黄铁矿热电性研究在谢家沟金矿评价中的应用          下载免费PDF全文

张志启  王建国  邓军  韦延光  闫顺令  马启光  刘娜 《山东国土资源》2005,21(11):26-29

谢家沟金矿是胶东地区新发现的大型金矿床,矿床类型为“焦家式”与“玲珑式”的过渡类型。对矿床3种主要矿石类型、不同中段的22个矿石样品进行了黄铁矿热电性测试,结果表明黄铁矿以N型导电为主,早期形成的黄铁绢英岩中黄铁矿热电系数最大,主成矿阶段形成的黄铁矿—黄铜矿绢英岩次之,晚期的黄铁矿—黄铜矿石英脉最小;从+130m中段到+242m中段,N型黄铁矿的出现率逐渐变小,热电系数也随之下降,认为矿体的浅部已被剥蚀,N型黄铁矿出现率表现较好的连续性说明深部资源潜力很大。  相似文献   

Zoned Zircon from Eclogite Lenses in Marbles from the Dabie-Sulu UHP Terrane, China： A Clear Record of Ultra-deep Subduction and Fast Exhumation   总被引：3，自引：0，他引：3  

Liu Fulai 《《地质学报》英文版》2007,81(2):204-225

Eclogite lenses in marbles from the Dabie-Sulu ultrahigh-pressure (UHP) terrane are deeply subducted meta-sedimentary rocks. Zircons in these rocks have been used to constrain the ages of prograde and UHP metamorphism during subduction, and later retrograde metamorphism during exhumation. Inherited (detrital) and metamorphic zircons were distinguished on the basis of transmitted light microscopy, cathodoluminescence (CL) imaging, trace element contents and mineral inclusions. The distribution of mineral inclusions combined with CL imaging of the metamorphic zircon make it possible to relate zircon zones (domains) to different metamorphic stages. Domain 1 consists of rounded, oblong and spindly cores with dark-luminescent images, and contains quartz eclogite facies mineral inclusion assemblages, indicating formation under high-pressure (HP) metamorphic conditions of T = 571-668℃and P = 1.7-2.02 GPa. Domain 2 always surrounds domain 1 or occurs as rounded and spindly cores with white-luminescent images. It contains coesite edogite facies mineral inclusion assemblages, indicating formation under UHP metamorphic conditions of T = 782-849℃and P > 5.5 GPa. Domain 3, with gray-luminescent images, always surrounds domain 2 and occurs as the outermost zircon rim. It is characterized by low-pressure mineral inclusion assemblages, which are related to regional amphibolite facies retrograde metamorphism of T = 600-710℃and P = 0.7-1.2 GPa. The three metamorphic zircon domains have distinct ages; sample H1 from the Dabie terrane yielded SHRIMP ages of 245±4 Ma for domain 1, 235±3 Ma for domain 2 and 215±6 Ma for domain 3, whereas sample H2 from the Sulu terrane yielded similar ages of 244±4 Ma, 233±4 Ma and 214±5 Ma for Domains 1, 2 and 3, respectively. The mean ages of these zones suggest that subduction to UHP depths took place over 10-11 Ma and exhumation of the rocks occurred over a period of 19-20 Ma. Thus, subduction from～55 km to > 160 km deep mantle depth took place at rates of approximately 9.5-10.5 km/Ma and exhumation from depths >160 km to the base of the crust at～30 km occurred at approximately 6.5 km/Ma. We propose a model for these rocks involving deep subduction of continental margin lithosphere followed by ultrafast exhumation driven by buoyancy forces after break-off of the UHP slab deep within the mantle.  相似文献   

开放体系下方铅矿和黄铁矿之间原电池反应的实验研究     

周丽  李和平  徐丽萍 《矿物岩石》2006,26(1):110-115

金属硫化物矿物之间的原电池反应对于酸性矿山排水的形成、硫化物矿床的次生富集作用、地球电化学勘探以及湿法冶金过程等都有很重要的影响。通过改变溶液中氧化剂组分F e3 的浓度、pH值、溶液的流动状况以及溶液的盐度(如N a2SO4的浓度),采用精密的电流计和电位计,对作为阳极的黄铁矿与作为阴极的方铅矿所形成的原电池反应的电流密度和整个原电池的混合电位进行研究,结果表明:溶液中[F e3 ],pH值以及溶液的流动状况对黄铁矿和方铅矿之间原电池反应的影响很大,而溶液的盐度对反应的影响不是很显著。实验还发现,当黄铁矿电极表面存在微小裂纹时,其电极电位可降低至同条件下方铅矿的电极电位以下。这一实验结果在混合电位理论和Bu tler-V o lm er方程中得到了理论上的解释。  相似文献   

