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41.
乌和尔楚鲁图钼矿床位于国内重要的二连东乌旗钼矿成矿带中,为近几年新发现的斑岩型钼矿床.本次就该矿床成矿岩体的地球化学及其U-Pb年代学开展相关研究.结果表明: 矿区中的成矿岩体属过铝质、高钾钙碱性系列;富集大离子亲石元素(LILE)、亏损高场强元素(HFSE),具有与南岭型花岗岩相似的地球化学特征.锆石LA-ICP-MS U-Pb定年显示,与乌和尔楚鲁图钼矿床成矿有关的花岗斑岩形成于中侏罗世((160 ± 1)Ma).因此,可推测乌和尔楚鲁图钼矿床斑岩型钼矿的成矿时代为燕山早期.综合研究认为乌和尔楚鲁图斑岩型钼矿床形成于后碰撞的构造环境. 相似文献
42.
三矿沟—多宝山—争光成矿带为东北地区重要的金属矿集区,发育有三矿沟矽卡岩铜铁矿床、多宝山斑岩铜钼矿床、争光浅成低温金矿床等典型矿床。基于已获得的研究成果,结合前人的资料,重点解剖多宝山、三矿沟和争光3个典型矿床的地质特征,发现3个矿床的成矿类型和地质特征大不相同,成矿时代(加里东期、燕山早期和燕山中期)各异。综合地质研究表明,多宝山矿床形成于岩浆弧背景,三矿沟矿床为弧后伸展背景的产物,争光矿床形成于碰撞后陆壳伸展背景。 相似文献
43.
Fluid Inclusions and Hydrogen,Oxygen, and Lead Isotopes of the Antuoling Molybdenum Deposit,Northern Taihang Mountains,China 总被引:1,自引:0,他引:1 下载免费PDF全文
Meng Zhe Jian‐zhong Hu Yang Song Xue‐qin Zhang Hai‐yang Ding Wei Zhou 《Resource Geology》2017,67(4):399-413
The Antuoling Mo deposit is a major porphyry‐type deposit in the polymetallic metallogenic belt of the northern Taihang Mountains, China. The processes of mineralization in this deposit can be divided into three stages: an early quartz–pyrite stage, a middle quartz–polymetallic sulfide stage, and a late quartz–carbonate stage. Four types of primary fluid inclusions are found in the deposit: two‐phase aqueous inclusions, daughter‐mineral‐bearing multiphase inclusions, CO2–H2O inclusions, and pure CO2 inclusions. From the early to the late ore‐forming stages, the homogenization temperatures of the fluid inclusions are 300 to >500°C, 270–425°C, and 195–330°C, respectively, with salinities of up to 50.2 wt%, 5.3–47.3 wt%, and 2.2–10.4 wt% NaCl equivalent, revealing that the ore‐forming fluids changed from high temperature and high salinity to lower temperature and lower salinity. Moreover, based on the laser Raman spectra, the compositions of the fluid inclusions evolved from the NaCl–CO2–H2O to the NaCl–H2O system. The δ18OH2O and δD values of quartz in the deposit range from +3.9‰ to +7.0‰ and ?117.5‰ to ?134.2‰, respectively, reflecting the δD of local meteoric water after oxygen isotopic exchange with host rocks. The Pb isotope values of the sulfides (208Pb/204Pb, 36.320–37.428; 207Pb/204Pb, 15.210–15.495; 206Pb/204Pb, 16.366–17.822) indicate that the ore‐forming materials originated from a mixed upper mantle–lower crust source. 相似文献
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45.
