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1.
A multivariate statistical analysis was carried out with log-transformed values of Cu, Ni, Co, Pb, Zn, Ag, Cr, Mn, Ca, and Sr in several sets of samples collected across the mineralized base metal zone in sheared soda granite, feldspathic schist, and chlorite schist from the central section of Mosaboni Mine of the famous Singhbhum Copper Belt of eastern India. Linear correlation coefficient matrices of two sets of ore samples (>0.5% Cu)—one from levels 18 and 21 and the other from levels 25 and 28—indicate two well-defined and distinct clusters comprising Cu, Ni, Co, Pb, and Zn on one hand and Ca, Sr, and Mn on the other. Varimax-rotatedR-mode factor analysis of two above-noted sample sets, taken along with available geologic information, indicates that over 80% of the variability in data matrices for 9–10 elements can be accounted for by four distinct processes: (a) an early phase of copper mineralization which apparently replaced Mn, Ca, and Sr in the host rock; (b) a silicate-cum-oxide phase of crystallization/recrystallization of host rock; (c) remobilization of sulfide-forming ore elements (Cu, Ni, Co, Pb, and Zn); and (d) a phase of mineralization of Ag which appears to have replaced Cr, Ca and Cu. Process (c) was quantitatively most important. Factor score studies are suggestive of preferred introduction of Ni, Co, Pb, and Zn along central parts of preexisting copper-mineralized zones.  相似文献   

2.
文章在阐述长坡锡多金属矿床地质特征的基础上总结了矿化富集规律:①长坡锡多金属矿床由上部锡石硫化物矿体和下部夕卡岩型锌铜矿体组成,锡石-硫化物型矿体形态主要表现为大脉型、细脉带型以及似层状;夕卡岩型锌铜矿化主要沿赋矿岩石的裂隙充填、交代,形成细脉状、层状以及浸染状矿化,矿体分为2段,南西段为锡多金属硫化物矿,北东段为锌铜矿;②长坡锡多金属矿床具有明显的水平以及垂向分带特征,平面上从岩体中心向外依次为Zn,Cu→(W,Sb)→Sn,Zn→Sn多金属→(Pb,Zn,Ag);垂向上自下而上依次为Zn,Cu→Sn,Zn→Sn多金属→(Pb,Zn,Ag);③长坡锡多金属矿床矿化富集与构造关系密切,尤其是次级构造部位,矿化富集程度高。夕卡岩型锌铜矿富集受花岗岩体影响明显,靠近花岗岩体矿化增强。  相似文献   

3.
The Chitradurga base metal sulfide deposit is associated with eugeosynclinal metabasalts (~ 2.5 b.y.) and banded pyritiferous cherts. The pre-tectonic character of the deposit and meta-volcanics is indicated by their deformational textures, structures and radioactive age data. The mineral assemblages of these ores are similar to the Zn-Cu type of massive sulfide deposits associated with Archean—Early Precambrian eugeosynclinal metavolcanics in other shield areas. The deposit has a rather high concentration of Co; microprobe data indicate that most of it is found as cobaltite and linnaeite and that it is inhomogenously distributed in these minerals. Very strong sympathetic correlation between Co and Cu, and the simultaneous increase of both of these elements with depth has been found. The geochemistry of the Chitradurga ores and metabasalts, especially their Zn:Cu:Pb and Pb:Zn ratios, suggests that the base metal sulfide content is probably genetically related to the basaltic flows. It appears that the Chitradurga deposit belongs to the ‘massive volcanogenic’ Cu-rich class of sulfide deposits. The metal content of the ores appears to have been supplied by rapidly degassing highly undifferentiated protomantle along with the basaltic magma.  相似文献   

