Distribution of environmental sensitive trace elements in the Eocene Sorgun coals, Turkey

The distribution of trace elements in the lower Eocene coal seam mined in the Yeniceltek, Kucukkohne and Ayridam coal mines from the Sorgun Basin was investigated in relation to ash content and maceral composition. The coal seam is mainly composed of huminite. In the present study, 35 samples from five seam sections were collected on the basis of megascopic characteristics. Results were determined using an energy dispersive polarised X-ray fluorescence (EDP-XRF) spectrometer on a whole-coal dry basis. Most of the major and trace elements studied are enriched in high-ash samples, while Ba, Br, Mn and W show relative enrichments in low-ash samples. Most of elements studied, such as Ga, Ce, La, Th, Nb, Rb, Zr, V, Cu, U, Pb, Sb, Cs, Sn, Cr, Se, Y and Zn, are primarily associated with mineral matter (clay minerals). Arsenic and a part of Zn, Se and Sb are probably concentrated in pyrites in the samples. Element concentrations show statistically significant negative correlations with many macerals and positive relationships with only attrinite that is mainly mixed with mineral matter (clay minerals and small quartz grains) in the samples. Nine trace elements (As, Cr, Mn, Ni, Pb, Sb, Se, Th and U), considered as potentially Hazardous Air Pollutants, are present in low to moderate concentrations. The mean values of trace element concentrations display relative enrichments in Se (2.8 ppm), Th (21 ppm) and W (26 ppm) in the investigated samples in comparison with other coals in the world.     

Trace Element Analysis of Geochemical Reference Samples by Energy Dispersive X-ray Fluorescence Spectrometry

A critical evaluation of trace element data derived by energy dispersive X-ray fluorescence (ED-XRF) analysis of over 40 geochemic reference samples shows that results for Rb, Sr, Y, Zr, Nb, and Th can be at least as good in terms of precision (better than ± 2 ppm (2s) or ± 3 % (2s relative), accuracy, and 3s detection limits (2 to 4 ppm) as those obtainable by other routine multi-element analytical techniques. Data obtained simultaneously for Ni, Cu, Zn, Ga, Pb and U are less precise because excitation conditions are less well optimised (with 3s detection limits of 6 to 12 ppm). The quality of data and the efficiency of simultaneous analysis of both sets of elements is well-suited to most geological applications. Following a critical appraisal of calibration accuracy, new trace element data are presented for 15 reference samples from the Geological Survey of Japan.     

Wavelength-dispersive X-ray fluorescence spectrometric determination of Sc, V, Cr, Co, Ni, Cu, Zn, Rb, Sr, Y, Zr, Nb, Ba, Pb, and Th in komatiites

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.     

Gold and Base Metals Associated with Uranium Mineralization in Some Lower Carboniferous Rock Units in the Wadi Abu El Mogheirat Area,Southwestern Sinai,Egypt

The Lower Carboniferous sediments at Wadi Abu El Mogheirat consist of four stratigraphic formations, from base upwards: Um Bogma, El Hashash, Magharet El Maiah and Abu Zarab formations. The most-concentrated radioactive anomalies at Wadi Abu El Mogheirat are in the middle member of the Um Bogma Formation. The gibbsitic marl in this formation shows the highest uranium contents (around 710 ppm). Gibbsitic marl and black gibbsite of the middle Um Bogma Formation show higher enrichment in Co, Cu, Mn, Ni, Pb, Zn, U, V, Ce and Th. Black gibbsite contains the highest total rare earth elements concentration, especially in terms of LREEs, while gibbsitic marl contains the highest content of HREEs. Anomalous contents of gold at Wadi Abu El Mogheirat are recorded for the first time in the gibbsitic marl (content: 10.4 ppm), black gibbsite (2.8 ppm) of the middle member of the Um Bogma Formation and in the siltstones of the El Hashash Formation (0.6 ppm). Gibbsitic marl shows the presence of uranothorite, celestite, zircon, atacamite, barite, xenotime and rutile. These characteristic demonstrate that the middle member of the Um Bogma Formation constitutes a potential source for gold. This conclusion is reinforced by the potential to exploit other metals such as Co, Cu, Mn, Ni, Pb, Zn, U, V, Th and Ce as by-products.     

