Including 73.63 Meters at 5.72 g/t Au in Drill Hole MT-IU-041
TORONTO, Nov. 05, 2019 (GLOBE NEWSWIRE) -- Gran Colombia Gold Corp. (TSX: GCM; OTCQX: TPRFF) announced today multiple additional higher-grade gold intercepts over broad widths from 21 diamond drill holes (11,600 meters) drilled into the Marmato Deeps Zone (“MDZ”) as part of the ongoing 2019 Phase 1 and Phase 2 infill drilling program (the “2019 drilling campaign”) at its 100%-owned Marmato Project in Caldas, Colombia. The 2019 drilling campaign was split into two phases, of which Phase 1 was targeted to further delineate and extend down-plunge the higher-grade core, with a cut-off grade of 1.7 g/t Au, referred to as the Main Zone (“MZ”), outlined by the 2018 drilling campaign within the MDZ envelope at a cut-off grade of 0.7 g/t Au. It was also aimed to convert the Inferred Resources within the MZ, above the 900 meters level, to Indicated Resources. The results from both the 2018 and 2019 Phase 1 drilling campaigns were included in the updated Mineral Resource Estimate and Preliminary Economic Assessment (“PEA”) for Marmato which was recently announced in the press release of October 15, 2019. Phase 2 infill drilling, above the 600 meters level, is still in progress and is designed to provide sufficient tonnes and grade in the measured and indicated mineral resource categories, within the MZ, to support the prefeasibility study (“PFS”) which is currently being carried out and expected to be finalized by mid-2020.
The 2019 drilling campaign, totaling 17,000 meters, started in March, and is being carried out with three contractor diamond drill rigs, one of which was added to the drilling campaign in early September, operating from four purpose-built underground drill stations. To date, the ongoing drilling campaign comprises 21 drill holes completed totaling approximately 11,600 meters, of which 4,600 meters in 7 drill holes are in Phase 1, and 7,000 meters in 14 drill holes are in Phase 2.Serafino Iacono, Executive Chairman of Gran Colombia, commented, “Our 2019 drilling campaign has generated some exciting results which have increased our confidence in the geological model, extending the MZ to approximately 500 meters along strike, with true widths varying between 35 meters and 150 meters and remaining open at depth and to the east. Drilling has also confirmed the strong vertical continuity of the MZ for more than 700 vertical meters that shows an average grade of 4.3 g/t Au, which is the primary target zone for expansion of underground mining operations in the Deeps Zone in the PFS. Recent Phase 2 drilling continues to demonstrate an improvement of grades in the MZ below the 900 meters level versus the mineral resource block model associated with the PEA. In addition, separate underground drilling and channel sampling programs undertaken since the latter part of 2018 on level 21 at Marmato have tested a block within the higher-grade zone that is being developed and will be placed into full production from the existing mining operation starting next year. All in all, we remain very encouraged by the progress we are making in the evaluation of the underground mining expansion opportunity at our Marmato Project."
Intersections with high gold grades generated from the seven drill holes of Phase 1 drilling reported herein, and included in the July 31, 2019 Mineral Resource Estimate update announced on October 15, 2019, include:
Drill hole MT-IU-025 which intersected 30.20 m at 4.55 g/t Au and 5.6 g/t Ag from 246.40 m to 276.60 m, and 41.95 m at 3.20 g/t Au and 2.2 g/t Ag from 543.65 to 585.60;
Drill hole MT-IU-026 which intersected 15.40 m at 2.96 g/t Au and 2.8 g/t Ag from 327.60 m to 343.00 m;
Drill hole MT-IU-027 which intersected 28.17 m at 3.10 g/t Au and 2.6 g/t Ag from 220.83 m to 249.00 m;
Drill hole MT-IU-028 which intersected 66.35 m at 2.39 g/t Au and 2.3 g/t Ag from 364.25 m to 430.60 m, and 26.00 m at 2.74 g/t Au and 2.3 g/t Ag from 556.45 m to 582.45 m;
Drill hole MT-IU-031 which intersected 127.75 m at 2.96 g/t Au and 3.7 g/t Ag from 278.25 m to 406.00 m.
