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1.
Estimating the undiscovered mineral resources of a terrane is a challenging, yet essential, task in mineral exploration. We apply Zipf’s law rank statistical analysis to estimate the undiscovered nickel sulphide resources in the Norseman-Wiluna Greenstone Belt, Western Australia. The analysis suggests that about 3.0 to 10.0 Mt of nickel sulphide resources are yet to be discovered in this belt, compared to the currently known total nickel sulphide endowment of 10.8 Mt. This undiscovered nickel sulphide endowment is likely to be hosted by incompletely delineated deposits and undiscovered deposits in less explored komatiites in the belt. Using the more detailed data subset of the Kambalda domain, this study manipulates Zipf’s law to estimate the sizes of undiscovered deposits, in addition to the domain’s total nickel sulphide endowment estimate. Importantly, regression analysis shows that the gradient of the line of best fit through the logarithmic rank-size plot for the detailed Kambalda data subset is −1. This gradient, which is the key Zipf’s law constant k, has the value of −0.92 for the Norseman-Wiluna Greenstone Belt which is collectively less mature than the Kambalda domain. This result corroborates the use of k = −1 in Zipf’s law predictive analyses of mineral resources for deposit populations for which the value of k = −1 has not yet been attained due to exploration immaturity.  相似文献   

2.
A.S. Yakubchuk   《Ore Geology Reviews》2009,35(3-4):447-454
The orogenic collages of the northern Circum-Pacific between Japan and Alaska revealed an endowment of about 450 Moz Au in various deposit types and diverse Mesozoic–Cenozoic tectonic settings. The area consists of predominantly late Paleozoic to Cenozoic turbidite to island arc terranes as well as Precambrian cratonic terranes that can be grouped into the Kolyma–Alaska, Kamchatka–Aleutian, and Nipponide collages. The latter can be linked via the Mongol–Okhotsk suture with the late Paleozoic to early Mesozoic terranes in the Mongolides.The early Yanshanian magmatic arc terranes in the fossil Kolyma–Alaska collage host copper–gold porphyry deposits, which have only recently received much attention. Exploration has revealed a large and growing gold endowment of more than 30 Moz Au in some individual deposits, with smaller role of epithermal deposits. This mineralization, formed at 140–125 Ma, is partly coeval with the collisions of magmatic arcs with the passive margin sequences of the Siberian craton and related granitoid magmatism. About 200 Moz of gold is known in the Kolyma–Alaska collage in the Mesozoic orogenic gold deposits and related Quaternary placers. The Central Kolyma, Indigirka, South Verkhoyansk, and North Chukotka subprovinces of the collage revealed an endowment of more than 10 Moz Au each. A similar and coeval event in the Mongolides in relation to the collision between Siberia and North China is largely reflected in still poorly dated intrusion-related gold deposits clustered along the Mongol–Okhotsk suture.The overlapping Yanshanian magmatic arcs in Transbaikalia and northeast China and the Okhotsk–Chukotka magmatic arc in the Russian Far East stitch the Kolyma–Alaska collage with the Paleozoic Central Asian supercollage and adjacent cratons. While the Okhotsk–Chukotka arc reveals a relatively simple and broad oroclinal pattern, the Yanshanian arcs in Mongolia, and NE China form a tightly deformed giant Z-shaped feature that was bent in response to the southward movement of the Siberian craton and northward translation of the Nipponides and North China craton to close the Mongol–Okhotsk suture in late Jurassic to Cretaceous times. The Yanshanian arcs host mostly small to medium-sized 100–70 Ma Au–Ag deposits, with the largest endowment discovered in the Baley district in Transbaikalia and at Kupol in the northern part of the Okhotsk–Chukotka arc. Some intrusion-related gold deposits were formed synchronously with this arc magmatism, with the largest known examples in the Tintina belt in Alaska formed at 104 and 93–91 Ma.The Kamchatka–Aleutian collage is still evolving in front of the westward-subducting Pacific plate. It's late Cretaceous to Paleogene magmatic arc rocks form immature island arc terranes, extending from the Aleutian islands towards the Nipponides via Kamchatka peninsula, Kuril islands and eastern Sakhalin. However, in the Nipponides, the Sikhote–Alin portion of the magmatic arc overlaps the Mesozoic turbidite terranes. The oroclinal pattern of this more than 8000 km-long magmatic arc indicates its westward translation in agreement with the movement of the Pacific plate so that the arc is presently colliding with itself along the island of Sakhalin, a seismically active intraplate lineament and a boundary between the Nipponide and Kamchatka–Aleutian collages. This magmatic arc is usually interpreted to be of intra-oceanic origin, with subsequent docking to Asia from the south; however, presence of the Sea of Okhotsk cratonic terrane between Sakhalin and Kamchatka suggests that it may be rather considered as an external arc system that separated from the rest of Asia due to backarc spreading events, therefore, forming the most external arc system at the active margin with the Pacific plate. The subduction-related events in the collage produced numerous late Mesozoic to Cenozoic 1–3 Moz gold epithermal deposit in Kamchatka and Sikhote–Alin as well as Au–Cu porphyry deposits, with currently largest gold endowment in the pre-Tertiary Pebble Copper deposit in Alaska. The westward translation of the Kamchatka–Aleutian collage might have controlled the emplacement of this porphyry deposit, as well as up to 30 Moz into intrusion-related gold deposits at 70–65 Ma in the Kuskokwim belt, immediately north from the porphyry cluster.  相似文献   

