General features of some polymetallic ore deposits in the Republic of North Macedonia

The general features of several important mineral deposits of polymetallic character in the Re public of Northern Macedonia that have been actively exploited in the past are described. These include the Buchim copper mine and Sasa, Zletovo and Toranica lead-zinc mines, as well as some ore prospects that have been extensively explored for years. In addition, sites with known ore re -serves, but which are not yet at the exploitation stage are presented, including Plavica, Ilovica, Kadiica, Borov Dol and others. The elaborated RIS-RESERVES program is used to affirm numer ous parameters related to the definition of ore reserves in the deposits, and has now provided the opportunity for preparation of an overview which shows the major metallogenetic characteristics of the deposits with their techno-economic parameters. This approach enables affirmation of the potential of the polymetallic ore deposits in the Republic of Northern Macedonia.


REGIONAL GEOTECTONIC AND METALLOGENIC SETTING OF THE MACEDONIAN POLYMETALLIC ORE DEPOSITS
The studied polymetallic deposits in the Republic of North Macedonia belong to two large geotectonic units; the Vardar zone to the west and to the east the Serbian-Macedonian Massif and they occupy the central parts of the Balkan Peninsula extending in a general northwest-southeast direction. The geological and geotectonic setting of these two large geotectonic units has been studied by DIMITRIJEVIC (1958), JANKOVIC (1977), AR-SOVSKI & IVANOV (1977), SERAFIMOVSKI (1993), DU-MURDZANOV et al (2005), ROBERTSON et al., (2009). ), LEHMANN et al., (2013), SCHIMDT et al., (2013), ANTIC et al., (2016) and ŠOSTER et al., (2020). The Vardar zone is treated as a zone of ophiolitic melange, while the Serbian-Macedonian Massif is described as a rigid mass built of Precambrian rocks that make up the base and Palaeozoic shales. In the post-collision processes in both settings, Oligo-Miocene volcanism took place (BOEV & YANEV, 2001) with which the polymetallic deposits in Macedonia and adjacent regions are associated (SERAFI-MOVSKI et al, 2003;ALDERTON & SERAFIMOVSKI, 2007 Fig. 1).
From a metallogenetic point of view, the polymetallic mineralizations on the territory of the Republic of North Macedonia belong to a part of the Lece-Chalkidiki metallogenetic zone, which is completely defined by SERAFIMOVSKI (1990), and it covers the contact parts between the Vardar zone and the Serbo-Macedonian massif (Fig. 1), while the other part belongs to the metallogenetic zones have an emphasized significance in regard to the polymetallic ore deposits (Fig. 2).
In terms of the production of lead, zinc and copper in the territory of the Republic of North Macedonia the ore regions of Kratovo-Zletovo, Sasa-Toranica, Damjan-Buchim, are particularly important as well as the ore fields Kadiica and Ilovica (SERAFI-MOVSKI, 1993;TASEV, 2010;FORWARD et al., 2017). The ore veins in the Zletovo deposit, as well as the quartz-graphite series in the Sasa and Toranica deposits are bountiful from the aspect of lead and zinc production (SERAFIMOVSKI & ALEKSAN-DROV, 1995). Copper ores are abundant in the Buchim (ČIFLIGANEC, 1993) and Borov Dol (VOLKOV et al., 2010;GJORGIEV, 2020) , while in terms of potentiality, the Plavica (SERAFIMOVSKI et al., 2017), Kadiica (TASEV, 2010 ) and Ilovica deposits (FORWARD, 2017) are interesting. Some of the more significant metallogenetic characteristics of these deposits are presented in the following section.

