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赣南漂塘钨矿锡石及共生石英中流体包裹体研究 总被引：13，自引：0，他引：13
漂塘钨矿床是赣南地区一大型石英脉型钨多金属矿床,钨锡共生是该矿床的重要特征.在详细的岩相学观察基础上,采用“流体包裹体组合”(FIA)的研究方法,对该矿床锡矿化显著的(绿柱石)、锡石、黑钨矿-石英脉阶段石英脉中锡石及与其共生的石英中流体包裹体进行了显微测温和拉曼探针的分析.结果表明,锡石与共生石英形成的物理化学条件并不一致,两类矿物中流体包裹体揭示的流体演化过程也明显不同.锡石中原生的流体包裹体反映了锡石形成时真实的温压条件,与锡矿化相关的流体为高温、中-低盐度的NaCl-H2O流体体系.研究认为,锡石中流体可能主要来自于岩浆的结晶分异,流体体系的冷却是锡在流体中沉淀的主要机制. 相似文献
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赣南淘锡坑石英脉型钨矿床成矿机制探讨:来自流体包裹体的证据 总被引：1，自引：1，他引：0
赣南地区淘锡坑钨矿床是典型的大型石英脉型钨锡多金属矿床。矿体赋存于震旦系浅变质砂(板)岩,并延伸至深部花岗岩内,按空间产出位置分为内带矿体和外带矿体,包括宝山、西山、烂埂子、枫岭坑4大脉组,矿体产出各不相同,矿物组合也具有明显分带特征。在详细的岩相学研究基础上,文章选择淘锡坑主成矿期石英为研究对象,并与共生黑钨矿作对比,从空间角度开展不同脉组、不同矿体或中段的流体包裹体的对比研究。根据流体包裹体岩相学,石英包裹体类型有H_2O-NaCl型包裹体(Ⅰ型)、H_2O-NaCl-CO_2型包裹体(Ⅱ型)和纯CO_2体系裹体(Ⅲ型)及少量含石盐子晶的多相包裹体,并同时捕获贫CO_2的盐水溶液包裹体和纯CO-2气相包裹体。包裹体显微测温结果显示:内、外带石英脉气液两相的包裹体均具有较宽温度和盐度范围,外带均一温度和盐度w(NaCl_(eq))分别集中于200～220℃、1%～6%,内带均一温度和盐度w(NaCleq)分别集中于100～220℃、3%～7%,流体为中-低盐度、富含CO_2的H_2O-CO_2-NaCl体系,不同脉组不同矿脉之间对比结果均显示出多期成矿的特征。在矿脉形成过程中,流体的成分和温度在内外接触带有明显变化,表明岩体与围岩接触界面是造成淘锡坑矿床内带矿体和外带矿体的成矿条件改变的转折位置,成矿流体在此附近发生CO_2逸失引起相分离的不混溶作用是成矿的主要因素。 相似文献
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《矿物岩石地球化学通报》2016,(3)
为揭示赣南荡坪钨矿的成矿流体特征及矿床成因,采用流体包裹体组合的研究方法,利用红外显微镜、冷热台和激光拉曼等测试手段,对黑钨矿和与其共生的石英中流体包裹体进行了系统的岩相学观察、显微测温及成分分析。结果表明,与黑钨矿形成相关的流体为中高温、中低盐度的NaCl-H_2O流体体系,与石英中流体包裹体相比,黑钨矿中包裹体的总体均一温度及盐度较高,分布范围狭窄,表明黑钨矿与共生石英中的流体包裹体形成的p-t-x条件不同。成矿流体在演化过程中的冷却作用是本矿床黑钨矿沉淀成矿的主要因素。 相似文献
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矽卡岩型锡矿是全球重要的锡金属来源,但是锡石沉淀成矿机制仍存在较大的争议。垄上矽卡岩型锡矿床位于湘东锡田锡多金属矿田中部,是南岭钨锡成矿带内矽卡岩型锡矿的典型代表。本文在野外考察、矿石矿相学、流体包裹体岩相学研究的基础上,采用流体包裹体组合法对垄上矽卡岩矿床不同矿化阶段代表矿物中的流体包裹体进行了详细研究。结果显示,垄上矽卡岩型多金属矿床成矿阶段可划分为矽卡岩阶段、退化蚀变阶段、云英岩-氧化物阶段、石英硫化物阶段以及萤石碳酸盐化等5个阶段,其中,锡石主要形成于云英岩-氧化物阶段。与锡石密切共生的石英中发育流体包裹体类型主要为富液相、富气相两相水溶液包裹体,含液相CO_(2)三相水溶液包裹体和纯CO_(2)型包裹体。流体温度和盐度具有较大的变化范围(200-400℃和2%-9%NaCleqv),指示流体在降温过程中经历了显著的不混溶。与硫化物共生的石英中主要为富液相两相水溶液包裹体,温度和盐度主要集中在190-261℃和3%-7%NaCleqv,指示流体冷却过程同时经历了流体混合。本次研究提出锡田矽卡岩型矿床中流体不混溶是导致云英岩-氧化物阶段锡石沉淀成矿的主要机制,而流体冷却和混合是导致硫化物沉淀的主要原因。 相似文献
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江西大吉山钨多金属矿床流体包裹体研究 总被引：8，自引：3，他引：5