3.
玻利维亚的铜矿规模以中小型为主,主要成矿类型为红层型(砂岩层)、沉积相关脉状型、VMS型和IOCG型等。金矿规模以中小型为主,主要成矿类型有火山成因浅成热液型、与深成岩相关的脉状矿床、造山型矿床和砂金矿。锡矿发育众多大型、超大型矿床,成矿类型以玻利维亚型多金属脉状矿床和与长英质深成岩相关的脉状矿床为主,少量砂锡矿。铁矿以El Mutún超大型BIF型铁锰矿著称。西科迪勒拉和玻利维亚高原有重要的浅成低温热液贵金属资源潜力;东科迪勒拉北部主要为钨、锡、金、锑资源,中部为锡、银、金、锑资源,南部有金、锑、银、铅、锌潜力;次安第斯带南部有银-锌资源潜力;查科-贝尼平原带有广泛的砂金矿资源;前寒武纪克拉通内金、铂、镍、钽、铜和铁锰资源潜力丰富。  相似文献   

4.
A probabilistic mineral resource assessment of metal resources in undiscovered porphyry copper deposits of the Ural Mountains in Russia and Kazakhstan was done using a quantitative form of mineral resource assessment. Permissive tracts were delineated on the basis of mapped and inferred subsurface distributions of igneous rocks assigned to tectonic zones that include magmatic arcs where the occurrence of porphyry copper deposits within 1 km of the Earth's surface are possible. These permissive tracts outline four north-south trending volcano-plutonic belts in major structural zones of the Urals. From west to east, these include permissive lithologies for porphyry copper deposits associated with Paleozoic subduction-related island-arc complexes preserved in the Tagil and Magnitogorsk arcs, Paleozoic island-arc fragments and associated tonalite-granodiorite intrusions in the East Uralian zone, and Carboniferous continental-margin arcs developed on the Kazakh craton in the Transuralian zone. The tracts range from about 50,000 to 130,000 km2 in area. The Urals host 8 known porphyry copper deposits with total identified resources of about 6.4 million metric tons of copper, at least 20 additional porphyry copper prospect areas, and numerous copper-bearing skarns and copper occurrences.Probabilistic estimates predict a mean of 22 undiscovered porphyry copper deposits within the four permissive tracts delineated in the Urals. Combining estimates with established grade and tonnage models predicts a mean of 82 million metric tons of undiscovered copper. Application of an economic filter suggests that about half of that amount could be economically recoverable based on assumed depth distributions, availability of infrastructure, recovery rates, current metals prices, and investment environment.  相似文献   

