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对铜陵地区石炭纪喷流 -沉积型 (Sedex)块状硫化物矿床成矿过程中流体运移的数值模拟 ,揭示该类型矿床底盘岩石中的流体活动和热影响范围主要局限在主排泄通道两侧较小的区域内 ;流体运移行为主要表现为海水下渗淋滤底盘岩石 ,最后汇入主排泄通道 ,与沿断裂上升热流体一道喷出海底。温度场和流场决定喷流 -沉积型块状硫化物矿床底盘岩石中的蚀变和矿化强度较弱 ,这是 Sedex型矿床底盘岩石蚀变和矿化强度不如以火山岩为容矿岩石块状硫化物矿床(VHMS型 )的原因。尽管温度场和流场的影响范围较小 ,但在铜陵地区 ,下渗海水从底盘岩石中淋滤出… 相似文献
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通过对闽西南地区石炭纪—早二叠世主要块状硫化物矿床的区域成矿背景、贮矿层位特征以及矿石矿物成分、结构构造,硫同位素地球化学特征、成矿温度等分析研究,指出该地区石炭纪—早二叠世块状硫化物矿床的形成多与海底火山活动有关,贮矿层中伴有典型的喷流沉积岩—硅质岩,并提出闽西南地区块状硫化物矿床存在海底喷流-沉积成矿作用的新认识。 相似文献
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论华南喷流—沉积块状硫化物矿床 总被引：28，自引：1，他引：27
现代海底喷流－沉积硫化物矿床的发现极大地推动了海底热液成矿理论的发展,也大大地提高了对古代海底喷流块充化物矿术的研究水平。本文指出喷流－沉积是重要的成矿作用,提出喷流－沉积矿床是华南Ｃｕ、Ｐｂ、Ｚｎ、Ｓｎ、Ａｇ、Ａｕ等矿产资源的重要来源,形成了一批超大型矿床,并将华南许多曾被认为属夕卡岩矿床重新确认为喷流－沉积岩床。文章还论述了华南喷流－沉积块状硫化物矿床的特征、分类、时空分布及其成矿特点等问题,提出断裂拗陷带型喷流－沉积块状硫化物矿床是华南具有特色的类型,而陆相断陷盆地中喷流－沉积矿床值得进一步深入研究。 相似文献
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喷流沉积成矿作用研究的若干问题 总被引：21，自引：0，他引：21
研究海底喷流沉积矿床形成和陆源沉积速率，可确定喷流沉积矿床处于上盘蚀变的找矿标志和块状硫化物矿床产出的海底深度。此外还探讨了陆相喷流沉积成矿的可能性。 相似文献
5.
阿尔泰可可塔勒铅锌矿床围岩蚀变及成因 总被引：2，自引：3，他引：2
可可塔勒铅锌矿床受火山喷发中心和沉积洼地控制，铅锌沉淀于海进阶段的局限还原卤水池中；矿下存在大型蚀变带，构成成矿流体对流循环过程中的水-岩作用带；后期造山挤压过程使地层和矿体倒转，矿床最终定位于麦兹倒转向斜之北东倒转翼的东南近转折部位。指出该矿床属海底火山喷流沉积改造型块状硫化物铅锌矿床。 相似文献
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《吉林地质》2017,(1)
海底热液成矿是近年来地质学家关注的热点问题。现代海底热液成矿作用的研究推动了古块状硫化物矿床成矿过程的认识。结合现今研究成果综合分析表明:海底热液成矿作用主要分布在张性活动板块边界,与大地构造活动紧密相连;成矿金属物质来源具有多元性,金属矿化的类型受基底类型(洋壳-陆壳)和岩性组合(基性岩石-中酸性岩石)的控制,岩浆来源的物质也可能对一些块状硫化物矿床有贡献;主导海底热液成矿作用的核心为对流热循环系统,对流循环具有单循环和双扩散对流模式;海底块状硫化物的堆积过程是烟囱的生长、倒塌堆积和热液流体充填与交代的过程,成矿热液流体的温度和密度在这个过程中起关键作用。基于海底热水矿床的重要性,建立完整的热水喷流成矿理论意义重大。 相似文献
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现代洋底多金属块状硫化物和陆上贱金属块状硫化物矿床中的含金性调查研究证实：海底沉积喷流作用不仅能形成十分重要的贱金属硫化物矿床,而且也能导致金的明显富集。通常形成于弧后或岛弧环境下的同长英质火山岩有关的块状硫化物中的金含量较高。大量的金矿床地球化学研究工作已识别出一些沉积喷流型金矿床,此外还发现即使是具有明显后生成矿特征的太古宙绿岩带中的脉状金矿床也显示出其同沉积喷流作用密切的时空关系 相似文献
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昆仑造山带钴矿找矿前景初步评价 总被引：10，自引：0，他引：10
