吉林省天宝山多金属矿矿床系列特征及其找矿意义   总被引：3，自引：0，他引：3  

孙钧 《吉林地质》1994,13(2):42-50

天宝山矿区是个有一百多年探采历史的矿山。多年来一直认为是典型的矽卡岩型矿床，近年来的勘查实践和综合研究，认为属于多类型、多成因和多来源的复成矿床。文章在概述成矿地质环境、划分并着重论述矿区四大矿床系列、六种矿床类型及其特征的基础上，指明了具体的找矿方向。从而提出了一个积极而又活泼的找矿新思路，并展示了矿区及其外围良好的找矿前景。  相似文献   

青海拉脊山东段水系沉积物地球化学异常特征     

罗开欢 《矿产与地质》1993,7(4):307-310

青海拉脊山东段水系沉积物地球化学测量,发现金源、喇嘛庙、七里寺峡Au、As、Ag、Bi、Sb、Hg等元素的水系沉积物组合异常.Au、Ag、As相对高浓度带发育形态、分布范围、异常浓集中心吻合,与区内已知尼旦沟金矿床地球化学异常特征可以类比,发现有金、铜矿体和金矿化,显示铜金成矿的有望远景地段.  相似文献   

再论铀的中和还原成矿作用     

史维浚  周文斌  袁晓庆 《铀矿地质》1993,(4)

反应指数是水文地球化学条件的实测值与水地化作用的临界值之间的相对值。中和还原沉淀作用的充分必要条件是与其有关的所有水文地球化学条件的反应指数都应符合反应指数法则。热力学计算和实验证明配位体浓度,如CO_3~(2-),F~-等,是阻碍铀还原沉淀的主要因素。降低CO_3~(2-)配位体浓度的主要作用是中和作用导致的CO_3~(2-)形式转化为CO_2逸出和CaCO_3沉淀。对相山矿田的铀成矿作用的水地球化学条件计算结果表明,中和作用是促使铀还原沉淀的促发钮,中和作用能导致与铀还原沉淀反应,有关的所有反应,有关的所有反应指数符合反应指数法则的要求。  相似文献   

小锍试金－无火焰原子吸收法测定地质样品中超痕量金铂铑钯   总被引：1，自引：1，他引：1  

郭炳北  张存正 《岩矿测试》1994,(2)

将锍试金改成小锍试金，用小锍扣捕集法把分解样品同富集贵金属与分离基体成份结合在一起进行，炼得的锍扣经酸处理除去贱金属硫化物，富集的贵金属采用无火焰原子吸收光谱测定。取一份样可以测定Ａｕ、Ｐｔ、Ｒｈ和Ｐｄ。测定方法的特征质量（ｇ）：Ａｕ１．１×１０￣（－１１），Ｐｔ１．３×１Ｏ￣（－１０），Ｐｄ１．３×１０￣（－１１），Ｒｈ１．２×１０￣（－１１）；线性范围（ｇ／ｍｌ）：Ａｕ０～０．０４０，Ｐｄ和Ｒｈ为０～０．０５０，Ｐｔ为０～０．５０。方法用于超基性岩标样的测定，结果与推荐值相符。  相似文献   

Gold—depleted Zone and Its Metallogenic Significance,Yinshan Ore Field,Jiangxi Proveince,China     

华仁民  陈克荣等 《中国地球化学学报》1994,13(3):246-253

Based on gold analyses of 213 samples of the Shuangqiaoshan Group in an area of 225km^2 with the Yinshan polymetallic ore district as the center, a depleted zone of gold is recognized around the ore district, suggesting that the Shuangqiaoshan Group may be a source bed for gold .Discus-sions were given concerning the alteration-mineralization features of the Yinshan deposit, the ore-controlling mechanism of the NE-trending fault zone and promising targets for further ore pros-pecting.  相似文献   

Geology,geochronology and geochemistry of large Duobaoshan Cu-Mo-Au orefield in NE China: Magma genesis and regional tectonic implications     

Wen-yan Cai  Ke-yong Wang  Jian Li  Li-juan Fu  Chun-kit Lai  Han-lun Liu 《地学前缘(英文版)》2021,12(1):265-292

