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1.
传统的地球化学异常评序方法,通常依据化探异常的"高、大、全",但实践证明,没有结合成矿地质条件进行排序的异常,不能更好地反映出成矿远景的大小,也就不能更好地进行异常查证工作。为此,这里把异常规模、元素组合特征以及成矿地质条件作为评价异常最重要的三个参数,使用模糊意见集中决策对研究区的异常作出排序。经野外异常查证工作证实,该方法能更好地指导异常查证工作。  相似文献   

2.
区域地球化学异常评序是异常检查和异常评价的重要环节,异常评序结果的准确与否直接影响到找矿效果。在区域化探资料整理中遇到的往往是大量不同类型矿床产生的异常,很难把它们按同一标准评序。笔者对赣西地区1:5万化探分散流扫面获得的成果进行异常评序研究,认为异常评序首先应按各元素的异常规模推测矿化类型,然后挑选出同一或相似矿化类型产生的异常进行主成矿元素多参数评序,这样的评序结果较合理,准确,可避免排序结果  相似文献   

3.
通过对贵州省松桃地区1∶5万水系沉积物测量资料进行综合处理,圈定了Pb、Zn、Cu等15种元素异常范围,依据元素地球化学特征、元素相关性及在测区的共生组合关系划分出亲铜元素类、亲铁元素类及其他元素类三类。根据异常元素组合特征圈定出38个综合异常,按其找矿意义大小对其进行了综合异常分类评序,对其中具有较大找矿意义的重要综合异常进行了评价。在此基础上依据工作区已发现的矿床、矿点,结合全区地球化学元素分布特征,异常分布规律以及地质背景因素等,将测区划分为Ⅰ、Ⅱ两级成矿远景区,并划分出5个找矿远景区,为从总体上认识和把握区内地球化学特征及找矿信息提供了重要的线索,为该区今后地质找矿工作提供了重要依据。  相似文献   

4.
《四川地质学报》2019,(2):326-329
为了研究青海省赛木隆地区找矿远景,基于工作区最新1∶5万水系沉积物地球化学测量数据,总结分析了元素丰度特征、元素的离散特征、元素的共生关系特征,并对主要异常进行评序,认为工作区主要成矿元素是Au、W、As、Hg、Sb、Mo。结合区域成矿地质条件,优选了3处成矿远景区,为工作区以后的地质勘查提供了重要的指导作用。  相似文献   

5.
罗素菲 《物探与化探》1986,10(5):332-342
对区域化探老资料及成矿区(带)的化探资料圈出的异常进行评价、分类、评序是一项紧迫工作。笔者用谢学锦和邵跃的异常评价方法思路提出了新的异常评序方法。方法是:先计算出异常的各种地球化学参数;每个异常按元素规格化面金属量NAP值从大至小依次排队,写出每个异常的多元素组合表达式;根据区域地球化学特征、区域地质矿产规律、成矿物质来源、控矿地质条件、已知矿区异常规律结合异常特征等对异常进行评价,对有找矿远景的异常进行矿种预测;按异常评价结论对异常进行分类;最后将各类异常中每一个异常的成矿元素及其前缘元素NAP值累加值作为异常评序参考值,按其值的大小序列进行排队,这样同类型矿床的异常就可以进行比较了。1981年至1982年对湖南省区域化探(老资料)中圈出来的132个异常评价、分类、评序取得较好的结果。经评序后已知大中型矿床的异常都排在每类的最前面,说明最前面的异常找矿规模也最大,其中排在前面的尚未见矿的异常一般是有找矿希望的异常。且这种序列与异常评价结论是一致的。异常评价后发现有七个异常的评价意见与新的储量资料相吻合。1983年至1984年在两个异常区钻探打到相应的工业矿体,说明这种异常评价、评序方法是可行的。  相似文献   

6.
为了研究青海省赛木隆地区找矿远景,基于工作区最新1∶5万水系沉积物地球化学测量数据,总结分析了元素丰度特征、元素的离散特征、元素的共生关系特征,并对主要异常进行评序,认为工作区主要成矿元素是Au、W、As、Hg、Sb、Mo。结合区域成矿地质条件,优选了3处成矿远景区,为工作区以后的地质勘查提供了重要的指导作用。  相似文献   

