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1.
西太平洋冲绳海槽烟囱硫化物矿床矿石化学特征与分带型式 总被引：12，自引：0，他引：12
西太平洋冲绳海槽烟囱式硫化物矿床分布于琉球弧后扩张盆地、产于尹是名洼陷盆地（深１４００ｍ），其特征与日本黑矿类似。硫化物矿石及烟囱主要有３种化学类型：Ｐｂ－Ｚｎ－Ｂａ型、Ｚｎ－Ｐｂ型和Ｃｕ－Ｚｎ型，三者分别代表温度不断升高的热液体系的早、中、晚３个成矿阶段产物，其中，Ｐｂ－Ｚｎ－Ｂａ矿石及烟囱形成于高ｆｏ２环境和高流速、低温、富Ｐｂ、Ｚｎ、Ｂａ热液体系，Ｃｕ－Ｚｎ矿石及烟囱形成于低流速、高温、富Ｃｕ热液体系，Ｚｎ－Ｐｂ矿石则介于其间。硫化物烟囱显示明显的矿物－化学分带。在Ｐｂ－Ｚｎ－Ｂａ矿石（烟囱），Ｚｎ、Ｃｄ集中于烟囱中央，Ｂａ、Ｆｅ、Ａｓ、Ｓｂ、Ａｇ、Ｐｂ集中于烟囱外带，Ｃｕ则富集于烟囱中外部。在Ｃｕ－Ｚｎ矿石，Ａｓ、Ｓｂ、Ｆｅ、Ａｇ、Ａｕ仍富集于烟囱外带，Ｃｕ、Ｚｎ、Ｐｂ则在烟囱中央富集。依此元素化学分带型式，建立了古代黑矿硫化物矿体分带与硫化物堆积模式。 相似文献
2.
古代与现代海底黑矿型块状硫化物矿床矿石地球化学比较研究 总被引：33，自引：1，他引：33
选择西南太平洋冲绳海槽现代海底烟囱硫化物矿床、日本小坂矿山上向黑矿（第三纪）和中国西南呷村黑矿型矿床（三叠纪）进行了矿石地球化学比较研究。黑矿型矿床矿石吨位－品位模式与其他火山成因块状硫化物（ＶＭＳ）矿床类似，矿田（２０－５０ｋｍ＾２）矿石吨位与单个喷气－沉积型（Ｓｅｄｅｘ）矿床相当，金属总量４－６Ｍｔ，为矿田范围内热液流体搬运的最大金属量。与洋脊环境ＶＭＳ矿床相比，岛弧裂谷环境产出的黑矿型矿床相 相似文献
3.
通过对江苏长江以北地区围岩、岩浆和构造三方面成矿条件分析，提出该区新生界覆盖地区金属矿产成矿潜力大致为：响水—淮阴一线以北浅覆盖地区主要预期类型为斑岩Ｃｕ（Ａｕ）、Ｃｕ－Ｍｏ矿床，金山式、焦家式和玲珑式Ａｕ矿，此外可能存在不同生的块状硫化物矿床。响水—淮阴一线以南为深覆盖地区，其中埋深在４０—５００ｍ间的隐伏隆起是现实的找矿目标区，可以预期与宁镇矿集区、铜陵矿集区或利国矿田相类似的各类矿床 相似文献
4.
卡林型金矿指示元素研究 总被引：5，自引：2，他引：5
研究表明，卡林型金矿带中金矿及其共生的低温Ｈｇ、Ａｓ、Ｓｂ矿床中普遍含有较高的Ｔｌ、Ｆ、Ｃｌ、Ｉ和Ｂ，这些元素与金有明显的相关性，它们含量变化从远矿赋矿岩→近矿围岩→矿化岩→矿石明显呈依次递增趋势。根据矿床岩矿石中Ｔｌ、Ｆ、Ｃｌ、Ｉ和Ｂ的含量变化和分布特点及其与Ａｕ的相关性，尝试把富集系数和铊含量作为指示元素的应用指标。富集系数〉５、５￣０．５和０．５￣０．１分别为矿床，矿田和矿带标志；铊含量〉１ 相似文献
5.
