Goran Tasev

The Alshar Epithermal Au-As-Sb-Tl Deposit, Southern Macedonia

The results of tectono-metallogenic, geological-structural, mineralogical, isotopic, and thermobarogeochemical studies at the Alshar deposit and in the adjacent area are discussed. The data obtained show that the gold mineralization at the deposit is similar to that observed at the Carlin-type deposits in the western United States. Similar characteristics include the Au-As-Sb-Tl-Hg geochemical assemblage; low Pb, Zn, Cu, and Ag contents in ore; widespread jasperoid and argillic metasomatic alterations of host siliciclastic-carbonate sedimentary rocks; and the spatial relations to fault zones. At the same time, the Alshar deposit differs from the Carlin-type deposits by the following features: (1) Pliocene age of mineralization, (2) expansion of mineralization over younger volcanics, (3) a high Tl grade in ore, and (4) localization of the ore field in a long-lived central-type magmatic structure. The results obtained can be used as an exploration model.

Heavy metal characteristics in Kočani Field plant system (Republic of Macedonia)

Heavy metal contamination of soils is widespread and induces a long-term risk to ecosystem health. This research focuses on the heavy metal contamination, transfer values and risk assessment in the Kočani Field plant system (Republic of Macedonia). To identify the heavy metal concentrations in Kočani crops (rice and maize), the geochemical analysis was performed by inductive coupled plasma mass spectrometer and thereupon the transfer factor (TF) and estimated daily intake amount values were calculated. The highest As, Cd, Mo, Pb and Zn values were determined in the rice samples grown in the paddy fields near the Zletovska River. The highest Pb and Mo concentrations measured in the maize samples were from the maize fields near the Zletovska River and Ciflik city. High TF values for Mo, Zn, Cd and Cu revealed a strong accumulation of Mo, Zn and Cd by rice and Mo and Zn by maize crops. The results of the estimated daily intake showed that the regular consumption of rice and maize crops containing the highest Cd, Mo, Pb and Zn concentrations could pose a serious threat to human health, because the daily intake of Cd, Mo, Pb and Zn for crops grown in the fields around the Zletovska River exceeded the recommended provisional tolerable daily intake values. Taking into account the results, the area around Zletovska River is considered as the most anthropogenically impacted part of Kočani Field.

Tectonic Position of the Alshar Au–As–Sb–Tl Deposit,Macedonia

During the second half of the 20th century, several dozen large and medium deposits of disseminated pyrite–marcasite ores with total gold reserves of more than 6000 t and annual gold production of ~200 t were found in the Basin and Range Province, Nevada, United States [1, 2]. This unique gold district is termed as the Carlin trend. The limited development of the Carlintype mineralization in other gold districts of the world is presently a debated issue. Naturally, each Carlin-type mineralization inferred beyond Nevada requires detailed investigations. In 2004, we began to study the Alshar deposit with Carlin-type mineralization together with Macedonian geologists [3]. The Alshar deposit is a large object in terms of Tl reserves and a medium reserve in terms of inferred Au reserves [3, 4].

Assessment of essential and nonessential dietary exposure to trace elements from homegrown foodstuffs in a polluted area in Makedonska Kamenica and the Kočani region (FYRM)

UNLABELLED The main purpose of the present study is to assess human dietary exposure to essential and non-essential trace elements via consumption of selected homegrown foodstuffs. Twelve essential and non-essential trace elements (Cd, Co, Cu, Cr, Hg, Mo, Ni, Pb, Sb, Se, Zn and As) were detected in various homegrown foodstuffs. Detailed questionnaires were also applied among a sample of the local population to collect information on sociodemographic characteristics. The results of the present study clearly indicate that the majority of the trace elements are at highly elevated levels in the studied foodstuffs, in comparison to international recommendations. The maximum measured levels of ETE and NETE are as follows [μgkg(-1)]: Cd 873, Co 1370, Cu 21700, Cr 59633, Hg 26, Mo 6460, Ni14.5, Pb 11100, Sb 181, Se 0.30, Zn 102 and As 693. Additionally, age, body mass index and gender were significantly associated with levels of dietary exposure. Further research is warranted on the potential health implication of this exposure. CAPSULE ABSTRACT The study merges the accumulation of ETE and NETE in home-grown foodstuffs and reflects considerably high health risks for inhabitants.