7.
利用多元素组合异常指示元素平均值与大兴安岭森林沼泽区水系沉积物地球化学元素丰度值的差,以及与其所在地球化学子区元素变化系数的乘积关系,度量多元素组合异常指示元素在成矿地质作用中的聚集变化强度;计算多元素组合异常元素变化强度的和,对多元素组合异常进行元素变化强度和的评序,遴选主要组合异常.利用多元素组合异常指示元素蕴涵R型因子分析因子结构组合元素矿化类型的意义,判别多元素组合异常因子矿化类型.依据主要组合异常分布、因子矿化类型以及与测区物探、遥感解译线性、环形构造的关系,建立测区主要组合异常聚集带、聚集区.依照主攻矿种元素、相应主要组合异常因子矿化类型信息和相关成矿地质理论,开展测区多元素组合异常优中选优的找矿验证工作.  相似文献   

8.
沈宏飞  闫鲜 《西北地质》2023,(2):109-118
笔者在1∶5万水系沉积物测量成果的基础上,对阿克塔木-阿克塔什一带的Cu、Au、Zn等18种元素地球化学特征进行了初步总结。发现该区Cu、Au等元素具有较高的背景,且分异较大。R型聚类分析显示Cu元素与Zn、Cd等亲硫元素相关性强,而Au元素显示了独立的成矿性。本次工作共圈定了35个以Cu、Au为主的综合异常,并对异常进行了评序和分类;共圈定甲类异常4个,乙类异常22个,丙类异常7个,丁类异常2个。结合区内成矿地质条件和异常检查工作,优选了萨洛依、小尚亥–依买克、古鲁滚涅克、阿克沙热、央布拉克及乌鲁阿特等6个地球化学成矿远景较好的靶区;指出该区的找矿方向应以寻找海相块状硫化物型铜(锌)矿和岩浆–热液石英脉型金(银)矿2个方向进行。  相似文献   

9.
利用摩洛哥苏斯—马萨—德拉地区内的地球化学信息,采用绘制三元图的方法推测地质体覆盖情况、元素组合异常强弱、预测矿产类型。该方法是在筛选相关性强的造岩(成矿)元素基础之上,利用三个单元的元素含量数据成图,依据三元图色标推断地质体和对成矿元素组合异常作出评价。结果显示三元图方法划分的地质体,圈定成矿元素组合异常、预测多金属矿产分布效果较好,证明该方法能反映地球化学分区特征。  相似文献   

10.
藏东达翁金矿区位于班公湖-怒江成矿带东段,其成矿地质背景和成矿地质条件优越。为研究该矿区找矿潜力,利用SPSS软件对1∶10000土壤地球化学测量获得的Au、Ag、Cu、Pb、Zn、As、Sb、Mo、W、Bi等10种元素数据进行多元统计分析,运用元素异常NAP值累加方法和组合元素NAP值异常评序方法分别对各元素的成矿潜力及综合异常的找矿潜力进行评价。结果表明:区内矿化与中酸性岩浆热液有关,Pb、As、Sb、Ag、Bi是矿化体前缘晕指示元素,Au是主成矿元素,W是近矿指示元素,Cu、Mo是矿化体尾晕指示元素;Au的成矿潜力最大,Bi、Mo成矿潜力较大,Sb、Ag有一定的成矿潜力;区内共圈定土壤地球化学综合异常5个,其中HS-1综合异常找矿潜力最大,其次是HS-4综合异常。结合成矿地质特征和异常查证结果认为,区内具有寻找隐爆角砾岩型金矿、斑岩型钼金矿的巨大潜力及热液型银锑铋多金属矿的较大潜力。  相似文献   