Uranium-thorium systematics of two Canadian coals

A detailed study of U-Th distribution in two Lower Cretaceous coals in Canada shows that for these coals formed in a continental fluvial and deltaic environment with no marine influence, the U contents are in the range 0.07–7.5 ppm with Th in the range 0.3–11.0 ppm. Average Th/U ratios are near 2 which indicates slight uranium enrichment. The environments of the two coals show different degrees of weathering (montmorillonite-illite and kaolin-gibbsite) and U values are lowest in the more weathered environment In sedimentary profiles associated with the coals, the maximum uranium values are not in the coals but in carbonaceoss clay sediments above and below coal seams. Uranium distribution patterns can be correlated cith Ni, Cu, Rb, Pb, Sr, and Zr, indicating contributions from heavy minerals plus more mobile species (possibly simple organic compounds) which are adsorbed or bonded onto claysor organic matter.     

Contaminant dispersion at the rehabilitated Mary Kathleen uranium mine, Australia

This study reports on the transfer of contaminants from waste rock dumps and mineralised ground into soils, sediments, waters and plants at the rehabilitated Mary Kathleen uranium mine in semi-arid northwest Queensland. Numerous waste rock dumps were partly covered with benign soil and the open pit mine was allowed to flood. The mineralised and waste calc-silicate rock in the open pit and dumps has major (>1 wt%) Ca, Fe and Mg, minor (>1,000 ppm) Ce, La, Mn, P and S, subminor (>100 ppm) Ba, Cu, Th and U, and trace (<100 ppm) As, Ni, Pb, Y and Zn values. Consequently, chemical and physical weathering processes have acted on waste rock and on rock faces within the open pit, mobilising many elements and leading to their dispersion into soils, stream sediments, pit water and several plant species. Chemical dispersion is initiated by sulfide mineral breakdown, generation of sulfuric acid and formation of several soluble, transient sulfate minerals as evaporative efflorescent precipitates. Radiation doses associated with the open pit average 5.65 mSv year⁻¹; waste dumps commonly have lower values, especially where soil-covered. Surface pit water is slightly acid, with high sulfate values accompanied by levels of U, Cu and Ni close to or above Australian water guideline values for livestock. Dispersion of U and related elements into soils and stream sediments occurs by physical (erosional) processes and from chemical precipitation. Plants growing in the mine void, on waste dumps and contaminated soil display evidence of biological uptake of U, LREE, Cu and Th and to a lesser degree of As, Ni, Pb, Y and Zn, with values being up to 1–2 orders of magnitude above background sites for the same species. Although rehabilitation procedures have been partly successful in reducing dispersion of U and related elements into the surrounding environment, it is apparent that 20 years after rehabilitation, there is significant physical and chemical mobility, including transfer into plants.     

The Svalbard western coast: site of baseline geochemistry and incipient contamination

 Potentially toxic metals tracked by the Arctic Monitoring and Assessment Program were analysed in sediments from the Svalbard western coastal zone. These include As and Hg found as contaminants in other Arctic seas as well as other elements (e.g. Pb, V, Cu, Zn, Cr, Ni). Svalbard shelf sediments contain average values of 12 ppm As, 12 ppm Pb, 56 ppb Hg and 114 ppm V. These values increase in Isfjorden sediments to 15 ppm As, 28 ppm Pb, 99 ppb Hg and 210 ppm V. Cluster analysis yields a major cluster that is likely related to clay minerals (Al, K, Ti, Mg) and sorption onto them of transition (Cu, V, Cr, Sc) and other elements (Pb, Rb). A second significant cluster includes Ca, Sr and plagioclase. The Svalbard western shelf is a natural geochemical environment. The possible incipient contamination of fjord sediments by As, Pb, Hg and V should be evaluated for possible links to anthropogenic sources. If links are found, remediation must be used to stop the input and preserve a pristine Svalbard fjord environment. Received: 21 December 1998 · Accepted: 15 March 1999     