5.
The use of mineral deposit density regression models to estimate the number of undiscovered deposits is gaining acceptance in mineral resources assessments. The deposit density regression models currently in use are based on well-established power law relationships between deposit density (deposits/km2) and the areal extent of the host rocks in well explored regions (control areas) worldwide. Although these generalized or global deposit density models can generate guideline estimates that are useful at the terrane scale, locally-derived terrane-based deposit density regression models may potentially yield more relevant estimates at the terrane scale. Using 12 selected komatiite-defined control areas in the Kalgoorlie Terrane, Western Australia, we found that the size (km2) of the control areas had power law relationships with (i) nickel sulphide deposit density, and (ii) nickel endowment density (nickel metal/km2). Regression analyses showed that both power law relationships are statistically significant at the 5% level. This suggests that nickel sulphide deposit and endowment density models could be used to estimate the number of undiscovered nickel sulphide deposits and amount of nickel metal endowment in less explored komatiites in the Kalgoorlie Terrane. This study shows that global geological relationships can be viably downscaled onto local geological terranes thereby supporting the hypothesis that the processes of mineral deposit formation and preservation are scale-independent and self-similar.  相似文献   

6.
Concerns about future supplies of raw materials demand careful examination of underlying assumptions and data. Flawed deposit information, ignored undiscovered resources and questionable assumptions about future consumption require a new look at copper resources.A careful compilation of 1978 copper-bearing mineral deposits totals 2700 million metric tons of copper including past production—considerably more than reported in previous studies. About 69% of the copper is in porphyry copper deposits and 12% in sediment-hosted copper, Magmatic sulfide (mostly intrusive Ni) deposits account for 5.1%, and IOGC adds about 4.7%. VMS deposits represent 45% of the 1978 deposits but only 4.9% of the copper.The largest 20% of the deposits account for over 92% of the total copper metal. In other words, total Cu content in the smaller 1600 deposits is only about 8% of all Cu known in all deposits. This is a consequence of highly skewed frequency distributions of deposit tonnages and contained metals in all kinds of mineral deposits. This relationship is critical if one is concerned about long-term supply of copper. Typically, distributions of contained metal can be modeled well by the lognormal distribution for individual types of deposits.Information used here and in many other studies on copper includes past production. Total past production through 2015 is about 667 million tons Cu. After subtracting past production from the total copper in known deposits, the remaining unproduced copper from known deposits is 2030 million tons. Known deposits inform us about undiscovered copper resources.Over 80% of known copper is in porphyry copper and sediment-hosted copper deposits. A reliable and robust USGS managed global assessment of 225 tracts for porphyry Cu and sediment-hosted Cu produced an expected value estimate of 3500 million tons Cu in undiscovered deposits. Deposit types not assessed such as IOGC are likely to have significant amounts of undiscovered copper. If the proportion of total Cu accounted for by the two major deposit types assessed is the same proportion in all undiscovered deposits, total Cu expected in these other deposit types would add an additional 850 million tons. The reasonable estimate of copper in undiscovered mineral deposits of 4350 million tons when added to the unmined 2030 million tons in known deposits provides an estimate of 6380 million of tons Cu, which far exceeds estimates published by other researchers.Growth in copper production appears to be exponential over time but appears to be linear with respect to population. Demand for copper is not driven by time, but rather by population and per capita income. Rates of population increases are slowing and incomes in many countries are increasing. Per capita consumption of copper will increase over the coming years as populous nations such as China and India develop increasing per capita incomes, but the demand will likely level off as their economies improve. The large estimated copper resources along with evidence of slowing demand for copper over the long term considerably extend the time of “peak copper” and the long mine life of large deposits means the decline in production after will not be rapid. The focus of copper supply concerns should be on important problems such as improving recovery rates, careful consideration of the benefits and costs of mining very large deposits, technologies to increase exploration success in covered areas and reducing costs of underground mining.  相似文献   

