ANNOUNCES HIGH GRADE DRILL RESULTS FROM ITS 2016 INFILL DRILLING CAMPAIGNS AT THE SEGOVIA AND MARMATO OPERATIONS
Gran Colombia Gold Corp. (GCM.V) has released results from its recently completed 2016 diamond infill drilling program at the Segovia operations. The Company also completed a small underground infill drilling program in 2016 to explore the extension of the mineralization in the Marmato Underground mine.
Infill drilling at Segovia was aimed to increase confidence levels of the mineral resources at both the Providencia and Sandra K mines and was carried out in areas where sparse previous surface drilling had intersected high gold grades. High gold grades generated from 74 drill holes (9,472 metres) were intersected on both vein systems with maximum grades of 134.6 g/t Au and 95.4 g/t Ag over 0.73 metres on the Providencia Vein, and 43.2 g/t Au with 37.5 g/t Ag over 2.05 metres on the Sandra K Techo Vein, part of the Sandra K vein system.
At Marmato, one of the holes in a small underground drilling campaign, MND-11-16, intersected 8.98 m at 20.99 g/t Au and 7.11 g/t Ag from 112.32 m to 121.30 m depth followed by 50.40 m at 2.20 g/t Au and 3.32 g/t from 121.30 m to the end of the hole at 171.70 m.
Serafino Iacono, Executive Co-Chairman of Gran Colombia Gold, commented: "We are pleased to report that the results for the latest Providencia exploration infill drilling campaign are significant for two reasons. First, infill drilling confirms the high-grade mineralized extension of the main ore body to the west of current production levels, and second, this drilling confirms the presence of another high-grade ore body at the east end of Level 12, which could increase Providencia's overall underground mine production in the medium term. Furthermore, we are pleased to report that the newly confirmed deep mineralization at Marmato is closer to the current mine workings and opens the potential for a completely different mining scenario which the Company will carefully assess."
Segovia Drilling Highlights and Key Intercepts
- -Drilling results from the Providencia Mine confirmed the widening of the high-grade ore shoot to the west of Level 13, currently one of the deepest levels. This ore shoot remains open at depth and we believe it offers the potential for another significant phase of resource growth at our flagship mine in Segovia.
- -Additional drilling allowed the Company to better define a second high-grade ore shoot previously discovered underground at the east end of Level 12 of the Providencia Mine.
- -The high-grade gold mineralized intercepts related to the main ore shoot confirm the higher grade mineralization at depth, and could potentially increase mining production at Providencia.
- -Drilling results from surface drilling at the Sandra K Mine confirmed the extension and grade of the two main ore shoots down plunge.
- -The Providencia and Sandra K drill programs continue to increase the confidence in the geological model of both ore bodies through increased drill density.
- -Drilling focused on providing increased definition and confidence in the near-term mine operation within the Indicated Mineral Resources, and include the following key intercepts:
Hole From (m) To (m) Width (m) Au (g/t) Ag (g/t) Providencia Mine PV-IU-002-A* 12.00 12.30 0.30 31.80 26.1 PV-IU-012* 56.36 62.37 6.01 43.32 30.6 including 58.82 60.82 2.0 126.99 90.6 PV-IU-021* 69.74 71.70 1.96 50.26 28.4 including 70.24 70.99 0.75 129.36 71.2 PV-IU-022* 64.00 64.75 0.75 15.57 15.1 PV-IU-023* 48.00 52.39 4.39 20.24 11.7 including 49.29 50.97 1.68 42.73 20.4 PV-IU-025-A* 64.67 65.39 0.72 13.13 15.6 PV-IU-040-A* 20.75 21.48 0.73 134.55 95.4 and 23.51 25.83 2.32 13.21 9.6 PV-IU-050* 40.31 41.01 0.70 18.94 35.1 Sandra K Mine SK-IS-001 242.67 244.72 2.05 43.16 37.5 including 243.50 244.16 0.66 132.88 108.8 SK-IS-002 147.76 148.54 0.78 14.72 40.6 SK-IS-003 255.30 255.64 0.34 8.41 12.8 SK-IS-012 230.56 232.00 1.44 9.24 68.7 including 231.34 232.00 0.66 20.14 149.1 SK-IS-023 159.20 159.72 0.52 10.47 51.2 SK-IS-025 173.10 173.50 0.40 16.70 33.1 * Denotes underground drill holes. The underground holes were drilled at -25 to -75 degrees from the horizontal, and the intersection lengths do not represent true widths. Sample grades over 8.0 g/t Au reported. Grades are for quartz vein intersections and are either single samples, or, for longer widths, are length-weighted composites. The length is the sample length and is not necessarily the true width of the vein. All gold and silver grades are uncut and are not diluted to a minimum mining width. Abbreviations: FW = foot wall vein.