11.
This paper reports the first results of a study of 11 isotope systems (3He/4He, 40Ar/36Ar, 34S/32S, 65Cu/63Cu, 62Ni/60Ni, 87Sr/86Sr, 143Nd/144Nd, 206–208Pb/204Pb, Hf–Nd, U–Pb, and Re–Os) in the rocks and ores of the Cu–Ni–PGE deposits of the Norilsk ore district. Almost all the results were obtained at the Center of Isotopic Research of the Karpinskii All-Russia Research Institute of Geology. The use of a number of independent genetic isotopic signatures and comprehensive isotopic knowledge provided a methodic basis for the interpretation of approximately 5000 isotopic analyses of various elements. The presence of materials from two sources, crust and mantle, was detected in the composition of the rocks and ores. The contribution of the crustal source is especially significant in the paleofluids (gas–liquid microinclusions) of the ore-forming medium. Crustal solutions were probably a transport medium during ore formation. Air argon is dominant in the ores, which indicates a connection between the paleofluids and the atmosphere. This suggests intense groundwater circulation during the crystallization of ore minerals. The age of the rocks and ores of the Norilsk deposits was determined. The stage of orebody formation is restricted to a narrow age interval of 250 ± 10 Ma. An isotopic criterion was proposed for the ore-bearing potential of mafic intrusions in the Norilsk–Taimyr region. It includes several interrelated isotopic ratios of various elements: He, Ar, S, and others.  相似文献   

12.
最新的流行病学研究表明,空气中较高浓度的悬浮细颗粒可能对人类的健康有不利的影响。根据该项研究显示,由于心脏病、慢性呼吸问题和肺功能指标恶化而导致死亡率的升高与细尘粒子有关。这些研究结果已经促使欧盟于1999年4月出台了限制空气中二氧化硫、二氧化氮、氧化氮、铅和颗粒物含量的法案(1999/30/EC),对各项指标包括对可吸入PM10颗粒的浓度提出了新的限制性指标。PM10颗粒是指可以通过预分级器分离采集的气体动力学直径小于10μm的细颗粒。目前研究的兴趣重点逐步偏向PM2.5这些更细微颗粒物,PM2.5这种颗粒物对健康有明显的不利影响。在欧盟指令2008/50/EC中,对PM10和PM2.5都提  相似文献   

13.
Komatiites are mantle-derived ultramafic volcanic rocks. Komatiites have been discovered in several States of India, notably in Karnataka. Studies on the distribution of trace-elements in the komatiites of India are very few. This paper proposes a simple, accurate, precise, rapid, and non-destructive wavelength-dispersive x-ray fluorescence (WDXRF) spectrometric technique for determining Sc, V, Cr, Co, Ni, Cu, Zn, Rb, Sr, Y, Zr, Nb, Ba, Pb, and Th in komatiites, and discusses the accuracy, precision, limits of detection, x-ray spectral-line interferences, inter-element effects, speed, advantages, and limitations of the technique. The accuracy of the technique is excellent (within 3%) for Sc, V, Cr, Co, Ni, Cu, Zn, Rb, Sr, Zr, Nb, Ba, Pb, and Th and very good (within 4%) for Y. The precision is also excellent (within 3%) for Sc, V, Cr, Co, Ni, Cu, Zn, Rb, Sr, Y, Zr, Nb, Ba, Pb, and Th. The limits of detection are: 1 ppm for Sc and V; 2 ppm for Cr, Co, and Ni; 3 ppm for Cu, Zn, Rb, and Sr; 4 ppm for Y and Zr; 6 ppm for Nb; 10 ppm for Ba; 13 ppm for Pb; and 14 ppm for Th. The time taken for determining Sc, V, Cr, Co, Ni, Cu, Zn, Rb, Sr, Y, Zr, Nb, Ba, Pb, and Th in a batch of 24 samples of komatiites, for a replication of four analyses per sample, by one operator, using a manual WDXRF spectrometer, is only 60 hours.  相似文献   