钴绝大多数呈伴生矿种出现于铜镍硫化物矿床、夕卡岩矿床以及海底喷流沉积矿床中。通过对昆仑－阿尼玛卿山－秦岭地区不同类型钴矿或含钴矿床地质特征的分析,认为该地区具有良好的钴矿成矿条件。钴不仅可以出现于完全不同类型的矿床中,而且还地块状硫化物脉出现,形成高芳富钴的独立钴矿床。这一地区有望迅速取得找矿突破的钴矿床类型可能是海底热水喷流沉积型（ＳＥＤＥＸ）,尤其在已发现的这类Ｆｅ、Ｃｕ、ＰｂＺｎ矿床或其周围 相似文献
10.
青海抗得弄舍重晶石型金多金属矿床成矿地质特征 总被引：1，自引：0，他引：1
抗得弄舍重晶石型金多金属矿床为近几年在东昆仑成矿带东段新发现的典型的热水喷流沉积型金多金属矿床,目前该矿床金矿和铅锌矿的规模均已达大型以上,矿床的发现对东昆仑成矿带东段的找矿带来了新的生机和活力。该矿床以典型的热水沉积岩重晶石含金矿为特点,矿床受地层岩性和同生断裂构造双重控制,矿化与蚀变具有明显的空间分带特征。研究表明硫化物中的铅主要来自地幔,硫来自海水或者海相硫酸盐。指出成矿作用经历了早期喷流沉积成矿期,主要在中低温条件下形成铅锌硫化物矿;晚期热水沉积成矿期,主要在低温条件下形成重晶石和金矿;后期热液及构造活动对矿床有了进一步的富集和改造。 相似文献
11.
XU Wenyi HOU Zengqian YANG Zhusen SHI Danian MENG Yifeng ZENG Pusheng Institute of Mineral Resources Chinese Academy of Geological Sciences Beijing 《《地质学报》英文版》2005,79(1):98-105
Numerical simulation of fluid migration during the ore-forming process of the Carboniferous exhalationsedimentary (Sedex) massive sulfide deposits in the Tongling district shows that fluid and thermal activities in lying-wall rocks were limited to a small area around the main draining passage, which led to weak mineralization and alteration in the lying-wall rock. Temperature and fluid fields indicate that mineralization and alteration in the lying-wall rock of the Sedex-type deposits are usually weaker than those of volcano-hosted massive sulfide deposits. Fluid migration involves the following processes: seawater penetrating and leaching the lying-wall rocks, then mixing with ascending hydrothermal fluids in the main draining passage, and finally jetting into seafloor. Although fluid activity-influenced area is rather small,the content of metals leached out from the lying-wall rocks is high enough to form large-scale ore deposits. Tensional contemporaneous faults accompanied with strong heat flows controlled the formation and distribution of Sedex deposits.The tensional tectonic regime on the northern margin of the Yangtze block during the Hercynian provided Sedex deposits with a prerequisite geodynamic condition. 相似文献
12.