The ultramafic massifs of the Serranía de Ronda (namely Ronda, Ojén and Carratraca) are portions of Proterozoic (∼1.2–1.8 Ga) subcontinental lithospheric mantle (SCLM) affected by partial melting and infiltration of melts. The latter of these events was broadly coeval with the tectonic emplacement of the peridotites into the continental crust in the Early Miocene. This resulted in the formation of chromite and Ni-arsenide ores (Cr-Ni) associated with orthopyroxenites and cordieritites. Six zircons recovered from a massive chromitite sample from the Ronda massif yield both concordant and discordant ages between 2309 ± 37 Ma and 109 ± 15 Ma, and δ18O between 8.3‰ and 9.4‰. Two Proterozoic ages obtained for zircons of this population (1815 ± 9 Ma and 1794 ± 17 Ma) are identical, within error, to those of zircons reported previously in the garnet pyroxenites of Ronda (1783 ± 37 Ma). Similarly, concordant Early Jurassic (192 ± 13 Ma) and Cretaceous ages (109 ± 15 Ma) obtained from the core and rim, respectively, of a single zircon from the chromitite are also consistent with the ages (180 ± 5 Ma, 178 ± 6 Ma, and 131 ± 3 Ma) already reported for magmatic zircons from corunudum-bearing garnet pyroxenites in the Ronda massif. The observation that chromitites and garnet-pyroxenites contain similar populations of zircons suggests that the parental melts of chromitites inherited zircons from their protolithic garnet pyroxenites, representing relics of oceanic/arc crust recycled in the mantle. Eleven zircons recovered from a massive cordieritite associated with chromitite in the Ronda massif yield scattered concordant and discordant ages between 568 Ma and 21 Ma, with correspondingly variable δ18O (4.8–13.5‰) and unradiogenic Hf-isotope ratios (εHf(t) from −12.36 to −4.43). The youngest age is concordant at 21.18 ± 0.4 Ma and matches the ages of zircons from the chromitite (weighted average age of 20.4 ± 0.87 Ma, n = 4) and a plagioclasite dyke (scattering between 20.1 ± 0.2 Ma and 17.9 ± 0.1 Ma; n = 11) associated with the Cr-Ni mineralization in the Ojén massif. These zircons show similar unradiogenic Hf-(εHf(t) between −14.5 and −7.6) and heavy O-isotope compositions (δ18O = 11.3–12.4‰). A sample of the massive cordieritite hosting the chromitites contains abundant zircons that yield scattered concordant, sub-concordant and discordant U-Pb ages varying from 33.8 ± 1 Ma to 781 ± 10 Ma; these zircons (n = 21) have variable U-contents (105–13900 ppm) and Th/U ratios (0.003–0.8). On the basis of O- and Hf-isotope compositions, these zircons define three populations independently of their ages: (1) grains with consistent high δ18O (6.1–12.7‰) and negative εHf(t) (from −14.42 to −6.88); (2) grains with high δ18O (7.6–11.1‰) and positive εHf(t) (3.10–4.84); and (3) grains with δ18O < 5.5‰ typical of mantle values. We suggest that zircons from this cordieritite with U-Pb ages older than Miocene are inherited, and were incorporated physically into the SCLM by fluids or melts produced during dehydration-melting of the crustal rocks wrapping the peridotite massifs. The population of Early Miocene zircons found in the chromitites and associated cordieritites and the plagioclasite dyke in the mineralization of the Ojén massif date the crustal emplacement of the peridotites and, therefore, the formation of the Cr-Ni ores. We propose a model in which the unique Cr-Ni mineralizations found in the ultramafic rocks of the Serranía de Ronda were formed as a result of contamination of the SCLM with crustal components. 相似文献
46.
Polymetallic vein-type Zn-Pb deposits are located in the Xiangxi–Qiandong zinc-lead metallogenic belt (XQMB) of the northwestern margin of the Jiangnan Orogen, South China. Ores are mainly found in fault-bounded quartz veins hosted in the upper part of the Banxi Group that consists of low-grade metamorphic sandstone, siltstone with minor tuff interbeds. The Zn-Pb deposits primarily contain sphalerite, galena, chalcopyrite and pyrite, accompanied by quartz and minor calcite. Zinc, lead, copper, indium and gallium are enriched in these ores. Investigation of the ore fluid reveals low temperature (87–262 °C) with scattered salinity (range from 2.73 to 26.64 wt% NaCleqv.). Hydrogen and oxygen isotopic compositions of fluid inclusions in quartz indicate mixing of magmatic hydrothermal fluid and meteoric water (δ18OH2O SMOW = 0.2‰ to 4.2‰; δDH2O SMOW = −126‰ to −80‰). Carbon and oxygen isotopic composition of carbonate samples indicate the magmatic hydrothermal origin of CO32− or CO2 in ore-forming fluid (δ13CPDB = −6.9‰ to −5.7‰, δ18OSMOW = 11.3‰ to 12.7‰). Sulfur and lead isotopic compositions (δ34SVCDT = 8.8–14.2‰ and 206Pb/204Pb = 17.156–17.209, 207Pb/204Pb = 15.532–15.508, 208Pb/204Pb = 37.282–37.546) demonstrate that sulfur sources were relatively uniform, and low radiogenic lead isotopic compositions indicate that ore metals were derived from a relatively unradiogenic source, probably by mixing of mantle with crust. Therefore, polymetallic vein-type Zn-Pb mineralization in this area probably arose from a magmatic-related hydrothermal system, and the deposition of sulfides occurred in response to cooling and boiling of magmatic hydrothermal fluids (high salinity, high δ18OH2O and δDH2O and metal-bearing), and is mainly the result of emplacement into open space and mixing with meteoric water (low salinity, low δ18OH2O and δDH2O). This study provides direct evidence that magmatism was involved in the ore-forming processes of the low temperature metallogenic district, South China, and it raises awareness about the presence of polymetallic vein-type Zn-Pb deposits in the northwest margin of Jiangnan Orogen and their potential as a source of zinc, copper, indium and gallium. 相似文献
47.