4.
“Magmato-Hydrothermal Space” is a new mathematical construct where 24 ore and pathfinder elements are used to quantify ore-element signatures. Quantification allows relationships between ore deposit samples to be mapped. The broad-scale view of Magmato-Hydrothermal Space reveals three important trends: (1) Zn-Pb sediment-hosted mineralisation to igneous-associated Cu-Au mineralisation, (2) Cu-Au mineralisation to Au-only mineralisation, and (3) ultramafic associated magmatic Ni-Cu-PGE mineralisation through Cu-Au mineralisation to granitoid-associated Mo, W and Sn mineralisation. The view provided by Magmato-Hydrothermal Space reveals that there is a spectrum of ore element signatures that mirrors the spectrum of ore deposit classes described in the literature.Geochemical variations within individual ore deposit classes are examined for orogenic-Au, VHMS, epithermal and sediment-hosted Cu samples. Sub-groups within each of these classes are compared on element enrichment diagrams and described in the context of Magmato-Hydrothermal Space. Orogenic Au samples are divided into two sub-groups of As-Sb rich mineralisation and four sub-groups of relatively As-Sb poor mineralisation. The As-Sb poor sub-groups include a Te-Cu-Ag rich sub-group that overlaps with the porphyry Cu class and a Te-W-(Bi-Mo) rich class dominated by granitoid hosted deposits. The VHMS class ranges from a Cu-rich sub-group that overlaps with porphyry Cu and IOCG classes through a Cu-Zn sub-group to two Zn-Cu sub-groups, one of which overlaps with the SHMS class. The epithermal class is divided into Zn-rich, Cu-rich and base metal – poor sub-groups.  相似文献   

5.
The South Australian portion of the Willyama Inliers hosts a diversity of small sulphide and uranium deposits and numerous outcropping gossans. This fact, together with geological similarities to the adjacent Broken Hill Block has led to extensive exploration. A broad classification distinguishes two main types of sulphide mineralisation: 1) stratiform iron sulphide-dominated (±Cu, Zn, Co) deposits which occur widespread within specific stratigraphic intervals, and stratabound occurrences of syn-depositional to diagenetic origin which show some structural control; 2) syn-tectonic to post-peak metamorphic replacement and vein-type deposits (Fe-Cu-Au and Cu-Zn-Pb), which are hosted by fractures and within faults and shear zones. These occurrences show no stratigraphic control and are not spatially related to type 1 mineralisation. Late-stage deposits also differ from stratiform/stratabound mineralisation in their texture, mineral assemblage and geochemical composition. Much of the sulphide mineralisation in the Olary Block has been interpreted as resulting from rift-associated syn- to diagenetic processes, such as hot spring exhalations and base metal precipitation along reduction-oxidation interfaces. Subsequent granitic intrusive, high grade metamorphic and multiphase deformation events would have induced remobilisation and redeposition of sulphides in a variety of epigenetic modes. However, a detailed petrographic and geochemical study of sulphide mineralisation in the Olary Block demonstrates that due to the lack of abundant pervasive fluids, translocation and modification of preexisting sulphides were restricted to less than a few centimetres. Instead, widespread syn-tectonic to epigenetic (i.e., post-peak metamorphic) mobilisation of ore constituents occurred to form retrograde sulphide mineralisation as well as multiple generations of late-stage vein deposits. These epigenetic deposits are genetically unrelated to synsedimentary and diagenetic occurrences, an aspect of significance for exploration in the Olary Block. Temporal separation of peak metamorphism in deeper crustal levels from its occurrence in shallow levels, periodic tectonic disturbances and repeated seismic pumping are processes believed to have resulted in intermittent mobilisation of ore constituents from a deep-seated metasedimentary reservoir.  相似文献   

6.
The Radiore Cu-Zn massive sulfide deposit occurs in Archean metavolcanic rocks of the Abitibi greenstone belt in northwestern Quebec. The ore forms a stratiform lens between a massive rhyolite flow and a unit of mixed basaltic and intermediate flows. Intrusions of thick dykes of gabbro-diorite, quartz-diorite and granodiorite, and of the Bell River igneous complex, closely surround the ore lens. All the volcanic rocks, the quartz-diorite, grandiorite and the igneous complex are tholeiitic, whereas the gabbro-diorite is of calc-alkaline affinity. Sedimentary structures are prevalent in the ore, and heavily chloritized and biotitized rocks form a stratiform alteration zone mainly below the ore, indicating a distal-type deposit.Ore enrichment factors (wt % metal in ore/wt % metal in source rock) are calculated from analyses of ore and source rocks, assuming that seawater-derived brines leached ore materials from underlying rocks and precipitated them at the point of brine discharge onto the seafloor. Cd, Zn, Cu, Au and Ag are most highly enriched, followed by Bi, Pb, Sn, As and Co. Mo, W, V, Cr, Mn and Ni are not enriched at Radiore.  相似文献   