火山成因块状硫化物矿床研究进展 总被引：3，自引：0，他引：3
火山成因块状硫化物（VMS）矿床可形成于太古宙至现代各个地质时期.现代海底热液成矿作用是赋存于海相火山岩系中的古代VMS矿床成矿作用的再现.VMS矿床可形成于多种构造环境,但均与拉张背景有关.按照构造环境和容矿岩系将VMS矿床分为黑矿型、塞浦路斯型、别子型和沙利文型.VMS矿床的热液蚀变由下盘蚀变带和上盘蚀变带两个结构单元组成.下盘蚀变一般有两种类型：（1）不整合的蚀变岩筒,直接产在块状硫化物带的下方;（2）半整合或层控的上盘蚀变带,并可以在区域范围内展布.与下盘蚀变类似,上盘蚀变也具有蚀变岩筒和半整合的蚀变带两种类型.成矿金属主要有两种可能的来源：（1）在岩浆侵入体和浅位岩浆房之上被加热的循环海水对含矿火山岩系及下伏基底物质的淋滤;（2）深部岩浆房挥发分通过释气作用直接释放.下渗的海水是成矿流体的主要来源,同时流体包裹体和稳定同位素资料显示岩浆流体对成矿流体系统亦有较大贡献.VMS矿床具有明显的金属分带现象,其金属序列组合从下至上依次为Fe→Fe-Cu→Cu-Pb-Zn→Pb-Zn-Ba,这种金属分带的演化反应了流体的演化和块状硫化物丘的生长机制.根据成矿流体温度变化而不断演化的4阶段成矿模式可以很好的解释经典丘堆式矿床的形成过程. 相似文献
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Geological Fluid Mapping in the Tongling Area： Implications for the Paleozoic Submarine Hydrothermal System in the Middle-Lower Yangtze Metallogenic Belt, East China 总被引：1，自引：0，他引：1 
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下载免费PDF全文 HOU Zengqian YANG Zhusen MENG Yifeng ZENG Pusheng LI Hongyang XU Wenyi 《《地质学报》英文版》2007,81(5):833-860
The Tongling area is one of the 7 ore-cluster areas in the Middle-Lower Yangtze metallogenic belt,East China,and has tectonically undergone a long-term geologic history from the late Paleozoic continental rifting,through the Middle Triassic continent-continent collision to the Jurassic-Cretaceous intracontinental tectono-magmatic activation.The Carboniferous sedimentary-exhalative processes in the area produced widespread massive sulfides with ages of 303-321 Ma,which partly formed massive pyrite-Cu deposits,but mostly provided significant sulfur and metals to the skarn Cu mineralization associated with the Yanshanian felsic intrusions. To understand the Carboniferous submarine hydrothermal system,an area of about 1046 km~2 was chosen to carry out the geological fluid mapping.Associated with massive sulfide formation,footwall sequences 948 m to 1146m thick,composed of the Lower Silurian-Upper Devonian sandstone,siltstone and thin-layered shale,were widely altered.This hydrothermal alteration is interpreted to reflect large- scale hydrothermal fluid flow associated with the late Paleozoic crustal rifting and subsidence.Three hydrothermal alteration types,i.e.,deep-level semiconformable silicification(S_1),fracture-controlled quartz-sericite-pyrite alteration(S_(2-3)),and upper-level sub-discordant quartz-sericite-chlorite alteration(D_3),were developed to form distinct zones in the mapped area.About 50-m thick semiconformable silicification zones are located at～1-km depth below massive sulfides and developed between an impermeable shale caprock(S_1)and the underlying Ordovician unaltered limestone. Comparisons with modern geothermal systems suggest that the alteration zones record a sub-seafloor aquifer with the most productive hydrothermal fluid flow.Fracture-controlled quartz-sericite-pyrite alteration formed transgressive zones,which downward crosscut the semiconformable alteration zones, and upwards grade into sub-discordant alteration zones that enveloped no economic stringer- stockwork zones beneath massive sulfides.This transgressive zone likely marks an upflow path of high- flux fluids from the hydrothermal aquifer.Lateral zonation of the sub-discordant alteration zones and their relationship to overlying massive sulfide lenses suggest lateral flows and diffusive discharging of the hydrothermal fluids in a permeable sandstone sequence.Three large-sized,14 middle-small massive sulfide deposits,and 40 massive sulfide sites have been mapped in detail.They show regional strata- bound characters and two major styles,i.e.,the layered sheet plus strata-bound stringer-style and the mound-style.Associated exhalite and chemical sedimentary rock suites include(1)anhydrite-barite,(2) jasper-chert,(3)Mg-rich mudstone-pyrite shale,(4)barite lens,(5)siderite-Fe-bearing dolomite,and (6)Mn-rich shale-mudstone,which usually comprise three sulfide-exhalite cyclic units in the area. The spatial distribution of these alteration zones(minerals)and associated massive sulfides and exhalites,and regional variation inδ~(34)S of hydrothermal pyrite and inδ~(18)O-δ~(34)C of hanging wall carbonates,suggest three WNW-extending domains of fluid flow,controlled by the basement faults and syn-depositional faults.Each fluid domain appears to have at least two upflow zones,with estimated even spacing of about 5-8 km in the mapped area.The repeated appearance of sulfide-sulfate or sulfide-carbonate rhythmic units in the area suggests episodically venting of fluids through the upflow conduits by breaking the overlying seals of the hydrothermal aquifer. 相似文献
14.
