BELGRADE COPPER PROJECT
INTRODUCTION
The Company holds a package of prospects (licences and licence applications) in Serbia (the “Belgrade Copper Project”). The prospects (Studena and Kopajska Reka) are prospective for copper-silver mineralisation. The Studena and Kopajska Reka prospects were originally part of Reservoir Minerals Inc’s (“Reservoir”) Serbian assets (ex TSX-V) prior to its 2016 US$365 million takeover by Nevsun Resources Ltd (“Nevsun”) and subsequent US$1.4 billion takeover by Zijin Mining Group Co in 2018, following the discovery of the Cukaru Peki high-sulphide epithermal and porphyry deposit with approximately 20Mt of contained copper.
The Studena prospect is located in eastern Serbia within the Ridanj-Krepoljin metallogenic zone which extends for more than 200km in a NW-SE direction. Both prospects are located west from the well-known Bor metallogenic region that hosts world class copper porphyry deposits, all of which are located within the CBMP.
Highlights:
- Excellent potential for major discoveries of world class sedimentary-hosted copper mineralisation similar to the Kupferschiefer style in Poland, one of the world’s largest copper deposits.
- Material landholding in Serbia’s prolific Carpatho-Balkanian Metallogenic Province (“CBMP”); which host the world class copper deposits of Bor and Cukaru Peki (30Mt contained copper1,2).
- More than 70km of untested prospective contacts.
- Historical surface rock chip assays exhibited exceptional values of up to 20% copper and 1,540ppm silver supported by recent fieldwork by Apollo Minerals that confirmed significant surface copper and silver anomalism, with rock chip assays up to 6.5% copper and 155ppm silver.
Figure 1: Belgrade Copper Project Location (yellow rectangles) – Displaying the project within the highly prospective CBMP Province
The initial exploration focus at the Project will be on the Kupferschiefer style mineralisation target (Figure 1 – Style 3), which is centred on the contacts between the Permian red sandstones and over lying Triassic and Jurassic limestone. In this region copper mineralisation may preferentially be hosted in calcareous sandstone and limestone units due to the redox reactions between mineralising fluids and reduced sediments. This style has not been tested historically and is considered to be highly prospective over the Project. Copper mineralisation in Serbia is noted to include copper porphyry associated, skarn-related or sediment hosted Red Bed style such as Kupferschiefer copper deposits.
Overall, the Project is considered highly prospective for four styles of copper-mineralisation (Figure 4):
- Red sandstone (Permian) Cu-Ag mineralisation associated with structural feeder zones;
- Calcareous sandstone hosted Cu-Ag mineralisation in stratigraphy overlying Permian red-sandstone;
- Red sandstone redox-trap related Cu-Ag mineralisation beneath ‘fetid’ limestone –which is considered an analogy to the Kupferschiefer style of mineralisation; and
- Carbonate replacement Pb-Zn-Cu-Ag mineralisation related to Paleogene volcanism.
Figure 1 : Targeting mineralisation model for the Nis Copper Project (Genova,2023)
Previous exploration at Studena was undertaken by Reservoir (2014-2015) with soil sampling and rock chip sampling focusing on copper occurrences within the Permian red-sandstone. Reservoir/Nevsun completed a total of six reconnaissance-level diamond drill holes in 2018 (five at Studena) focused on mineralisation in the Permian sediments. The holes were focused on meeting regulatory exploration requirements and were sub-optimally located in the Permian sediments at the time, not targeting the proposed contact horizons, and accordingly no significant intersections resulted from this reconnaissance level drilling.
The Studena license (Figure 1) contains several known historical copper occurrences with small-scale underground mining occurring in the 1900’s for copper. One adit, ‘Studena’, is reported to be ~50m deep with two levels of development up to 95m in length; however no detailed production records are available. Other known copper occurrences include the Gradac, Bancarevo and Bukovac localities. The area has had limited modern exploration within the exploration license with recent work focused on high-level mapping and rock-chip sampling by the current owner.
The Studena Project is hosted within the Suva Planina zone of the CBMP, part of the Eastern Tethyan Belt. The Project lies adjacent to the major regional fault zone, Ridan-Krepoljin fault. The Suva Planina zone is host to Silurian metamorphics, Devonian turbidite sequences, Upper Carboniferous sandstones, Permian sandstones, Lower Triassic sandstones, Middle Triassic, Jurassic and Lower Cretaceous limestone.
Regional structure of the Project areas is dominated by folded sequences of sedimentary units with several anticlinal structures within the tenement packages. Numerous faults have been mapped in the Project areas.
Mineralisation previously identified by Reservoir is hosted within the Permian red sandstone units and at the top of the sequence adjacent to the overlying Triassic and Jurassic carbonate units.
Studena -Kopaska Reka
Outcropping sedimentary sequences found within the granted tenements of Studena include Permian sandstones overlain conformably by Triassic dolomites and sandstones, Jurassic and Cretaceous limestones.
Weak alteration is noted within bleached sandstone units and calcareous limestones. Bedding and contacts noted in the regional anticlines are shallow to moderately dipping (20-40 degrees) with fold axis trending towards the southeast. The contacts between the Permian sandstone and the Jurassic limestone units have been extensively mapped within the tenements.
At Studena (Figure 1), Permian red sandstone units are the host to the Cu-Ag mineralisation which have been mined by small-scale underground adits in the 1900’s at locations such as Studena, Gradac and Bancarevo. Mineralisation appears to be hosted in the upper red sandstone units comprised of malachite and azurite with rare amounts of chalcocite noted in the area.
The Donja Mutnica prospect geology (Figure 2) comprises Permian red sandstone overlain by Jurassic sandstone and limestone units. On the western portion of the tenement lies major thrust fault that dislocates the stratigraphy with Paleozoic greenschist units. Copper occurrences within the Donja Mutnica prospect is noted to occur within malachite, azurite and chalcocite within the red sandstone units.
Historical and recent rock chip sampling of sub-crop and mine spoils completed by Reservoir and Apollo Minerals has identified copper and silver grades of significance with up to 20% Cu and 1,540ppm Ag noted in chalcocite-rich rock chip samples.
Within Kopajska Reka (Figure 2), the red Permian sandstones are interpreted to be 100’s of metres thick comprising sandstone, siltstone and mudstone units. Minor quartz-calcite veining is found within the sandstone units and sporadic occurrences of secondary copper minerals such as malachite and azurite along fractures or in bleach sandstone beds. Overlying the Permian sandstone are the Triasssic and Jurassic laminated and massive limestones.
At Sokolovica within Kopajska Reka, a small-scale open pit (50m x 200m in size) has been identified with occurrences of malachite and azurite in outcrop with grades of up to 1.5% Cu and 100ppm Ag. Minor copper occurrences are located near the localities of Kopajkosara and Grbavce within red sandstone at or near the contact with limestones (Figure 2).
Figure 1: Studena Geology including rock chip and drilling information
Figure 2: Kopajska Reka Geology including rock chip information
The future work programs at the Belgrade Copper Project will aim to develop drill ready targets at the prospect and test for redox related sedimentary copper. These planned activities include detailed soils to cover the main Permian red-bed/limestone contact regions and over red-bed sandstone units, trenching over identified anomaly regions, airborne magnetic surveys, target generation and subject to the results from aforementioned activities, drilling.