7.
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  
侯增谦  T. Urabe 《地球学报》1997,18(2):171-181
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   

8.
The presence of base‐metal mineralization at Woodlawn was first recognised early in 1968 when a roadside reconnaissance geochemical sampling survey, conducted over felsic volcanic rocks in the Goulburn‐Tarago area, encountered anomalous B horizon soils containing up to 200 ppm Cu, 800 ppm Pb and 300 ppm Zn. Regional soil thresholds have been determined at 50 ppm Cu, 90 ppm Pb and 50 ppm Zn. Chip samples from the subsequently located gossan revealed up to 2000 ppm Cu, 8000 ppm Pb and 2000 ppm Zn, 500 ppm Sn, 25 ppm Ag and 3000 ppm As.

The first grid B horizon soil geochemical survey was conducted in 1968 over the gossan and surrounding area, and repeated with closer spaced sampling in the first half of 1970. The first survey delineated strong Cu (to 1000 ppm) and Pb (to 2500 ppm) anomalies coincident with the gossan zone, and intense hydromorphic zinc anomalies (to 3000 ppm) located down slope from the gossan in residual clay‐soils derived from dolerite bedrock. Threshold values have been determined at 140 ppm Cu, 700 ppm Pb and 580 ppm Zn. Ag and Sn in B horizon soils show pronounced anomalies coincident with the gossan and are suitable metals for geochemical target definition. Of fourteen trace elements determined in 1974 from B and C horizon soils on two lines across the ore zone Cu, Pb, Zn, Se, Ba, Sn and Ag show direct correlation with the mineralization, whereas Cd and Mn show moderate hydromorphic dispersion, having accumulated principally in clay soils derived from dolerite weathering. As, Sb and Bi, whilst responding over the ore zone, show elevated values in soils over hanging‐wall units; Ni and Co show maximum levels in soils over dolerite bedrock.

Bark and leaves of Acacia mearnsii, collected from a line across the gossan, contain anomalous levels of Cu, Pb, Zn, Sn and Ti near the ore zone, and weaker, but clearly anomalous Mn and Ni levels over dolerite bedrock. Both bark and leaves of Acacia mearnsii reflect the presence of concealed mineralization. The shrub Solanum linearifolium grows preferentially over and close to the Woodlawn ore zone, where it contains up to 840 ppm Cu, 250 ppm Pb, 7300 ppm Zn, 6 ppm Sn and 250 ppm Ti in leaf ash compared with levels of 200 ppm Cu, 2 ppm Pb, 400 ppm Zn, 0.8 ppm Sn and 60 ppm Ti in plants growing 1.5 km from the ore zone. This shrub has potential as an indicator of base‐metal mineralization.  相似文献   

9.
A small Kuroko-type Cu-Zn deposit exhibiting metal zoning and alteration assemblages comparable with documented proximal volcanogenic deposits, occurs at the top of a felsic fragmental pile, mantling a large sodic rhyolite domal complex. The domal complex occurs within predominantly mafic to intermediate lavas and volcaniclastic rocks with low-potash island-arc tholeiitic affinities, representing the basal section of the early Tertiary (Eocene to middle Miocene) Wainimala Group near the southern coast of Viti Levu, Fiji.Lithogeochemical trends identified in analyses of rock chip samples from traverses across the domal complex reflect alteration zoning. Sodium, Ca and Sr are strongly depleted within the quartz-sericite foot-wall alteration zone (Zone I) 200 m below mineralization. Potassium, Rb and weaker Mn, Zn and Co depletion and Cu, Pb and Mg enrichment define clay-sericite (Zone II) and clay carbonate (Zone III) footwall alteration 600 to 1200 m below mineralization. Hanging-wall albite-chlorite-calcite-zeolite alteration (Zone IV) is accompanied by enhanced Zn, Pb, Co, Mn, Sr and Na values.Significant mine-scale lithogeochemical trends obtained from systematic sampling of a mineralized borehole section include K and Rb enrichment in the zone of strongest quartz-sericite alteration associated with mineralization and broad depletion of Mn, Na, Ca and Sr within altered footwall fragmental rocks. Minor Cu, Pb, Zn and Ag enrichment has accompanied low-grade propylitic alteration of hanging-wall rocks up to 50 m above mineralization. Analysis of weathered bedrock samples from traverses above the mineralized borehole section indicates that primary geochemical trends occur in the weathered zone. Outcropping gossan has strongly anomalous Cu (535 ppm-21.5%), Zn (3300 ppm-6.15%), Pb (420–8200 ppm), As (200–7000 ppm) and Hg (33–670 ppm) values.Application of lithogeochemistry as a follow-up exploration method in a tropical area such as Wainaleka was investigated as a possible replacement for ridge, spur and base-of-slope soil sampling techniques. Ridge-top auger samples and creek outcrop samples were collected at approximately 100 m intervals and a density of 70/km2. Elements (including Cu, Pb, Zn, Mn, Rb, Sr, Na, K, Ca and Mg) were selected for analysis because of specific associations with mineralization and alteration, and low analytical costs. Single- and multi-element dispersions effectively outline mineralization and attendant alteration.  相似文献   

