Todor Serafimovski

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.

Potentially toxic contamination of sediments, water and two animal species in Lake Kalimanci, FYR Macedonia: Relevance to human health

The objectives of the research were: (1) to examine the concentrations of metals in Vimba melanops and Rana temporaria and (2) to evaluate the potential risks of the contaminated organisms to human health in Makedonska Kamenica region. Analyses identified high levels of Cr, Hg, Ni and Pb in studied animals, which also exceeded their permissible levels in food. In sediment and soil samples, levels of Cd, Cu, Cr, Pb, Zn and As were perceived, while Cd, Cu, Ni, Pb, Se and As were increased in water samples. Results of transfer factor revealed that the examined animals had higher bioaccumulation rate from surrounding waters than from sediments or soils. The accomplished Health Risk Index disclosed that studied animals can have considerably high health risks for inhabitants. Conclusively, they could be considered as highly contaminated with metals and can consequently harm human health, especially children in their early development stages.

Dwarf copper-gold porphyry deposits of the Buchim-Damjan-Borov Dol ore district, Republic of Macedonia (FYROM)

The metallogenic aspects, tectonic setting, magmatism, structure, and composition of Au- and Ag-bearing porphyry copper deposits in the Buchim-Damjan-Borov Dol ore district and their genetic features are considered and compared with earlier published data. Special attention is paid to supergene gold in heavy concentrate halos of the Borov Dol deposit. The total Cu reserves of the deposits discussed in this paper do not exceed 150 kt. The Buchim deposit likely is the world’s smallest deposit of this type currently involved in mining. A comprehensive study of these dwarf porphyry copper deposits is undertaken to answer questions on the conditions of their formation. How do they differ from formation conditions of giant deposits?

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.

Formation mechanism of dwarfish Cu-Au porphyry deposits of Macedonia

Regularities in the distribution and formation mechanism of giant Cu porphyry deposits have been discussed by many authors. Most recent works are dedicated to the problem of their formation [1]. The deposits of Macedonia discussed in this communica� tion usually contain up to 150 000 t of copper with the Buchim deposits likely being the smallest in the world among similar recently mined deposits. The long�term economically profitable development of the latter refutes the traditional opinion that only Cu porphyry deposits with reserves at least of 2 500 000 t and Cu content exceeding 0.5% are profitable for exploitation. Therefore, complex study of dwarfish deposits of Macedonia is as important as research into giant depos� its of the Pacific ore belt for solving the problem of their formation mechanism and answering the question of how they differ compared to giant deposits.

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].

Native gold of the porphyry copper mineralization in the Borov Dol deposit (Republic of Macedonia)

Mineralogical study of gold in disseminated porphyry copper ores is complicated by its fine (often micrometer size) segregations and low contents micrometer size) segregations and low contents (O.n glt). This paper presents the results of investigation of gold in porphyry copper ores of the Borov Dol deposit (Republic of Macedonia) by an ingenious method. Macedonia is located in the Serbian-Macedonian sector of the Eurasian metallogenic belt of the Tethys. The metallogeny of this region is related to the Cenozoic activation and formation of the volcanoplutonic rock complex in the course of scattered spreading.

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.

Amphibolite-hosted Fe-Ti oxide mineralization of the Mitrashinci deposit, Eastern Macedonia

The Mitrashinci deposit in Eastern Macedonia represents a unique type of metamorphosed Fe-Ti deposits. Fe-Ti oxide mineralization was identified in amphibolites from the metamorphic complex of the Serbo-Macedonian massif, which comprise two different stratigraphic horizons striking NW-SE. At Mitrashinci, Fe-Ti oxide mineralization is hosted by deeply buried amphibolites of the second stratigraphic horizon. Two types of amphibolites were recognized, almost barren garnet-biotite and mineralized garnet-cummingtonite. The mineralized zone (varying in thickness from 20 to 300 m) has been traced for 12 km within amphibolite host rocks. Several lens-like ore bodies hosted by garnet-cummingtonite amphibolites striking NW-SE have been intersected by mining operations at Kobilski Rid, Gromadna, Leskovica, Dolga Poljana, and Bliznakov Cukar. The contents of Fe and Ti vary greatly in the ores (13–23% and 4–9.1%, respectively). The ore bodies consist mainly of Fe-Ti oxides, such as magnetite, titanomagnetite, ilmenite, and hematite (martite), and minor pyrite, chalcopyrite, pyrrhotite, rutile, titanite, leucoxene, and goethite. The major ore minerals (ilmenite, titanomagnetite, and magnetite with a minor sulfide phase) were formed during the magmatic phase of ore deposition and were not considerably affected by subsequent polyphase metamorphism.

Native Gold of the Borovik Ore Field,Republic of Macedonia (FYROM)

Mineralogical and geochemical study has shown that native gold from the Borovik ore field, Republic of Macedonia (FYROM) is homogeneous in composition, high in fineness, and contains appreciable admixtures of Fe and Cu. The chemical composition of native gold does not depend on the morphology of gold grains that indicates closeness of primary source. The results are similar to previous data on gold geochemistry from the Borov Dol porphyry copper and the Plavica high sulfidation epithermal deposits. Electrum was found in placer gold neither in the Borovik ore field nor at the adjacent Plavica deposit. Pan sampling within porphyry copper and silver-gold high sulfidation epithermal deposits and ore fields allows identification and detailed study of the chemical composition and morphological features of native gold from deposits of these types. This procedure is recommended to be applied at prospect and prospect-and-evaluation works. The composition of native gold and morphology of gold grains predict high sulfidation epithermal mineralization in the Borovik ore field.