大吉山钨矿床是赣南地区的一个大型钨多金属矿床,由石英脉型钨矿体和花岗岩浸染型钨、钽、铌、铍矿体构成.在详细的岩相学观察的基础上,文章采用“流体包裹体组合”法,对石英脉型矿体和花岗岩浸染型矿体石英中的流体包裹体进行了显微测温和拉曼探针分析.研究表明,与石英脉型矿体成矿相关的流体为中-高温、中-低盐度的NaCl-H2O-CO2-CH4±N2体系,与花岗岩浸染型矿体成矿相关的流体为高温、中-低盐度的NaCl-H2O±CO2±CH4体系,两者流体的性质不同.笔者认为,在流体体系冷却过程中,所发生的以CO2逸失为特征的流体不混溶作用是石英脉型矿体的主要形成机制,而花岗岩浸染型矿体中金属元素的沉淀则主要由流体体系的冷却作用所致,这两类矿体的成矿流体的来源可能不同. 相似文献
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赣南茅坪钨矿流体包裹体研究 总被引：3，自引：0，他引：3
赣南茅坪钨矿是近年来探明的一个大型钨锡多金属矿床,矿床由石英脉型矿体和云英岩化花岗岩型矿体组成.本文在详细的岩相学观察基础上,对该矿床含矿石英脉石英和黄玉中的流体包裹体进行了显微测温和拉曼探针分析,并尝试用红外显微镜对黑钨矿中的流体包裹体进行了显微测温.结果表明,石英和黄玉中的流体包裹体主要为富液相的两相( H2O-NaCI)型水溶液包裹体,其中石英中尚有极少量的含CO2三相水溶液包裹体.石英中流体包裹体的均一温度、盐度范围较宽且均一温度分为较为明显的两个区间,石英中含CO2三相水溶液包裹体的均一温度与富液相两相水溶液包裹体的高温区间较为一致,盐度则明显低于后者,但均一方式不同.黑钨矿中流体包裹体的均一温度及盐度最高,黄玉中流体包裹体的均一温度及盐度较高且分布范围较窄.石英中流体包裹体的均一温度、盐度特征表明了成矿作用的多阶段性和流体演化的复杂性.流体包裹体特征表明,流体的早期沸腾作用和晚期混合作用可能是茅坪钨矿床石英脉型黑钨矿形成的主要机制. 相似文献
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广西大厂矿田高峰锡多金属矿床流体包裹体研究 总被引：1，自引：1，他引：0
广西大厂锡多金属矿田是世界著名的锡矿产地之一。矿田内绝大部分锡锌资源量分布在西成矿带的高峰和长坡-铜坑两个矿床之中,其中赋存在中泥盆统生物礁灰岩中的高峰100号体以其品位高(Sn 1. 79%、Zn 10. 1%、Pb 5. 21%、Sb4. 8%、Ag 235g/t)、规模大(矿石量超过1300万吨)而在整个大厂矿田中占据非常重要的地位。本文在扫描电镜-阴极发光(SEM-CL)图像分析的基础上,对高峰锡多金属矿床成矿早期锡石-毒砂-磁黄铁矿阶段和成矿晚期硫化物-硫盐-碳酸盐阶段的流体包裹体岩相学、显微测温学及其气相成分的激光Raman光谱进行了系统研究。结果表明,成矿早期锡石-毒砂-磁黄铁矿阶段石英和锡石中主要发育富含CO2和CH4气相流体包裹体,其均一温度和盐度分别为360～410℃和3%～6%Na Cleqv;成矿晚期硫化物-硫盐-碳酸盐阶段石英中则仅发育气-液两相盐水流体包裹体,具有相对低的均一温度(270～310℃)和盐度(3%～6%Na Cleqv)。石英和锡石的H-O同位素组成指示成矿流体主要来源于岩浆热液。对比矿田内其他矿床,进一步发现高峰矿床富CO2气相流体的盐度(3%～6%Na Cleqv)与拉么矽卡岩型Zn-Cu矿床富CO2气相流体的盐度(7%～9%Na Cleqv)相近,认为高峰矿床与拉么矿床可能具有相同的成矿流体来源,两者均来源于深部岩浆房中分异出的超临界流体。高峰矿床成矿流体可能主要来源于深部矽卡岩阶段富CO2气相流体的压缩和冷却(vapor contraction and cooling)。流体冷却过程可能是锡石-硫化物成矿的主要控制因素。高峰矿床-200m中段以上矿体,锡石和石英中的流体包裹体以富CO2和CH4气相流体包裹体为主,而缺失多子晶流体包裹体组合,推测高峰矿床-200m中段以下可能存在富含成矿金属的高密度卤水,从而形成高品位的锡多金属脉状矿体或矽卡岩型Zn-Cu矿体。 相似文献
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大井矿床锡铜矿体成矿流体研究及其成因意义 总被引：17，自引：3，他引：14
大井矿床锡铜矿体萤虫中存在中－高温度、低盐度含锡和中－低温度、中等盐度含铜两种流体包裹体,该两种流体包裹体的分布、气流比、温度－盐度关系初步显示它们是两种不同的流体体系,而不是一种流体从高温向低温、高盐度向低盐度的系列演化,与成矿阶段的划分基本吻合,表明大井矿床锡铜矿体很可能是两种不同来源持成矿流体在同一空间上的叠加成矿,因而锡和铜可以形成单独矿体,该两种流体包裹体的发现才研究对进一步追大索大井矿 相似文献