Enhanced diffusion of Uranium and Thorium linked to crystal plasticity in zircon

The effects of crystal-plasticity on the U-Th-Pb system in zircon is studied by quantitative microstructural and microchemical analysis of a large zircon grain collected from pyroxenite of the Lewisian Complex, Scotland. Electron backscatter diffraction (EBSD) mapping reveals a c.18° variation in crystallographic orientation that comprises both a gradual change in orientation and a series of discrete low-angle (<4°) boundaries. These microstructural data are consistent with crystal-plastic deformation of zircon associated with the formation and migration of dislocations. A heterogeneous pattern of dark cathodoluminescence, with the darkest domains coinciding with low-angle boundaries, mimics the deformation microstructure identified by EBSD. Geochemical data collected using the Sensitive High Resolution Ion MicroProbe (SHRIMP) shows a positive correlation between concentrations of the elements U, Th and Pb (ranging from 20–60 ppm, 30–110 ppm, and 14–36 ppm, respectively) and Th/U ratio (1.13 – 1.8) with the deformation microstructure. The highest measured concentrations and Th/U coincide with low-angle boundaries. This enrichment is interpreted to reflect enhanced bulk diffusion of U and Th due to the formation and migration of high-diffusivity dislocations. ²⁰⁷Pb/²⁰⁶Pb ages for individual analyses show no significant variation across the grain, and define a concordant, combined mean age of 2451 ± 14 Ma. This indicates that the grain was deformed shortly after initial crystallization, most probably during retrograde Inverian metamorphism at amphibolite facies conditions. The elevated Th over U and consistent ²⁰⁷Pb/²⁰⁶Pb ages indicates that deformation most likely occurred in the presence of a late-stage magmatic fluid that drove an increase in the Th/U during deformation. The relative enrichment of Th over U implies that Th/U ratio may not always be a robust indicator of crystallization environment. This study provides the first evidence of deformation-related modification of the U-Th system in zircon and has fundamental implications for the application and interpretation of zircon trace element data.     

岩石中低量稀土和其他痕量元素的X-荧光光谱测定

用X-荧光光谱测定岩石中低量稀土元素的仪器参数和测定条件,文[1]已作过讨论。本文介绍样品分析所采用的基本校正,谱线重叠校正和背景处理方法,并将这些方法应用于其他少量和痕量元素的测定。基体的吸收校正岩石样品中最重的主元素是铁,镧系元素La～Er的La线和Ti,Sc,Cr,Mn,Fe,     

The determination of trace elements in whole coal by rhodium tube X-ray fluorescence spectrometry: a rock-based synthetic coal calibration

A method is presented for the determination of 15 trace and minor elements (Fe, Ti, V, Cr, Mn, Ni, Cu, Zn, Pb, Sr, Rb, Ba, Zr, Y, Nb) in whole coal, by X-ray fluorescence spectrometry. A Rhanode X-ray tube is used and matrix corrections are derived from the intensity of the rhodium Kα Compton scattered tube line. The calibration is based on synthetic coals made from mixtures of standard rocks with graphite and cellulose, emulating the range of compositions likely to be encountered in bituminous coals. Robust pellets are made from 9 g of coal blended with a powdered binder. Results are presented for a number of standard coals.     

Trace element characterisation of Cretaceous Orange Basin hydrocarbon source rocks

Trace elements in the kerogen fraction of hydrocarbon source rock samples from two wells obtained from the Cretaceous units of the Orange Basin, South Africa were determined using X-ray fluorescence spectrometry, in order to determine their distribution and geochemical significances. The concentrations of the elements (As, Ce, Co, Cu, Fe, Mo, Ni, Pb and V) determined ranged from 0.64 to 47,300 ppm for the samples analysed. The total organic carbon (TOC) values indicate that the samples are organic rich but did not show any trend with the distribution of the trace metals except Ce, Mo and Pb. Dendrogram cluster analysis discriminated the samples into three groups on the basis of their level of thermal maturity. Thermal maturity has a significant effect on the distribution of the trace metals. Cobalt/Ni and V/Ni ratios and cross plots of the absolute values of V and Ni indicate that the samples had significant marine organic matter input. The V and Ni contents and V/(V + Ni) ratio indicate that the organic matter of the source rocks had been deposited in reducing conditions. Despite the similarities in the organic matter source input and depositional environment of the organic matter of the samples from the two well, cross plots of Co/Ni versus V/Ni and Mo/Ni versus Co/Ni were able to reveal subtle differences. Cluster analysis of the samples was also able to reveal the subtle thermal maturity differences of the samples.     