Plavica
The area where the Plavica deposit mineralization is located is a classic volcanic cone, which is part of the famous Tertiary volcanism in the Zletovo-Kratovo volcanic area (STOJANOV, 1980). It consists of ignimbrite, dacite-andesite volcanic tuff, breccia and dacite-andesite as well as quartz-latite intrusions which form the   Fig.3), which resembles a typical volcanic caldera that is degraded on its southern side (MARK-OVIC, 1971;SERAFIMOVSKI, 1990).
The general characteristic of the mineralized part of the Plavica is the intense hydrothermal alteration which is dominated by kaolinization, sericization, silicification and allunization. Several types of mineralization have been identified as part of a long research process that began intensively in 1971 and continues to this day with some interruptions. Porphyry copper mineralizations have been of primary interest, but the remains of the old mining (primarily adits) attest to the fact that the quartz-pyriteenargite veins were exploited in Roman times and in the period after World War II (IVANOV & DENKOVSKI, 1978;IVANOV & DENKOVSKI, 1980). Gold-bearing mineralizations in the quartz-alunite zones (vuggy silica) are of economic interest with the gold content of up to 3 g/t Au (SERAFIMOVSKI & RAKIC, 1999). In the northwestern and southeastern peripheral parts of the mineralized volcanic apparatus, thin lead-zinc veins have been registered, which continue towards the southeast and the Zletovo deposit. The economic parameters for the Plavica deposit were prepared in accordance to Selection criteria parameters -Geological criteria, Social licensing, Environmental management, Project permitting, Skills availability (Appendix 1 - Table  1 and Table 2, which were adjusted to Republic North Macedonian standard) and their summary is in Appendix 2; Table 1.

Buchim
Buchim has long been the only copper mine not only in Macedonia, but also in the Lece-Chalkidiki zone. Copper ores of the porphyry type with characteristically low contents of 0.25% Cu and 0.3 g/t Au have been exploited for more than 40 years (ČIFLIGANEC, 1993;VOLKOV et al., 2010). The porphyry cop-per ores in the Buchim deposit are spatially localized around the andesitic intrusions in the Precambrian gneiss and amphibolite (SERAFIMOVSKI, 1993). The Tertiary volcanic intrusions aged 27-24 Ma (LEHMANN et al., 2013) intruded in the form of dykes and necks in the Precambrian complex 27-24 Ma ago. Three types of copper mineralization are distinguished in the Buchim deposit: primary chalcopyrite, secondary deposits? in the cementation zones (chalcocite-covellite; secondary sulfide enrichment) and a mixed deposit localized mainly in the Vrsnik ore body (ČIFLIGANEC, 1987;ČIFLIGANEC, 1993;STRMIĆ PALINKAŠ et al., 2022). Cu-Au mineralization is associated with hydrothermal alteration assemblages within and around the ore body as it is shown for the youngest Buchim ore body of Vršnik (STRMIĆ PALINKAŠ et al., 2022). The productive remaining mineralization of the porphyry ores in the Buchim mine is located in the Bunardzik and Cukar 2 East ore bodies (Fig. 4).
The potential of the Buchim ore deposit from the aspect of primary mineralization can be observed below the 405 m level, where the mineralization shows continuity in distribution. The economic parameters for the Buchim deposit were prepared in accordance to Selection criteria parameters -Geological criteria, Social licensing, Environmental management, Project permitting, Skills availability (Appendix 1 - Table 1 and Table 2, which were adjusted to the Republic of North Macedonia standard) and their summary can be found in Appendix 2; Table 1.

Borov dol
The Borov Dol deposit spatially belongs to the Vardar zone Different phases of Tertiary volcanic rocks, 32-27 Ma , where stratified volcanic tuffs and volcanic breccia participate in its lithological construction (TUDZAROV, 1993;LEHMANN et al., 2013). Porphyry copper mineralization is localized around the fine-grained andesite that has intruded the coarse-grained altered Kaolinization, silicification and sericitization are the most intense hydrothermal alterations of the volcanic rocks while the higher parts are affected by epidotization, chloritization and limonization (KNEŽEVIĆ et al., 1975;GJORGJIEV, 2020).
The porphyry copper mineralization style is defined by a genesis study of the Borov Dol deposit, especially fluid inclusions, isotope compositions, geochronological and alteration type studies. Primary ore solutions were defined by carbon and oxygen isotopes (TUDZAROV & SERAFIMOVSKI, 1994;TUDZAROV & SERAFIMOVSKI, 1995) and sources of metal by the sulfur isotope compositions (SERAFIMOVSKI, 1993;SE-RAFIMOVSKI & TASEV, 2013;GJORGJIEV, 2020). Geochronological data were defined by LEHMANN et al., (2013). The economic parameters for the Borov Dol deposit were prepared in accordance to Selection criteria parameters -Geological criteria, Social licensing, Environmental management, Project permitting, Skills availability (Appendix 1 - Table 1 and Table 2, which were adjusted to the Republic of North Macedonia case) and their summary can be found in Appendix 2; Table 1.
Morphostructural analysis classifies ore bodies as poor hypogenic copper mineralizations (<0.15% Cu) and richer ore bodies of secondary sulfide enrichment of copper (with average cop- per concentrations of around 0.22% Cu). Hypogenic mineralization is of a disseminated stockwork character with variable contours. At depth, copper mineralization occupies a space between the 90 and 220 m levels (TASEV, 2010). Calculated ore reserves and the associated economic parameters of Bukovik-Kadiica were prepared in accordance to Selection criteria parameters -Geological criteria, Social licensing, Environmental management, Project permitting, Skills availability (Appendix 1 - Table 1 and Table 2, which were adjusted to the Republic of North Macedonia case) and summarised in Appendix 2; Table 1.
The study of the fluid-inclusions within quartz associated with the mineralizations confirmed that the formation of the copper mineralization in the Kadiica deposit took place over a wide temperature range (627-326 °C) and with three main composi-tional phases of the ore solutions. The solutions were characterized by different salinities i.e. from 6-16 wt% NaCl through 3-24 wt% NaCl equiv to those with 32-45 wt% NaCl (TASEV, 2010;TASEV et al., 2018)

