Isotope Geochemistry of the Pb-Zn-Ba(-Ag-Au) Mineralization at Triades-Galana,Milos Island,Greece     

Robert Marschik  Tobias Bauer  Ana-Sophie Hensler  Nikos Skarpelis  Stefan Hölzl 《Resource Geology》2010,60(4):335-347

The Pb-Zn-Ba(-Ag-Au) mineralization in the Triades and Galana mine areas is hosted in 2.5–1.4 Ma pyroclastic rocks, and structurally controlled mostly by NE-SW or N-S trending brittle faults. Proximal pervasive silica and distal pervasive sericite-illite alteration are the two main alteration types present at the surface. The distribution of mineralization-alteration in the district suggests at least two hydrothermal events or that hydrothermal activity lasted longer at Galana. The Sr isotope signature of sphalerite and barite (⁸⁷Sr/⁸⁶Sr = 0.709162 to 0.710214) and calculated oxygen isotope composition of a fluid in equilibrium with barite and associated quartz at temperatures of around 230°C are suggestive of a seawater hydrothermal system and fluid/rock interaction. Lead isotope ratios of galena and sphalerite (²⁰⁶Pb/²⁰⁴Pb from 18.8384 to 18.8711; ²⁰⁷Pb/²⁰⁴Pb from 15.6695 to 15.6976; ²⁰⁸Pb/²⁰⁴Pb from 38.9158 to 39.0161) are similar to those of South Aegean Arc volcanic and Aegean Miocene plutonic rocks, and compatible with Pb derived from an igneous source. Galena and sphalerite from Triades-Galana have δ³⁴S_VCDT values ranging from +1 to +3.6‰, whereas barite sulfate shows δ³⁴S_VCDT values from +22.8 to +24.4‰. The sulfur isotope signatures of these minerals are explained by seawater sulfate reduction processes. The new analytical data are consistent with a seawater-dominated hydrothermal system and interaction of the hydrothermal fluid with the country rocks, which are the source of the ore metals.  相似文献   

云南水头山铅锌矿床闪锌矿Rb-Sr定年及其地质意义          下载免费PDF全文

张传昱  李文昌  余海军  李婉婷  罗建宏  沙建泽  吴清华  潘泽伟 《沉积与特提斯地质》2022,42(1):122-132

水头山铅锌矿床位于保山地块南端芦子园矿集区,区内以发育矽卡岩型和热液脉型两类铅锌矿化为特点.为查明铅锌多金属成矿作用过程,本文对水头山热液脉型铅锌矿床主成矿阶段的闪锌矿开展了Rb-Sr同位素组成测定,获得闪锌矿的Rb-Sr等时线年龄为135.8±4.2Ma(MSWD=1.70,n=6),结合区内其他矿床的成矿年龄,认为...  相似文献   

凡口铅锌矿区闪锌矿的成因矿物学特征研究   总被引：3，自引：0，他引：3  

张术根  丁存根  李明高  刘慎波 《岩石矿物学杂志》2009,28(4):364-374

通过野外观察、光学显微镜、X射线衍射、扫描电镜及微区能谱分析、流体包裹体成分及盐度测定、稳定同位素(S、O、H)分析等手段,研究了广东凡口铅锌矿区闪锌矿的某些成因矿物学特征.结果表明,凡口矿区闪锌矿具有3个世代,分别形成于铅锌成矿期的3个成矿阶段.各世代闪锌矿在产出特征,表观颜色,结晶形态,解理发育程度,晶体常数,铁含量,流体包裹体的成分、盐度、氢氧同位素组成、硫同位素组成及同与其连生的方铅矿的平衡分馏温度等方面均存在规律性差别.从早期阶段到晚期阶段,成矿流体的演化特征是:成矿温度和成矿流体盐度从低到高再到低,流体包裹体成分从Na+-Ca+-Cl-型到K+-Ca+-Cl-型再到Na+-Ca+-Cl-型,δ18O、δD及δ34S均由高到低变化,但δ18O、δD及δ34S自中期阶段到晚期阶段降幅显著大于从早期阶段到中期阶段的降幅,反映晚期阶段至少有部分δ18O、δD及δ34S均显著较低的岩浆源流体参与成矿.认为凡口铅锌矿成矿流体主要为燕山早期区域岩浆热事件加热的中低温混合源循环热卤水,成矿中晚期有岩浆热液参与成矿.  相似文献   