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《大地构造与成矿学》2020,(3)
湘中锑矿带中的渣滓溪锑钨矿床,是我国典型的大型脉状充填型锑矿床,前人对其成矿流体研究较少,该矿的矿石沉淀机制和成矿过程,目前尚不清楚。本次采用红外显微测温和传统显微测温相结合的方法,对渣滓溪矿区的白钨矿、辉锑矿及与其共生的石英中的流体包裹体,进行了系统的岩相学和显微测温研究。研究表明,该区矿物中发育的流体包裹体有四种类型,纯液相包裹体、富液相的气液包裹体、富气相的气液包裹体和纯气相包裹体。该区白钨矿中流体包裹体的均一温度为147～285℃,盐度为2.4%～6.0%NaCleqv,与其共生的石英中流体包裹体的均一温度为147～314℃,盐度为3.1%～6.2%NaCleqv;辉锑矿中流体包裹体的均一温度为124～269℃,盐度为0.4%～4.5%NaCleqv,与其共生的石英中流体包裹体的均一温度为114～298℃,盐度为0.2%～5.9%NaCleqv,成矿流体为一种中温、低盐度,以H2O为主的热水溶液。该区钨矿石中的白钨矿和石英、锑矿石中的辉锑矿和石英分别具有相似的均一温度和盐度。钨矿石和锑矿石具有不同的沉淀机制,前者是由于流体混合作用导致的,而后者则是由于流体沸腾引起的。湘西浅变质岩中的锑矿床和湘中碳酸盐岩中的锑矿床,两者锑矿石的形成过程与沉淀机制明显不同:前者的矿石矿物与脉石矿物的均一温度和盐度基本一致,是从同一溶液中沉淀的,流体沸腾作用导致锑矿石发生沉淀;而后者的矿石矿物与脉石矿物的均一温度和盐度明显有别,是不同流体作用的产物,锑矿石的形成是流体混合作用所致。 相似文献
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The Pemali tin deposit is located in a Triassic granite pluton the magmatic evolution of which is characterized by a decrease of compatible Ca, Mg, Ti, P and Zr in the sequence: medium- to coarse-grained biotite granite, megacrystic medium-grained biotite granite, two-mica granite/muscovite granite. The tin mineralization is confined to the two-mica granite and consists of disseminated cassiterite as well as greisen-bordered veins. The highly evolved muscovite granite is tin-barren and is distinguished from the two-mica granite by its low mica content and low loss-on-ignition values. The fluid inclusions in quartz and fluorite of the two-mica granite and of the greisen homogenize in the 115–410 °C temperature range; the salinities are in the range of 0.4–23 equiv wt% NaCl and the CO2 concentrations are < 2 mole%. 相似文献
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Daizo ISHIYAMA Ryoji SATO Toshio MIZUTA Yohei ISHIKAWA Jingbin WANG 《Resource Geology》2001,51(4):377-392
Abstract: The Anle Sn‐Cu and Huanggangliang Fe‐Sn deposits have been exploited in the Linxi district, which is located 165 km northwest of Chifeng City in northern China. In this study the formation mechanisms of the tin deposits in the Anle and Huanggangliang mining area were investigated to understand the mechanisms of tin mineralization in northern