金龙山——丘卡林型锑金矿床稀土元素地球化学 总被引：3，自引：1，他引：2
金龙山－－丘岭卡林型Ｓｂ－Ａｕ矿床的形成受沉建造和岩相、剪切变表构造、反生成矿作用３种因素的控制,根据ＲＥＥ含量、组成和特征参数,即∑ＲＥＥ、∑ＶＣｅ／∑Ｙ、（Ｌａ／Ｓｍ（Ｎ、（Ｌａ／Ｙｂ）Ｎ、εＥｕ、εＣｅ,探讨了该矿床的稀土元素地球化学及它与金龙山一丘岭矿床形成和演化的关系。 相似文献
6.
蚀变超基性岩金（镍）矿床中的贵金属元素：以云南墨江金矿和陕西煎… 总被引：2，自引：0，他引：2
云南墨江金矿和陕西煎茶岭金矿中Ａｇ，Ａｕ和ＰＧＥ的丰度和共生状况如下：（１）两矿床中的Ａｇ－Ａｕ关系呈三种情况：硅质岩型矿石和其他类型低金矿石中Ａｇ－Ａｕ基本上不具相关关系；石英脉型矿石中Ａｇ－Ａｕ呈明显的正相关关系；氧化矿石中Ａｇ－Ａｕ呈负相关关系。（２）所有样品中的ＰＧＥ均低于７１×１０＾－９，其ＰＥＧ的特征是Ｐｔ≥Ｐｄ和Ｒｕ〉Ｏｓ，Ｉｒ，Ｒｈ。（３）这些样品的地幔标准化ＰＧＥ分布模式是以ＲＨ 相似文献
7.
川西呷村超大黑矿型矿床成矿流体烯土元素组成 总被引：20，自引：5，他引：15
本文用ＩＣＰ－ＭＳ首次测定了呷村银多金属黑矿型矿床矿石流体包裹体中的稀土元素含量,研究表明,主成矿期流体稀土元素配分模式均为轻稀土富集,Ｅｕ具明显正异常,通过初步对比,本区主成矿期流体与东太平洋脊、大西洋脊等现代高温酸性地热系统热液具有相似的稀土模式,反映了它们物化条件的相似性;但前者∑ＰＥＥ高于后者,且两者Ｅｕ／Ｅｕ＾＊值不同,经过分析,本区成矿流体Ｅｕ正异常主要为Ｔ、ｐＨ、ｆｏ２控制,另外,围 相似文献
8.
粤西大降坪超大型黄铁矿矿床微量元素特征及其成因意义 总被引：15，自引：0，他引：15
研究了大降坪超大型黄铁矿矿床中Ａｕ、Ａｇ、Ｃｕ、Ｐｂ、Ｚｎ、Ａｓ等在不同岩石、矿石及黄铁矿中的含量，除Ｐｂ作为综合利用外，其余均为工业利用价值，原始热水沉积的条带状矿石与经后期热液叠加变富的块状矿石具有不同的微量元素的组成，矿石与岩石的一些元素比值和图解可作为两类矿石成因的判据。 相似文献
9.
拉尔玛—邛莫金矿床的地质特征及成矿模式 总被引：1，自引：0，他引：1
拉尔玛－邛莫金矿床产于西秦岭南亚带寒武系硅岩建造中，受地层，岩性，构造控制十分明显，但与其它层控金矿相床比较，该矿床不仅含矿主岩特殊，而且矿石矿物和元素组合十分复杂，矿床中除Ａｕ外，Ｃｕ，Ｕ，Ｍｏ，Ｓｂ，Ｖ，Ｚｎ等元素在局部地段亦可圈出独立矿体。同时，矿床中存在铂族元素（ＰＧＥ）铟的高异常以及硒的矿化富集体，从而构成了Ａｕ－Ｃｕ－Ｕ－Ｍｏ－Ｓｅ－ＰＧＥ建造矿床，研究表明，金矿床的形成，至少经历了喷 相似文献
10.
研究区位于北祁连造山带西段尕大坂矿田,区内已发现的矿床均产于北侧的大柳沟-白柳沟火山穹窿的酸性火山岩和基性火山岩的接触部位。对尕大坂矿床和郭米寺矿床地质特征的研究及矿石化学成分的分析,认为矿床具"双岩石组合",是典型的海底热水喷流沉积的标志,主要为Zn-Pb-Cu型多金属矿床,属于黑矿型。通过对矿田黑茨沟组含矿火山岩系的岩石地球化学研究,表明形成环境与弧后裂谷相似。 相似文献
11.