7.
Mineral Deposit Densities for Estimating Mineral Resources   总被引:1,自引:0,他引:1  
Estimates of numbers of mineral deposits are fundamental to assessing undiscovered mineral resources. Just as frequencies of grades and tonnages of well-explored deposits can be used to represent the grades and tonnages of undiscovered deposits, the density of deposits (deposits/area) in well-explored control areas can serve to represent the number of deposits. Empirical evidence presented here indicates that the processes affecting the number and quantity of resources in geological settings are very general across many types of mineral deposits. For podiform chromite, porphyry copper, and volcanogenic massive sulfide deposit types, the size of tract that geologically could contain the deposits is an excellent predictor of the total number of deposits. The number of mineral deposits is also proportional to the type’s size. The total amount of mineralized rock is also proportional to size of the permissive area and the median deposit type’s size. Regressions using these variables provide a means to estimate the density of deposits and the total amount of mineralization. These powerful estimators are based on analysis of ten different types of mineral deposits (Climax Mo, Cuban Mn, Cyprus massive sulfide, Franciscan Mn, kuroko massive sulfide, low-sulfide quartz-Au vein, placer Au, podiform Cr, porphyry Cu, and W vein) from 108 permissive control tracts around the world therefore generalizing across deposit types. Despite the diverse and complex geological settings of deposit types studied here, the relationships observed indicate universal controls on the accumulation and preservation of mineral resources that operate across all scales. The strength of the relationships (R 2=0.91 for density and 0.95 for mineralized rock) argues for their broad use. Deposit densities can now be used to provide a guideline for expert judgment or used directly for estimating the number of most kinds of mineral deposits.  相似文献   

8.
《Ore Geology Reviews》2010,37(4):282-292
Accretionary orogens throughout space and time represent extremely fertile settings for the formation and preservation of a wide variety of mineral deposit types. These range from those within active magmatic arcs, either in continental margin or intra-oceanic settings, to those that develop in a variety of arc-flanking environments, such as fore-arcs and back-arcs during deformation and exhumation of the continental margin. Deposit types also include those that form in more distal, far back-arc and foreland basin settings. The metallogenic signature and endowment of individual accretionary orogens are, at a fundamental level, controlled by the nature, composition and age of the sub-continental lithosphere, and a complex interplay between formational processes and preservational forces in an evolving Earth. Some deposit types, such as orogenic gold and volcanic massive sulfide (VMS) deposits, have temporal patterns that mimic the major accretionary and crustal growth events in Earth history, whereas others, such as porphyry Cu–Au–Mo and epithermal Au–Ag deposits, have largely preservational patterns. The presence at c. 3.4 Ga of (rare) orogenic gold deposits, whose formation necessitates some form of subduction–accretion, provides strong evidence that accretionary processes operated then at the margins of continental nuclei, while the widespread distribution of orogenic gold and VMS deposits at c. 2.7–2.6 Ga reflects the global distribution of accretionary orogens by this time.  相似文献   

9.
据有关资料统计,我国伴生金占金保有储量的43.39%.加强伴生金的找矿研究和开发利用不仅能迅速增长金的储量和产量,而且也是提高矿产品经济价值和矿山经济效益的有效途径.我国伴生金矿金矿类型主要有:岩浆型硫化物铜镍矿床、斑岩铜铜矿床、夕卡岩型矿床、火山岩型矿床和热液型矿床.伴生金矿床资源潜力巨大.因此对伴生金矿床特征的研究及找寻是迫在眉睫的地质工作.  相似文献   

