The structural style is different from the rest of the Marmato deposit, forming a deep, high grade core, with no major veins. Further work is required by the Company to investigate the depth and strike continuity of this deep mineralization.
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Gran Colombia announces discovery of new, deep mineralization and additional drill results at the Marmato project
TORONTO , Jan. 9, 2012 /CNW/ - Gran Colombia Gold Corp. (TSX: GCM.TO - News) is pleased to announce the discovery of a deep mineralization trend below the current, preliminary pit outline at its Marmato gold project in Colombia , further highlighting the geological upside of this project. Highlights from an additional 82 drill holes totalling 24,697 metres from the diamond drilling program include hole MT-1455A which returned 1.4 grams per tonne (g/t) gold and 6.4 g/t silver over 357 metres and hole MT-1445, which returned 1.4 g/t gold and 2.3 g/t silver over 239 metres.
The current drilling has also produced a number of deep gold intersections, which include those highlighted above, and which extend mineralization trends to approximately 300 metres below the limit of the current preliminary pit outline. The deep mineralization is still open at depth and in all directions except to the southwest. These deep intersections show that mineralization at the Marmato Project extends for a vertical interval of more than 1,040 metres to the 560 metre level, and is open at depth.
Serafino Iacono, Executive Co-Chairman of the Company, commented: "While it is still very early days in terms of our understanding of this new deep mineralization we are very excited as a result of the significant extension to the vertical range of the system at the Marmato Project as well as the recognition of a new style of gold occurrence at the Marmato Project. This new zone remains wide open and we believe it offers the potential for another significant phase of resource growth at our flagship project."
Mineralization in the deep gold intersections is related to parallel veinlets of quartz-pyrrhotite-chalcopyrite. Gold appears to be related to the presence of chalcopyrite, and copper assays are awaited for these holes. The veinlets have a narrow halo of intermediate argillic alteration. The style of alteration and mineralization is similar to that seen throughout the Marmato deposit and the grades of gold are higher (and copper is also expected to be higher). The structural style is different from the rest of the Marmato deposit, forming a deep, high grade core, with no major veins. Further work is required by the Company to investigate the depth and strike continuity of this deep mineralization.
Since January, 2010, the total number of metres drilled to date is 116,677 in 334 holes. Including all previous drilling the total is 197,571 metres in 713 holes. The surface drilling program was completed in December, 2011 and samples from the final holes are at the laboratory and awaiting results. The final 7 underground holes are planned to be completed this month which will conclude the resource drilling campaign for the upcoming Feasibility Study. All of the results to date, together with a map showing the locations of the drill holes, are available on the Company's website at www.grancolombiagold.com. Once all of the drilling results are received, an updated resource and reserve estimate will be made.
The Marmato Project is the subject of a Technical Report prepared by SRK Consulting (UK) Ltd. announced on September 4, 2011 showing a measured and indicated mineral resource of approximately 306.7 million tonnes at an average gold grade of 1.0 g/t containing 10.0 million ounces of gold plus 68.3 million tonnes grading 1.1 g/t containing approximately 2.4 million ounces of gold classified as inferred resources at a cut-off grade of 0.3 g/t. Measured and indicated silver resources amounted to 63.9 million ounces grading 6.5 g/t plus a further 11.2 million ounces classified as inferred resources grading 5.1 g/t. The complete Technical Report is available at www.sedar.com as well as the Company's website.
SRK also completed a Preliminary Economic Assessment in May 2011 , indicating that the preferred mining method is open pit with contractor mining. Based on processing 283 million tonnes of ore at a rate of 40,000 tonnes per day, production would average 340,000 ounces of gold and 1.3 million ounces of silver per year over a 21-year mine life. The cash operating cost is expected to be $525 per ounce of gold, net of silver credits. Assuming a life of mine capital cost of $550 million , total cost per ounce is estimated to be $643 . Assuming gold and silver prices of $1,200 and $16 per ounce respectively, this method resulted in a net present value of $1.1 billion assuming a discount rate of 5%. These estimates assume an average gold grade of 0.9 g/t, a stripping ratio of 3.3:1 and a metallurgical recovery of 88% for gold and 60% for silver. Mineral resources that are not mineral reserves do not have demonstrated economic viability. The complete Preliminary Economic Assessment is available at www.sedar.com as well as the Company's website.
Hatch has been retained to prepare a Pre-feasibility Study based on the September 4, 2011 resource estimate, the results of which are expected at the end of the first quarter of 2012. |