Intersections with high gold grades generated from the fourteen drill holes of Phase 2 drilling reported herein, which are not yet reflected in the Mineral Resource Estimate, include:
Drill hole MT-IU-033 which intersected 45.00 m at 3.37 g/t Au and 2.8 g/t Ag from 402.55 m to 447.55 m;
Drill hole MT-IU-036 which intersected 64.70 m at 4.66 g/t Au and 6.4 g/t Ag from 365.25 m to 429.95 m;
Drill hole MT-IU-038 which intersected 69.35 m at 3.16 g/t Au and 4.0 g/t Ag from 334.70 m to 404.05 m;
Drill hole MT-IU-041 which intersected 174.96 m at 3.86 g/t Au and 6.0 g/t Ag from 226.94 m to 401.90 m including 73.63 m at 5.72 g/t Au and 8.8 g/t Ag from 226.94 m to 300.57 m;
Drill hole MT-IU-045 which intersected 71.70 m at 3.50 g/t Au and 5.3 g/t Ag from 230.30 m to 302.0 m and 84.75 m at 3.21 g/t Au and 8.7 g/t Ag from 420.10 m to 504.85 m.
Gold mineralization in the MDZ is structurally controlled and is hosted in narrow quartz veinlets of T and R´ type, which are related to a sinistral transpressional shearing system associated with WNW-ESE compression. The MDZ style of mineralization is characterized by very narrow veinlets of quartz-pyrrhotite-bismuth tellurides-free gold with minor amounts of pyrite and chalcopyrite rimmed by a narrow halo of sodic-calcic alteration. The high-grade intercepts within the MZ are related to a higher veinlet density, with veinlets usually showing free gold, as highlighted by consultant geologist Dr. Richard H. Sillitoe on his most recent visit to the project in July 2019.
Key Highlights and Intercepts from Phase 1 drilling
The long low-grade intercepts of MDZ style of mineralization, with downhole intersections up to 423.85 meters long (hole MT-IU-031), have an average grade greater than 1.0 g/t Au, and all fit well into the initial Leapfrog grade shell at a cut-off grade of 0.7 g/t Au, which confirms the current model;
All of the drill holes of Phase 1 reported herein end within the low grade shell with the result that the MDZ is open on the east side. This is due to the location of underground drill stations above and close to the steeply plunging low grade shell. The holes achieved their objective of fully cutting the high grade MZ;
Several of the long low-grade intercepts (MT-IU-025, MT-IU-027, MT-IU-029, MT-IU-031) would fit in the top positions of the Top Ten Gold Drill Results – August 2019 chart issued by Mining.com on October 23rd, 2019 based on grade-width (calculated as the width of the drill intersection in meters multiplied by the Au grade in g/t);
Phase 1 drilling, combined with previous drilling, has confirmed the strike length of the MDZ model at a cut-off grade of 0.7 g/t Au to approximately 650 meters, with true widths ranging from 40 meters up to 235 meters. The model is branching off to the west and is still open to the east and at depth;
Phase 1 drilling has further outlined the MZ that occurs within the central portion of the MDZ envelope, which has been outlined by using a grade shell at a cut-off grade of 1.7 g/t Au. The MZ extends along strike with an excellent continuity for approximately 500 meters, and true widths that vary between 35 meters and 150 meters. All the intercepts in the MZ have grades greater than 2.0 g/t Au. This zone is still open to the east and at depth;
Phase 1 drilling has also confirmed the strong vertical continuity of the MZ for more than 700 vertical meters, from Level 21 (1,020 meters amsl) down to 300 meters amsl, with an inferred further extension down to 200 meters amsl;
Phase 1 drilling has achieved the conversion of approximately 470,000 ounces of gold from Inferred Resources to Indicated Resources at a cut-off grade of 1.3 g/t Au.
The following table is a list of significant intersections from the drill holes of Phase 1 included in the recent PEA, which had hole MT-IU-031 as the cut-off hole, since the Company’s press release dated April 25th, 2019:
All are underground drill holes. They were drilled at -45 to -75 degrees from the horizontal, and the intersection lengths do not represent true widths. Sample lengths are on average 1.50 metres long but may be varied for geological and recovery factors. Intersections were calculated using a cut-off grade of 0.5 g/t gold, and no more than 5.0 m of continuous internal dilution for intervals up to 50 m, no more than 10 m of continuous internal dilution for intervals of 50-200 m, and no more than 20 m of continuous internal dilution for intervals greater than 201 m. Gold grades were capped at 13.0 g/t gold which affects 16 samples out of a total of 1653 samples. Intervals greater than or equal to 1.0 g/t Au are reported. Grade-width is calculated as the width of the drill intersection in meters multiplied by the Au grade in g/t.