10.
After a century of virtual neglect, exploration in the Yandal greenstone belt of the Yilgarn Craton of Western Australia has yielded resources of 12 Moz Au during the 1990s. Success has come from a combination of conceptual geological models, surface prospecting, understanding the weathering environment, and systematic drilling. The Archaean Yandal greenstone belt comprises a lowermost banded iron formation, extensive basalt and dolerite sills, ultramafic rocks, intermediate to felsic volcanic rocks, and variable clastic sedimentary rocks. Early shear zones trend NNW and form the greenstone belt margins, or trend N–S within the belt. Later brittle cross-faults are critical in gold localization. Gold resources and past production at major deposits include Bronzewing (4 Moz Au), Jundee (5 Moz) Mt.␣McClure (1 Moz) and Darlot (3␣Moz, some of which was produced before 1990). All major deposits are hosted by Fe-rich mafic rocks, and mineralization displays a combination of different orientations and morphologies. Quartz veins are surrounded by broad carbonate alteration with proximal K-mica and Fe-sulphides. The recognition of a critical role for the late brittle structures in localizing gold implicates mid-crustal processes within the greenstone belt for fluid generation, and with the host rock control, supports the model in which fluid was derived by metamorphic devolatilization. Received: 19 September 1997 / Accepted: 7 January 1998  相似文献   

11.
新疆伊吾琼河坝地区铜、金矿成矿时代及其找矿前景   总被引:14,自引:1,他引:13  
文章采用高分辨率、高灵敏度离子探针(SHRIMP)和Rb-Sr等时线定年技术,对新疆伊吾琼河坝地区的云英山斑岩铜矿和淖毛湖北山金矿床的岩体和矿体进行了年代学研究,获得云英山斑岩铜矿区内斜长花岗斑岩体SHRIMP锆石U-Pb年龄为(411.7±7.1)Ma(95%置信度,MSWD=3.0),该矿床的含矿石英脉石英矿物Rb-Sr等时线年龄为(357±15)Ma(95%置信度,MSWD=0.16);淖毛湖北山金矿含矿石英脉中石英矿物Rb-Sr等时线年龄为(346±10)Ma(95%置信度,MSWD=0.19).测定结果显示,该区斑岩型铜矿和破碎带蚀变岩型金矿的形成时间为晚泥盆世-早石炭世,表明云英山式斑岩型铜金矿和淖毛湖式金矿成矿作用与泥盆纪-石炭纪汇聚阶段的火山-次火山岩浆活动有关,也意味着在琼河坝地区具有寻找与火山作用有关的铜、金多金属矿的潜力.  相似文献   

12.
For national or global resource estimation of frequencies of metals a lognormal distribution has sometimes been assumed but never adequately tested. Tests of frequencies of Cu, Zn, Pb, Ag, Au, Mo, Re, Ni, Co, Nb2O3, REE2O3, Cr2O3, Pt, Pd, Ir, Rh, and Ru, contents in over 3000 well-explored mineral deposits display a poor fit to the lognormal distribution. Neither a lognormal distribution nor a power law is an adequate model of the metal contents across all deposits. When these metals are grouped into 28 geologically defined deposit types, only nine of the over 100 tests fail to be fit by the lognormal distribution, and most of those failures are in two deposit types suggesting problems with those types. Significant deviations from lognormal distributions of most metals when ignoring deposit types demonstrate that there is not a global lognormal or power law equation for these metals. Mean and standard deviation estimates of each metal within deposit types provide a basis for modeling undiscovered resources. When tracts of land permissive for specific deposit types are delineated, deposit density estimates and contained metal statistics can be used in Monte Carlo simulations to estimate total amounts of undiscovered metals with associated explicit uncertainties as demonstrated for undiscovered porphyry copper deposits in the Tibetan Plateau of China.  相似文献   

