VANCOUVER, British Columbia, June 08, 2020 (GLOBE NEWSWIRE) — Marimaca Copper Corp. (“Marimaca Copper” or the “Company”) (TSX: MARI) is pleased to announce it has recently completed a thorough review of the data from previous drilling campaigns and its associated geology at its flagship Marimaca Copper Project (“Marimaca” or “the Project”). This has resulted in an updated geological interpretation indicating the potential for sulphide mineralization beneath the Marimaca Oxide Deposit (“MOD”).
HighlightsNumerous deeper holes drilled at Marimaca during Phase II drilling intercepted sulphide mineralization below the MOD. Significant results previously released to the market include:
° 42 metres averaging 0.57% CuT from 272 metres in ATR-30
° 26 metres averaging 0.97% CuT from 178 in ATR-78
° 16 metres averaging 1.4% CuT from 122 in ATR-79
° 44 metres averaging 1.05% CuT from 206 in ATR-82
° 26 metres averaging 0.84% CuT from 148 in ATR-84
° 36 metres averaging 1.68% CuT from 84 in ATR-85
° 38 metres averaging 1.04% CuT from 180 in ATR-93; and
° 48 metres averaging 1.30% CuT from 78 in ATR-94.Structures that host the oxide mineralization at surface are interpreted to have the potential to extend into the sulphide mineralized zones with the same geometry
° Indicates surface structure hosting Marimaca deposit has strong potential to continue beneath the MOD
• Strong evidence that oxide deposit has been generated by in-situ oxidation of sulphide mineralisation and grades in sulphide are, therefore, expected to be broadly similar to Marimaca
° If surface deposit geometry continues the volume and tonnes for the sulphide zone could be significantReview of key geological and mineralogical features shows strong relationship between chalcopyrite and magnetite throughout deposit
° Allows generation of sulphide exploration targets below the MOD using geophysical methods
• Marimaca Copper is conducting a drone mounted high resolution magnetometry survey with results expected shortly
• Induced Polarization (IP) plannedObjective to test the sulphide targets generated by geophysics during 2H 2020Michael Haworth, Executive Chairman of Marimaca Copper commented:“During the 2018/19 exploration drilling program at Marimaca, many of the deeper drill holes encountered interesting sulphide zones in terms of widths and grades. Following a detailed review of the structural controls of the deposit, and the relationship between the oxide and sulphide zones, the geological team believes the structures which host the MOD at surface have the potential to extend below it and host further sulphide mineralization.“What is most exciting is that copper mineralization in this type of IOCG deposit can extend down dip substantially. Several reviews, including one by reputed copper geologist, Richard Sillitoe, indicate that if the deposit is correctly judged to be only modestly eroded, then the sulphide mineralization could extend down-dip for several hundred metres. If this were the case, Marimaca could host a meaningful sulphide resource. Drilling will be required to test this hypothesis, but Management believes there is sufficient evidence to warrant additional capital to be invested in examining the sulphide potential.“While the excitement of this geological interpretation lends itself to immediately drilling some deeper holes at the Project, a thorough review of the mineralogy of the deposit also showed some interesting geological markers, which we believe will allow the use of geophysics to delineate high priority drilling targets. The geophysical campaign, which will include high resolution magnetometry and induced polarization, has commenced and is expected to be completed during 2H 2020. These programs should allow our team to understand the size of the potential target below the MOD. We will need to obtain additional permits for drilling and will be working to achieve this as quickly as possible noting the potential impacts of the ongoing Coronavirus pandemic.“The PEA for Marimaca continues to progress well and we look forward to releasing the results to the market in July 2020.”Marimaca Copper Project OverviewMarimaca Copper released an updated Mineral Resource Estimate (“MRE”) for Marimaca of 70 million tonnes, with an average grade of 0.60% copper, within the Measured & Indicated Categories (approximately 420Kt of contained copper) and 40 million tonnes, with an average grade of 0.52% copper, within the Inferred Category (approximately 224kt of contained copper) (refer release on 2 December 2019). This represents an increase of almost 100% from the MRE released in April 2018 and makes the Project one of the most significant copper oxide discoveries in Chile in the last decade.The Company is currently undertaking a PEA for the Project, which is anticipated to be released in early July 2020. The Project is expected to benefit from low upfront capital development costs and, due to the favourable geometry of the orebody and relatively simple oxide processing through SX-EW, Management believes the Project will have very competitive operating costs, delivering compelling economics in the PEA. Overview of Geological Model for Sulphide Potential and Exploration PlansThe Marimaca Project comprises a dominant structural feature of broad zones of sheeted dykes and fracture zones, oriented north-north-east and dipping 45-60o to the east, which host copper mineralisation at surface.There is strong evidence that the oxide zones encountered at surface were generated as a result of the in-situ oxidation of primary sulphide minerals, mostly chalcopyrite. During the 2018/19 drilling program, numerous drill holes intercepted sulphide mineralisation below the current resource within the broader MOD. The location of the Marimaca deposit is interpreted to be controlled by a dilationary structural jog and the Company believes that this control applies both to the MOD and to its downwards continuation into the sulphide zone.Figure 1: Schematic Diagram of Structural Controls Showing Potential for Down-Dip Sulphide Extensions at Marimaca
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