Key Highlights and Intercepts from Phase 2 drilling
The drill intercepts (MT-IU-036, MT-IU-041, MT-IU-045) from Phase 2 drilling continue to demonstrate an improvement of grades in the MZ below the 900 meters level versus the mineral resource block model associated with the PEA;
Phase 2 drilling has increased the average grade of the MZ from 3.8 g/t Au to 4.3 g/t Au (calculated using the arithmetic average of the drill intersections);
The results from Phase 2 infill drilling continue to impress both in terms of grades and widths and will undoubtedly lead to an important resource growth coupled with a greater flexibility for mining;
Most of the drill holes of Phase 2 reported herein end within the low grade shell with the result that the MDZ is open on the east side. This is due to the location of underground drill stations above and close to the steeply plunging low grade shell. The holes achieved their objective of fully cutting the high grade MZ;
Most of the higher-grade intercepts (MT-IU-036, MT-IU-041, MT-IU-045) would fit in the Top Ten Gold Drill Results – August 2019 chart issued by Mining.com on October 23rd, 2019.
The following table is a list of significant intersections from the drill holes of Phase 2 drilling that, combined with all the previous ones, will support the PFS level resources and reserves statement:
All are underground drill holes. They were drilled at -38 to -74 degrees from the horizontal, and the intersection lengths do not represent true widths. Sample lengths are on average 1.50 metres long but may be varied for geological and recovery factors. Intersections were calculated using a cut-off grade of 0.5 g/t gold, and no more than 5.0 m of continuous internal dilution for intervals up to 50 m, no more than 10 m of continuous internal dilution for intervals of 50-200 m, and no more than 20 m of continuous internal dilution for intervals greater than 201 m. Gold grades were capped at 13.0 g/t gold which affects 28 samples of a total of 2316 samples. Intervals greater than or equal to 1.0 g/t are reported. NSI means no significant intervals. Grade-width is calculated as the width of the drill intersection in meters multiplied by the Au grade in g/t.
Please refer also to the attached illustrative section in Attachment 1 showing the location of the drill holes and the higher-grade MZ zone at a cut-off grade of 1.7 g/t Au.
Qualified Person
Dr. Stewart D. Redwood, PhD, FIMMM, Senior Consulting Geologist to the Company, is a qualified person as defined by National Instrument 43-101 – Standards of Disclosure or Mineral Projects and prepared or reviewed the preparation of the scientific and technical information in this press release. Verification included a review of the quality assurance and quality control samples, and review of the applicable assay databases and assay certificates.
Quality Assurance and Quality Control
The Marmato Project core samples were prepared and assayed by SGS Laboratories Ltd (ISO 9001:2008) at their laboratory in Medellin, Colombia. Gold was assayed by 30 g fire assay with atomic absorption spectrophotometer (“AAS”) finish. Samples over 10.0 g/t gold were re-assayed by 30 g fire assay with gravimetric finish. Silver was assayed by aqua regia digestion and AAS finish. Blank, standard and duplicate samples were routinely inserted for quality assurance and quality control.
About Gran Colombia Gold Corp.
Gran Colombia is a Canadian-based mid-tier gold producer with its primary focus in Colombia where it is currently the largest underground gold and silver producer with several mines in operation at its Segovia and Marmato Operations. Gran Colombia is continuing to focus on exploration, expansion and modernization activities at its high-grade Segovia Operations and, through a spin out transaction with Bluenose Gold Corp. announced on October 7, 2019, Gran Colombia is progressing toward a major expansion and modernization of its underground mining operations at the Marmato Project.
Additional information on Gran Colombia can be found on its website at www.grancolombiagold.com and by reviewing its profile on SEDAR at www.sedar.com.
Cautionary Statement on Forward-Looking Information
This news release contains "forward-looking information", which may include, but is not limited to, statements with respect to anticipated business plans or strategies, including exploration programs and mineral resources and reserves. Often, but not always, forward-looking statements can be identified by the use of words such as "plans", "expects", "is expected", "budget", "scheduled", "estimates", "forecasts", "intends", "anticipates", or "believes" or variations (including negative variations) of such words and phrases, or state that certain actions, events or results "may", "could", "would", "might" or "will" be taken, occur or be achieved. Forward-looking statements involve known and unknown risks, uncertainties and other factors which may cause the actual results, performance or achievements of Gran Colombia to be materially different from any future results, performance or achievements expressed or implied by the forward-looking statements. Factors that could cause actual results to differ materially from those anticipated in these forward-looking statements are described under the caption "Risk Factors" in the Company's Annual Information Form dated as of March 27, 2019 which is available for view on SEDAR at www.sedar.com. Forward-looking statements contained herein are made as of the date of this press release and Gran Colombia disclaims, other than as required by law, any obligation to update any forward-looking statements whether as a result of new information, results, future events, circumstances, or if management's estimates or opinions should change, or otherwise. There can be no assurance that forward-looking statements will prove to be accurate, as actual results and future events could differ materially from those anticipated in such statements. Accordingly, the reader is cautioned not to place undue reliance on forward-looking statements.
For Further Information, Contact:
Mike Davies
Chief Financial Officer
(416) 360-4653
investorrelations@grancolombiagold.com
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