Determination of major and trace elements in sphalerite using laser ablation double focusing sector field ICP-MS   总被引：1，自引：0，他引：1  

M.D Axelsson  I Rodushkin   《Journal of Geochemical Exploration》2001,72(2):727

The analytical performance of laser ablation (LA) for the determination of Co, Fe, Cd, Ag, Mn, Cu and S in sphalerite was evaluated using double focusing sector field inductively coupled plasma mass spectrometry (ICP-SFMS). Samples were collected from Zinkgruvan, situated in the south central Sweden. The use of Zn for internal standardisation, together with correction for FeS impurities in sphalerite, allows straightforward quantification without using external methods for the determination of the actual Zn content. LA–ICP-SFMS results were compared with data obtained by conventional pneumatic nebulisation introduction of sample solutions following acid digestion. Good agreement between the two methods was obtained for homogeneously distributed elements. For the majority of the elements under consideration, LA–ICP-SFMS precision was better than 10% RSD.  相似文献   

天然含铁闪锌矿的可见光催化还原活性研究   总被引：2，自引：0，他引：2  

李艳鲁安怀  王长秋 《岩石矿物学杂志》2007,26(6):481-486

通过电子探针(EMPA)、X射线光电子能谱(XPS)、漫反射谱(DRS)、光致发光谱(PL)、透射电镜(TEM)、扫描电镜(SEM)和霍尔效应(Hall-effect)等测试手段对天然闪锌矿样品的半导体物理化学性能进行了表征分析。分析结果认为,天然闪锌矿良好的可见光响应性能主要源自其晶格内丰富的类质同像替代离子。此外,样品中的变价元素Fe能够参与价带光生空穴的捕获,提高导带光生电子的利用率,从而提高其光催化活性。样品中丰富的缺陷也有利于光催化活性的提高,大量的解理面和裂开面能够提供较完整的晶面增加反应活性点位,空位缺陷和晶格膨胀畸变等可以提高光生电子空穴对的分离效率。与其特殊的物理化学性质相符,天然闪锌矿光催化还原降解甲基橙的实验证明了其较高的可见光催化还原活性。本研究结果也预示着天然半导体矿物闪锌矿作为一种新的低成本、高效率的可见光催化材料将在环境污染治理领域具有一定的应用前景。  相似文献   

在退火环境闪锌矿颗粒的生长实验研究     

邱小平吴春京  陈方远 《地质学报》2004,78(5):699-703,i010

应用高温显微镜和显微加热装置及自动录像等设备，对广东凡口铅锌矿区的铅锌矿石进行退火生长实验。退火实验条件为：500℃，12h；540℃，132h；600℃，12h。样品仓通氩气保护试样表面、电炉加热、循环水冷却。实验表明闪锌矿在540℃退火静态重结晶过程中，有些颗粒长大，有些颗粒则缩小甚至消失，颗粒的凸界面趋于退缩，凹界面趋于变凸，向球状闪锌矿方向演化。虽然总体积基本保持不变，但ZnS组分在局部得到明显富集，类似于自然界的成矿过程。退火实验后的球状闪锌矿颗粒，与实验前样品的主成分对比，Zn、Fe含量明显增加，S含量却明显降低，证明退火重结晶作用直接导致Zn元素的进一步富集。600℃时方铅矿和部分闪锌矿矿物出现蒸发现象。凡口矿区中生代晚期热事件的加热和保温层的覆盖，使得早期贫矿体经历退火静态重结晶作用，使贫矿体向内部收缩和圆化呈截然边界，总体演变成为高品位的超大型铅锌矿床。  相似文献   

The Relationship Between Mineralogical Characteristics and Isotopic Composition of Sphalerite,as Exemplified by the Huxu Deposit,China     