10.
兰坪白秧坪Cu-Ag多金属矿集区夹持于金沙江和澜沧江断裂之间,属兰坪-思茅中新生代坳陷带之兰坪盆地北部,可分东矿带和西矿带二部分。本文通过对白秧坪金属矿集区东西2个矿带的矿石矿物电子探针分析、成矿元素含量和组合分析及S同位素的讨论得出:(1)东西2个矿带矿石矿物组合类型及微量元素组合特征具明显不同,前者矿石矿物组分较为简单,西带较为复杂,不仅有Pb、Zn和Cu的独立矿物,还存在Co和Bi的矿物;(2)东矿带Ag、As、Cd、Pb、Sb和Zn的富集从南到北依次减弱,Bi的富集依次增强,Cu的富集趋势越往北越富集,亏损元素为Co、Cr、Ni和V;西矿带Ag、Pb、Zn的富集属吴底厂和李子坪矿段最富集,而Cu则在小丫口和白秧坪矿段最富集。亏损元素为Ba、Co、Cr、Ni和V,但各个矿段这些元素的亏损程度有所不同,有的矿段部分元素有稍富集趋势;(3)Co、Ni和Cr等微量元素西带高于东带,而Sr、Pb、Zn和Ba元素则东带高于西带,与各自的矿物组合类型一致,且元素的共生分异机制与构造分带存在一定的耦合关系;(4)兰坪盆地火山岩为白秧坪多金属矿集区提供了主要物源,Mo、Co和Ni等元素显示其成矿可能与隐伏基性-超基性岩浆有关的深部来源有关;S同位素特征表明东西矿带金属硫化物硫源均以幔源为主。  相似文献   

11.
Weathering of heavy metal enriched black shales may be one of the most important sources of environmental contamination in areas where black shales are distributed. Heavy metal release during weathering of the Lower Cambrian Black Shales (LCBS) in western Hunan, China, was investigated using traditional geochemical methods and the ICP-MS analytical technique. Concentrations of 16 heavy metals, 8 trace elements and P were measured for samples from selected weathering profiles at the Taiping vanadium ore mine (TP), the Matian phosphorous ore mine (MT), and Taojiang stone-coal mine (TJ). The results show that the bedrock at these three profiles is enriched with Sc, V, Cr, Co, Ni, Cu, Zn, Pb, Th, U, Mo, Cd, Sb, Tl, and P. Based on mass-balance calculation, the percentages of heavy metals released (in % loss) relative to immobile element Nb were estimated. The results show significant rates of release during weathering of: V, Cr, Co, Ni, Cu, Zn, U, Mo, Cd, Sn, Sb, and Tl for the TP profile; Sc, Cr, Mn, Co, Ni, Cu, Zn, Pb, Th, Cd, and Sn for the MT profile; and Sc, Mn, Co, Ni, Zn, Th, Cd, Sn, and Tl for the TJ profile. Among these heavy metals, Co, Ni, Zn, Cd, and Sn show very similar features of release from each of the three weathering profiles. The heavy metals released during weathering may affect the environment (especially topsoil and surface waters) and are possibly related to an observed high incidence of endemic diseases in the area.  相似文献   

