Surface lithogeochemical studies about a distal volcanogenic massive sulphide occurrence at Limerick,New South Wales

The results of a surface rock chip sampling study over a small distal volcanogenic massive sulphide deposit at Limerick, N.S.W., Australia are presented and compared with drill core and soil geochemical patterns. Major element halos are narrow in comparison to the pervasive patterns reported from major proximal deposits. Narrow zones of Mg and K enhancement are associated with sulphide mineralization. High levels of Na occur in these rocks in contrast to the regularly described pattern of Na depletion. Weathering, particularly in the presence of sulphides, has resulted in the leaching of Ca, Na and, to a lesser extent, K from surface rock chip samples, whereas Fe, Pb and Zn contents are enhanced compared to those in fresh rocks. Despite the problems of sample heterogeneity, variable weathering and the limited extent of alteration halos which exist in this environment, surface lithogeochemical methods in comparable situations may be useful in the confirmation and interpretation of soil geochemical anomalies.     

Exploration rock geochemistry — detection of trace element halos at heath steele mines (N.B., Canada) by discriminant analysis

The Heath Steele massive sulphide deposit in northern New Brunswick lies conformably within a sedimentary-volcanic sequence of probable Ordovician age which has been metamorphosed to the greenschist stage. The dominant sulphide mineral is pyrite, and the main economic minerals are sphalerite, galena, and chalcopyrite; the general grade of the ore is 5% Zn, 2% Pb, and 1% Cu.The distribution of Pb and Zn in acid volcanic rocks stratigraphically above the massive sulphides is compared with the distribution in similar rocks stratigraphically below the sulphides. Whereas there are discernable differences in the populations, there is also considerable overlap between them. To enable individual samples to be classified, linear discriminant functions were calculated for the two groups; Pb and Zn were found to be the most useful variables to separate the two populations. The functions were then tested on hanging wall and footwall samples not used in computing the functions. A halo region, extending about 1,200 ft above the sulphides and 4,000 ft along the same stratigraphic horizon as the sulphides was outlined by samples classified as “hanging wall”. Beyond the halo zone there is no significant difference in the distribution of Pb and Zn between the hanging wall and footwall acid volcanic rocks.The results demonstrate that rocks at Heath Steele, which show no evidence of mineralogical alteration attributable to mineralization, have a trace element halo of considerable extent spatially associated with the sulphides. If similar halos can be shown to be a general feature of massive sulphide deposits, the technique described should have wide application for exploration for deeply buried deposits of this type.     

Electron paramagnetic resonance (EPR) spectroscopy in massive sulphide exploration, Rosebery mine area, western Tasmania, Australia

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.     

The application of stepwise discriminant analysis to geochemical data from the host rocks of the Sullivan Pb-Zn-Ag deposit, Kimberley, B.C., Canada

The Sullivan Pb-Zn-Ag massive sulphide deposit in southeastern British Columbia occurs within middle Proterozoic argillite, siltstone and quartz wacke of the Purcell Group. Rock samples were collected from the hangingwall and footwall of the eastern section of the mine and from outcrop up to 50 km from the Sullivan deposit. The samples were analyzed for Cu, Pb, Zn, S, Mn, Ba, Fe, K, Ca, Na and specific conductance. A stepwise discriminant analysis applied to the analytical data determined the group of variables that differentiate between hangingwall, footwall and outcrop or “Background” samples. Hangingwall and footwall rock samples were most effectively discriminated from “background” rock samples on the basis of specific conductance with Cu, Pb, S, Na, and Ba selected as less efficient discriminators. The variables that discriminate hangingwall from footwall rock samples are Cu, Zn and S. The selection of the discriminating variables in each case can be explained in terms of the chemical changes that occur as a result of host rock alteration and sulphide deposition during the mineralizing event at the Sullivan deposit.Stepwise discriminant analysis was used to reduce a number of potential pathfinder variables to an optimum group of pathfinder variables. These optimum pathfinders represent the variables that most effectively differentiate the host rocks of the Sullivan deposit from rocks outside of the mineralized zone that apparently do not contain massive sulphide mineralization.     