Duobaoshan is the largest porphyry-related Cu-Mo-Au orefield in northeastern(NE)Asia,and hosts a number of large-medium porphyry Cu(PCDs),epithermal Au and Fe-Cu skarn deposits.Formation ages of these deposits,from the oldest(Ordovician)to youngest(Jurassic),have spanned across over 300 Ma.No similar orefields of such size and geological complexity are found in NE Asia,which reflects its metallogenic uniqueness in forming and preserving porphyry-related deposits.In this study,we explore the actual number and timing of magmatic/mineralization phases,their respective magma genesis,fertility,and regional tectonic connection,together with the preservation of PCDs.We present new data on the magmatic/mineralization ages(LA-ICP-MS zircon U-Pb,pyrite and molybdenite Re-Os dating),whole-rock geochemistry,and zircon trace element compositions on four representative deposits in the Duobaoshan orefield,i.e.,Duobaoshan PCD,Tongshan PCD,Sankuanggou Fe-Cu skarn,and Zhengguang epithermal Au deposits,and compiled published ones from these and other mineral occurrences in the orefield.In terms of geochronology,we have newly summarized seven magmatic phases in the orefield:(1)Middle-Late Cambrian(506-491 Ma),(2)Early and Middle Ordovician(485-471 Ma and~462 Ma),(3)Late Ordovician(450-447 Ma),(4)Early Carboniferous and Late-Carboniferous to Early Permian(351-345 and 323-291 Ma),(5)Middle-Late Triassic(244-223 Ma),(6)Early-Middle and Late Jurassic(178-168 Ma and~150 Ma),and(7)Early Cretaceous(~112 Ma).Three of these seven major magmatic phases were coeval with ore formation,including(1)Early Ordovician(485-473 Ma)porphyry-type Cu-Mo-(Au),(2)Early-Middle Triassic(246-229 Ma)porphyry-related epithermal Au-(Cu-Mo),and(3)Early Jurassic(177-173 Ma)Fe-Cu skarn mineralization.Some deposits in the orefield,notably Tongshan and Zhengguang,were likely formed by more than one mineralization events.In terms of geochemistry,ore-causative granitoids in the orefield exhibit adakite-like or adakite-normal arc transitional signatures,but those forming the porphyry-/epithermal-type Cu-Mo-Au mineralization are largely confined to the former.The varying but high Sr/Y,Sm/Yb and La/Yb ratios suggest that the ore-forming magmas were mainly crustal sourced and formed at different depths(clinopyroxene-/amphibole-/garnet-stability fields).The adakite-like suites may have formed by partial melting of the thickened lower crust at 35-40 km(for the Early Ordovician arc)and>40 km(for the Middle-Late Triassic arc)depths.The Early Jurassic Fe-Cu skarn orecausative granitoids show an adakitic-normal arc transitional geochemical affinity.These granitoids were likely formed by partial melting of the juvenile lower crust(35-40 km depth),and subsequently modified by assimilation and fractional crystallization(AFC)processes.In light of the geological,geochronological and geochemical information,we proposed the following tectonometallogenic model for the Duobaoshan orefield.The Ordovician Duobaoshan may have been in a continental arc setting during the subduction of the Paleo-Asian Ocean,and formed the porphyry-related deposits at Duobaoshan,Tongshan and Zhengguang.Subduction may have ceased in the latest Ordovician,and the regional tectonics passed into long subsidence and extension till the latest Carboniferous.This extensional tectonic regime and the Silurian terrestrial-shallow marine sedimentation had likely buried and preserved the Ordovician Duobaoshan magmatic-hydrothermal system.The south-dipping Mongol-Okhotsk Ocean subduction from north of the orefield had generated the Middle-Late Triassic continental arc magmatism and the associated Tongshan PCD and Zhengguang epithermal Au mineralization(which superimposed on the Ordovician PCD system).The Middle Jurassic closure of Mongol-Okhotsk Ocean in the northwestern Amuria block(Erguna terrane),and the accompanying Siberia-Amuria collision,may have placed the Paleo-Pacific subduction system in NE China(including the orefield)under compression,and formed the granodiorite-tonalite and Fe-Cu skarn deposits at Sankuanggou and Xiaoduobaoshan.From the Middle Jurassic,the consecutive accretion of Paleo-Pacific arc terranes(e.g.,Sikhote-Alin and Nadanhada)onto the NE Asian continental margin may have gradually distant the Duobaoshan orefield from the subduction front,and consequently arc-type magmatism and the related mineralization faded.The minor Late Jurassic and Cretaceous unmineralized magmatism in the orefield may have triggered mainly by the far-field extension led by the post-collisional(Siberia-Amuria)gravitational collapse and/or Paleo-Pacific backarc-basin opening.  相似文献   

