially the Pb isotopic composition of galena shows an obvious linear correlation with some other relevant parameters(e.g.β and γ).The comprehensive analysis suggested that lead in galena(maybe including sphalerite and pyrite) was derived principally from wall rocks and underlying basement,and that in chalcopyrite only originated from the basement.The single-stage model ages of these sulfides couldn’t indicate the time limit of metallogenesis(Pb,Zn,Cu,etc.),and the positive linear correlations for the Pb isotopic composition of galena are of no single-stage and two-stage Pb-Pb isochron significance.Furthermore,there are significant differences in Pb isotopic composition characteristics between the genetic type of deposits in this polymetallic ore belt and the Mississippi Valley type(MVT).In addition,the authors also pointed out that there is a phenomenon of differentiation(not paragenesis) for lead and copper elements during the process of metallogenesis in this ore belt. 相似文献
16.
东秦岭钼矿带是我国最重要的钼多金属成矿带,近年来在东秦岭板厂地区取得了新的找矿突破。本文利用区域成矿动力学、硫化物的硫、铅同位素组成研究,结合成矿地质特征,对板厂铜钼多金属矿床成矿物质来源进行示踪,并以板厂矿床为基点总结东秦岭钼矿带的稳定同位素时空分布特征。板厂矿床12件硫化物样品δ(34S)范围为1.2×10-3~5.7×10-3,平均值0.6×10-3,与地幔(0±3×10-3)硫同位素值相近;东秦岭钼矿床δ(34S)位素值有随成矿时代渐新而逐渐升高的趋势,印支期钼矿床(221~226Ma)δ(34S)同位素值偏负,燕山期第一阶段钼矿床(138~151Ma)δ(34S)值由"0"值向正值变化,燕山期第二阶段钼矿床(113~131 Ma)δ(34S)值较高(平均4.93‰)。板厂矿床深部硫化物206Pb/204Pb值为17.121~17.798,207Pb/204Pb值为15.369~15.433,208Pb/204Pb值为36.867~37.485,具有明显的低放射性成因铅特征,其铅同位素组成与华北克拉通南缘的类熊耳群和太华群相似,幔源特征明显;浅部硫化物铅同位素值相对较高,206Pb/204Pb值为18.266~18.392,207Pb/204Pb值为15.560~15.622,208Pb/204Pb值为37.611~38.438,反映了造山带混合铅特征。板厂矿床形成于中国东部构造体制转折阶段,深部构造体制重新调整导致地幔物质上侵以及壳幔混合物的重新熔融,岩浆沿着深大断裂上涌,并将一定规模的含矿流体运移至浅部,由于物理化学条件的变化以及浅部流体的混合,成矿流体在最终构造薄弱带沉淀Cu、Mo等金属,形成板厂铜钼多金属矿床。综上,在晚侏罗世-早白垩世,东秦岭地区地幔熔体活动强烈,板厂铜钼多金属矿床成矿物质来源以幔源为主,有少量壳源物质混入。 相似文献
17.
Central Fujian Rift is another new and important volcanogenic massive sulfide Pb-Zn polymetallic metallogenetic belt. In order to find out the material genesis and mineralization period of Meixian-type Pb-Zn-Ag deposits, S and Pb isotope analysis and isotope geochronology of ores and wall rocks for five major deposits are discussed. It is concluded that the composition of sulfur isotope from sulfide ore vary slightly in different deposits and the mean value is close to zero with the 834S ranging from -3.5‰ to ＋5.6‰ averaging at ＋2.0‰, which indicates that the sulfur might originate from magma or possibly erupted directly from volcano or was leached from ore-hosted volcanic rock. The lead from ores in most deposits displays radioactive genesis character （206pb/204pb〉18.140, 207Pb/204pb〉15.584, 208pb/204pb〉38.569） and lead isotope values of ores are higher than those of wall rocks, which indicates that the lead was likely leached from the ore-hosted volcanic rocks. Based on isotope data, two significant Pb-Zn metallogenesis are delineated, which are Mid- and Late-Proterozoic sedimentary exhalative metailogenesis （The single zircon U-Pb, Sm-Nd isochronal and Ar-Ar dating ages of ore- hosted wall rocks are calculated to be among 933-1788 Ma.） and Yanshanian magmatic hydrothermal superimposed and alternated metallogenesis （intrusive SHRIMP zircon U-Pb and Rb-Sr isochronal ages between 127-154 Ma）. 相似文献
18.
《Resource Geology》2018,68(3):227-243
As a newly discovered medium‐sized deposit (proven Pb + Zn resources of 0.23 Mt, 9.43% Pb and 8.73% Zn), the Dongzhongla skarn Pb–Zn deposit is located in the northern margin of the eastern Gangdese, central Lhasa block. Based on the geological conditions in this deposit of ore‐forming fluids, H, O, C, S, Pb, Sr, and noble gas isotopic compositions were analyzed. Results show that δ18OSMOW of quartz and calcite ranged from −9.85 to 4.17‰, and δDSMOW ranged from −124.7 to −99.6‰ (where SMOW is the standard mean ocean water), indicating magma fluids mixed with meteoric water in ore‐forming fluids. The δ13CPDB and δ18OSMOW values of calcite range from −1.4 to −1.1‰ and from 5.3 to 15.90‰, respectively, show compositions consistent with the carbonate limestone in the surrounding rocks, implying that the carbon was primarily sourced from the dissolution of carbonate strata in the Luobadui Formation. The ore δ34S composition varied in a narrow range of 2.8 to 5.7‰, mostly between 4‰ and 5‰. The total sulfur isotopic value δ34S was 4.7‰ with characteristics of magmatic sulfur. The 3He/4He values of pyrite and galena ranged from 0.101 to 5.7 Ra, lower than those of mantle‐derived fluids (6 ± 1 Ra), but higher than those of the crust (0.01–0.05 Ra), and therefore classified as a crust–mantle mixed source. The Pb isotopic composition for 206Pb/204Pb, 207Pb/204Pb, and 208Pb/204Pb values of the ores were in the ranges of 18.628–18.746, 15.698–15.802, and 39.077–39.430, respectively, consistent with the Pb isotopic composition of magmatic rocks in the deposit, classified as upper‐crust lead. The ore lead was likely sourced partially from the crustal basement of the Lhasa Terrane. The initial (87Sr/86Sr)i value from five sulfide samples ranged from 0.71732 to 0.72767, and associated ore‐forming fluids were mainly sourced from the partial melting of the upper‐crust materials. Pb isotopic compositions of ore sulfides from the Dongzhongla deposit are similar to that of the Yuiguila and Mengya'a deposit, indicating that they have similar sources of metal‐rich ore‐forming solution. According to basic skarn mineralogy, the economic metals, and the origin of the ore‐forming fluids, the Dongzhongla deposit was classified as a skarn‐type Pb–Zn deposit. 相似文献