Base and precious metals exploration company Lykos Metals Limited (ASX: LYK) has commenced diamond drilling at the Rastovaca – Debela Kosa (“RDK”) copper-cobalt prospect, part of the Company’s 100%-owned Sinjakovo Project in Bosnia-Herzegovina.
The Phase 1 drilling program consists of 19 diamond holes at 200-metre centres for a total of 4,600 metres and will target copper mineralisation along the interpreted strike of the lithology which hosts the copper mineralisation at the historic mining area. Mining activities at the historic mining area ceased in the early 20th century with reported head grades of 3% copper. At the time it was considered waste and reportedly used as backfill, or stockpiled at the portal.
The RDK Prospect comprises the historic copper mine, a 15-16kt waste rock dump (historically estimated to contain approximately 3% copper and 35% iron), and a ~3km strike length of favourable siderite-ankerite rock unit that is interpreted to host copper-iron mineralisation.
The copper mine was operational from 1894 until 1910 where reported grades of 3-25% copper ore was extracted from underground tunnels, with the mining operation having ceased once head grades dropped below 3% copper as, at the time, material grading less than 3% copper was considered waste and used to backfill tunnels or stockpiled at the portal.
Samples taken in 2021 from the waste dump returned grades of up to 5.21% copper and 965 g/t cobalt, as reported in the Lykos Prospectus of September 2021.
The geology of the prospect consists of younger Triassic limestone and older Carboniferous schists with ankerite-siderite interbeds. Historical geological reports describe the mineralisation as chalcopyrite layers 2-6.5m thick associated with the ankerite-siderite interbeds. These favourable rock units are concordant and gently dipping, mapped on surface for 2km strike length north and 1 km south of the historic mine. The quartz-porphyry intrusives found 1km east of the mine are interpreted to be a potential source of the stratabound copper-cobalt mineralisation.
RDK Drilling Plan
Drilling will test two target planes – the primary upper target plane and a deeper hypothetical target plane – which requires deeper drilling past the primary target. Actual end depth of drilling will be subject to observations from ongoing drilling, individual geology in each drill hole and targeting from 3D modelling that is being developed simultaneously.
Drilling is designed to intersect the host lithology at high angle (80-90°) at a projected depth range of 30-210m in vicinity of the historic mine (down-dip, up-dip and lateral from the historic mine), 30-290m north of the mine and 120-140m in the zone south-east of the mine. This relatively shallow depth of mineralisation will enable fast drill-testing and a relatively inexpensive overall drilling program.
Drillhole SIDD001 has commenced and will test the down-dip extension of the host rock unit to the south of the historic mine where waste dump sampling in 2021 returned grades of up to 5.21% copper and 965g/t cobalt.
Eight diamond holes (including SIDD001) will test the interpreted host lithology near the historic mining area, eight holes will test the northern extent and three will test the southeast extension of the host lithology.
Phase 1 is scheduled to take up to five months to complete with one drilling rig and results will inform Phase 2 drilling which will seek to aggressively test the resource potential at the prospect. Depending upon outcomes the Phase 1 program may, however, be accelerated through the deployment of a second rig to the programme.
Lykos Metals Managing Director Mladen Stevanovic said:
“We are delighted to commence drilling at the Sinjakovo Project, with drill hole SIDD001 being the first exploration drilling in the project area in modern times.
“We are drill-testing for high-grade copper and cobalt mineralisation potential at RDK prospect. Through our systematic and targeted drilling programs, the exploration team will grow our knowledge of the area over the coming months, and this will inform the follow-up, Phase 2 program.
“We are continuing with our systematic exploration programs at all three of our projects, where we expect to define many more compelling exploration targets for future drilling.”