云南鲁春VMS 锌铅铜多金属矿床的成矿金属来源

鲁春VMS 锌铅铜多金属矿床产于金沙江构造带内鲁春-红坡牛场伸展裂谷盆地中,是三江地区典型的火山成因块状硫化物矿床,其含矿层位为双峰式火山岩系中的流纹质火山--沉积岩系。通过研究该矿床的主成矿元素、双峰式火山岩和矿石的稀土元素特征,对其成矿金属来源、赋矿火山岩及构造环境进行研究表明,鲁春多金属矿床属Zn --Pb --Cu 型火山成因块状硫化物矿床,形成于碰撞造山后在薄陆壳( 陆缘弧) 基底上伸展而成的裂谷盆地环境; 矿石的主成矿元素含量特征w ( Zn) /w ( Pb + Zn) 均值为0. 64,与日本黑矿和四川呷村矿床较为接近; ΣREE 为( 15. 99 ～ 144. 43) × 10 － 6,平均73. 99 × 10 － 6,LREE/ HREE 为3. 59 ～ 11. 40,平均6. 30,呈典型的LREE 富集型; δEu 为0. 13 ～ 0. 46,平均0. 28,Eu 负异常明显,与矿区流纹岩极为相似。矿体与流纹岩空间上的密切关系以及地球化学特征的一致性表明,成矿金属元素源自下伏的长英质岩系。     

The mineralogy and chemical composition of the Woodlawn massive sulphide orebody

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.     

The Wilga base-precious metals deposit, Benambra, Victoria, Australia

Wilga is one of several Au-bearing volcanogenic massive sulphide deposits localized within Silurian felsic volcanics of the Lachlan Fold Belt of NE Victoria. Exploration has delineated a resource of 3.7 Mt averaging 3.4% Cu, 5.5% Zn, 0.4% Pb, 31 g/t Ag and 0.5 g/t Au within a lensoid-shaped sulphide body which strikes NE, dips NW and occurs at a depth of 50–160 m below surface. This body has maximum dimensions of 470 m strike, 350 m down-dip and 37 m true width delineated by 59 surface diamond drill holes and an exploration adit with 40 underground diamond drill holes. There are two main types of mineralization: Stratiform massive sulphides , (mainly pyrite, low-Fe sphalerite, variable chalcopyrite and minor galena with very minor silica/dolomite gangue) and Stratiform chloritic sulphides (mainly chalcopyrite, with subordinate pyrite and sphalerite, in a gangue of chlorite and minor dolomite). The deposit is layered with at least 6 distinct stratigraphic horizons/cycles of mineralization each characterized by a Cu-rich base and Pb-(Zn)-Au-As-rich top. Facies variations are locally rapid. Economically the deposit consists of 3 sub-lenses of roughly equal tonnage: a Cu-rich central lens of Chloritic Sulphides (av. 5.9% Cu, 3.6% Zn, 0.3% Pb, 32 g/t Ag and 0.2 g/t Au) between upper and lower lenses of Zn-rich Massive Sulphides (av. 1.8% Cu, 6.7% Zn, 0.5% Pb, 31 g/t Ag and 0.7 g/t Au). Gold mineralization, locally up to 7 g/t over 6 m, shows a strong spatial association with Pb, (Zn) and As in pyritic massive sulphides.     

