Timok gold project is held by DPM Avala d.o.o., a Serbian registered, indirect, wholly-owned subsidiary of Dundee Precious Metals Inc.
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Summary:
The Timok Project is located within the north-western part of the Timok Magmatic Complex (TMC) in eastern Serbia.
The dominant mineral prospects in the clastic sedimentary rocks along the western margin of the TMC are relatively low-temperature auriferous deposits that share many characteristics with Carlin-type gold deposits. The interpretation of the sediment-hosted gold prospects within the Project area as Carlin-type is based upon the following criteria (Knaak et al., 2016):
• Character of the sedimentary host;
• The metal association (gold, arsenic, mercury, thallium, sulphur and antimony);
• The fine-grained nature of the gold, high gold-to-silver ratio and alteration types including argillisation, decarbonisation, and locally, addition of quartz.
Four important mineralised areas have been defined in the Potaj Cuka Tisnica exploration licence, comprising of the Bigar Hill deposit, the Korkan and Korkan West deposits and the Kraku Pester deposit. All four zones share a similarity of mineralisation style, which has been most clearly defined at the Bigar Hill deposit and are associated with a large hydrothermal system that has been identified within the Timok Project.
Bigar Hill Deposit
The Bigar Hill Deposit is the most advanced Mineral Resource within the Project. The deposit comprises Bigar Hill and the adjacent Bigar Au-polymetallic replacement showing (immediately south and east from Bigar Hill) and is located immediately north and outside of the thermal aureole of the Potaj Cuka monzonite.
Gold mineralisation at Bigar Hill is located principally along two stratigraphic horizons, with lesser amounts present along peripheral steeply dipping fracture zones within the clastic rocks and an andesite sill. A lower zone is localised along the unconformable and brecciated lower contact between the clastic S1 and isolated karst-infill zones above the KLS unit. The most continuous horizons lie at shallow stratigraphic levels along the contact between the S1 and S2 units, forming a middle zone.
Above this zone, gold mineralisation occurs within the andesite intrusive unit. Mineralisation is found within sub-horizonal vein zones and silicified breccia infills located on the contacts.
Mineralisation is continuous and follows the dips of the stratigraphy. It has a north-south extent of approximately 900 m and an east-west extent of approximately 900 m. Mineralisation is largely from surface, and in the south its depth extent is greatest (approximately 500 m). Depth extent reduces to 200–300 m below surface moving further north. There is a small zone in the centre, where mineralisation starts from approximately 80 m vertical depth from surface.
Korkan Deposit
The Korkan Deposit is the second most advanced exploration target within the Project, after the Bigar Hill Deposit. The deposit constitutes a generally easterly-trending zone of mineralised rocks and incorporates both the Korkan and adjacent Korkan East zones. Korkan East is located to the east of
Korkan, across a braided post-mineralisation, strike-slip fault zone.
Mineralisation at the Korkan deposit is generally southeast-northwest trending and shares similar characteristics with the Bigar Hill deposit. Unlike Bigar Hill, stratiform gold mineralisation at Korkan occurs primarily along the unconformable and breccia-like lower contact zone of the clastic S1 sequence against the underlying KLS limestone unit, and in karst-infill zones at the upper boundary of the KLS limestone unit.
Mineralisation is less continuous at Korkan compared to Bigar Hill, due to higher structural complexity. As at Bigar Hill, it tends to follow the dips of the stratigraphy. The mineralised footprint has a northeast-southwest extent of approximately 1,100 m and a northwest-southeast extent of approximately 1,100 m. Mineralisation commences from surface and can be traced to a maximum depth of 400 m below surface.
Korkan West deposit
The Korkan West deposit is the newest discovery within the Project. It lies between the Bigar Hill and Korkan deposits, along a northwest trending structural corridor. The Korkan West deposit shares many characteristics with the Bigar Hill deposit, located approximately 1 km to the southeast, and the Korkan deposit located approximately 1 km to the northeast. Almost all mineralised intervals are manifested as oxide and transitional weathering states.
Host rocks for gold mineralisation are: (1) oxidised fine to very coarse-grained (0.1 mm to 2 mm) sandstone belonging to the S1 or S2 units; (2) conglomerate layers containing quartzite clasts and/or not limestone clasts (S1 or S2 units). Mineralisation at S2/S1 contact can commonly be observed.
The orientation of structures in the Korkan West area are currently interpreted to be striking predominantly along a west-northwest to east-southeast orientation. These structures are located within a 300 m wide and 600 m long corridor and were most likely the feeder zones for hydrothermal fluids.
Kraku Pester deposit
The Kraku Pester Deposit is the third most advanced exploration target within the Project after the Bigar Hill and the Korkan Deposits. Kraku Pester shares similar characteristics with the Bigar Hill Deposit, 3.7 km to the north, and is located in an embayment at the north-western tip of the Potaj Cuka monzonite.
Gold at Kraku Pester is hosted in a variably disrupted stratigraphic sequence comprising, from base to top, shale metamorphosed to biotite ± magnetite phyllite, calcareous rocks; including marl and limestone metamorphosed to calc-silicate hornfels and marble, and tuffaceous rocks that locally may be calcite-rich and interbedded with coherent hornblende andesite. Metamorphism is due to emplacement of the Potaj Cuka monzonite unit that produced a thermal aureole up to 800 m in width. Direct correlation of the stratigraphic sequence at Kraku Pester with those recognised regionally at Bigar Hill and Korkan is uncertain.
Mineralisation is less continuous at Korkan compared to Bigar Hill, due to greater structural complexity. As at Bigar Hill, it tends to follow the dips of the stratigraphy. It has a northeast-southwest extent of approximately 700 m and a north-south extent of approximately 600 m. Mineralisation can generally be traced from approximately 30 m below surface, and has a depth extent of 300 m. Disruption of stratigraphic continuity at Kraku Pester indicates structural complication of the host sequence. Low-dipping structures of appreciable thickness are exposed, and fabric asymmetries associated with these faults indicate accommodation of down-dip extension. The presence of massive Jurassic limestone structurally above the heterogeneous Cretaceous sedimentary sequence suggests that the moderately-dipping structures originated as reverse faults that were reactivated. Steeply dipping fault damage zones have also been recognised, and cataclastic zones noted in the monzonite are locally host to auriferous pyrite.
Unlike Bigar Hill, gold mineralisation at Kraku Pester is hosted in brittle fault rocks composed of pyritised fault breccia to cataclasite, with relatively higher gold concentrations being associated with finer-grained cataclasite. Fluid flow associated with gold mineralisation was controlled by a permeability fabric produced by brittle reactivation of a complicated geometric architecture in a north-westerly trending cross fault and the footwall intrusive contact with the monzonite.