A multi-element geochemical study of the wall rocks of intermediate to felsic volcanic-hosted massive sulfide deposits was carried out to identify pathfinder elements which significantly enlarge the size of exploration targets. Drill core samples from the Crandon massive sulfide deposit in Wisconsin, and outcrop samples from the United Verde and Iron King deposits in Arizona, and from the Captains Flat, Mt. Costigan, and Wiseman Creek deposits in New South Wales, Australia were analyzed. Because anomalously high fluorine values have been described in several volcanic-hosted ore systems, fluorine was included in the study.All of the above deposits have patterns of fluorine enrichment around ore. Drill core samples from two noneconomic prospects within ten miles of the Crandon deposit contain background to only weakly anomalous fluorine values.At the large Crandon deposit (> 50 million tons of zinc, copper ore), fluorine enrichment extends approximately 320 m into the footwall rocks and at least 220 m into the hanging wall rocks. At the large United Verde deposit (> 50 million tons of copper, zinc ore), fluorine enrichment is recognizable in the footwall rocks at least 650 m from the ore. At the smaller Iron King deposit (five million tons production of zinc, lead, copper ore), fluorine enrichment extends for a distance of approximately 60 m into the footwall rocks. At the small deposits in New South Wales (< five million tons production of zinc, lead, copper ore), fluorine enrichment is easily recognizable, but with the samples collected, the limits of the anomalous patterns cannot be defined.Fluorine occurs in some hydrothermal systems unassociated with mineralization and is therefore not a specific signature of ore-forming processes. From the work completed, many massive sulfide deposits in volcanic rocks occur in hydrothermal systems which contain fluorine. On the basis of the data presented, if anomalously high fluorine values do exist in an exploration search area, the chances of finding a massive sulfide ore deposit are improved.Genetic models for volcanic-hosted massive sulfide ore deposits have concentrated on rock textures, alteration mineralogy, and geochemistry of the ore metals. From the data presented, fluorine should be considered as a component of massive sulfide systems in intermediate to felsic volcanic rocks, and should be considered as a possible complexing agent for the ore metals. 相似文献
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铜陵矿集区块状硫化物矿床地质特征 总被引：3，自引：0，他引：3
蚀变-流体填图揭示，铜陵地区石炭系黄龙组喷流沉积含矿岩系中普遍存在块状硫化物矿床，上部为层状块状硫化物矿层，下部为浸染状、细脉-网脉状硫化物矿体，具有典型的双层结构。自下而上矿石具有垂直分带性：硅质矿石、石膏矿石、黄铁矿矿石、黄铁矿-重晶石矿石和菱铁矿．铁质燧石矿石。矿石发育胶状和莓球结构，微细层纹状-马尾丝构造。矿石成分以黄铁矿和菱铁矿为主。矿床发育一套独特的热液气爆角砾岩不规则网脉和相互连通的虫管状．树枝状-姜块状黄铁矿管道系统，矿化形式为弥散式多喷口席状矿化，厚度一般不超过100m。 相似文献
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The Jiaodong Peninsula, the most productive gold province in China, is dominated by Jiaojia-type gold deposits that formed at ca. 120 Ma. The deposits are characterized by widespread alteration and mineralization resulted from fluid–rock reactions in the footwall of regional faults. It is known that the interrupted appearance of continuous mineralization zones and barren zones along regional faults is controlled by changes in the dip direction and dip angle of these faults, which can cause local dilational sense. In the continuous mineralization zone, intensive fluid–rock reactions occurred. Yet whether and how the fluid–rock reaction impacted on the mineralization intensity are not well constrained. In this study, we selected the Xinli Jiaojia-type gold deposit associated Sanshandao–Cangshang fault, located on the northwest margin of the Jiaodong Peninsula, to examine in detail the distribution of orebody parameters and to observe the mineralization occurrences. We applied the number–size