13.
A review of previous studies of the world's large hydrothermal gold deposits indicates that the largest deposits tend to show complicated parageneses where multiple gold enrichment events and processes have been involved in the deposit generation. These observations suggest that multistage processes may even be a requirement for the formation of large deposits. In some deposits (e.g. Witwatersrand, Boddington Cadia, Sukhoi Log or Carlin) the different enrichment processes occur millions of years apart. In others, such as many large porphyry deposits, the different stages are much closer in time. In many deposits, particularly sedimentary-hosted deposits, early diffuse enrichment occurs within a particular province that is then upgraded by more focused processes (e.g., Sukhoi Log; Kalgoorlie). The presence of this early diffuse enrichment could explain the tendency for gold deposits to cluster into camps.This model has important implications, as the presence or absence of multiple gold events could be used to discriminate, at the exploration and feasibility stages, between small deposits with single stage ore genesis and more complicated deposits with multistage enrichment and the potential for larger gold endowment.  相似文献   

14.
Mineralization distributions are very heterogeneous in nature. As large or superlarge mineral deposits are quite rare whether in time or in space, it is difficult to detect all the largest mineral deposits in a region in a limited period of time owing to the restriction of technology and exploration degrees-this is called "not all discovered". However, all discovered large, especially superlarge, mineral deposits generally have a complete census in the geological literatures. On the other hand, not all discovered small mineral deposits are recorded in the geological literatures because for economic reasons people have not much interest in them-this is called "not all recorded". This practice often results in the observation truncations, that is, the data points near the two ends in an observable population, which is obtained by fitting a power law size-frequency distribution to discovered mineral deposits in a given region, show concave-down departure from the correlation line fitted. The authors sugges  相似文献   

15.
斑岩型金矿分类探讨   总被引:4,自引:0,他引:4  
斑岩型金矿是重要的金矿类型,为我国金矿第三重要类型,但对其在认识远不如其它金矿 。通过研究,提出斑岩型金矿可分为三类:伴生/共生一斑岩型金矿、角砾/网脉-斑岩型金矿和单脉/网脉-斑岩型金矿。  相似文献   

16.
The Laowan metallogenic belt in China is an important metallogenic belt within the Tongbai orogenic belt, and contains the medium-sized Laowan and Shangshanghe gold deposits, the small Huangzhuyuan lead–zinc–silver–gold deposit and some gold and Cu–Pb occurrences. These deposits are hosted in Mesoproterozoic plagioclase amphibolite (or schist) and mica-quartz schist. The gold ores are mainly quartz veins and veinlets and disseminated altered ores. Subordinate ore types include massive sulfides and breccias. The Laowan gold deposit is characterized by three right-stepping en-echelon fracture-controlled alteration zones that dip gently to the south and includes disseminated, sheeted and stockwork ores. These lodes were formed by the interaction of ore-forming fluid with foliated-to laminated cataclasite within the transpressional faults. The Shangshanghe gold deposit is characterized by parallel ore lodes that dip steeply to the north, and includes quartz veins and breccias in addition to ores in altered wallrocks. These lodes were formed by focusing of fluids into transtensional faults. These ore controlling faults displaced early barren quartz veins 10 m horizontally with a dextral sense of motion. The ore-hosting structures at the Laowan and Shangshanghe deposits correspond to the P and R-type shears of a brittle dextral strike-slip fault system, respectively, which make angles of about 15° and − 15° to the Laowan and Songpa boundary faults. The ore-controlling fault system post-dated formation of a ductile shear zone, and peak regional metamorphism. This precludes a genetic relationship between hydrothermal mineralization and regional metamorphism and ductile shear deformation. These gold deposits are not typical orogenic gold deposits. The metallogenic belt displays district-scale-zoning of Mo  Cu–Pb–Zn–Ag  Au relative to Songpa granite porphyry dike zone, suggesting the mineralization may be closely related to the granite porphyry. Measured δ34S of sulfides and δ18O and δD of fluid inclusion waters in auriferous quartz also are consistent with a magmatic source for sulfur and ore fluids. The similarity of Pb isotope ratios between the ores and Yanshanian granitoids suggests a similar source. As the age (139 ± 3 Ma) of granite porphyry obtained by zircon U–Pb isotope overlaps the mineralization age (138 ± 1 Ma: Zhang et al., 2008a), the gold and polymetallic metallogenesis of the Laowan gold belt has close spatial, temporal and possibly genetic relationships with Yanshanian high level magmatism.  相似文献   