12.
2014年发现的维拉斯托锡锌矿是继20世纪末该矿区铜锌矿之后的重要找矿进展,已控制Sn金属资源量10万t。成矿作用与隐伏花岗岩体有关,该岩体侵入于前寒武纪变质岩中。矿化类型包括岩体顶部的花岗岩型锡锌矿、岩体外侧的石英脉型锡锌矿以及外围的铜锌矿。针对花岗岩、各类矿体开展了岩石学、矿床学、主微量元素地球化学、年代学等研究,初步查明岩浆演化机制、矿床成因及三类矿化的关系。细粒斑状碱长花岗岩La-ICPMS锆石UPb年龄(139.5±1.2)Ma(MSWD=3.3)。岩石中发育多级斑晶,结晶(沉淀)顺序为钠长石→石英→钾长石→钠长石→石英、黄玉、锡石、闪锌矿。花岗岩富Si O2贫Al2O3、Ti O2、TFe2O3、Ca O等,高Rb、Cs、Nb、Ta及W、Mo、Bi、Cu、Zn、In等元素,低Sr、Ba等,钠长石An0.3,与锡钨多金属矿成矿花岗岩性质相似。岩浆晚期经历了岩浆-热液过渡阶段(浆液过渡态流体),自硅酸盐相中分离出富Si、富F和富S的流体相,分别形成花岗岩型矿石中的石英、黄玉、锡石-闪锌矿囊状体(珠滴),伴随熔融包裹体和熔流包裹体,晚期逐渐、连续地向热液阶段过渡。岩浆-热液过渡阶段在岩体顶部形成花岗岩型锡锌矿石,热液阶段在岩体外侧和外围形成石英脉型锡锌矿及铜锌矿、铅锌银矿。这些矿体连同成矿花岗岩共同构成岩浆-热液型锡多金属矿床成矿系统。锡林郭勒—赤峰地区,很多脉状铅锌银矿的成矿作用与酸性侵入岩有关,深部可能存在大规模岩浆-热液型锡(钨)多金属矿。  相似文献   

13.
刘永春 《地质与资源》1993,2(3):188-197
前河金矿控矿构造主要为发育在区域性卢氏-潘河-马超营断裂北侧的近东西向断裂构造,按断裂间的相互关系、蚀变矿物及其共生组合特征,划分出6次构造活动并相应划分出6个矿物生成阶段。以硅化、绿帘石化、绢云母化、绿泥石化等为标志的第二至第五阶段为成矿阶段。碎裂岩带是矿体的主要控矿构造类型;受节理控制的矿体多分布于控矿断裂的两侧。在断裂带中Ag、Cu、Pb、Zn、Mo、Ni等元素含量普遍增高。沿断裂微量元素的含量有一定变化,在矿区东段Ag、Cu、Pb、Zn含量相对增高,而Bi、Mo、Cr、Co、Ni等在西段较高。Ag、Cu、Pb、Zn等多集中分布在矿体上部;而Bi、Mo、Cr、Co、Ni等主要集中分布在矿体的中下部。据此认为东段目前所出露的矿体是整个矿体的中上部,而西段是整个矿体的中下部。故应注意在东段下部的找矿。  相似文献   

14.
陈建平  郝金华 《西北地质》2012,45(1):236-243
青海南部三江北段构造成矿带经历了复杂而完整的多期次复合造山及叠加改造地质构造过程,导致复杂丰富的成矿演化,发育一系列大型、超大型的铜、金、铅锌等金属矿床。研究认为,目前青海三江北段主要的成矿系统为:与三叠纪火山喷发作用有关的铁、铜、铅、锌、银等成矿系列,与新生代浅成侵入岩有关的钼、铜、铅、锌多金属成矿系列,与新生代有关的热液叠加改造型铅、锌多金属成矿系列。这些成矿系统代表了区域矿矿产资源进一步勘查的方向。  相似文献   