fractal model and the lacunarity method to quantify the distribution of gold concentration along drifts, with the goal of clarifying the ambiguities noted above. The drifts in continuous mineralization zones can be divided into stable and unstable types, according to lateral changes in the dip direction and dip angle of the Sanshandao–Cangshang fault. Stable and unstable drifts share several common features. (1) Statistical results show that changes in the dip direction and dip angle of this fault bear almost no relationship to the thickness or grade–thickness of the orebody. (2) Mineralization along drifts is most intense at some distance from the fault plane rather than at locations immediately adjacent to the fault plane where fracturing is most extensive and, according to fluid infiltration theory, would be the most likely regions of intense mineralization. (3) Gold-bearing sulfide pods and veinlets in the alteration zone commonly possess irregular and corroded boundaries that are considered to be an indicator of fluid–rock reactions. (4) The threshold (the gold concentration that divides a segment with a lower fractal dimension in a lower concentration range from one with a higher fractal dimension in a higher concentration range) and the lacunarity (the parameter that evaluates the evenness of high gold concentration distribution) show positive and negative relationships, respectively, to the thickness and grade–thickness of a drift. We thereby argue on the basis of these features that fluid–rock reactions were an important factor responsible for the mineralization upgrade in continuous mineralization zones. An increase in the threshold and a decrease in the lacunarity indicate that fluid–rock reactions causing gold precipitation are more intensive and more evenly distributed throughout the footwall for better mineralization. These phenomena suggest that fluid–rock reactions responsible for the gold precipitation possibly own the characteristics of spatial self-organization mechanism, which is widely developed in various geological fluid–rock reaction processes. 相似文献
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The Ashele Deposit: A Recently Discovered Volcanogenic Massive Sulfide Cu-Zn Deposit in Xinjiang, China 总被引：1，自引：0，他引：1
Abstract: The Ashele Cu-Zn deposit is a recently discovered volcanogenic massive sulfide deposit in Xinjiang, Northwestern China. It is the largest Cu-Zn deposit in this type of deposits in China, which were formed in the early period of later Palaeozoic Era. This deposit is hosted within a suit of bimodal submarine volcanic rocks of the Ashele Formation of Lower-Middle Devonian System formed in an environment of paleocontinental margin rift setting. Lensoid orebodies occur between spilitic rocks developed at footwall and quartz-keratophyric tuff at hanging wall. Zonation of metal elements in the Ashele mine is one of typical volcanic-related exhalative Cu-Zn sulfide deposits in the world. Black ores enriched in Pb, Zn and Ag occurs on the top of the No. 1 orebody in the Ashele deposit, yellow ores enriched in Cu in the middle part, and the chalcopyritization stringer below the massive sulfide ores. Zonation of ore-structure in the No. 1 orebody is also apparent and corresponds to the zoning of elements, i. e. lamellar and/or banded sulfide-sulfate ores on the top, massive sulfide ores in the middle, and stockwork veinlets associated with altered breccia pipe on the bottom. Four epochs of mineralization in the Ashele deposit has been recognized. The first period of syngenetic-exhalative deposition of sulfides is the main epoch of mineralization, and the ores deposited subsequently subjected to thermo-metamorphism at the second epoch, superimposed by hydrothermal mineralization at the third epoch, and weathered or oxidized at the fourth epoch.