Geochemistry of an oceanite-ankaramite-basalt suite from East Island,Crozet Archipelago

The petrology and geochemistry of East Island have been investigated for the first time. The island is a deeply dissected remnant of a Pleistocene shield volcano, one of several emerging from an oceanic rise forming part of the southwest branch of the Indian Ocean ridge system. The lavas form a flat-lying sequence of oceanites, ankaramites, olivine basalts and feldsparphyric basalts, the ankaramites containing 1 cm phenocrysts of diopsidic clinopyroxene. X-Ray fluorescence analyses were made of 43 lavas for the major elements plus Cr, Ni, Rb, Sr, Ba, Pb, and Th and the minerals were analysed by electron microprobe. The elements Mg, Cr, and Ni are strongly concentrated in spinel, olivine and clinopyroxene phases and in the ankaramites and oceanite lavas with maximum concentrations of 18% MgO, 1,000 ppm Cr, 380 ppm Ni, while Al, Ti, K, Rb, Ba, Th, Na, P, Sr concentrate in the groundmass and in the feldspathic and aphyric basalts. The elements Si, Ca, Fe and Mn remain virtually constant throughout the series.Correlations of +0.95 or better exist between the concentrations of elements within the two groups given above, and negative correlations between elements in different groups. The fractionation trends are unique with respect to the constant Al/Ti ratio and K/Sr ratio, but all trends may be reproduced by calculating the effect of subtraction of suitable amounts of chromite, olivine and low Ti clinopyroxene from an alkaline olivine basalt parent. Either fractionation has taken place involving these three phases under low pressure conditions or it is the result of different degrees of partial melting of mantle material.A complex magnesian chrome spinel is found in the ankaramites and is often jacketed by a chromian titanomagnetite. A complete series of intermediate compositions appears to exist between the two end members.     

Chalcophile elements in western Canadian coals

Concentrations of chalcophile elements (As, Co, Cu, Hg, Mo, Ni, Pb, Sb and Zn) in western Canadian coals were determined using INAA and AAS. The concentrations of these elements in western Canadian coals are within the range for most world coals. However, there are some high values for coals from outcrops and from areas which are not currently being mined.Arsenic content in the majority of western Canadian coals, particularly those currently being mined, is low (0.2–3 ppm). However, there are coals with high arsenic content; for example, lignites from Hat Creek A zone contain between 4.0 and 14.0 ppm As. In some samples from Comox and Suquash, the As concentration is as high as 240 ppm and 1400 ppm, respectively. The enrichment of As in high arsenic coals is related to the geology and nature of country rocks associated with the coal seams. The concentration of other elements for most western Canadian coals, particularly those being mined, are within the range for most world coals. In these coals, the concentration ranges (in ppm) of chalcophile elements are 0.3-3.6 for Sb, 0.8-4.6 for Co, 7–35 for Cu, <0.1 for Hg, 2–6 for Mo, 4–94 for Ni, 6–22 for Pb, 2–7 for Se and 7–110 for Zn.     

Abundances and modes of occurrence of trace elements in the Çan coals (Miocene), Çanakkale-Turkey

This study presents the concentrations and modes of occurrence of trace elements in 81 coal samples from the Çan basin of northwestern Turkey. The concentration of trace elements in coal were determined by inductively coupled plasma-mass spectrometry and inductively coupled plasma-atomic emission spectrometry. Additionally, traditional coal parameters were studied by proximate, ultimate, X-ray diffraction, and petrographic analyses. Twenty trace elements, including As, B, Ba, Be, Cd, Cu, Co, F, Hg, Mo, Ni, Pb, Sb, Se Sn, Th, Tl, U, V, and Zn, receive much attention due to their related environmental and human health concerns. The Çan coals investigated in this study are lignite to sub-bituminous coal, with a broad range of ash yields and sulphur contents. The trace element concentrations show variety within the coal seams in the basin, and the affinities vary among locations. The concentrations of B, Ba, Be, Cd, Cu, Co, F, Hg, Mo, Ni, Pb, Sb, Se, Sn, Tl, and Zn in Çan coals are within the Swaine's worldwide concentration range, with the exception of As, Th, U, and V. On the other hand, compared with world coals, the Çan basin coals have higher contents of As, B, Cu, Co, Mo, Pb, Th, U, V, and Zn. Based on statistical analyses, most of the trace elements, except for U, show an affinity to ash yield. Elements including As, Cd, Hg, Se, Cu, Mo, Ni, and Zn, show a possible association with pyrite; however, the elements Se, B, and Mo can be have both organic and inorganic associations.     