Ilovitsa
The porphyry Cu deposit of Ilovitsa is another example of mineralization within the Lece-Chalkidiki-Thassos metallogenic zone (SERAFIMOVSKI, 1990;HEINRICH & NEUBAUER, 2002;TASEV, 2003). The geological basis of the Ilovitsa ore deposit is composed of Precambrian (two-mica gneiss, biotite gneiss, muscovite gneiss, mica-schist and amphibolite) and Riphean-Cambrian (amphibolite and epidote-quartz-sericite-chlorite schist) rocks. At the time of the Palaeozoic (Hercynian orogeny) this foundation was intruded by granite in the form of batholiths. Later in the Late Eocene-Oligocene this area was protruded by dacites and andesites, which are characterized by mineralization of economic or non-economic character (Fig. 7).
The Tertiary rocks are affected by hydrothermal alterations, which in places lead to the complete destruction of the primary structures and change of the initial mineral composition. These alterations are manifested by an advanced argillic zone, phyllic zone and potassic core, while silicification, sericitization, alunitization, opalization and chloritization were rarely determined (Fig. 7). The mineralization is associated spatially and genetically with a granodiorite stock that occupies a surface area of 100 x 200 m (100 m to the north-south and 200 m to the east-west), while at depth can be detected down to approximately 700 m. The main ore minerals of the stockwork mineralization are: chalcopyrite, pyrite, bornite, native gold, magnetite, haematite, tennantite, galena, sphalerite, chalcocite, covellite, etc. A cementation zone formed below the oxidation zone, and has a thickness in the range of 3.5 to 9 m, and the main ore minerals are chalcocite and covellite (SERAFIMOVSKI, 1993;SERAFIMOVSKI & TASEV, 2011). The economic parameters for the Ilovitsa deposit were prepared in accordance to Selection criteria parameters -Geological criteria, Social licensing, Environmental management, Project permitting, Skills availability (Appendix 1 - Table  1 and Table 2, which were adjusted to the Republic of North Macedonia case) and are summarised in Appendix 2; Table 1.