China. The veins of the Anle deposit are divided into cassiterite–quartz–chlorite veins, chalcopyrite‐bearing quartz veins, cassi–terite–chalcopyrite–bearing quartz veins and sphalerite‐quartz veins. The sequence of mineralization is tin mineralization (stage I), copper mineralization (stage II), and lead‐zinc mineralization (stage III). The Huanggangliang tin deposit consists of magnetite skarn orebodies and many cassiterite‐bearing feldspar–fluorite veins and veinlets cutting the magnetite orebodies. The fluid inclusions in quartz and fluorite in ores from the Anle and Huanggangliang tin deposits are divided into two‐phase fluid inclusions, vapor‐rich fluid inclusions and poly‐phase fluid inclusions. The final homogenization temperatures of fluid inclusions of quartz in the ores of the Anle deposit and fluorite of tin‐bearing feldspar veins in the Huanggangliang tin deposit range from 195 to 425C and from 215 to 450C, respectively. The fluids responsible for the Anle and Huanggangliang tin deposits were of very high temperature and NaCl‐rich ones containing K, Ca, Al, Si, Ti, Fe and Cl in addition to ore metals such as Sn and Cu. The temperature and chemical composition of fluid in fluid inclusions of igneous rocks in the mining area are very similar to those of fluid in fluid inclusions in the ores of these deposits. The fluid for these ore deposits had a close relation with the fluid coexisting with melt of Late Jurassic granitic rocks in this mining area. Salinities of fluid inclusions from these ore deposits and granitic rocks in the mining area were estimated to range from 35 to 50 wt % NaCl equivalent. Based on arsenopy‐rite geothermometry and fluid inclusion studies, a fluid containing 40 wt% NaCl (eq.) could be formed by phase separation of fluid having 6 wt% NaCl (eq.) at a temperature of 420 to 500C and a pressure of 0.3 to 0.4 kb. The temperatures and pressures presented above indicate an NaCl‐rich magmatic fluid derived from granitic melt that had intruded into a shallow level of crust caused the Sn–Fe–Cu mineralization of the mining area. The geological relationship between these ore deposits and granitic bodies around the ore deposits, and the similarity of fluids forming these ore deposits and coexisting with granitic melt, suggest that these ore deposits were formed by the activity of fluid derived from granitic melt in Late Jurassic age. 