华南地区三叠纪矿床地质特征、成矿规律和矿床模型     

谢桂青  毛景文  张长青  李伟  宋世伟  章荣清 《地学前缘》2021,28(3):252-270

华南以中生代成矿大爆发为特征,燕山期矿床成矿规律的研究程度较高,近年来发现越来越多的三叠纪矿床,但三叠纪矿床的分布规律和矿床模型是值得关注的重要科学问题。本文基于最新研究成果,论述华南三叠纪矿床地质特征和矿床类型,提出成矿规律,初步地建立成矿动力学模型。华南地区三叠纪矿床分布较为广泛,目前确定的46个三叠纪矿床分布于5个区带,形成于晚三叠世 (230~200 Ma),被划分为花岗岩有关的钨锡多金属矿床、侵入岩有关的远端金锑矿床、卡林型金矿床和MVT型铅锌矿床4种主要类型。在空间上,华南三叠纪矿床存在成矿元素分带性,由西向东依次为MVT型铅锌矿床、卡林型金矿床、侵入岩有关的远端金锑矿床、花岗岩有关的钨锡多金属矿床。华南5个成矿区带普遍存在印支期和燕山期的叠加成矿作用,在南岭西段桂北苗儿山—越城岭和滇东南老君山地区还发育加里东和印支期的叠加成矿作用。  相似文献   

西藏班公湖-怒江成矿带西段拿厅斑岩Cu(Au)矿床的火成岩岩石成因与成矿物质来源     

李玉彬  钟婉婷  郭建慈  秦志鹏  张志  李建力  邓时强  李玉昌 《岩石学报》2019,35(6):1717-1737

位于西藏班公湖-怒江成矿带西段多龙矿集区内的拿厅斑岩Cu(Au)矿床是近年来开展勘查取得重大找矿突破的矿床之一,控制Cu资源量已达到大型规模。但目前对该矿床的地质特征、成矿岩石成因及成矿物质来源还缺乏深入的了解和研究。本文基于系统的野外地质观察、岩相学研究,结合精细的锆石SIMS U-Pb定年、锆石Hf-O同位素、岩石地球化学和蚀变-矿石矿物的H-O-S同位素分析,认为该矿床是形成于121～118Ma的斑岩型Cu(Au)矿床,与多龙Cu(Au)矿集区内多不杂、波龙、拿顿、色那、拿若和铁格隆南(荣那)矿床为同一期岩浆-热液成矿事件,其成岩-成矿峰期为120～118Ma。拿厅斑岩铜(金)矿床成矿岩体显示轻稀土富集的分配型式和缺少Eu异常,且富集大离子亲石元素(如Rb、Ba等),而亏损高场强元素(如Nb、Ta等),显示弧岩浆的特征,形成于班公湖-怒江洋向北俯冲的大陆边缘弧背景。锆石Hf-O同位素模拟结果显示,矿区早期的安山-英安质次火山岩(ε_(Hf)(t)=-2. 0～10. 3;δ~(18)O=5. 07‰～6. 77‰)具有早期幔源岩浆和经历MASH过程混入壳源的岩浆(10%～20%壳源物质)的特征;而二长花岗斑岩和成矿花岗闪长斑岩(ε_(Hf)(t)=1. 7～3. 3;δ~(18)O=6. 40‰～6. 95‰)则是MASH过程逐渐演化(壳源-幔源混合,约20%～40%壳源物质)的产物。在形成拿厅斑岩铜金矿成矿岩浆的过程中,没有发生陆壳加厚的过程;岩浆演化过程中有较少斜长石分离结晶,主要为角闪石和钛铁氧化物结晶分异。另外,热液蚀变(石英、磁铁矿)和硫酸盐-硫化物(硬石膏、黄铜矿、黄铁矿)的H-O-S同位素结果显示,拿厅成矿流体和成矿物质主要来源于岩浆,与岩浆流体出溶过程密切有关。  相似文献   

