Gran Colombia Gold Announces Multiple Additional Higher-Grade Gold Intercepts in Recent Phase 2 Drilling in the Deeps Zone at Its Marmato Project Including 73.63 Meters at 5.72 g/t Au in Drill Hole MT-IU-041

2019-11-05 / @nasdaq

 

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.

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."

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.

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:

Hole IDFrom (m)To (m)Width (m)Au Grade
(g/t)
Ag Grade
(g/t)
Grade-WidthZone
MT-IU-025246.40705.50459.101.802.1826Deeps
including246.40276.6030.204.555.6137Deeps
including311.55386.7075.152.622.9197Deeps
including451.20502.5051.302.141.5110Deeps
including543.65585.6041.953.202.2134Deeps
Including624.90648.9024.002.851.968Deeps
MT-IU-026295.20703.50408.301.181.5482Deeps
Including295.20312.2017.001.431.324Deeps
Including327.60343.0015.402.962.846Deeps
Including363.50379.1015.601.882.329Deeps
Including459.50482.9523.451.371.532Deeps
Including536.15557.4321.281.931.641Deeps
Including566.64617.6050.962.161.5110Deeps
Including644.75667.9023.152.061.548Deeps
MT-IU-027220.83605.20384.371.471.8565Deeps
including220.83249.0028.173.102.687Deeps
including286.00336.0050.001.672.384Deeps
including478.60503.7025.102.811.771Deeps
including546.70605.2058.502.311.7135Deeps
MT-IU-028259.40665.90406.501.402.3569Deeps
including364.25430.6066.352.393.5159Deeps
including556.45582.4526.002.742.371Deeps
MT-IU-029346.68677.70331.021.712.5566Deeps
including346.68385.6038.921.312.351Deeps
including385.60411.9026.302.022.853Deeps
including411.90439.1527.251.273.535Deeps
including439.15475.5136.362.504.391Deeps
including521.80562.1040.301.512.061Deeps
including562.10591.3529.252.502.173Deeps
including602.00636.7034.702.271.979Deeps
including658.30677.7019.402.784.054Deeps
MT-IU-030265.60568.20302.601.573.0475Deeps
Including265.60281.2015.601.432.122Deeps
Including312.85329.4516.601.661.728Deeps
including347.00387.4540.452.506.9101Deeps
including387.45412.0024.551.362.633Deeps
including412.00431.7019.702.992.659Deeps
including443.55464.7021.152.6810.657Deeps
including480.15494.2514.102.171.431Deeps
including515.60568.2052.601.531.880Deeps
MT-IU-031253.45677.30423.851.812.4767Deeps
including278.25406.00127.752.963.7378Deeps
including406.00478.1072.101.272.292Deeps
including478.10509.7531.652.102.366Deeps
including509.75536.3526.601.721.846Deeps
including601.45629.0027.552.011.955Deeps
including656.30677.3021.001.791.138Deeps

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:

Hole IDFrom (m)To (m)Width (m)Au Grade
(g/t)
Ag Grade
(g/t)
Grade-WidthZone
MT-IU-032334.46682.75348.291.533.1533Deeps
including334.46391.0356.571.544.987Deeps
including391.03416.0825.052.555.964Deeps
including438.32463.0524.732.034.150Deeps
including495.00524.4529.451.765.252Deeps
including566.75601.4034.652.312.180Deeps
including623.40646.1022.702.211.450Deeps
including663.10682.7519.652.561.250Deeps
MT-IU-033287.35707.25419.901.842.4773Deeps
including287.35334.0046.652.317.1108Deeps
including402.55447.5545.003.372.8152Deeps
including456.60494.0037.402.722.2102Deeps
including580.80612.0031.203.161.899Deeps
including634.30652.8018.503.002.156Deeps
MT-IU-034314.05501.00186.951.342.2251Deeps
including419.65465.7546.102.582.7119Deeps
MT-IU-035149.10305.73156.631.273.5199Deeps
including177.05199.9522.902.554.258Deeps
MT-IU-036365.25670.60305.352.742.9837Deeps
including365.25429.9564.704.666.4302Deeps
including469.00490.6021.603.552.477Deeps
including531.10670.60139.502.542.0354Deeps
MT-IU-037208.93326.35117.421.822.8214Deeps
including208.93255.8546.922.532.1119Deeps
including286.90310.2523.352.164.550Deeps
MT-IU-038255.25501.25246.002.033.00499Deeps
including280.30300.1519.853.193.563Deeps
including334.70404.0569.353.164.0219Deeps
MT-IU-039204.35356.20151.851.783.0270Deeps
including218.50237.0018.502.705.550Deeps
including253.05294.7041.652.503.1104Deeps
including314.45332.3017.852.094.237Deeps
MT-IU-040186.80337.65150.852.014.4303Deeps
including224.60260.4535.853.409.3122Deeps
including260.45295.3034.852.582.790Deeps
MT-IU-041189.07452.70263.632.834.9746Deeps
including226.94401.90174.963.866.0675Deeps
including226.94300.5773.635.728.7421Deeps
including300.57333.2532.681.464.548Deeps
including333.25401.9068.653.003.8206Deeps
MT-IU-042286.75379.2092.451.001.792Deeps
MT-IU-043NSI    0 
MT-IU-044229.88501.30271.421.041.8282Deeps
including421.50434.7013.202.732.036Deeps
including467.20484.4517.252.802.948Deeps
MT-IU-045195.25607.15411.902.154.7886Deeps
including230.30302.0071.703.895.3279Deeps
including420.10504.8584.753.308.7280Deeps
including563.50607.1543.651.922.384Deeps

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

A photo accompanying this announcement is available at https://www.globenewswire.com/NewsRoom/AttachmentNg/db8c85c2-5e55-44a5-bf17-d0771264fa4d

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Marmato Deeps Zone

Location of drill holes in Main Zone in Marmato Deeps Zone

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