An updated mineral resource estimate for the Segovia Operations incorporating the new drill results is currently being prepared by SRK Consulting and is expected to be available by the end of March.
Marmato Drilling Highlights
A small underground drilling campaign was carried out at Marmato to explore the extension of the vein mineralization between Level 21, the deepest level of the mine, down to Level 24. One of these holes, MND-11-16, intersected 8.98 m at 20.99 g/t Au and 7.11 g/t Ag from 112.32 m to 121.30 m depth, followed by 50.40 m at 2.20 g/t Au and 3.32 g/t from 121.30 m to the end of the hole at 171.70 m. The mineralization in both intersections related to narrow veinlets, with a higher veinlet density in the higher grade zone, and resembles the style of mineralization that was intersected in previous drill holes that characterize the deep body (refer to the Company's press release dated October 10, 2012).
- -Drilling results from this drill hole are interpreted to form the top of the deep zone of veinlet-hosted mineralization, which begins about 100 metres down below the current mine workings, forming a deep body that could be suitable for underground bulk mining.
- -The strike extent of this deep body is approximately 800 metres, while the vertical extent is approximately 850 metres, with a width not less than 100 meters. This body is still open along strike and at depth.
- -The deep gold mineralization is related to narrow veinlets of quartz-pyrrhotite with minor amounts of pyrite and chalcopyrite and a narrow halo of intermediate argillic alteration. These change upwards to pyrite veinlets with pervasive intermediate argillic alteration. They overprint earlier potassic alteration with porphyry-style quartz veinlets, and propylitic alteration. The porphyry style alteration and veining does not carry significant mineralization. The copper values are very low and are not of economic interest.
- -The Marmato Deep Zone mineralization is not included in the current mineral resource estimate for Marmato dated August 7, 2012 and lies below the open pit resource.
- -Previous significant results (greater than 20 gram-metres) for the Marmato Deep Zone are summarized below (see the Company's press release dated October 10, 2012):
Hole From (m) To (m) Width (m) Au (ppm) Ag (ppm) MT-1445* 275.0 300.0 25.0 0.9 5.3 MT-1445* 429.4 668.4 239.0 1.4 2.3 MT-1445* 68.5 83.0 14.5 1.7 4.3 MT-1455A* 164.0 183.6 19.6 1.4 5.8 MT-1455A* 284.0 327.0 43.0 0.6 2.5 MT-1455A* 424.0 483.0 59.0 0.6 3.0 MT-1455A* 491.0 848.1 357.1 1.4 1.3 M-1498* 204.0 943.5 739.5 1.5 1.1 M-1499A* 33.0 179.0 146.0 0.7 3.2 M-1499A* 292.0 816.0 524.0 1.7 2.3 including 292.0 317.0 25.0 2.1 11.7 and 325.0 816.0 491.0 1.7 1.9 MT-1500* 10.0 74.0 64.0 1.2 6.5 MT-1500* 394.0 1,012.1 618.1 1.6 1.5 including 872.0 888.9 16.9 35.2 3.9 * Denotes underground drill holes. The underground holes were drilled at -55 to -85 degrees from the horizontal, and the intersection lengths do not represent true widths. Sample lengths are normally 2.0 metres but may be varied for geological and recovery factors. Intersections were calculated using a cut-off grade of 0.1 g/t gold and no more than 6.0 metres of internal dilution. Gold grades were capped at 20.0 g/t and silver grades at 500 g/t. The high-grade intercept from hole MT-1500 was not capped and shows a different style of mineralization. It has a true width of approximately 4.4 meters.
SRK Consulting is preparing an updated mineral resource estimate for Marmato Underground incorporating the new drill results that is expected to be completed in the second quarter of this year.
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 in respect of the drilling results from the Marmato Project. Dr. Redwood verified the data disclosed in this news release, including the sampling, analytical and test data underlying the information contained in this news 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 samples were prepared and assayed by SGS Laboratories Ltd (ISO 9001:2008) at their laboratory in Medellin, Colombia. Gold was assayed by fire assay with atomic absorption spectrophotometer ("AAS") finish. Samples over 10 g/t gold were re-assayed by fire assay with gravimetric finish. Silver was assayed by aqua regia digestion and AAS finish. Silver samples above 100 g/t were re-assayed by fire assay with gravimetric finish. Blank, standard and duplicate samples were routinely inserted for quality assurance and quality control.
The Marmato intersection in hole MND-11-16 was calculated using a cut-off grade of 1.0 g/t Au, uncut assays, and a maximum actual interval below cut-off grade of 4.35 m.
About Gran Colombia Gold
Gran Colombia is a Canadian-based gold and silver exploration, development and production company with its primary focus in Colombia. Gran Colombia is currently the largest underground gold and silver producer in Colombia with several underground mines in operation at its Segovia and Marmato Operations.