论华南喷流—沉积块状硫化物矿床

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。     

A new indicator of glacial dispersal: Lead isotopes

Lead isotope ratios from glacigenic sediments have been successfully used as glacial indicators to define dispersal patterns in mineralized areas of the Canadian Shield and the Appalachian Orogen. Sediments adjacent to and down ice from volcanogenic massive sulphide (VMS) deposits have Pb isotope ratios that reflect an input of Pb from the deposits. These ratios are distinctly different from those of the surrounding country rocks. Vertical sections overlying one of the deposits show that the Pb isotope signature is preserved in much of the succession, although incursions of Pb from other sources are also identified by Pb isotope ratios that are much higher than those of the deposit. Sections away from known deposits have isotopic ratios characteristic of the country rocks.Pb from some VMS deposits can form an ideal glacial indicator. The reasons for this are: (i) the deposits can be considered point sources; (ii) the Pb in old VMS deposits is isotopically different from the country rocks; (iii) the Pb abundance in the deposits is significantly enriched relative to average crustal abundances; (iv) the Pb isotope ratios are independent of the Pb concentration in samples containing low to moderate amounts of Pb; (v) isotope ratio measurements can be made on small quantities of material; and (vi) the isotope ratios of till enriched in VMS-derived Pb are not measurably affected by weathering.     

岩浆溶离型Cu—Ni硫化物矿床元素组合和地球化学评价指标

铜镍矿床的地球化学勘查评价实质上是基性－超基性岩体含矿性的评价。岩浆铜镍硫化物矿床与基性、超基性岩体具有空间和成因联系，其主要成晕微量元素以Cu、Ni、Co、Cr、Ag为主，而且含矿岩体的这些元素的平均值高、离差大。矿床区域地球化学异常发育，异常的分布受基性－超基性岩岩群和岩带制约，异常浓集中心与矿田的岩矿体一致。矿区异常继承了区域异常的组分，异常的高值区与矿床对应。矿床的原生晕具有组分分带，前缘元素是I、F、B、Ba、As、Mo；近矿元素是Ag、Cr；矿元素是Cu、Ni、Co。利用原生晕的组分分带特征可判断矿体的剥蚀程度和预测隐伏的岩矿体。     

Origin of the Cretaceous ore-bearing granitoids in the Beihuaiyang Zone,northern margin of the Dabie Orogen,Eastern China

ABSTRACT

The Beihuaiyang Zone (BHY) is one of the most important Mo–Pb–Zn polymetallic metallogenic belts in China, and the BHY deposits are genetically and geographically associated with Cretaceous magmatic rocks. In this article, we present new zircon U–Pb ages and Hf isotope data, whole-rock major and trace-element analytical results, and Sr–Nd–Pb isotope data for the granite porphyry of the Shapinggou (SPG) Mo deposit and the quartz monzonite porphyry of the Gongdongchong (GDC) Pb–Zn deposit. The high contents of SiO₂, crust-like rare-earth-element and trace element patterns, and the enriched Sr–Nd–Pb–Hf isotopic compositions indicate that both porphyries originated from crustal melting. Inherited Neoproterozoic zircons are common in both porphyries, which implies that their crustal sources were the South China Block rather than the North China Block. Whole-rock ε_Nd(t) values (?10.8 to ?9.8 for the GDC deposit, ?12.9 to ?12.4 for the SPG deposit) and zircon ε_Hf(t) values (?14.3 to ?11.1 for the GDC deposit, ?18.4 to ?13.3 for the SPG deposit) for the ore-bearing rocks are significantly higher than the values found in the widespread and older ore-barren rocks, indicating that the magma sources of the ore-bearing rocks were younger than those of the ore-barren rocks. An integrated study of the Sr–Nd–Pb–Hf isotope contents shows that these younger source rocks are similar to the gneisses found in the South and Central Dabie units, which represent the upper crust of the subducted South China Block. Given the geochemical behaviour of molybdenum, a surface enrichment process would have been an essential prerequisite for the formation of the large Mo deposit. The early Paleozoic Mo–Pb–Zn-enriched black shales, which are widespread in the upper layers of the South China Block, might have been scraped off during Triassic subduction and then transported to deep-crustal levels below the BHY, thus forming an ideal source for the ore-bearing porphyries. An upper-crustal origin for the ore-bearing magmatic rocks is also consistent with the data for most other deposits distributed in the BHY of the Dabie Orogen.     