相似文献
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大兴安岭锡矿带是中国北方唯一成型的锡多金属成矿带。新近发现的内蒙古维拉斯托锡多金属矿床位于大兴安岭南段,隶属中亚造山带东段的兴蒙造山带。该矿床为一典型的大型斑岩型热液脉型锡多金属矿床,矿区内锡矿化主要赋存于石英斑岩体顶部及其上部的石英脉中。矿床成矿阶段包括石英斑岩体内的滴状锡锌矿化阶段、石英斑岩体上部石英脉中的辉钼矿矿化阶段、石英锡石黑钨矿阶段和石英多金属硫化物阶段。流体包裹体研究结果显示：流体包裹体类型主要为气液两相包裹体,尤其是富液相包裹体,其次为含子矿物的三相包裹体。斑岩体内矿化阶段流体包裹体均一温度为324~333 ℃,盐度为6.5%~7.5% NaCleqv,密度为0.73~0.74 g/cm3;石英脉型矿化阶段包裹体均一温度为201~324 ℃,盐度为3.4%~9.9% NaCleqv,密度为0.73~0.92 g/cm3。包裹体显微测温分析结果显示该矿区成矿流体具有中高温、低盐度、中密度的特征。激光拉曼光谱分析表明,气液两相包裹体液相成分主要为H2O,气相成分主要有H2O、CO2和CH4。氢氧同位素研究结果表明该矿床石英斑岩体上部石英脉矿化阶段的成矿流体为岩浆水和大气降水混合来源,以岩浆水为主。岩浆流体与大气降水的混合以及流体演化中的降温过程是该矿床矿石沉淀的主要机制。 相似文献
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Frederico Sousa Guimares Alexandre Raphael Cabral Bernd Lehmann Francisco Javier Rios Moiss Augusto Bacellar vila Marco Paulo de Castro Glucia Nascimento Queiroga 《地学学报》2019,31(4):358-365
Native bismuth in the form of metallic melt has been considered instrumental to the formation of some metallic ore deposits via a mechanism dubbed the “Liquid Bismuth Collector Model.” Here, we provide petrographical documentation of trail‐forming, μm‐sized blebs of native bismuth in cassiterite–quartz veins from the Santa Bárbara greisen Sn deposit in the Rondônia tin province of northern Brazil. These inclusions suggest the trapping of a Bi melt that took place during vein formation, in a mechanism similar to the entrapment of fluid inclusions. 相似文献
16.
湖南骑田岭芙蓉锡多金属矿田锡的赋存状态及迁移形式 总被引：1，自引：0，他引：1
芙蓉矿田锡矿床按成因可分为构造蚀变带-矽卡岩复合型、构造蚀变带型、蚀变岩体型、矽卡岩型、脉状云英岩型等五种类型。各类型矿体中锡主要以锡石锡的形式出现,其分布率由92.17~97.77%,硫化锡、胶态锡、硅酸锡的分布率<8%。锡元素在钠长石化成矿作用阶段,很可能是以氧的络阴离子SnO33-、氢氧络阴离子〔Sn(OH)6〕2-的形式迁移;在云英岩化成矿作用阶段,主要以氟的络合物,如Na2SnF6,Na2〔Sn(OH、F)6,〕SnF4,K2SnF6等形式搬运;到了绿泥石化锡石硫化物阶段,锡又以硫化锡酸盐、硫化物(Na2SnS3,SnS2,SnS)和氯的络合物(Na2SnC l6)、氟的络合物等形式进行迁移和搬运。 相似文献
17.