Zletovo
The lead-zinc deposit of Zletovo is a typical vein type hydrothermal deposit of subvolcanic character, localized in the ignimbrite and tuff of Tertiary age which are intruded by dacite and andesite dykes and necks [SERAFIMOVSKI, 1993;SERAFIMOVSKI & ALEKSANDROV, 1995;TASEV, 2003]. The ore veins in the Zletovo deposit have a general trend of northwest-southeast and belong to the group of single or simple ore veins (Fig. 8).
Only ore veins 13 and 10 have opposite directions of strike and slip, but have the same mineral characteristics as the other ore veins (SERAFIMOVSKI, 1990).. The third shape of the ore bodies in the Zletovo mine is the ore pillars or the thickening of the ore veins in their surface parts. These are parts of ore veins with a high concentration of predominantly galena ores, and the lead content is about 0.15% Pb. On average, the thickness of the ore veins ranges from 1 to 3 m, and the salband parts of the veins are mostly kaolinized, silicified and carbonized. Zoning of the basic ore metals in the ore veins going from surface to depth is characteristic. In the superficial parts, lead dominates, followed by a transition with Pb + Zn, then Pb + Zn itself and in the deeper parts Zn + Cu [EFREMOV, 1993;TOMSON et al., 1998]. The mineral association is dominated by galena and sphalerite, followed by chalcopyrite, pyrite, tetrahydrite, tennantite, arsenopyrite, argentite, polybasite. It is regularly associated with quartz, siderite and barite with kaolinite [SERAFIMOVSKI 1990;. The content of lead and zinc and their economic parameters within the Zletovo ore deposit were prepared in accordance to Selection criteria parameters -Geological criteria, Social licensing, Environmental management, Project permitting, Skills availability (Appendix 1 - Table 1 and Table 2, which were adjusted to the Republic of North Macedonia case) and their summary can be found in Appendix 2; Table 2.
From the genetic point of view Zletovo can be defined as a sub-volcanic hydrothermal vein type ore deposit with Pb-Zn mineralization localized within the volcanic tuff and ignimbrite of andesite and dacite composition. A fluid inclusion study confirmed the hydrothermal character of the ore-bearing fluids dominated by their chloride composition with homogenization temperatures within the range of 335-145°C and salinities from 4.4 to 8.6 wt% eqv. NaCl (TASEV & SERAFIMOVSKI, 2012; TA- SEV et al., 2019), while within the lower temperature cleophane parageneses, salinity ranged between 10-25 wt% eqv. NaCl. Sulfur isotope composition in galena and sphalerite has an endogenic origin while the carbon isotope composition points to the participation of meteoric waters in ore-bearing fluids (MUDRINIĆ & SERAFIMOVSKI, 1990-91).

Toranica
The lead-zinc ore deposit of Toranica belongs to the group of deposits that were explored in the period between 1974 -1978, when the mine started active exploitation (BOGOJEVSKI & GASTE-OVSKI, 1990). The ore is located in Precambrian metamorphic rocks such as gneiss and quartz-graphite schist, intruded by Tertiary volcanics dated at 32 Ma (TASEV et al., 2005). Productive lead-zinc ore is localized predominantly in quartz graphite schists in the form of elongated pseudolayers and lenses in the so-called hanging wall gneiss (BOGOJEVSKI, 1990;DOBROVOLS-KAYA & STANKOVSKI, 1997;STANKOVSKI, 1997). The contact ore bodies between gneiss and quartz latite, as well as between quartz graphite schist and quartz latite, are less significant than the so-called central ore bodies (Fig. 9) localized in quartz graphite schist (SERAFIMOVSKI & ALEKSANDROV, 1995).
The qualitative-quantitative characteristics of the ores in the Toranica deposit were prepared in accordance to Selection criteria parameters -Geological criteria, Social licensing, Environmental management, Project permitting, Skills availability (Appendix 1 - Table 1 and Table 2, which were adjusted to the Republic of North Macedonia case) as summarised in Appendix 2; Table 2.
Analysis of the mineral compositions, ore textures and structures as well as the chemical properties of the main ore sulfides defines the following mineral parageneses: quartz-pyrrhotitеgalеna-sphalerite, pyrite-chalcopyrite-sphalerite, quartz-epidotesphalerite-galena, quartz-calcite. The slight difference in the parageneses is defined by sulfide predominance. Parageneses of pyrite, sphalerite, galena, quartz, calcite, epidote and actinolite are represented by several generations. The composition of sphalerite is discriminated from early to late parageneses by the percentage of Fe, Mn, Cd, Cu, while galena has a variable composition of Bi, Ag, Se. The rock-forming minerals differ in the percentage of Fe and Mn . Geochemical properties of minerals and their structural relationship indicate the repeated input of ore-forming solutions (SE-RAFIMOVSKI et al., 2006). A fluid inclusion study of quartz, calcite and sphalerite, confirmed the hydrothermal character of ore-bearing fluids and the intermittent input of the ore-bearing solutions. The initial stage occurred at 320-370°C and higher salinities (14-16% wt eqv. NaCl; , while the later ore-forming stage is characterized by temperatures ranging between 190-250°C and respective lower salinities (4-9 %wt eqv. NaCl). Such numbers indicated later ore forming stages when the ore-bearing capacity decreased significantly.