Ržanovo metamorphosed lateritic Fe-Ni deposit, Republic of Macedonia

The Ržanovo deposit is a unique example of metamorphosed lateritic Fe-Ni deposits in the wellknown Vardar ophiolitic belt of the Balkans, where Fe-Ni mineralization is a product of the Early Cretaceous lateritic weathering mantle after Jurassic ultramafic rocks subsequently redeposited into the Cretaceous shallow-water marine basin. As a result, a layer of Fe-Ni ore 30–50 m thick with an average Ni grade of ∼1% was formed at the Ržanovo deposit; this layer is traced for more than 4 km along the strike and 500 m down the dip. At the end of the Late Cretaceous, intense Alpine tectonic faulting and folding resulted in overturning of the initially horizontal ore layer, which is now nearly vertical. The most abundant fissile hematite ore contains 0.70–1.27% Ni, whereas the economically most important massive hematite ore with 0.93–1.49% Ni occurs locally. The major Ni-bearing minerals are magnetite, hematite, chromite, sulfides, talc, chlorite, amphibole, and stilpnomelane.

Environmental Characterization of Lake Ecosystems Located in Serbo Macedonian Massif (FYRM)

This chapter represents the mineralogical, geochemical and isotopic characteristics of recent lacustrine sediments, shells of the Anodonta cygnea and fish species (Rutilus rutilus dojranensis) from the Lake Dojran (FY Republic of Macedonia, southern part of the Serbo-Macedonian Massif (SMM)) which provide indirect evidence regarding biomineralization and calcification processes as well as various geological problems. Environmental pollution can seriously contribute to different biological processes concerning the condition of physiological secretion of carbonate material into the shells. For comparison, sediments and fish species V. melanops from the Lake Kalimanci, located in northern part of the SMM, were also implicated into the study. X-ray powder diffraction (XRD), inductively coupled plasma mass spectrometry (ICP-MS) and C and O stable isotope analyses were performed, and thereupon enrichment factor (EF) values were calculated. The XRD results revealed close association of sediment mineralogy with the prevailing metamorphic, volcanic and igneous rocks of the region surrounding both lakes (Dojran and Kalimanci). According to the EF value results, surficial Lake Dojran sediments are little enriched with Co, Cr, Cu, Pb, and Zn, moderately enriched with Au, Ni and Sb, moderately severely enriched with Au, severely enriched with Sb and very severely enriched with As. This elemental enrichment originates from various geogenic (geological background and polymetallic mineralization) and anthropogenic (tourism, traffic, coatings, untreated wastewater discharge and agrochemicals) sources. Calculated EF revealed that surficial sediments from Lake Kalimanci are extremely severe enriched with Pb, Zn, and Cd, meanwhile As and Cu shows very severe enrichment. Comparing to Lake Dojran, calculated EF is much higher in Lake Kalimanci than in Dojran. Stable isotope signature results showed that Lake Dojran sediments were strongly influenced by evaporation effect. Their δ18O values range from -5.60 to +1.49 ‰ and the δ13CVPDB composition range from -6.45 to -1.65 ‰. Shells Anodonta cygnea are mainly composed from mineral aragonite and their δ18O values varies between 0.43 ‰ and +1.94 ‰, and δ13CVPDB between -2.48 to -1.72 ‰. δ18O signature in shells might be explained by precipitation of the carbonate from isotopically heavier oxygen lake water. The unussualy heavy skeletal oxygen suggested calcification at the elevated temperature and evaporation. Analyses also identified particularly high levels for Cr, Hg, Ni and Pb in fish (V. Melanops) and frog (R. Temporaria) samples from Lake Kalimanci with mean values [µgkg-1]: 1090 – 6.5, 339 – 117, 567 – 5100 and 1127 – 435, respectively. Meanwhile, the contents of Cr, Hg, Ni and Pb in fish samples (R. rutilus dojranensis) from Lake Dojran are a bit lower [µgkg-1]: 2320, 1690, 700 and 50.