浙江湖州黑龙洞黄铁矿矿床特征及成矿条件浅析     

潘志龙 《化工矿产地质》2007,29(1):6-10

浙江省湖州黑龙洞黄铁矿矿体赋存于石炭系中统黄龙组三段燧石灰岩或硅质灰岩和二段白云质大理岩中。矿体呈扁豆状,黄铁矿体之上为含金铁帽。通过对其成矿条件的分析,认为矿床成因类型总体上属于沉积-热液改造型矿床。  相似文献   

青海东昆仑阿斯哈金矿床含金黄铁矿微量元素地球化学特征及其地质意义   总被引：1，自引：0，他引：1  

岳维好  周家喜 《矿床地质》2022,41(1):106-120

阿斯哈金矿床是青海东昆仑造山带东段金矿床的典型代表.金矿体主要赋存于闪长岩和花岗闪长岩体的构造破碎带内,受NNE向和NNW向-NW向断裂构造控制.与金矿化密切相关的蚀变类型为黄铁矿化、硅化、绢云母化和黄铜矿化.矿石矿物主要为黄铁矿,其次是黄铜矿、方铅矿、毒砂、自然金和银金矿.据矿脉穿插关系、矿石矿物共生组合和结构构造特...  相似文献   

Causes of variation in crystal morphology in metamorphogenic pyrite deposits of the Cameros Basin (N Spain)     

J. Alonso‐Azcrate  M. Rodas  L. Fernndez‐Díaz  S.H. Bottrell  J. R. Mas  S. Lpez‐Andrs 《Geological Journal》2001,36(2):159-170

The low‐grade metasediments of the Cameros Basin, northern Spain, host a number of deposits of spectacular quality pyrite mineralization. These formed during regional metamorphism and the pyrite crystals exhibit a wide range of morphologies. On the basis of pyrite crystal habit, the deposits can be classified into two groups: Group I comprises deposits with cubic, elongated or platy crystals; Group II comprises deposits characterized by pyritohedra and cubo‐pyritohedra with striated faces, along with blocky crystals and fine‐grained aggregates. Group I deposits are formed in sequences dominated by meandriform fluviatile sediments, while Group II is hosted by deltaic plain and lacustrine metasediments. Temperature differences between deposits and As content are possible causes of the different pyrite morphologies in the deposits, but no significant variation exists between the two groups for either factor. Comparison with experimentally grown pyrite crystals suggests that Group I deposits have morphologies indicative of lower degrees of pyrite supersaturation than pyrite crystals in Group II deposits. The sedimentary facies hosting Group II deposits provides a greater availability of sedimentary sulphur (pyrite and sulphates). Moreover, reactions involving sulphate during metamorphism may have modified fluid chemistry, which would also act to produce higher degrees of pyrite saturation in fluids derived from the sulphate‐rich deltaic plain and lacustrine metasediments hosting the Group II deposits. This hypothesis is confirmed by sulphur isotope data on the pyrites, which show a larger component of³⁴S‐enriched sulphate‐derived sulphur in these deposits. Copyright © 2001 John Wiley & Sons, Ltd.  相似文献   

山东莱州曲家金矿黄铁矿微量元素对成矿过程的指示          下载免费PDF全文

杨德平  刘鹏瑞  宋英昕  舒磊  熊玉新  刘继梅 《岩石矿物学杂志》2023,42(6):788-808

曲家金矿位于我国重要的蚀变岩型金矿矿集区之焦家金矿带的中段，矿床赋存标高为-726～-1 334 m。为研究黄铁矿的演化及其对金成矿过程的指示，运用LA-ICP-MS分析黄铁矿原位微量元素含量，结合岩相学观察和点群分析对黄铁矿进行了分类。发现黄铁矿中Co、Ni、As等微量元素主要以类质同像形式赋存，而Au、Ag、Cu、Zn、Pb、Bi等元素主要以纳米级、微米级矿物包裹体形式赋存。黄铁矿主要分为5种类型：富Co型Py1,富Ni型Py2,富Au、As型Py3,富Au、Ag、Pb、Bi型Py4及“干净”型Py5。黄铁矿微量元素特征指示成矿物质可能主要来源于前寒武纪变质基底岩石和中生代岩浆岩，少量来源于地幔，成矿热液可能属变质热液、岩浆热液和浅部大气降水的混合成因。不同类型黄铁矿反映成矿热液由富Co、Ni经富As、Au向富Pb、Bi、Au、Ag演化。Py1和Py2形成后受构造活动影响发生强烈破碎，裂隙表面对热液中金络合物增强的吸附作用促使金在裂隙中沉淀，对金的富集成矿可能起重要作用。Co、Ni含量较低，同时Au、Ag、As、Pb、Bi等元素含量较高的黄铁矿与成矿作用有密切关系。另外，黄铁矿中C...  相似文献