Geochemical stream sediment survey in Winder Valley, Balochistan, Pakistan

A pilot scale geochemical survey of sediments from the Winder Stream (SW Pakistan) and its tributaries was carried out. The Winder Stream mainly receives sediment from the southern extensions of the Mor and Pab Ranges in the District of Lasbela (Balochistan). In these two mountain ranges, rocks from Jurassic to Cretaceous age are exposed. Rocks of the Ferozabad Group comprise of carbonates and siliciclastics of Lower–Middle Jurassic age and occupy the dominant part of the Mor Range. These strata host syngenetic and epigenetic Zn–Pb–Ba mineralizations of Stratiform Sediment-Hosted (SSH) and Mississippi Valley Type (MVT) deposits.Quantitative estimates of mobile and immobile elements were made from active stream sediments of the Winder stream and its tributaries. The samples were analyzed for Ag, Zn, Pb, Cu, Ni, Co, V, Mn, Fe and Ba using atomic absorption spectroscopy. The abundance of these elements is discussed in relation to local geological conditions such as bedrock, climate, weathering, mobility and pH of the dispersing waters. A number of Zn anomalies have been distinguished in the study area. Kharrari (Zn, 360 ppm), Sand (Zn, 340 ppm) and Draber (Zn, 210 ppm) are demarcated as new areas for Zn mineralization. The present study also indicates prospects of Ag, Cu and V in the rocks of the Mor Range.Relationships between various elements have been identified from scattergrams and reflect genetic associations. Whereby the positive correlation between Cu–Zn (0.55, n=18) and Cu–Pb (0.63) is related to possible sulphide mineralization.     

The pollution of marine sediments by trace elements in the coastal region of Togo caused by dumping of cadmium-rich phosphorite tailing into the sea

 The marine coastal sediments from Togo have been analysed for the trace elements Cd, Cr, Cu, Ni, Pb, Sr, V, Zn and Zr to ascertain the geo-ecological impact of dumping of phosphorite tailings into the sea. Trace element concentrations ranged from 2–44 ppm for Cd, 22–184 ppm for Cu, 19–281 ppm for Ni, 22–176 ppm for Pb, 179–643 ppm for Sr, 38–329 ppm for V, 60–632 ppm for Zn and 18–8928 ppm for Zr. Regional distribution of trace elements in the marine environment indicates that the concentrations of Cr, Cu, Ni, Pb, V, Sr and Zn increase seawards and along the coastal line outwards of the tailing outfall, whereas Cd and Zr showed reversed spatial patterns. Sorting and transport of phosphorite particles by coastal currents are the main factors controlling the distribution of particle-bound trace metals in the coastal environment. The Cd, Sr and Zn concentrations decrease with decreasing grain size in marine coastal sediments, whereas Cr, Cu, Ni and Zn concentrations increase with decreasing grain size. Percolation and shaking experiments were carried out in laboratory using raw phosphate material and artificial sea water. Enhanced mobilization of Cd from phosphorites by contact with the sea water was observed. Received: 11 May 1998 · Accepted: 20 October 1998     

Trace elements and their variation along seam profiles of certain coal seams of Middle and Upper Barakar formations (Lower Permian) in East Bokaro coalfield,district Hazaribagh,Bihar, India