Three types of ore mineralization at the Vrshnik ore body, Buchim copper mine, Republic of Macedonia

The ore body Vrsnik as a constitutional part of the Buchim ore deposit is the most complex and completely zoned of all four of them. There strictly were distinguished three main ore types: oxide, sulfide and mixed. The oxide ore, that is of major interest within this paper, mainly was developed in shallow or near surface parts, i.e. in the first 20 m from the surface to depth (E660/675), than mixed oxide-sulfide or so-called cementation zone that stretches up to 50 m in depth, while below elevation 630 m continues sulfide primary (hypogene) ore. Total quantity of oxide and mixed ore is 5 Mt with an average content of 0,342 % Cu and it represents an important copper raw material for copper leaching facility within the Buchim mine. Total ore reserves within the Vrsnik ore body were calculated at approximately 14 Mt with an average content of 0,305 % Cu.

TECHNO-ECONOMIC PARAMETERS RELATED TO THE VRSHNIK CU-AU ORE BODY, BUCHIM COPPER MINE, EASTERN MACEDONIA

Calculated ore-bearing coefficient in the Vrshnik ore body was 0.78%, meaning that within the ore body boundaries only 22% of mass is not mineralized somehow, which is highly compatible with remaining three ore bodies within the Buchim porphyry copper mine. The calculated value of variation coefficient (V) has shown value of 70% that is in the range of 43-100%, which displays that this ore body belongs to the third group of deposits with uneven mineralization. An average copper, gold and silver concentrations were determined as 0.305% Cu, 0.18g/t Au and 0.91 g/t Ag, respectively. Minimal economic content (MEC) within the Vrsnik ore body, as represent of this kind of mineralization, was determined as 0.160% Cu. In similar manner was calculated the lowest copper boundary (cutoff grade), which have shown value of 0.138% Cu and thus allowing certain decrease of contents in exploited ore. Also, there were calculated so called copper monometal values, which included influence of the present gold and silver in the ore. Calculated copper monometal was set at relatively fair 0.399% Cu that represents solid mainstay for exploitation of copper in these low percentage ores. Calculated ore reserves in this particular ore body were 13 577 267 t of ore with 0.305% Cu, 0.18 g/t Au and 0.91 g/t Ag and increased mine life for additional 6 years.

Influence of the Buchim copper leaching factory on the environ around the active Buchim copper mine

Within this paper we are going to present a review of results for some particular contaminants such are: Co, Cu, Cd, Al, Fe, U etc., until the 2011 as well as review of results of monitoring (2012-2013) following the construction of the copper leaching facility. For the period covering period 1979-2011, in marked contrast, the water from the mine used to be acidic (pH <5) and had some dramatically high concentrations of particular elements: 75 mg/L Al, 1.16 mg/L Co, 140 mg/L Cu, 61 mg/L Mn, 0.905 mg/L U and etc. These very high values occurred within about 3 km of the mine but the influence of the mine extends downstream. For instance, the Cu concentrations used to be elevated (>0.5 mg/L) 24 km downstream, where the River Madenska joins the River Bregalnica. Positive effects in regards to environmental pollution following the construction of the leaching facility were confirmed by the results of the 2012 monitoring and especially by the results of the 2013 monitoring. According to the monitoring in 2013, copper values ranged from <0.01 to 1.6 mg/L Cu, silver in the range 0.001÷0.02 mg/L Ag, ammonia 0.006÷0.90 mg/L NH4 as well as pH 4.58÷7.86, which itself speaks about the positive effects achieved with constructions of the leaching facility and engulfed drainage waters.

The Rganovo Fe–Ni Deposit: An Example of the Reworked Lateritic Weathering Crust in the Vardar Ophiolite Zone

The Rganovo deposit (Republic of Macedonia) is a typical representative of unique reworked lateritic Fe– Ni deposits in the well-known Vardar ophiolite zone of the Balkan Peninsula (Fig. 1). The Rganovo mine was developed over 30 years with brief gaps. Since the 1980s, approximately 11.2 million tons of ores with an average nickel content of 0.92–0.94% were produced by this mine. During the last two years, ore reserves at deep levels of the deposit were thoroughly reassessed. These works were accompanied by scientific investigations, which made it possible to analyze the new geological data, study the mineralogical–geochemical properties of ores from this deposit using advanced analytical methods, and specify, based on these materials, their formation model.