17.
研究目的】金矿是华北地区的优势矿种之一,资源丰富、类型多样。开展华北地区金矿资源特征与成矿规律研究,对于进一步开展金矿勘查工作部署具有重要意义。【研究方法】本文系统收集和整理了已有金矿地质资料,全面总结了华北地区金矿资源禀赋、矿床类型、时空分布规律、控矿因素、成矿演化及资源潜力。【研究结果】从矿床成因角度,华北地区金矿类型可划分为花岗-绿岩型、火山岩型、岩浆热液型、变质碎屑岩中热液型、砂金型和风化壳型等6大类;从矿产预测角度,可划分为44个矿产预测类型,其中与岩浆岩、火山岩、绿岩建造有关金矿类型最为重要。根据金矿演化规律,将华北地区金成矿划分为五台—吕梁期、华力西期、印支期、燕山期、喜马拉雅期等5个主成矿期,其中燕山期为金矿爆发期。金矿主要产出于华北克拉通边缘、裂谷带及造山带内,形成于大陆裂谷、岛弧(火山弧)、活动大陆边缘等构造环境。【结论】本文在华北地区划分出47处金矿重要找矿远景区,并提出加强重要找矿远景区及矿集区深部金矿资源勘查是实现找矿突破的重要途径。创新点:全面系统地梳理、总结了华北地区金矿资源特征、矿床类型、时空分布规律及资源潜力,划分了47处金矿重要找矿远景区。  相似文献   

18.
斑岩型金矿是云南重要的金矿类型。将与富碱斑岩有关的金矿床从斑岩类型角度划分为四种类型:与二长斑岩有关的构造破碎带蚀变岩型金矿床;与正长斑岩有关的岩体接触构造带脉状金矿床;与正长(粗面)斑岩有关的构造破碎带型金矿床;与花岗斑岩有关的石英-多金属硫化物金矿床。同时从不同类型斑岩、成矿构造和地球化学条件等多角度阐述了斑岩型金矿床形成的条件,认为本区斑岩型金矿床具有多类型、多成因与成矿作用多期次的特点。  相似文献   

19.
中亚成矿域中的斑岩型铜(钼金)矿,有别于滨太平洋区的斑岩铜矿,它们大部分是形成于大洋消亡之后,与A型俯冲或后碰撞阶段的构造岩浆作用有关,并非都形成于岛弧发展阶段,且常与浅成低温热液型金矿(产于陆相-亚陆相火山岩内)时间相随、空间相伴,两者属于一个统一的岩浆系统;浅部是浅成低温热液型金矿,深部是高温斑岩型铜(钼金)矿,其成矿特点表现出两者元素组合连续、过渡与转化,两者类型相随相伴。  相似文献   

20.
斑岩体的存在是斑岩型铜矿重要的特征,查明隐伏斑岩体对于斑岩铜矿找矿预测有着重要的意义。文章以多宝山矿集区的岩石标本物性特征为基础,对重力、磁法、广域电磁法资料进行了处理和分析,根据矿化蚀变中心一般位于斑岩体顶部和矿化蚀变具有电阻率显著降低的特征,从已知到未知,对多宝山铜矿、铜山铜矿和争光金矿的隐伏花岗闪长斑岩体进行了识别,进而推断出矿体位置。根据电性异常特征推测:多宝山铜矿可以扩大外围找矿部署,铜山铜矿矿体有往下延伸的趋势,隐伏斑岩体南侧可能存在大型矿体;争光金矿深部可能存在斑岩型铜矿。多宝山铜矿、铜山铜矿、争光金矿同属斑岩型铜矿系统,多宝山矿集区具“上金下铜”的成矿特征。钻孔揭示了铜山矿区隐伏斑岩体南侧矿体的存在,新增资源量达到大型矿床规模。证实了方法的有效性,同时也显示出矿集区矿产资源潜力巨大。  相似文献   

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