Geology,Fluid Inclusions,and Isotopic Geochemistry of the Jinman Sediment‐Hosted Copper Deposit in the Lanping Basin,China 
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下载免费PDF全文 The Jinman Cu polymetallic deposit is located within Middle Jurassic sandstone and slate units in the Lanping Basin of southwestern China. The Cu mineralization occurs mainly as sulfide‐bearing quartz–carbonate veins in faults and fractures, controlled by a Cenozoic thrust–nappe system. A detailed study of fluid inclusions from the Jinman deposit distinguishes three types of fluid inclusions in syn‐ore quartz and post‐ore calcite: aqueous water (type A), CO2–H2O (type B), and CO2‐dominated (type C) fluid inclusions. The homogenization temperatures of CO2–H2O inclusions vary from 208°C to 329°C, with corresponding salinities from 0.6 to 4.6 wt.% NaCl equivalent. The homogenization temperatures of the aqueous fluid inclusions mainly range from 164°C to 249°C, with salinities from 7.2 to 20.2 wt.% NaCl equivalent. These characteristics of fluid inclusions are significantly different from those of basinal mineralization systems, but similar to those of orogenic or magmatic mineralization systems. The H and O isotope compositions suggest that the ore‐forming fluid is predominantly derived from magmatic water, with the participation of basinal brine. The δ34S values are widely variable between ?9.7 ‰ and 9.7 ‰, with a mode distribution around zero, which may be interpreted by the variation in physico‐chemical conditions or by compositional variation of the sources. The mixing of a deeply sourced CO2‐rich fluid with basinal brine was the key mechanism responsible for the mineralization of the Jinman deposit. 相似文献
18.
R. L. Linnen 《Mineralium Deposita》1998,33(5):461-476
The most important tin mineralization in Thailand is associated with the Late Cretaceous to Middle Tertiary western Thai granite
belt. A variety of deposit types are present, in particular pegmatite, vein and greisen styles of mineralization. A feature
common to most of the deposits is that they are associated with granites that were emplaced into the Khang Krachan Group,
which consists of poorly sorted, carbonaceous, pelitic metasediments. Most of the deposits contain low to moderately saline
aqueous fluid inclusions and aqueous-carbonic inclusions with variable CH4/CO2 ratios. Low salinity aqueous inclusions represent trapped magmatic fluid in at least one case, the Nong Sua pegmatite, based
on their occurrence as primary inclusions in magmatic garnet. Aqueous-carbonic inclusions are commonly secondary and neither
the CO2 nor NaCl contents of these inclusions decrease in progressively younger inclusions, implying that they are not magmatic in
origin. Reduced carbon is depleted in the metasediments adjacent to granites and the δD values greisen muscovites are variable,
but are as low as −134 per mil, indicative of fluid interaction with organic (graphitic) material. This suggests that the
aqueous-carbonic fluid inclusions represent fluids that were produced, at least in part, during contact metamorphism-metasomatism.