15.
Metal and metalloid (As, Cd, Co, Cu, Pb and Zn) distribution in soils from the Katanga Copperbelt (Democratic Republic of Congo) is investigated in order to characterize the environmental impacts of mining and smelting activities in that area. The concentrations of Cu, Co, As, Zn, Pb and Cd in soils from mining sites are higher than in non-metalliferous sites and above permissible metal and metalloid concentrations in soils. Moreover, the fractionation and mobility of Co, and Cu in such environment is assessed using the application of both ammonium acetate-EDTA extraction and speciation modeling (WHAM 6). The resulting data set covers wide range of environmental conditions (pH, trace metals concentration, natural soils and soils affected by mining and ore processing). These extractions show that only a small fraction of Cu and Co is mobile, with variation depending on sites: mobility is higher in soils affected by mining and ore processing. The strong affinity of Mn-oxides for Co may explain lower Co mobility in Mn-rich soils. The high Mn and Fe contents of Cu–Co soils from Katanga may actually exert a protective effect against the toxic effects of Co. Finally, Cu–Co speciation modeling of contaminated sites emphasizes that organic matter strongly sorb Cu whereas Co speciation is mostly by Mn content. This type of study leads to a better understanding of metal fractionation and can guide to define different practices of phytoremediation.  相似文献   

16.
The sedimentary basin of Gavkhuni playa lake includes two sedimentary environments of delta and playa lake. These environments consist of mud, sand and salt flats. There are potentials for concentration of heavy metals in the fine-grained sediments (silt and clay) of the playa due to existence of Pb/Zn ore deposits, industrial and agricultural regions in the water catchment of Zayandehrud River terminating to this area. In order to study the concentration of heavy metals and the controlling factors on their distribution in the fine-grained sediments, 13 samples were taken from the muddy facies and concentration of the heavy metals were determined. The results showed that the heavy metal concentrations range in the sediments (in ppm) are Mn (395.5–1,040), Sr (100.4–725.76), Pb (14.66–91.06), Zn (23.59–80.9), Ni (37–73.66), Cu (13.83–29.83), Co (5.73–13.78), Ag (3.03–4.76) and Cd (2.3–5.5) in their order of abundances. The concentration of Ag is noticeable in the sediments relative to the average concentration of this element in mud sediments. The amounts of Pb and Zn are relatively high in all the samples in comparison with the other elements. The concentration of Ni is relatively high in the oxidized samples. The distribution of Pb is directly related to organic matter content of the sediments. The concentrations of Zn, Sr, Cu, Co and Cd in the samples of the playa are lower than those in the delta. The amount of illite is another factor influencing Zn and Pb concentrations. Sr is more concentrated in the sediments with the high content of calcium carbonate. The distribution pattern of Cu, Co, Pb and Mn resembles to that of the clay content of the sediments. The clay content shows positive correlations with Co, Cu and Mn concentrations and negative correlation with Ag. The Sr and Ag concentrations are positively correlated with the amount of CaCO3. The amounts of Co, Cu, Ni and Mn show negative correlations with the calcium carbonate content. Pb and Co are noticeably correlated with Mn.  相似文献   

17.
百里坪银、多金属矿化集中区白垩纪岩浆岩主要有花岗质与闪长质两个岩石系列。前者为富钾质钙碱性岩石,后者为富钠质碱钙性岩石,二者具有不同的变异曲线特征;花岗质岩石Co/N i值平均为2.644,闪长质岩石平均为0.498;花岗质岩石R b/S r值平均为0.223,闪长质岩石平均为0.020;在R b、S r、B a演化趋势上,花岗质岩石趋向富集R b,闪长质岩石趋向富集S r、B a,二者明显不同;两个岩系代表性岩石在稀土含量、稀土比值以及稀土模式上都不相同。两者的成矿专属性为:花岗质岩石对A g、Cu、P b、Zn矿化有利,闪长质岩石对A g、A u矿化有利。  相似文献   