Abstract. The Takara volcanogenic massive sulfide (VMS) deposit occurs in Miocene formation of the Misaka Mountain, the South Fossa Magna region, central Japan. The tectonic setting of the Misaka Mountain is reconstructed to be a part of the paleo Izu-Ogasawara arc which collided with the Honshu arc and to form accreted body in the present position. The Takara deposit, therefore, is considered to have formed in the paleo Izu-Ogasawara arc.
The ores from the Takara deposit are classified into pyrite-type ore, chalcopyrite-type ore, and sphalerite-type ore on the basis of chemical composition and their mineral assemblages. Some pyrite-type ores are characterized by their high Au content. The Au content is hardly recognized in the chalcopyrite-type and sphalerite-type ores.
The ores from the Takara deposit have intermediate bulk chemical composition between those from the Besshi-type deposits and the Kuroko-type deposits that are two representative VMS deposits. However, the bulk chemical composition is closer to that from the Kuroko-type deposits. And moreover, chemical composition of tetrahedrite-tennantite series minerals (tetrahedrite) is similar to that from the Kuroko-type deposits. The bulk chemical composition (Cu, Zn, Co, Pb, and As contents) of ores is affected by the chemical composition of volcanic rocks associated with VMS deposits. 相似文献
The ores from the Takara deposit are classified into pyrite-type ore, chalcopyrite-type ore, and sphalerite-type ore on the basis of chemical composition and their mineral assemblages. Some pyrite-type ores are characterized by their high Au content. The Au content is hardly recognized in the chalcopyrite-type and sphalerite-type ores.
The ores from the Takara deposit have intermediate bulk chemical composition between those from the Besshi-type deposits and the Kuroko-type deposits that are two representative VMS deposits. However, the bulk chemical composition is closer to that from the Kuroko-type deposits. And moreover, chemical composition of tetrahedrite-tennantite series minerals (tetrahedrite) is similar to that from the Kuroko-type deposits. The bulk chemical composition (Cu, Zn, Co, Pb, and As contents) of ores is affected by the chemical composition of volcanic rocks associated with VMS deposits. 相似文献
12.
笔者简单介绍了乔夏哈拉铜(铁)金矿床的基本成矿及其微量元素地球化学特征,指出其主矿体具有“垂向分带”及“铜、金向下同步富集”的特点,认为其容矿火山岩与中基性侵入岩脉具有基本相似的微量元素地球化学行为,铜、金矿石同其容矿火山岩相比具有相对贫K、Rb、Th、Ba,相对富W、Ni、Co、As、Sb、Zn及明显偏低的Th／Ta、La／Yb值。研究稀土元素地球化学,发现铜、金矿石具有明显不同于其容矿火山岩的强Eu富集,后期形成的地质体一般具有相对更为偏低的∑REE值。综合分析表明,该铜(铁)金矿床为一与“层状夕卡岩”有关的火山热液型“层控”矿床。 相似文献
13.
塔里木克拉通东北缘坡北、磁海等地二叠纪幔源岩浆活动形成了镍钴硫化物矿床和铁钴氧化物矿床,两者赋矿镁铁-超镁铁岩体的年龄相近(290～260 Ma),主、微量元素和Sr-Nd-Hf同位素组成相似,分配系数接近的微量元素比值分布于相同趋势线,揭示两者岩浆源区相同,可能为俯冲板片流体交代的亏损地幔或软流圈地幔。两类矿床镁铁-超镁铁质岩中Co与Ni含量正相关,Co主要富集在基性程度高的岩石中;块状硫化物与磁铁矿矿石中Co与Ni相关性差,Co和Ni具有不同的富集机制,Co热液富集作用明显。北山镁铁-超镁铁杂岩体是地幔柱相关软流圈上涌,诱发俯冲板片交代的亏损岩石圈地幔发生部分熔融,形成的高镁母岩浆演化过程中经历壳源混染、硫化物饱和富集镍钴形成铜镍钴硫化物矿床,富铁母岩浆氧逸度高、富水,岩浆分离结晶磁铁矿、叠加热液作用富集钴,形成铁钴氧化物矿床。 相似文献
14.
