Pampa Medina Continues to Deliver Extraordinary Cu-Ag Grade-Widths - Drilling Intersects 216m of 1.0% Cu and 7.2g/t Ag Including 62m of 2.2% Cu and 21.5g/t Ag from SPRD-15

VANCOUVER, BC / ACCESS Newswire / September 8, 2026 / Marimaca Copper Corp. ("Marimaca Copper" or the "Company") (TSX:MARI)(ASX:MC2) is pleased to report further assay results from its ongoing drilling program at the Pampa Medina deposit, located approximately 28km east of the Company's Marimaca Oxide Deposit ("MOD") in Chile's Antofagasta Region (Figure 1). Drilling within the central high-grade sulphide zone continues to deliver consistent, high-grade results within the defined 3km x 1.5km area of interest ("AOI"). The mineralization across the target lithological horizons continues to show continuity both horizontally and vertically. Drilling on 150m centers returned 216m of 0.96% Cu and 7.2g/t Ag from 466m, including 62m of 2.20% Cu and 21.5g/t Ag from 602m downhole from SPRD-15. Step-out drill holes outside of the central corridor extended the mineralized sediment horizon 300m to the south and west, with strong results from SPRD-12, SPD-13 and SPRD-17. Additional scouting RC holes were completed to the north and northwest of the defined AOI to determine the depth of the start of the target sediments (see Figure 3).

Drilling on 150m spacing continues to validate the continuity of the thick, ultra high-grade, stacked-mantos across the core of Pampa Medina

SPRD-15 intersected thick, continuous, high-grade mineralization at the target manto horizon:

216m of 0.96% Cu and 7.2g/t Ag from 466m (sulphide), including

82m of 1.72% Cu and 16.3g/t Ag from 600m, including

62m of 2.20% Cu and 21.5g/t Ag from 602m, including

14m of 3.05% Cu and 26.7g/t Ag from 606m, and

12m of 3.25% Cu and 36.7g/t Ag from 632m

6m of 2.00% Cu and 12.0g/t Ag from 506m

The manto demonstrates remarkable continuity of high-grade mineralization vertically across the horizon (see Figure 4) - a defining fe