Announcement • Jul 08
Marimaca Copper Reports Additional Assay Results from Ongoing Step-Out Drilling At Pampa Medina Deposit
Marimaca Copper Corp. reported additional assay results from ongoing step-out drilling at the Pampa Medina deposit, located approximately 28km east of the Company's Marimaca Oxide Deposit in Chile's Antofagasta Region. Results continue to extend the central high-grade sulphide zone and confirm multiple stacked manto-style copper-silver horizons across the sedimentary and volcanic sequence. Hole SPRD-07 extended the ultra-high-grade bornite zone 300m south of previously released drilling, returning 20m at 2.65% Cu and 13.9 g/t Ag from 564m, including 6m at 6.11% Cu and 24.0 g/t Ag, and 104m at 1.01% Cu and 4.7 g/t Ag from 664m, including 40m at 2.04% Cu and 11.1 g/t Ag. Drilling in SPRD-08B also intersected mineralization in basement metasediments for the first time, indicating potential for depth extensions beyond the previously defined host units. The ongoing step-out program continues to support the geological model: multiple high-grade, stacked mantos with dominantly bornite-chalcocite mineralization hosted in interbedded sediments and volcaniclastics. Drilling extended mineralization into the basement metasediments for the first time at Pampa Medina, with SPRD-08B being the deepest hole drilled to date to a depth of 1,052m. Indicates potential for further extension at depth at Pampa Medina. SPRD-07 drilled 300m south of previously released SPRD-05 intersected multiple stacked high-grade mantos down hole, including 20m of 2.65% Cu and 13.9g/t Ag from 564m (sulphide), including 6m of 6.11% Cu and 24.0g/t Ag from 574m, 104m of 1.01% Cu and 4.7g/t Ag from 664m (sulphide), including 40m of 2.04% Cu and 11.1g/t Ag from 670m, including 14m of 3.36% Cu and 17.7g/t Ag from 688m, including 4m of 6.54% Cu and 38.5g/t Ag from 698m. Central high-grade bornite-manto extended 300m south of previously released SPRD-05. Near surface oxide mineralization also intersected in volcanics 150m west of the historic Pampa oxide footprint, 10m of 0.31% Cu and 2.8g/t Ag from 180m (oxide). SPRD-08B drilled ~150m south of previously released SMRD-16 and 300m west of SPRD-07 intersected broad, consistent mineralization across sediments and tuffs into basement metasediments, 660m of 0.41% Cu and 1.8g/t Ag from 386m, including multiple stacked mantos, 98m of 1.21% Cu and 7.6g/t Ag from 386m (mixed), including 16m of 2.90% Cu and 21.2g/t Ag from 388m, 58m of 1.08% Cu and 6.5g/t Ag from 426m, 10m of 1.10% Cu and 1.8g/t Ag from 516m (sulphide), 8m of 0.96% Cu from 580m (sulphide), 14m of 0.83% Cu from 662m (sulphide). Deeper drilling intersected the mineralized sequence in the basement unit but was impacted by post-mineralization dykes, 66m of 0.70% Cu from 802m (sulphide), including 14m of 1.05% Cu from 834m, 6m of 1.40% Cu from 862m. SPRD-09, drilled 300m south of SPRD-07, extended the mineralized sequence but intersected multiple barren dykes orientated WNW, 30m of 1.26% Cu and 2.6g/t Ag from 440m (sulphide), including two high-grade stacked mantos, 6m of 2.34% Cu and 10.7g/t Ag from 440m, 6m of 2.50% Cu and 2.3g/t Ag from 464m, 32m of 0.85% Cu and 4.4g/t Ag from 506m (sulphide), including 18m of 1.11% Cu and 7.4g/t Ag from 520m (sulphide), drilling continued through favourable rocks into the metasediment unit at depth, 6m of 0.77% Cu and 2.0g/t Ag from 940m (sulphide), 6m of 1.05% Cu and 8.3g/t Ag from 1,006m (sulphide). Pampa Medina is a manto-style copper deposit dominantly hosted in Jurassic-Triassic sedimentary units (sandstones, conglomerates, tuffs and black shales) overlain by andesitic volcanics and underlain by an Upper Paleozoic complex of metamorphosed sediments, volcanics and intrusions. Copper was originally identified in near-surface oxide mineralization dominated by atacamite, chrysocolla and secondary chalcocite, and has now been identified in high-grade zones of bornite, chalcopyrite, covellite and chalcocite which extend at depth beyond the oxide-primary transition. Elevated silver grades are present in both oxide and sulphide copper-mineralized zones and are generally correlated with copper grade. Following Marimaca's consolidation of the project area and surrounding land packages in 2024, the Company reinterpreted all available geological information and developed an updated geological model for Pampa Medina, which identified the lower sedimentary units of interbedded sandstones, shales, tuffs and conglomerates as the priority target horizons for future drilling. Marimaca's 2026 drilling campaign is focused on three priority goals: definition of the high-grade central Area of Interest, delineating the identified oxide extensions, and further step-out drilling to test potential extensions of the broader system identified in geophysical work completed to date. All intervals are reported as downhole lengths. True widths are estimated at approximately 80% of reported intervals. Diamond drill holes were sampled on a 2m continuous basis, halved by a conventional core splitter on site with one half sent to the Andes Analytical Assay preparation laboratory in Copiapó and the pulps then sent to the same company laboratory in Santiago for assaying. Samples were prepared using the following standard protocol: drying; crushing all samples to -1/4" and passing through a secondary crusher to better than 80% passing -10#; homogenizing; splitting; pulverizing a 400-600g subsample to 95% passing -150#; and a 125g split of this sent for assaying. All samples were assayed for sequential copper %CuT (total copper); %CuS (acid soluble copper), %CuCN (cyanide soluble copper) and CuRes (residual copper). In addition to copper analyses, multi-element analysis including silver (Ag) was undertaken using ICP (multi-element Optical Inductively Coupled Plasma).