14.
《Applied Geochemistry》2001,16(2):137-159
Five hundred and ninety-eight samples of terrestrial moss (Hylocomium splendens and Pleurozium schreberi) collected from a 188,000 km2 area of the central Barents region (NE Norway, N Finland, NW Russia) were analysed by ICP-AES and ICP-MS. Analytical results for Al, B, Ba, Ca, K, La, Mg, Mn, Na, P, Rb, Si, Sr, Th, U and Y concentrations are reported here. Graphical methods of data analysis, such as geochemical maps, cumulative frequency diagrams, boxplots and scatterplots, are used to interpret the origin of the patterns for these elements. None of the elements reported here are emitted in significant amounts from the smelting industry on the Kola Peninsula. Despite the conventional view that moss chemistry reflects atmospheric element input, the nature of the underlying mineral substrate (regolith or bedrock) is found to have a considerable influence on moss composition for several elements. This influence of the chemistry of the mineral substrate can take place in a variety of ways. (1) It can be completely natural, reflecting the ability of higher plants to take up elements from deep soil horizons and shed them with litterfall onto the surface. (2) It can result from naturally increased soil dust input where vegetation is scarce due to harsh climatic conditions for instance. Alternatively, substrate influence can be enhanced by human activity, such as open-cast mining, creation of ‘technogenic deserts’, or handling, transport and storage of ore and ore products, all of which magnify the natural elemental flux from bedrock to ground vegetation. Seaspray is another natural process affecting moss composition in the area (Mg, Na), and this is most visible in the Norwegian part of the study area. Presence or absence of some plant species, e.g., lichens, seems to influence moss chemistry. This is shown by the low concentrations of B or K in moss on the Finnish and Norwegian side of the (fenced) border with Russia, contrasting with high concentrations on the other side (intensive reindeer husbandry west of the border has selectively depleted the lichen population).  相似文献   

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《Chemical Geology》2007,236(1-2):13-26
We examined the coprecipitation behavior of Ti, Mo, Sn and Sb in Ca–Al–Mg fluorides under two different fluoride forming conditions: at < 70 °C in an ultrasonic bath (denoted as the ultrasonic method) and at 245 °C using a Teflon bomb (denoted as the bomb method). In the ultrasonic method, small amounts of Ti, Mo and Sn coprecipitation were observed with 100% Ca and 100% Mg fluorides. No coprecipitation of Ti, Mo, Sn and Sb in Ca–Al–Mg fluorides occurred when the sample was decomposed by the bomb method except for 100% Ca fluoride. Based on our coprecipitation observations, we have developed a simultaneous determination method for B, Ti, Zr, Nb, Mo, Sn, Sb, Hf and Ta by Q-pole type ICP-MS (ICP-QMS) and sector field type ICP-MS (ICP-SFMS). 9–50 mg of samples with Zr–Mo–Sn–Sb–Hf spikes were decomposed by HF using the bomb method and the ultrasonic method with B spike. The sample was then evaporated and re-dissolved into 0.5 mol l 1 HF, followed by the removal of fluorides by centrifuging. B, Zr, Mo, Sn, Sb and Hf were measured by ID method. Nb and Ta were measured by the ID-internal standardization method, based on Nb/Mo and Ta/Mo ratios using ICP-QMS, for which pseudo-FI was developed and applied. When 100% recovery yields of Zr and Hf are expected, Nb/Zr and Ta/Hf ratios may also be used. Ti was determined by the ID-internal standardization method, based on the Ti/Nb ratio from ICP-SFMS. Only 0.053 ml sample solution was required for measurement of all 9 elements. Dilution factors of ≤ 340 were aspirated without matrix effects. To demonstrate the applicability of our method, 4 carbonaceous chondrites (Ivuna, Orgueil, Cold Bokkeveld and Allende) as well as GSJ and USGS silicate reference materials of basalts, andesites and peridotites were analyzed. Our analytical results are consistent with previous studies, and the mean reproducibility of each element is 1.0–4.6% for basalts and andesites, and 6.7–11% for peridotites except for TiO2.  相似文献   