Sasa
The Sasa ore deposit, from an economic perspective is the most important lead-zinc deposit in the Republic of North Macedonia, and is listed in the group of several major deposits in Europe. The geological structure of the deposit consists of Precambrian gneiss, Lower Palaeozoic quartz-graphite schist, chlorite-sericite schist with intercalation of limestone, calcite schist and quartzlatite dykes of Tertiary age (BOGOJEVSKI, 1964;ALEKSAN-DROV, 1992). Lead-zinc mineralization is localized mainly within the quartz-graphite series with calcite skarn, johansenite and bustamite skarn (Fig. 10). The concentration of lead and zinc in some pseudo-layers and lenses in places is very high and exceeds 20% Pb + Zn, with a silver content of over 50 g/t Ag (SERAFIMOVSKI & ALEKSANDROV, 1995). This productive zone extending from the northwest to the southeast and a southwest dipping slope at depth can be followed for more than 1200 m with an average width of 50 m. The main ore minerals and bearers of lead-zinc mineralization are galena and sphalerite, regularly followed by a lot of pyrrhotite, pyrite and silver-bearing minerals (ALEKSANDROV et al., 1990). Skarn paragenesis consists of garnet, large johansenite, bustamite, ilvaite, epidote and in places calcite and aragonite in the lower parts (SERAFI-MOVSKI & ALEKSANDROV, 1995;ALEKSANDROV et al., 1999;STRMIĆ-PALINKAŠ et al., 2013;STRMIĆ-PALINKAŠ et al., 2018) The qualitative-quantitative characteristics of the ores in the Sasa deposit were prepared in accordance to Selection criteria parameters -Geological criteria, Social licensing, Environmental management, Project permitting, Skills availability (Appendix 1 - Table 1 and Table 2, which were adjusted to the Republic of North Macedonia case) and are summarised in Appendix 2; Table 2.
The origin of lead-zinc ores in the Sasa mine, stratified in the Palaeozoic quartz-graphite schist was interpreted as a syngenetic type TUFAR & STRUCAL (1984). However, BOGO-JEVSKI (1964), ALEKSANDROV (1992) defined this deposit as hydrothermal whereas the lead-zinc mineralization is localized in the calcite skarn. This thesis is also supported by STRMIĆ-PALINKAŠ et al., (2018), who also analytically confirms hydrothermal lead-zinc ores within the calcite and bustamite skarn. Our position is based on lead, sulfur, carbon and oxygen isotope analyses data and fluid-inclusions that define the primary origin of ore metals and ore fluids and the hydrothermal character of the deposit.
Most of the analyzed samples indicate the pronounced anomaly of lead isotopic composition (uranogenic or torogenic; SE-RAFIMOVSKI et al., 1997 Analysis of sulfur in sulfides from the Sasa ore deposit shows narrow ranges of variation. In pyrite values were determined from +4.34 to +6.94‰ δ 34 S, in sphalerite -1.22 to +5.18‰ δ 34 S, in galena from +2.13 to +3.64 ‰ δ 34 S, pyrrhotite from +1.80 to +3.97 ‰ δ 34 S and chalcopyrite from +4.39 to +4.41 ‰ δ 34 S, which together indicates a magmatic origin of S (OHMOTO & RYE, 1979;. The study of the isotopic composition of carbon from the Sasa ore deposit (from -5.50 to -1.48 ‰ δ 13 C) indicates its endogenous origin (OHMOTO & RYE, 1979;. The δ 18 O isotopic composition results varied from +16.79 to +23.21‰ δ 18 O, probably indicating the significant fractionation of oxygen from the place of mineral material deposition and its mobilization from carbonates , which is very representative for similar mid to low-temperature hydrothermal ore deposits where meteoric water formed a significant part of hydrothermal solutions (OHMOTO & RYE, 1979).
A study of fluid inclusions in quartz determined primary and secondary fluid inclusions (STRMIĆ PALINKAŠ et al., 2013). Primary fluid inclusions were characterized as two-phase (L+V) inclusions with variable shapes and a degree of fill of 0.75. Temperatures of homogenization vary from 270°C to 300°C while salinities were on the lower end (6.3-7.9 wt% equ NaCl). Post-mineralization minerals analysis, mainly in calcite, proved homogenization temperatures of 125-233°C and even lower salinities, which suggests deposition from colder and relatively diluted ore-bearing fluids.