By comparing the western Thai belt with other Sn-W provinces it is evident that there is a strong correlation between fluid
composition and pressure in general. Low to moderately saline aqueous inclusions and aqueous-carbonic inclusions are characteristic
of mineralization associated with relatively deep plutonic belts. Mineralized pegmatites are also typically of deeper plutonic
belts, and pegmatite-hosted deposits may contain cassiterite that is magmatic (crystallized from granitic melt) or is orthomagmatic-hydrothermal
(crystallized from aqueous or aqueous-carbonic fluids) in origin. The magmatic aqueous fluids (those that were exsolved from
granitic melts) are interpreted to have had low salinities. As a consequence of the low salinities, tin is partitioned in
favour of the melt on vapour saturation. Thus with a high enough degree of fractionation, the crystallization of a magmatic
cassiterite (or different Sn phase such as wodginite) is inevitable. Because tin is not partitioned in favour of the vapour
phase upon water saturation of the granitic melts, it is proposed that relatively deep vein and greisen systems tend to form
by remobilization processes. In addition, many deeper greisen systems are hosted, in part, by carbonaceous pelitic metasediments
and the reduced nature of the metasediments may play a key role in remobilizing tin. Sub-volcanic systems by contrast are
characterized by high temperature-high salinity fluids. Owing to the high chlorinity, tin is strongly partitioned in favour
of the vapour and cassiterite mineralization can form by of orthomagmatic-hydrothermal processes. Similar relationships between
the depth of emplacement and fluid composition also appear to apply to other types of granite-hosted deposits, such as different
types of molybdenum deposits.
Received: 8 September 1997 / Accepted: 28 October 1997 相似文献
19.
Geological and fluid inclusion studies of the Dongpo tungsten skarn ore deposit,China 总被引：1，自引：0，他引：1
The Dongpo tungsten ore deposit, the largest scheelite skarn deposit in China, is located at the contact of a 172-m. y. biotite
granite with a Devonian marble. The mineralization associated with the granite includes W, Bi-Mo, Cu-Sn and Pb-Zn ores. Several
W mineralization stages are shown by the occurrence of ore in massive skarn deposits and in later cross-cutting veins. The
high garnet/pyroxene ratio, the hedenbergite and diopside-rich pyroxene and the andradite-rich garnet show the deposit belongs
to the oxidized skarn type. Detailed fluid inclusion studies of granite, greisen, skarn and vein samples reveal three types
of fluid inclusion: (1) liquid-rich, (2) gas-rich and (3) inclusions with several daughter minerals. Type (3) is by far the
most common in both skarn and vein samples. The dominant daughter mineral in fluid inclusions is rhembic, highly birefringent,
and does not dissolve on heating even at 530°C. We assume that this mineral is calcite. The liquid phase in most of the fluid
inclusions has low to moderate salinities: 0–15 wt. %; in a few has higher salinities (30–40 wt. % NaCl equivalent). The homogenization
temperatures of inclusions in the skarn stage range from 350°C to 530°C, later tungsten mineralization-stage inclusions homogenize
between 200°C and 300°C, as do inclusions in veins. Fluid inclusions in granite and greisen resemble those of the late tungsten
mineralization stage, with low salinity and homogenization temperatures of 200°–360°C. The tungsten-forming fluids are probably
a mixture that came from biotite granite and the surrounding country rocks. 相似文献
20.
松山锡矿位于滇西临沧花岗岩基的西北侧。矿体主要赋存于临沧黑云母二长花岗岩与松山组绢云石英片岩接触带矽卡岩以及花岗岩和围岩的裂隙中。由于缺乏精确的成矿年代学数据,在一定程度上限制了对矿床成因的认识,并制约了进一步的找矿勘查工作。本文首次利用LA-SF-ICP-MS微区原位U-Pb同位素测年技术对松山锡矿床矽卡岩型和电气石石英脉型矿石中的锡石矿物开展了 U-Pb年代学研究获得2件锡石样品的~(207) Pb/~(206)Pb-~(238) U/~(206) Pb谐和年龄分别为76.6±1.5Ma和79.6±3.6Ma,说明松山锡矿锡的成矿作用主要发生在晚白垩世,与临沧花岗岩主体侵位时间(三叠纪)明显不同。结合地质特征和前人年代学研究成果本文认为该地区存在明显的晚白垩世锡的成矿事件,研究区下一步的找矿工作应围绕岩体与围岩接触带,以及岩体和围岩中的断裂展开。 相似文献