18.
Most sulfide-rich magmatic Ni-Cu-(PGE) deposits form in dynamic magmatic systems by partial melting S-bearing wall rocks with variable degrees of assimilation of miscible silicate and volatile components, and generation of barren to weakly-mineralized immiscible Fe sulfide xenomelts into which Ni-Cu-Co-PGE partition from the magma. Some exceptionally-thick magmatic Cr deposits may form by partial melting oxide-bearing wall rocks with variable degrees of assimilation of the miscible silicate and volatile components, and generation of barren Fe ± Ti oxide xenocrysts into which Cr-Mg-V ± Ti partition from the magma. The products of these processes are variably preserved as skarns, residues, xenoliths, xenocrysts, xenomelts, and xenovolatiles, which play important to critical roles in ore genesis, transport, localization, and/or modification. Incorporation of barren xenoliths/autoliths may induce small amounts of sulfide/chromite to segregate, but incorporation of sulfide xenomelts or oxide xenocrysts with dynamic upgrading of metal tenors (PGE > Cu > Ni > Co and Cr > V > Ti, respectively) is required to make significant ore deposits. Silicate xenomelts are only rarely preserved, but will be variably depleted in chalcophile and ferrous metals. Less dense felsic xenoliths may aid upward sulfide transport by increasing the effective viscosity and decreasing the bulk density of the magma. Denser mafic or metamorphosed xenoliths may also increase the effective viscosity of the magma, but may aid downward sulfide transport by increasing the bulk density of the magma. Sulfide wets olivine, so olivine xenocrysts may act as filter beds to collect advected finely dispersed sulfide droplets, but other silicates and xenoliths may not be wetted by sulfides. Xenovolatiles may retard settling of – or in some cases float – dense sulfide droplets. Reactions of sulfide melts with felsic country rocks may generate Fe-rich skarns that may allow sulfide melts to fractionate to more extreme Cu-Ni-rich compositions. Xenoliths, xenocrysts, xenomelts, and xenovolatiles are more likely to be preserved in cooler basaltic magmas than in hotter komatiitic magmas, and are more likely to be preserved in less dynamic (less turbulent) systems/domain/phases than in more dynamic (more turbulent) systems/domains/phases. Massive to semi-massive Ni-Cu-PGE and Cr mineralization and xenoliths are often localized within footwall embayments, dilations/jogs in dikes, throats of magma conduits, and the horizontal segments of dike-chonolith and dike-sill complexes, which represent fluid dynamic traps for both ascending and descending sulfides/oxides. If skarns, residues, xenoliths, xenocrysts, xenomelts, and/or xenovolatiles are present, they provide important constraints on ore genesis and they are valuable exploration indicators, but they must be included in elemental and isotopic mass balance calculations.  相似文献   

19.
This paper discusses the result of the detailed investigations carried out on the coal characteristics, including coal petrography and its geochemistry of the Pabedana region. A total of 16 samples were collected from four coal seams d2, d4, d5, and d6 of the Pabedana underground mine which is located in the central part of the Central-East Iranian Microcontinent. These samples were reduced to four samples through composite sampling of each seam and were analyzed for their petrographic, mineralogical, and geochemical compositions. Proximate analysis data of the Pabedana coals indicate no major variations in the moisture, ash, volatile matter, and fixed carbon contents in the coals of different seams. Based on sulfur content, the Pabedana coals may be classified as low-sulfur coals. The low-sulfur contents in the Pabedana coal and relatively low proportion of pyritic sulfur suggest a possible fresh water environment during the deposition of the peat of the Pabedana coal. X-ray diffraction and petrographic analyses indicate the presence of pyrite in coal samples. The Pabedana coals have been classified as a high volatile, bituminous coal in accordance with the vitrinite reflectance values (58.75–74.32 %) and other rank parameters (carbon, calorific value, and volatile matter content). The maceral analysis and reflectance study suggest that the coals in all the four seams are of good quality with low maceral matter association. Mineralogical investigations indicate that the inorganic fraction in the Pabedana coal samples is dominated by carbonates; thus, constituting the major inorganic fraction of the coal samples. Illite, kaolinite, muscovite, quartz, feldspar, apatite, and hematite occur as minor or trace phases. The variation in major elements content is relatively narrow between different coal seams. Elements Sc,, Zr, Ga, Ge, La, As, W, Ce, Sb, Nb, Th, Pb, Se, Tl, Bi, Hg, Re, Li, Zn, Mo, and Ba show varying negative correlation with ash yield. These elements possibly have an organic affinity and may be present as primary biological concentrations either with tissues in living condition and/or through sorption and formation of organometallic compounds.  相似文献   

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