Song Xuexin Xu Qingsheng Guo Yuemin Mao Xueying Ouyang Hong Institute of Mineral Deposits Chinese Academy of Geological Sciences Beijing Institute of High Energy Physics Chinese Academy of Sinices Beijing 《《地质学报》英文版》1997,71(3):263-272
REE ratios and patterns for massive pyrite ore and massive cuprous pyrite ore ofthe Baiyinchang orefield are quite similar to those for quartz keratophyritic tuff and quartzalbitophyre of the same orefield. However, massive cuprous pyrite ore of the Ashele Cu-Zn de-posit is similar to basalt-diabase of the same district in REE geochemistry. Comparison of theChinese VMS ores with those from Rio Tinto, Spain and Que River, Australia, in REEgeochemistry has been made. REE ratios and patterns of bedded-massive and massive ores ofthe Changba-Lijiagou Zn-Pb deposit, the second largest SEDEX deposit in China are similarto those of their host rocks, the Qinling shales of Devonian age and the Changba adamellite.The three types of ore and their host rocks of the Dongshengmiao pyrite (pyrrhotite)-Zn-Pbdeposit have parallel REE ratios and patterns. 相似文献
15.
New data on platinum mineralization in ores, metasomatic rocks, concentrates, and tailings and wastes of some gold–polymetallic, Au–Bi, Cu–Mo porphyry, Cu–Ni, and titanomagnetite ore deposits and occurrences of the Upper Amur Region are presented. The contents of platinoids, Au and Ag in multimetal ores of gold-polymetallic, Au–Bi, Cu–Mo porphyry, Cu–Ni, and titanomagnetite ore deposits and ore occurrences are given. In addition, recommendations on the necessity of continuing scientific studies, revision, and resampling works in the search for platinoids in other complex ores of deposits and occurrences of the Upper Amur Region are given. 相似文献
16.
D. E. Ayres 《Australian Journal of Earth Sciences》2013,60(3-4):155-168
The main Woodlawn ore lens is a polymetallic, massive sulphide deposit’ with pyrite the major constituent, variable sphalerite, galena and chalcopyrite, and minor arsenopyrite, tetrahedrite‐tennantite, pyrrhotite and electrum. The silicate gangue minerals are chlorite, quartz, talc and sericitic mica. Other mineralization in the vicinity consists of footwall copper ore in chlorite schist and several smaller massive sulphide lenses. The predominant country rocks are felsic volcanics and shales, with abundant quartz, chlorite and mica, and talc in mineralized zones. An important textural feature of the massive ore is the fine compositional banding. Bands, which vary in thickness from a few tens of micrometres to several millimetres, are produced by variations in the sulphide content. Post‐depositional metomorphism and minor fracturing have only slightly modified this banding. Apart from the major element constituents—Pb, Zn, Fe, Cu and S—the ore is characterized by significant (100–1000 ppm) values for Ag, As, Cd, Mn, Sb and Sn, and lower (1–100 ppm) values of Au, Bi, Co, Ga, Hg, Mo, Ni, Tl. In and Ge. Variations in the base‐metal sulphide content, the gangue mineralogy, and trace elements, are used to separate the orebody into hanging‐wall and footwall zones. The hanging‐wall zone shows a more variable trace element content, with higher Tl, Sn, Ni, Mn, Ge and Sb, but lower Ag, Cd, and Mo, than the footwall zone. In general style of mineralization, mineralogy, and chemistry, the Woodlawn deposit resembles other volcanogenic massive sulphide deposits in eastern Australia, in New Brunswick in Canada, and the Kuroko deposits of Japan. 相似文献
17.
The bulk composition, mineralogy and mineral chemistry of base-metal sulfides have been investigated in the Fe-Ni-(Cu) ore deposits of the Ivrea-Verbano basic complex.The sulfide ores mostly display textural evidence of having been primarily deposited as an immiscible melt. Bulk compositions of the ores indicate that considerably low Ni/Fe and Ni/Co ratios are found in deposits developed close to metasedimentary country rocks, possibly as a result of mixing with sedimentary sulfur.Phase relations of primary sulfides indicate that early crystallization of the ore was dominated by a monosulfide solid solution (Mss) with a pyrrhotite composition, from which pentlandite and chalcopyrite were formed through subsolidus exsolution. Pentlandite from contaminated ores is typically enriched in Co. Troilite and hexagonal intermediate pyrrhotite intergrowths frequently occur due to low-temperature equilibration of metal-rich pyrrhotites, suggesting a low S fugacity of the original sulfide melt.The sulfides may be locally mobilized and redeposited along shear zones within the same host rock, giving rise to fairly massive ores having a typical cemented-breccia texture. Bulk composition and assemblages suggest that mobilization occurred at various temperatures during the cooling history of the ore, when sulfides were still in the molten state or at a lower temperature under the influence of abundant deuteric fluids. In this last case, growth of pyrite is seen as being possibly due to sulfurization and/or oxidation. 相似文献
18.