Cyclic ore formation of some volcanogenic massive sulfide deposits in the skellefte district,Sweden

The Näsliden and Rävliden deposits in the Skellefte field consist of stratiform massive sulfide ores associated with submarine volcanic and clastic rocks. The ores are pretectonic. Consequently, the orebodies are considered to have formed syngenetically with deposition of the host rocks. Banding and interlayering with host sediments are common features. Cu : Zn and Zn : Pb ratios of the ores show stratigraphically and laterally defined trends. Cu : Pb : Zn ratios correspond with those found in other deposits of volcanogenic origin. Nonstratiform breccia Cu mineralizations occur directly under the massive stratiform ores in the footwall rocks where hydrothermal alteration is strongest. Ore formation took place intermittently resulting in clusters of ore systems occurring at slightly different stratigraphical levels within each deposit.     

河南省嵩县萑香洼金矿矿床地球化学特征

莅香洼金矿发育有与金矿关系密切的地球化学异常,Au及相关元素的平均含量从安山岩→蚀变安山岩→蚀变岩→矿化蚀变岩呈几何级数递增。沿F985构造蚀变带走向,Pb、Ag与Au的组合异常通常与金的矿体晕分布一致,而As、Sb组合则更多反映了矿体前缘晕的组合特点,沿倾向,Au及相关元素自浅而深具有分段富集特征,并在1023m标高和976m标高构成二个浓集中心。其理想的元素轴向分带序列为：前缘晕As、Sb—Ba,矿体晕Au、Ag、Pb、Zn、Cu、Mo,矿尾晕（Cu、Mo）-（Co、Ni、Bi）。文章在前人研究的基础上,系统总结了莅香洼金矿床的地球化学特征,总结了构造蚀变岩型金矿床的地球化学找矿标志,建立了萑香洼金矿床的地球化学找矿模型。     

Regional reconnaissance exploration rock geochemistry for massive sulphides, New Brunswick, Canada

In the Bathurst District of New Brunswick there are more than 50 known occurrences of base metal sulphide mineralization within an area of Palaeozoic volcanic-sedimentary rocks approximately bounded by the Rocky Turn deposit in the north, the Key Anacon deposit in the east, the Heath Steele deposit in the south, and the Devil's Elbow deposit in the west. Only four of these occurrences are, or have been, producing mines; 19 are classed as “major occurrences”. The area is highly prospective for massive sulphide deposits of the Brunswick Mining and Smelting and Heath Steele type; it would obviously be of considerable importance to define the zones within the sequence where major occurrences should be sought.To determine whether exploration rock geochemistry could be used on a regional reconnaissance scale, 419 samples of rhyolite from an area of 2000 km² (at an average density of one sample per 5 km²) were analyzed for total content of Cu, Pb, Zn, Ca, Mg, K, Na, Fe, and Mn. The data were processed by calculating the geometric mean of all samples in cells of approximately 10 km². Contrary to the relations documented on a mine scale (within one kilometre of major deposits), where the clearest halos are given by major elements, it is the ore elements that give the best regional patterns.The producing mines and the most important of the known occurrences all lie in zones where rhyolite contains less than 10 ppm Cu. Element ratios considerably enhance anomalous relations. The Zn:Pb ratio of the sulphides in the main deposits is 2.4–2.8, regardless of grade. It is demonstrated that all present and past producing mines and the most important known major occurrences lie within well-defined zones of Zn:Pb ratios of 2.4–2.8. Similarly, zones where the Pb:Cu ratio is > 3.0 and the Zn:Cu ratio is > 7.0 also define the most important deposits. These ore-element relations derived from a low sample-density survey define priority zones for detailed exploration for significant major massive sulphide deposits.     