中国贵州与美国内华达卡林型金矿对比及对找矿勘查的指示作用   总被引：1，自引：1，他引：0  

谢卓君  夏勇  Jean Cline  谭亲平  李松涛  赵亦猛  韦东田  王泽鹏  闫俊 《矿床地质》2019,38(5):1077-1093

文章从区域地质及矿床地质等方面对内华达和贵州卡林型金矿进行详细的总结和对比,结果表明两地金矿有很多相似,也有很多差异。主要的相似性包括:两地构造背景演化均经历了早期拉张裂陷、沉积一套被动大陆边缘海相沉积地层、之后造山挤压和晚期拉张;矿体主要受富铁地层和构造控制;与金矿化相关的蚀变作用均有硫化、去碳酸盐岩化、硅化和泥化;金主要以不可见金赋存于含砷黄铁矿中;晚期雄黄、雌黄、辉锑矿、方解石等矿物以脉状充填在开放空间。重要差别体现在:矿床区域分布控制因素;绝大部分贵州金矿矿床范围内未见岩浆岩;贵州金矿特有的白云石化以及相对较弱的去碳酸盐化、硅化(似碧玉岩)和泥化;载金黄铁矿的形貌和微量元素含量;部分贵州金矿含成矿期-成矿晚期毒砂;贵州有大量晚期石英-(方解石)脉;贵州成矿流体更富集CO_2,且具有更高的温度、压力和pH值。相似性和差异性的鉴定对于卡林型金矿(尤其是贵州卡林型金矿)找矿勘查具有重要指示作用。斜坡相地层是卡林型金矿最好的赋矿层位,卡林型金矿勘查中需要多关注斜坡相地层,尤其是富铁斜坡相地层。近期在贵州玄武岩分布区的区域不整合面(又称"构造蚀变体",即SBT)中,金矿勘查取得重大突破,玄武岩富含铁,是一种潜在的卡林型金矿赋矿岩性。在贵州地区,识别茅口组和龙潭组(或峨眉山玄武岩)之间的SBT及SBT上部的构造高点对于台地相区的区域金矿勘查至关重要。识别切割泥盆纪碳酸盐岩台地的区域同沉积断裂,对于调查矿床的区域分布(尤其是盆地相中金矿的区域分布)非常关键。大量似碧玉岩露头或者石英-方解石脉表明该区发生了大量的水-岩反应,预示周围可能有大规模成矿作用发生。辉锑矿、雄黄、雌黄等成矿晚期矿物多以脉状充填在矿体周围的开放空间,比矿体的分布范围更广,对矿体有很好的指示意义。  相似文献   

四川木里梭罗沟金矿床流体包裹体研究及矿床成因   总被引：1，自引：0，他引：1  

杨永飞  刘书生  聂飞  张文林 《矿床地质》2019,38(2):261-276

四川木里梭罗沟金矿床是产于甘孜-理塘金矿带南端的大型金矿床。矿体产于近东西向断裂控制的构造蚀变带内,矿石类型主要为蚀变蚀变玄武岩矿石、凝灰岩矿石。由深部至浅部,依次发育硅化、黄铁绢英岩化、碳酸盐化蚀变。流体成矿过程包括早、中、晚3个阶段,分别以石英-他形黄铁矿组合、石英-五角十二面体黄铁矿-毒砂组合和石英-碳酸盐±少量立方体黄铁矿组合为标志。矿石矿物主要沉淀于中阶段,五角十二面体黄铁矿和毒砂是主要的载金矿物。早阶段热液石英中发育CO_2-H_2O型包裹体(C型)和水溶液包裹体(W型),中、晚阶段只发育水溶液包裹体(W型)。早阶段流体包裹体均一温度集中于251～371℃,盐度w(NaCleq)为3.3%～13.7%;中阶段流体包裹体均一温度集中于187～294℃,盐度w(NaCleq)为1.6%～13.9%;晚阶段流体包裹体均一温度集中于144～224℃,盐度w(NaCleq)介于0.2%～10.6%之间。估算的早阶段流体捕获压力为102～343 MPa,推测最大成矿深度为10～11 km。上述流体包裹体研究表明,成矿流体由早阶段中高温、富CO_2的变质热液演化至晚阶段的低温、贫CO_2的大气降水热液;流体温度降低、CO_2逃逸是控制成矿物质沉淀的主要因素。矿床地质及流体包裹体特征指示梭罗沟金矿床可能为断控造山型金矿床。  相似文献