More than 100 categories of minerals have been recognized in the Ashele mine, but only pyrite, chalcopyrite, sphalerite, tetrahedrite, galena, barite, quartz, chlorite, sericite, and calcite are dominant, making up various types of ores, and alteration pipes or horizons. Studies of ore petrology suggest that the massive ores were volcanogenic and deposited by exhalative process. 相似文献
More than 100 categories of minerals have been recognized in the Ashele mine, but only pyrite, chalcopyrite, sphalerite, tetrahedrite, galena, barite, quartz, chlorite, sericite, and calcite are dominant, making up various types of ores, and alteration pipes or horizons. Studies of ore petrology suggest that the massive ores were volcanogenic and deposited by exhalative process. 相似文献
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Györgyi Tuba Ferenc Molnár Doreen E. Ames Attila Péntek David H. Watkinson Peter C. Jones 《Mineralium Deposita》2014,49(1):7-47
The Amy Lake PGE zone is a “low-sulfide-type” Cu-(Ni-)PGE mineralization in the East Range footwall of the 1.85 Ga Sudbury Igneous Complex occurring in a 100-m-wide Sudbury Breccia belt that coincides with an impact-related major fracture zone (Bay Fault zone). Detailed hydrothermal alteration mapping, fluid inclusion, trace element, and stable isotope studies revealed a complex alteration and mineralization history in a multi-source, multi-stage Sudbury-related hydrothermal system. The two major stages of syn-Sudbury hydrothermal activity are characterized by similarly high-salinity, high-temperature fluids that are (1) locally derived from footwall granophyre bodies, and typified with high Ni/Cu and PGE/S ratios and high REE contents (magmatic–hydrothermal stage), and (2) a more voluminous Cu–Ni–PGE-rich fluid flux probably originated from the Sudbury Igneous Complex/footwall contact (hydrothermal stage). The second hydrothermal flux was introduced by brittle fractures in the area and resulted in a complex zonation of alteration assemblages and mineralization governed by local footwall composition. The Sudbury-related hydrothermal event was overprinted by shear-related epidote veining and calcite–chlorite replacement, both regionally present in the Sudbury structure. Based on analogies, the most important factors involved in the formation of hydrothermal low-sulfide mineralization are proposed to be (1) accumulation of PGE-enriched fluids, (2) large-scale brittle structures as conduits to these fluids, and (3) adequate host rock composition as a chemical trap resulting in sulfide and PGM precipitation. In environments meeting these criteria, hydrothermal PGE mineralization is known to have formed not only in the Sudbury footwall but also from mafic–ultramafic intrusions associated with primary magmatic PGE from several locations around the world. 相似文献
20.
Electron paramagnetic resonance (EPR) spectroscopy of hot HNO3 insoluble residues of rock powders is used as a new exploration technique for the volcanic-hosted massive sulphide (VHMS) deposit in the Rosebery mine area. The EPR signal intensities measured in 326.5±5 mT sweeps are strong in the altered rocks, and show a negative correlation with Ca, Na and Sr, and a positive correlation with K/Na, Rb/Sr and (K × Rb)/(Ca × Na × Sr). The EPR intensities measured in 326.5±100 mT sweeps show high values in the footwall pyroclastics, host rocks and hanging wall pyroclastics near and around the Rosebery deposit, and correlate positively with K, Fe, Mn, Ba, F, Rb, Zn, Pb and Zr. The Rosebery deposit and associated footwall alteration zone are located at the intersection of two elongated paramagnetic halos. The first is characterized by strong intensities of [AlO4]° signals measured at magnetic flux density sweeps over 326.5±5 mT, trends NE–SW, and passes discordantly from the west to the east the White Spur Formation, altered footwall (footwall alteration zone), host rock of the Rosebery deposit, hanging wall and Mount Black Volcanics. The second, largely stratabound, halo is defined by strong intensities of Mn2+ sextets observed at magnetic flux density sweeps over 326.5±100 mT, runs N–S following the stratigraphic trend, and outlines the mineralized host rock and footwall alteration zone. It also extends toward the south into the unaltered footwall and hanging wall rocks. The first type of halo is considered to be related to wall rock alteration due to the VHMS mineralization processes as well to later Devonian metamorphism, and the second is thought to be related to massive sulphide mineralization alone. 相似文献