Liu Tiegeng  Ye Lin 《中国地球化学学报》1995,14(2):160-167

The relationship between mineralogical characteristics and isotopic composition of sulfides has not received its proper share of attention from geologists, although many references are available concerning the application of sulfur isotopes to geological problems. Located in the vicinity of the contact region between the Yangtze Platform and the South China Caledonian Folding Zone, the Huxu deposit is hosted in a structural zone in quartz-diorite-porphyrite emplaced in Jurassic volcanic rocks. Sphalerite and galena are the principal ore minerals in the deposit. (1) Sphalerite is highly variable in color and this variation can be related to its chemical composition and sulfur isotopic characters. Dark colored sphalerites are poor in Zn and Ni, rich in Pb, Cu, Fe, Ag and Au and have high δ³⁴S values, while the opposite is true for light-colored ones. (2) δ³⁴S of sphalerite is negatively correlated with the contents of Zn and Ni and positively correlated with the contents of Pb, Cu, Ag and Au, with the absolute values of the correlation coefficients being greater than 0.7. The above two characters suggest that the sulfur isotopic composition of sphalerite is controlled not only by the physicochemical conditions under which the mineral was formed, but also by mineralogical characteristics of the host mineral. (3) Apparent correlations exist among the constituent elements in the sphalerite. For example, Zn is negatively correlated with Cu, Pb, Fe, Ag and Au and positively correlated with Ni. (4) Sphalerites of the same color in the same hand specimen always show similar characters with respect to trace element and sulfur isotopes. (5) Two distinct trends of evolution can be recognized between Zn and Cu, Zn and Pb, Zn and Ag and between these elements on one hand and δ³⁴S on the other, reflecting that the ore-forming solutions may have resulted from mixing of fluids of different origins. (6) Pb is uniformly distributed in sphalerite and shows positive correlations with Cu, Fe, Ag and δ³⁴S, suggesting isomorphic substitution in the sphalerite lattice. This project was financially supported by the Open Laboratory of Ore Deposit Geochemistry, Institute of Geochemistry, Chinese Academy of Sciences.  相似文献   

酸性氨基酸在铜、铅、锌迁移与沉积过程中的作用   总被引：2，自引：0，他引：2       下载免费PDF全文

姚志健  韩蔚田 《地质科学》1992,(4):348-355

对酸性氨基酸(谷氨酸)在铜、铅、锌迁移与沉积过程中的作用,进行了模拟实验研究。结果表明,酸性氨基酸在热卤水中的存在,比中性氨基酸更有利于铜、铅、锌的活化迁移。但是,随作用时间,特别是随温度的变化,不同金属在热液中的活化迁移情况则明显地不同。这表明金属与氮基酸形成的易溶络合物,其稳定性不仅与金属和氨基酸的种类有关,而且还受温度的直接影响。  相似文献   

凤凰县茶田汞矿床汞闪锌矿矿物学特征   总被引：2，自引：0，他引：2  

郑沛之  刘振云 《湖南地质》1992,11(3):221-224

汞闪锌矿在湖南系首次发现,它是闪锌矿中富汞的变种,含汞达19.48％。主要粉晶数据:3. 15(10),1.922(9),1.64(7),1.25(5),1.11(5)。此外,本文还从物理性质,光学性质,反射光谱,颜色指数,化学成份,红外光谱特征等对该矿物进行了较详细的研究。据目前所掌握的资料,是我国所发现的汞闪锌矿中含汞最高者。  相似文献   

Photocatalytic Reduction of Cr^Ⅵ by Natural Sphalerite Suspensions under Visible Light Irradiation   总被引：4，自引：0，他引：4  

LI Yan LU Anhuai WANG Changqiu 《《地质学报》英文版》2006,80(2):267-272

The photocatalytic reductive capability of a natural semiconducting mineral, sphalerite has been studied for the first time. The sphalerite from the Huangshaping deposit of Hunan Province performed great photoreductive capability that 91.95% of the Cr^6＋ was reduced under 9 h visible light irradiation, higher than the 70.58% under 9.5 h UV light irradiation. The highly reductive ability results from its super negative potential of electrons in the conduction band. Furthermore, Fe substitution for Zn introduces donor states, and the oxidation process of Fe^2＋ to Fe^3＋ makes it an effective hole-scavenger. Cd and Cu substitute for Zn also reduce the bandgap and help broaden the absorbing edge towards the visible light. These substituting metal ions in natural sphalerite make it a hyper-active photocatalyst and very attractive for solar energy utilization.  相似文献