MINING POTENTIAL
As can be seen from published data by the World Mining Data (REICHL & SCHATZ, 2022), the Republic North Macedonia contributes to the World mining of copper, lead and zinc at relatively fair level. Between 2019 and 2020, copper, lead and zinc were officially listed, ranking Republic North Macedonia on position 49 and 47 in regards to copper production, position 15 and 13 in regards to lead production and position 31 in regards to zinc production (REICHL & SCHATZ, 2022). Aforementioned data based on the real geological potential identified for the three commodities, copper, lead and zinc, Republic North Macedonia is capable of performing even at higher level. Here we are discussing, the three indicators of mining potential, grouped by commodity.

Copper
The World production of copper was 20 788 363 metric tons in 2019, and at the same time, copper production originating from the Republic of North Macedonia reached 6 625 metric tons, which is 0.03% of the total production in 2019. Bearing in mind the reserves and resources of the active copper deposits (mines) within the Republic of North Macedonia and the annual production of 4 to 5 Mt of ore annually, a mine lifetime of more than 20 years looks very realistic. At the present rate of copper production (2019-2020), Macedonia ranks in the lower part of the list (REICHL & SCHATZ 2022), partly due to the fact that in the respective period there was a transition from the production at the Buchim Mine to the newly developed Borov Dol mine.

Lead
With regard to lead, annual production from Macedonia amounts to 44 930 metric tons compared to the 4 747 983 metric tons of World production. This represents 0.95% of world production of lead. Bearing in mind only the reserves of the active lead (and zinc) mines within the Republic of North Macedonia (> 31 Mt of ore)) and annual production of 1.5-2 Mt of ore annually, a mine lifetime of more than 15 years looks very realistic, even not considering the resources. At the present rate of lead production (2019-2020), Macedonia ranks in the top 33 % of the World producer rankings list (REICHL & SCHATZ 2022).

Zinc
The World production of zinc reached 12 608 299 metric tons in 2019, and at the same time, zinc production in the Republic of North Macedonia was 31 750 metric tons, (0.25% of total world production in 2019). Due to the fact that zinc is exploited together with lead from the lead-zinc mines (Toranica, Sasa and Zletovo), reserves of more than 31 Mt of lead-zinc ore and an annual production of 1.5-2 Mt of ore should be sufficient for a mine lifetime of more than 15 years (combined). This mine life projection doesn't consider resources. At the present rate of zinc production (2019-2020), Macedonia ranks in the middle of the World producers ranking list (REICHL & SCHATZ 2022).

Indicator 2: Self-sufficiency
Recently one of the most vital issues related to the mineral commodities industry became the topic of self-sufficiency. Namely, we cannot ignore the fact regarding the import of necessary mineral commodities. With regard to copper, lead and zinc we would like to emphasize that the Republic of North Macedonia's, according to official statistics (SIMOVSKI, 2020), imports are either very low or absent for these commodities. In contrast, the export of the aforementioned commodities is at significant levels. Before presenting numerical data we would like to stress that due to the proximity of smelting facilities and ports for export, the majority of copper, lead and zinc concentrated production is exported to the neighbouring country of Bulgaria, although certain quantities are coming back to Macedonia due to industry needs. Of a total copper concentrate production if 31 226 metric tons and 28 484 metric tons (in 2019 and 2020, respectively; SI-MOVSKI, 2020) around 97-98% was exported. Lead concentrate production amounted to 60 154 metric tons and 62 400 metric tons (in 2019 and 2020, respectively; SIMOVSKI, 2020) of which around 86-97% was exported while in the case of zinc concentrate production (31 254 metric tons and 46 959 metric tons in 2019 and 2020, respectively; SIMOVSKI, 2020) around 49-77% was exported.

Indicator 3: Economic Contribution
The mining potential of the Republic of North Macedonia can also be expressed through economic parameters. As can be seen in SIMOVSKI (2020), the export of copper, lead and zinc from active mines in the Republic of North Macedonia, expressed in monetary units, reaches 163 256 000 US$, which compared with the total exports for 2019 of 7 185 157 000 US$ represents a 2.27% contribution. However, in regards to the economic importance of this industry, the contribution to the Gross domestic product of the Republic of North Macedonia in 2020 of up to 1.8% is more illustrative, while the related industry category that includes mining and quarrying, manufacturing, electricity, gas, steam and air conditioning supply as well as water supply; sewerage, waste management and remediation activities contributed up to 18.1% in 2019 and 17.3% in 2020 of total GDP SIMOVSKI, 2020). Also, here we should take into account the estimated values of reserves/resources of the Kadiica ore deposit, which are up to 369 000 000 US$ (as of year 2014), the Plavica ore deposit of up to 622 000 000 US$ (as of year 2014) and the Ilovitsa ore deposit of up to 3 500 000 000 US$ (as of 2011), which makes an impressive sum of approximately 4.5 billion US $. In the case of the Kadiica, Plavica and Ilovitsa ore deposits we would like to emphasize that calculations were based on their respective years of calculation of reserves, but since then metal prices have increased substantially, which should increase their values accordingly.