18.
The Wilga and Currawong copper-zinc massive sulphide deposits in northeastern Victoria occur within a sequence of Silurian volcanics and sediments. The Wilga deposit which was discovered in mid 1978 consists of a single lens while the Currawong deposit, discovered in early 1979, consists of at least two lenses.The first indication of the presence of base metal mineralization in the area was provided by an assessment of stream sediment geochemical data contained in open-file Exploration Licence reports at the Victorian Department of Minerals and Energy.The massive sulphide mineralization does not outcrop, but the ore horizons are weakly mineralized and give rise to stringer gossans as far as 150 m up dip from ore grade mineralization. These can be identified by their trace element chemistry (anomalous values of Bi, Fe, As, Au, Pb, Hg, Se, Co, Ag and Mn) corresponding to the trace element signature of both stringer and massive sulphides.Soils in the area are essentially skeletal and residual with some colluvial movement on the steeper slopes. The soils are highly anomalous in Cu, Pb, and Zn over the projected horizon of the Wilga mineralization and the No. 2 lens at Currawong.The stream sediment responses at both Wilga and Currawong result from a combination of chemical and elastic dispersion. Downslope from the surface expression of the Wilga mineralization a spring discharges directly into the Tambo River. The spring has a very low pH and is rich in base metals resulting in enhanced metal values in both stream water and stream sediments.Analyses of selected samples of the more prominent vegetation species have failed to show a clear relationship to the mineralization.  相似文献   

19.
北山地区植被属戈壁荒漠植被类型,主要植物群落为红沙,红沙中多数元素特别是成矿元素及其伴生元素的含量和变化系数矿区大于背景区,元素含量背景区呈对数正态分布,矿区呈偏对数正态或多峰分布,红沙中的元素组合分类背景区为Au,Cu,Pb,Zn,As,Sb,Mo,V,Mn和Ag,Sn,Sr,Ba及Ti,Cr,Co,Ni,金矿区为Au,Ag,As,Sb,Mo,Mn,Sr和Cu,Pb,Zn,Sn,Ba及Co,Ni,Ti,V,Cr,铜矿区为Cu,Pb,Zn,Mo,Au,Ag,Ba和As,Sb,Sn,Mn及Ti,V,Cr,Co,Ni,Sr,矿区红沙中浓集系数较大的元素多数在矿区岩石中的浓集系统亦较大,金,铜矿床红沙和岩石中的特征元素分别都有Au,Ag,Ag,Sb,Mo,(Mn)和Cu,Pb,(Ba,Ti,Cr)。在金,铜矿床(体上方分别发育有良好的Au和Cu的生物地球化学异常和元素组合及分带,根据红沙的地球化学特征能,判断金或铜矿种类型,并能对掩埋,隐伏金,铜矿床(体)进行定位预测。  相似文献   

20.
The distribution of radioactive Cs and heavy metals (V, Cr, Mn, Co, Ni, Cu, Zn, Cd, Hg, and Pb) in the lichen-substrate system and in lichen tissues were examined using the example of Cladonia genera. The upper podetia-lower podetia-dead podetia-base-substrate system was sampled at 32 sites in Novosibirsk oblast and Altai administrative territory, 16 of which were selected for detailed studying of the trace element distribution in the upper and lower podetia using cold press and the modified Dexter technique. One in vivo and two in vitro experiments simulated the influence of metal-rich atmospheric fallouts on the lichen carpet. The lichen carpet was irrigated by solution of metal nitrates (Co, Cu, Zn, Cd, Hg, and Pb) in the former case and loaded in these solution during the latter experiment. The experiment performed in the laboratory conditions (in vitro) was aimed at studying the dynamics of metal accumulation in lichen constituents and their subsequent extraction with distilled water to monitor metal sorption on the podetium cell walls. The metal contents and the activity of radioactive Cs in the lichen samples, including lichen cell sap, as well as in the base and substrate, were determined by atomic-absorption and gamma spectroscopic methods. In terms of accumulation, the elements are subdivided into two groups. The lowest contents of Group-1 elements (137 Cs, Zn, Cd, Hg, and Pb) were found in the substrate, and the highest contents, detected at the base and dead podetium, are presumably of technogenic origin. The Group-2 elements (Cr, Mn, Co, Ni, and Cu) enrich the substrate. It was established that the elements are mainly accumulated in lichens in cell walls and the membrane. The lichen sap and water-soluble compounds of protoplasma contain less than 0.1% of the total element content in the tissue. Most Zn, Cd, Co, and Pb ions (about 80% of the total absorbed amount) migrated from experimental solution into lichen cells during the first 12 h.  相似文献   

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