Primary geochemical and mineralogical dispersion in the vicinity of the Lady Loretta Zn-Pb-Ag deposit, Northwest Queensland

Lady Loretta is a stratiform Zn-Pb-Ag deposit occurring within carbonate- and pyrite-rich argillaceous rocks of the southern part of the Lawn Hill Platform, northwestern Queensland. The deposit consists of a single massive sulphide lens within a steep-sided basinal structure and contains reserves of 8 690 000 tonnes of ore at 18.1% Zn, 6.7% Pb and 110 g t⁻¹ Ag.The proportion of pyrite-rich layers in the host rocks increases progressively from about 2% at 150 m stratigraphically below the ore to > 90% in the top 10 m of the footwall rocks. Hanging-wall rocks contain up to 20% pyrite-rich layers for at least 100 m above the ores. Siderite is the carbonate phase present within the ore and within the host rocks in an aureole that extends from 75 m beneath to 50 m above the ore. Both older and younger rocks are dolomitic. The two carbonate phases do not occur together within unmineralized host rocks although they may coexist within veins. Siderite contains up to 13 mol% ZnCO₃ and 32 mol% MgCO₃. There is an antipathetic relationship between Zn and Mg, the latter increasing with distance from the ore.Zinc and, to a lesser extent, Hg, Pb, Ag and Ba show extensive primary dispersion within the host rocks. Within the plane of sedimentation, haloes vary in width from 50 m to 1.5 km and these dispersions are thought to be dependent on the shape of the sedimentary basin floor at the time of exhalative activity. Perpendicular to the sedimentary layering, Zn and Hg show the most extensive primary dispersion with anomalous values extending up to 100 m into the footwall and at least 50 m into the hanging wall.     

Distinctive features of Late Palaeozoic massive sulphide deposits in South China

More than 20 sediment-hosted massive sulphide deposits occur in Late Palaeozoic basins in South China. These deposits are accompanied by a certain amount of volcanic rocks in the host sequence and are economically important for their Cu, Pb, Zn, Au and Ag reserves. The deposits and their host strata were commonly intruded by Mesozoic granitoids. Remobilisation of sedimentary ores and magmatic hydrothermal overprinting processes resulted in the coexistence of massive sulphides with vein-, skarn- and porphyry-type orebodies in the same region or within a single deposit. The ore-containing basins occur in different tectonic settings. The Lower Yangtze basin occurs on a passive continental margin, where the deposits are high in Cu and Au with minor Pb and Zn and recoverable Ag, Co and Mo. The ores have a lower concentration of radiogenic lead, and δ³⁴S values close to zero. Fluid inclusions are highly saline and Na-rich. Fluids and metals of the Lower Yangtze Region are interpreted to have been derived essentially from deep sources including the Precambrian basement. By contrast, basins of the Nanling Region formed in an intracontinental setting developed on a folded Caledonian basement. These deposits are higher in Pb, Zn, Sn and W, as well as Cu, with recoverable Ag, Sb, Hg, U, Bi, Tl and Mo. The ores are characterised by a higher concentration of radiogenic lead and a wide variation of δ³⁴S composition. Fluid inclusions have lower salinities and higher K⁺/Na⁺ ratios. Fluids are considered to have been sourced substantially from seawater by convection. Metals for the Nanling deposits were essentially derived from the Caledonian basement by leaching. The contrast in ore composition between these two regions appears to have been controlled by differences in basement composition of the ore-forming basins.     

Metavolcanic host rocks,mineralization, and gossans of the Shaib al Tair and Rabathan volcanogenic massive sulphide deposits of the Wadi Bidah Mineral District,Saudi Arabia