CONCLUSION
The polymetallic ore deposits (lead, zinc, copper, gold and silver) in the territory of the Republic of North Macedonia are spatially related to the Vardar Zone and the Serbo-Macedonian Massif as the two large geotectonic units of regional scale, and are paragenetically connected to the Tertiary complexes which belong to the metallogenetic zones of Lece-Halkidiki and Besna Kobila-Osogovo-Thassos, both within the Serbo-Macedonian metallogenetic province.
Two types of lead-zinc deposits have been defined in the Republic of North Macedonia, a typical lead-zinc Zletovo deposit and skarn Pb-Zn deposits at Sasa and Toranica, with the latter having the greater potential. Porphyry copper deposits are located at Plavica, Buchim Borov Dol, Kadiica and Ilovitsa. The most important porphyry copper deposit is at Ilovitsa, which belongs to the Serbo-Macedonian Massif, with proven ore reserves of around 500 Mt. Ore reserves in the Plavica, Buchim and Borov Dol localities are in the order of 100 to 150 Mt, which generally corresponds to the quantities of ore in the porphyry deposits within the Lece-Halkidiki zone, where the Lece deposit in Serbia and the Skouries deposit in Greece have similar features. All of them are located in the contact zones between the Serbo-Macedonian Massif and the Vardar Zone and are a product of calc-alkaline volcanic intrusions that were intruded at sub-volcanic levels. The Kadiica deposit may be promising, but for now only porphyry mineralizations in the oxidation and cementation zones have been defined in that area, while the primary mineralizations need to be further explored.

ACKNOWLEDGEMENT
The proposed review article was part of the activities in the frame of the RIS-RESEERVE project (https://eitrawmaterials. eu/project/reseerve/), funded by the EIT RawMaterials, part of the European Innovation Institute (EIT), funded by the European Union. for detailed geological and additional exploration of the deposits, as well as the availability of qualitative and quantitative characteristics of the useful mineral components in the deposit).

Appendix 1
All geological information on treated polymetallic deposits is public and accessible and very well structured and classified.
High level of availability of geological data and data related to major ore and associated metals for active polymetallic mines of: copper, lead and zinc. Geological data available from professional and scientific papers and scientific publications and operational data available from geological reports that are prepared every 5 years. Annual Metal Production Reports are also a good source of relevant information. Copper deposits (Plavica, Kadiica, Ilovica) that are in the stage of detailed exploration, but are not active have good quality information, at the level of scientific publications and reports, but not at the level of periodic reports and official state data. In regards of the polymetallic deposits that are in active exploitation (Buchim, Borov Dol, Sasa, Toranica, Zletovo) only certain parts have the character of unexplored potential area (Anishte in the area of Toranica, Crn Vrv-Koshevo in the area of Buchim, Petrova Reka in the area of Sasa, Blizanci in the area of Zletovo) and there the information is mostly old, mainly fund sources and old reports for prospective and in some places detailed geological exploration with drilling, but without updating the data, and the potential is given based on similar criteria from main sites, only. In the polymetallic, mainly copper deposits such are Kadiica and Ilovica, which are still at the level of detailed exploration, the information about the new nearby potential areas is based on modern geophysical research (tellur geophysics) or on the basis of scientific assessment of the potential of the locality-area.
Level of current geological knowledge-quantity Lead-Zinc: Level A, more than 3.000.000 t of reserves (A+B+C category) and expert judgement. Copper: Level A data quality, more than 10.000.000 t of reserves (A+B+C category).
Lead-Zinc: Level B, less than 2.000.000 t of reserves (A+B+C category) and expert judgement. Copper: Level A data quality, less than 10.000.000 t of reserves (A+B+C category). Lead-zinc: Any level of data quality, inaccessible documentation, expert judgement-short explanations based on area geological characteristics and historical data. Level C of data quality with inaccessible reserves documentation considering expert judgement..