四川甲基卡矿田是中国乃至于世界上锂矿资源最集中的地区之一,目前运用遥感技术开展甲基卡型锂矿的研究工作尚较为薄弱,文章运用遥感技术在甲基卡特殊地貌区开展找矿填图应用研究,建立了研究区典型岩石及矿物的波谱数据库,总结了研究区黑云母片岩、十字石片岩、十字石堇青石片岩、角岩、二云母花岗岩、含锂辉石伟晶岩、无矿伟晶岩、石英脉、长石斑晶、锂辉石单晶、云母、绿柱石的波谱特征;之后分别基于中等分辨率遥感数据Landsat 8和高空间分辨率遥感数据Geoeye-1进行图像处理和信息提取,开展了地质填图应用初步研究。研究结果表明遥感技术作为一种新兴的技术手段,对甲基卡型锂矿的填图及找矿具有重要的指导意义,可以作为今后地质找矿工作的"先头兵"。 相似文献
48.
试样经烘干处理后,利用硫酸和氢氟酸溶矿,硝酸提取,加氨水以氢氧化铁为载体沉淀磷酸盐,分离镍、铬、钴、铜等干扰离子,制备成硝酸溶液。中和后,以钼酸铵—酒石酸锑钾为显色剂,以抗坏血酸为还原剂,显色,在700nm处测量吸光度,利用计算机拟合标准曲线计算磷含量。此方法精密度与加标回收率均能满足质量要求。 相似文献
49.
通过对安徽省沙坪沟钼矿床矿石物质成分及结构、构造的分析,发现矿石中辉钼矿常呈细小鳞片状、浸染状分布于细脉中。针对岩芯易沿含矿裂纹破裂造成鳞片状辉钼矿丢失,本矿区全部采用金刚石刀具切割分取岩芯。制样过程试验中将样品无缩分粗碎、中碎至Ф〈-1.0mm,进行了K值试验,取0.5。缩分后密封棒磨6小时(充分混匀、磨碎)至-200目。分析了该矿区伴生元素不干扰测定的情况,不加Fe:O。载体,刚玉坩埚-Na2O2熔矿,降低空白值,严格质量监控,采用硫氰酸盐分光光度法测定钼量,获得的结果稳定可靠。本试验成果可为从事同类型大型钼矿的分析测试和质量监控提供参考。 相似文献
50.
新华龙钼矿床位于中国东北地区吉林省东部,是一个新发现的斑岩型钼矿床。矿床产于花岗闪长斑岩中。矿床成矿阶段包括石英-浸染状辉钼矿、石英-网脉状辉钼矿、石英-黄铁矿-黄铜矿、石英-多金属硫化物和石英-碳酸盐化5个阶段。流体包裹体实验结果表明:流体包裹体的类型主要为气液两相包裹体,其次为纯气相和纯液相包裹体,还有少量含子矿物的多相包裹体。流体包裹体的均一温度为172~385 ℃,盐度(w(NaCl))为8.51%~45.44%。从早阶段到晚阶段成矿流体温度具有规律的演化,均一温度分别为360~390 ℃、270~350 ℃、250~260 ℃、220~230 ℃、170~190 ℃。其中:含子矿物多相包裹体均一温度为272~385 ℃,盐度为35.79%~45.44%,密度为1.07~1.08 g/cm3;气液两相包裹体均一温度为172~381 ℃,盐度为8.51%~23.36%,密度为0.70~0.99 g/cm3。激光拉曼光谱分析表明,包裹体的气体成分主要为CO2、H2O、N2和CH4。包裹体岩相学及测温表明,流体由早期的高温、高盐度、含二氧化碳的含矿流体在主成矿阶段发生流体包裹体的沸腾、CO2逸出、温度降低等过程,导致大量金属硫化物沉淀。结合氢氧同位素特征,初步确定该矿床的成矿流体主要以岩浆水为主,后期有大气水的加入。流体沸腾是新华龙钼矿床成矿的重要机制。 相似文献