Trace-element data are presented for the first time for any coal seam in India, across a full working section, based on systematically collected channel samples of coal, together with their maceral composition. The trace-element variation curves along the seam profile are presented together with group maceral compositions of Kargali Bottom, Kargali Top, Kargali, Kathara, Uchitdih, Jarangdih Bottom, Jarangdih, and Jarangdih Top seams, East Bokaro coalfield. The Kathara and Uchitdih seams have also been sampled at two other localities and lateral variation in data in their trace-element and maceral compositions is also evaluated.The East Bokaro coals have: Ba and Sr > 1000 ppm; Mn < 450 ppm; Zr < 400 ppm; Ni and V < 250 ppm; Cr < 185 ppm; La < 165 ppm; Cu, Nb, and B < 125 ppm; Pb, Co and Y < 75 ppm; Ga, Sn, Mo, In and Yb < 15 ppm; Ag 2 ppm; and Ge 7 ppm. Petrographically, the coals are dominant in vitrinite (33–97%), rare in exinite (<15%), and semifusinite (0.8–49%) is the dominant inertinite maceral, with variable mineral and shaly matter (11–30%), graphic representation of trace elements versus vitrinite, inertinite, and coal ash indicates the affinity of (a) vitrinite with Cu, Ni, Co, V, Ga and B; (b) inertinite with Nb and B; and (c) coal ash (mineral matter) with Pb, Cu, Ni, La, Mn and Y; Ba, Cr, Sr, Zr, Cu and Ni are of organic as well as inorganic origins.The trend of the variation patterns and average compositions of the different seams are shown to be distinct and different. The variation along the same profile is inferred to be different for different seams of the coalfield.Trace-element data for certain coals of seams from different coalfields in the Gondwana basins of India are presented. There is a wide difference for each of these basins with respect to certain elements. This is suggestive of the proportions of Cu, Ni, V, Y, Ba, Sr, Cr, B, Zr and Ag, characterizing the different Gondwana Basins.     

Radioactive quartz-pebble conglomerates from western margin of Bonai granite pluton,Sundargarh district,Orissa — A new find

Several radioactive quartz-pebble conglomerate (QPC) occurrences at the western margin of Archaean Bonai granite and overlying Iron Ore Group (IOG) rocks have recently been located over a total strike length of 8–10 km intermittently in a NE-SW to E-W trend with steep dips due north-west to north in parts of Sundargarh district of Orissa. The QPC samples have analysed up to 0.039% U₃O₈ and 0.035% ThO₂ with high concentration of Y (74 to 518 ppm), La(<100 to 880 ppm), Cr ( 126 to 633 ppm), Zr (137 to 1250 ppm) and Pb (31 to 581 ppm). Cellulose Nitrate (CN) film studies of few QPC samples indicated adsorbed uranium over goethite and infiltrated ferruginous material (limonite), secondary uranium as encrustation and fracture filling and discrete sub-rounded grains of monazite, zircon, allanite and rare xenotime in the matrix of QPC as radioactive phases. Higher content of Th over U, elevated concentration of Y and La in QPC eliminates the possibility of its low temperature product by epigenetic processes. Poor correlation of U with elements like Pb, Y, Zr, La and Cr can be explained due to surficial leaching of uranium from QPC after its deposition as reflected by adsorbed U over iron-oxides and low U/Th ratio in QPC in the area.     

Surface geochemical and biogeochemical expression of base‐metal mineralization at Woodlawn,New South Wales,Australia

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.     

Statistical assessment of geochemical pattern in overbank sediments of the river Sava,Croatia

Four overbank profiles from the three terraces of different age were sampled in 10 to 20 cm intervals for the bulk content of major and minor (Ca, Mg, Fe, Ti, Al, Na, K and P) and trace (Mo, Cu, Pb, Zn, Ni, Co, Mn, As, U, Th, Sr, Cd, Sb, V, La, Cr, Ba, W, Zr, Ce, Sn, Y, Nb, Ta, Sc, Li, Rb and Hf) elements in the minus 0.125 mm fraction. Univariate statistics together with analysis of variance discriminated between the lower-lying carbonate (CA) population dominantly composed of carbonates and the overlying silicate (SI) population being dominantly of silicate mineralogy. This stratified pattern resulted from the intensive erosive action of melting glaciers exerted on limestones and dolomites in the alpine region, followed by local inputs mainly of silicate composition. Elements exhibiting the greatest between-population variability are Ca and Mg being enriched in the CA population and Fe, Mn, P, Sr, Al, Na, K, Li, Rb, Y, Zr, Ni, Cr and Ti being enriched in the SI population. Anomalously high Hg, Pb and Ba concentrations (maximum values: 6,500±2,860 ppb, 225±13 ppm and 1,519±91 ppm, respectively) in the lowermost part of the profile S7, which is nearest to the Croatian-Slovenian border, derive from the mineralized Slovenian catchment area. This profile also contains trimodal frequency distributions of Fe, Mn and P whose highest concentrations coincide with increased values of Zn and Cu which are bimodally distributed. Geochemical patterns of majority of elements in all four profiles consistently reflect the average compositions of the upstream drainage basins.