Major minerals (sulfates, sulfides, quartz) are distributed in different parts of submarine hydrothermal ore deposits. For instance, the abundance of barite increases stratigraphically upwards in the massive orebodies of the Kuroko deposits (black and yellow ores), while quartz is abundant in the lower parts (siliceous ore). The different distribution of barite and quartz in the Kuroko deposits can not be accounted for by thermochemical equilibrium calculations based on the precipitation due to mixing of ascending hydrothermal solutions with ambient cold seawater. In the present study, a coupled fluid flow‐precipitation kinetics model was used to calculate the amounts of quartz, barite, and anhydrite precipitated from a hydrothermal solution mixed with seawater, assuming reasonable values for temperature, precipitation rate, fluid flow velocity, mineral surface area/fluid mass ratio (A/M), and initial concentrations of hydrothermal solution and seawater before mixing occurred. The results indicate that barite precipitates more efficiently than quartz from discharging fluids with relatively higher flow velocity, lower temperatures and under the condition of lower A/M ratios on the seafloor (black ore), whereas quartz precipitates more effectively from solutions with lower flow velocity, higher temperatures and higher A/M ratios beneath the seafloor (siliceous ore) and in the orebody (barite ore, ferruginous chert ore). Anhydrite precipitates in shallow sub‐seafloor environments with lower precipitation rates and higher A/M ratios than barite and higher precipitation rates and lower A/M ratios than quartz. These results explain the observed occurrences of barite, anhydrite, and quartz in the Kuroko deposits. Namely, barite is abundant in black ore and barite ore which formed above the seafloor, anhydrite formed in high‐permeability tuff breccias, and quartz formed in low permeability dacite intrusive bodies in the sub‐seafloor environment. 相似文献
19.
Neodymium, Sr and Pb isotopic compositions, along with rare earth element (REE) concentrations were determined for twelve black ores and one yellow ore from twelve localities of the Kuroko deposits, Japan. The ores were generated by submarine hydrothermal activity during the Miocene age. Neodymium isotopic compositions of the ores (Nd: –4.9 to +6.5) mostly overlap with spatially associated igneous rocks. On a Nd versus Sr isotopic correlation diagram, however, 87Sr/86Sr ratios are shifted from the associated igneous rocks towards the higher contemporaneous seawater ratio. REE patterns are highly variable, ranging from light REE enriched to depleted, and show no Ce anomalies, as would be expected if they were derived from seawater. These results suggest that the REEs contained in ores were mainly derived from the associated igneous rocks, but that the ore Sr is a mixture derived from both seawater and the igneous rocks. Most Pb isotopic compositions fall within the range defined by the associated igneous rocks (206Pb/204Pb=18.35–18.84, 207Pb/204Pb=15.59–15.97 and 208Pb/204Pb=38.53–39.90), although several samples have very radiogenic compositions that were most likely derived from basement rocks. Our new Pb isotopic results display greater variation, and have a larger range of more radiogenic compositions than has been noted previously for these ores. In addition, the black ore with the most radiogenic Pb isotopic composition also has the least radiogenic Nd isotopic composition. This suggests that at least some of the Pb contained in the ores was derived mainly from older basement rocks. The large positive Eu anomalies for some black ores are consistent with a high-temperature origin for the parental fluids, irrespective of the source rock. The single yellow ore examined, however, has a small negative Eu anomaly, which may indicate derivation from a lower temperature fluid. Previous studies suggested that the Kuroko ores were formed in the presence of organic materials in an anoxic basin. Combined Nd, Sr, Pb and Os isotopic and REE abundance data indicate that multiple sources were involved in the genesis of Kuroko ores. 相似文献