The Wadi Bidah Mineral District of Saudi Arabia contains more than 16 small outcropping stratabound volcanogenic Cu–Zn–(Pb) ± Au-bearing massive sulphide deposits and associated zones of hydrothermal alteration. Here, we use major and trace element analyses of massive sulphides, gossans, and hydrothermally altered and least altered metamorphosed host rock (schist) from two of the deposits (Shaib al Tair and Rabathan) to interpret the geochemical and petrological evolution of the host rocks and gossanization of the mineralization. Tectonic interpretations utilize high-field-strength elements, including the rare earth elements (REE), because they are relatively immobile during hydrothermal alteration, low-grade metamorphism, and supergene weathering and therefore are useful in constraining the source, composition, and physicochemical parameters of the primary igneous rocks, the mineralizing hydrothermal fluid and subsequent supergene weathering processes. Positive Eu anomalies in some of the massive sulphide samples are consistent with a high temperature (>250°C) hydrothermal origin, consistent with the Cu contents (up to 2 wt.%) of the massive sulphides. The REE profiles of the gossans are topologically similar to nearby hydrothermally altered felsic schists (light REE (LREE)-enriched to concave-up REE profiles, with or without positive Eu anomalies) suggesting that the REE experienced little fractionation during metamorphism or supergene weathering. Hydrothermally altered rocks (now schists) close to the massive sulphide deposits have high base metals and Ba contents and have concave-up REE patterns, in contrast to the least altered host rocks, consistent with greater mobility of the middle REE compared to the light and heavy REE during hydrothermal alteration. The gossans are interpreted to represent relict massive sulphides that have undergone supergene weathering; ‘chert’ beds within these massive sulphide deposits may be leached wall-rock gossans that experienced silicification and Pb–Ba–Fe enrichment from acidic groundwaters generated during gossan formation.     

招远大尹格庄金矿床微量元素特征及其意义

该文以山东招远大尹格庄金矿床中微量元素为研究对象,通过对矿床围岩、矿石等微量元素的研究,表明大尹格庄金矿围岩中微量元素以富含 Bi,Au,Pb,W,Ag,Sn 为特点,矿体和矿化体中元素组合为 Au,Ag,As,Sb,Hg,B, Cu,Zn,Bi,Mo,Mn,Co,Ni,W。在5个成矿阶段中,第二阶段与第三阶段微量元素的富集程度较明显,表现为 Au, Ag,As,Co,Bi,Cu,Pb,Zn 等的富集,成矿元素可分为2个分带序列,主成矿元素为 Au Ag Cu Pb Zn Bi 组合、头晕元素 As Sb Hg 组合和尾晕元素 Co Ni 组合。     

张全庄金矿元素地球化学特征及找矿意义

张全庄金矿是河北省一危机矿山.矿山多为采空区,矿脉中硫化物分布不均匀.矿脉的不同围岩为统一的元素地球化学整体.通过采取与矿脉等距近矿蚀变岩,研究这些蚀变岩中元素的带入带出特征,分析成矿规律,建立了张全庄金矿矿脉原生晕元素组合分带模式,即As、Sb、Ag等元素为头晕元素,Cu、Ag、Au、Pb、Zn等元素为矿中元素,Mo为尾晕元素.运用此模式对张全庄金矿进行深部成矿预测,成功地发现了新矿体.     

青海果洛龙洼金矿床地球化学垂向分带研究

通过系统采样分析,运用格里戈良分带指数法,探讨了青海果洛龙洼金矿床原生晕垂向分带特征。果洛龙洼金矿床元素分带序列由浅到深为:Au-Pb-As-Ag-W-Co-Cu-Bi-Hg-SbZn-Sn-Ni-Mo。金矿床的矿上晕元素Au、Pb、Ag集中于该矿床的最上部,尾晕元素Sn、Ni、Mo在该矿床下部富集,矿上晕元素与尾晕元素按照理论金矿床垂向分带规律分布,代表了该矿床主成矿期的元素分带特征,而在主成矿期形成的位于矿床最上部的前缘晕元素分布空间已被风化剥蚀。结果表明,金矿床的前缘晕元素As、Hg、Sb,和矿上晕元素Cu、Zn以叠加晕的形式穿插于矿上晕元素及尾晕元素之间,反映了该矿床成矿具有两期次叠加成矿的特征,矿床深、边部找矿工作应围绕这两期成矿作用形成的矿化富集带进行。