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Corporate Presentation - Marmato Underground

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Gran Colombia Corporate Presentation - Marmato Underground

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Corporate Presentation - Marmato Underground

  1. 1. SHIFTING FOCUS To MARMATO’s UNDERGROUND MINING POTENTIAL November 2017
  2. 2. 2
  3. 3. 3 MARMATO GOLD DEPOSIT Property Location La Maruja mine operated by Mineros Nacionales Caldas Dept.
  4. 4. 4 1,198 Ha covered by the mining titles granted to GCG MARMATO GOLD DEPOSIT Mining Titles 1,270 m
  5. 5. 5 Mineros Nacionales Cerro El Burro Cien Pesos Echandía Pantano Creek 1,270 m MARMATO GOLD DEPOSIT Panoramic View
  6. 6. 6 ❖ There are no published records of the historical and actual gold and silver production. ❖ Historical research in archives was carried out, which allowed to obtain recovered gold production data for six incomplete periods: 1778-1823; 1832-1836; 1909-1914; 1931-1935; 1941-1944; and 1967 to 1998 . Data excludes Echandía and Zona Baja post-1925. ❖ The total production recorded is 205,834 ounces in 56 years out of a period of 231 years (data for 24% of years) from 1778 to 2008, with an average of 3,954 ounces per year (based on 50 years with complete data). ❖ Total production for the period 1778 to 2008 is estimated at 900,000 ounces using the average annual production figure of 3,954 ounces per year. In addition there is contraband gold plus two millennia of pre-Colombian gold mining. A guestimate of 0.5 to 1.0 million ounces is made for this period, giving an estimated total gold production of about 1.4 to 1.9 million ounces at Marmato. To this can be added a further 300,000 ounces for Zona Baja (1993-2008) and estimated 50,000 ounces for Echandia (1929-2009). This gives a total estimated gold mined of 2.6 to 3.5 million ounces for all Marmato. MARMATO GOLD DEPOSIT Historical & Actual Gold Production HISTORICAL
  7. 7. 7 YEAR Tonnes Au grade (g/t) Ag grade (g/t) Au ounces Ag ounces 2003 161383 4.61 37.06 20,659 39,678 2004 186330 4.16 30.22 21,583 41,504 2005 231540 3.69 54.63 23,673 39,669 2006 260717 3.64 42.74 25,975 38,321 2007 256848 3.32 14.26 22,916 35,193 2008 253617 3.44 14.25 24,021 35,272 2009 250638 3.51 17.23 24,372 39,656 2010 252136 3.39 19.01 23,318 36,548 2011 250553 3.18 14.21 22,715 35,030 2012 268137 2.85 12.08 21,717 35,176 2013 274191 2.9 12.36 22,567 39,916 2014 295023 2.85 9.13 24,111 34,752 2015 303279 2.79 9.33 23,960 34,545 2016 341309 2.56 9.24 23,515 36,303 2017 sept. 274366 2.49 9.63 19,067 29,820 3, 860,067 3.21 18.99 344,169 551,383 MARMATO GOLD DEPOSIT Historical & Actual Gold Production La Maruja Mine is operated by Mineros Nacionales since 1993 ACTUAL
  8. 8. 8 Marmato• is located on the eastern flank of the Western Cordillera of the Colombia Andes. This is separated from the Central Cordillera by the Cauca River. The• Marmato deposit lies within the Cauca-Romeral Terrane, an oceanic terrane comprising metamorphosed mafic to ultramafic complexes, ophiolite sequences and oceanic sediments of probable Late Jurassic to Early Cretaceous age. This terrane was accreted to the continental margin along the Romeral Fault, which lies east of the River Cauca, in the Aptian (125 to 110 Ma). The• Cauca-Romeral Terrane is bounded by the Romeral System Fault to the east and Cauca-Patia System to the west. The• Marmato porphyry stock is 18 km long by 3 to 6 km wide and is elongated north-south. It intrudes the Arquia Complex and the Amaga and Combia formations. MARMATO GOLD DEPOSIT Regional Geology
  9. 9. 9 Marmato Stock • At Marmato the intrusion is 4.6 to 5.8 km wide and extends up to the Cauca River, where is in contact with schist. • Five porphyry pulses have been identified in the Marmato deposit by distinctive textures and cross-cutting relationships in drill core and geological mapping. • The five porphyries pulses have been named P1 to P5 from oldest to youngest. The two main intrusions, dacite P1 and andesite P4, are stocks, while P2, P3 and P5 form dikes. • The main host rocks to mineralization are P1 and P4 dacite/andesite porphyry stocks. • The P1 porphyry stock has been dated at 6.58±0.07 Ma, whereas P5 yielded an age of 5.74±0.14 Ma (Miocene age). U/Pb of zircon by LA-ICP-MS. (Univ. Brasilia, Brasil). MARMATO GOLD DEPOSIT Local Geology P1 P4
  10. 10. 10 MARMATO GOLD DEPOSIT Local Geology Petrography (Santacruz et al., 2016, en revisión)
  11. 11. 11 FIRST magmatic event 6.58 to 6.3 Ma (U/Pb of zircon) 5.96±0.02 Ma to 6.05±0.2 Ma Ar/Ar of Adularia SECOND magmatic event 5.7 Ma (U/Pb of zircon) MARMATO GOLD DEPOSIT Geochronology (Santacruz et al, 2016, en revisión)
  12. 12. 12 Within the Marmato area there are four principal trends of mineralized structures related to syn-mineralization WNW-ESE compression that reactivated some of the basement structures as well as generating a range of second order shear and extensional structures fitting in a sinistral transpressional shearing system. ▪ NNW-trending steep to sub-vertical faults reactivated as a sinistral transpressional shears (140-150°N), ▪ NW-trending steep to moderately inclined structures (120-130°N), ▪ E-W-trending structures (100-090°N) that tend to have moderate to relatively low- angle dips, and ▪ ENE to NE-trending structures (065-080°N) that show a range of dips. In addition to these ore-bearing structures, there is a set of NNE-trending structures of varying dips that appear to represent different components of a reverse/thrust fault system. MARMATO GOLD DEPOSIT Structural Controls on Mineralization
  13. 13. 13 MARMATO GOLD DEPOSIT Drilling to Date MED, GCG and MN drilling was designed to identify a bulk mineable deposit of low grade gold and silver. Total meters drilled to date 201,506 in 719 drill holes
  14. 14. MT-1455-A MT-1499-AMT-1498 MT-1500 THE DEEPS ZONE Discovery hole below existing mine Results pending Blue polygon: boundary of SRK M&I resources. 357m@1.43 g/t Au
  15. 15. THE DEEPS ZONE Drilling Summary & Best Intercepts MND_282_01_17 MT-1445 MT-1455-A MT-1499-A MT-1498 MT-1500 MND_282_03_17 MND_11_16 Level 21 Level 20 Level 19 HOLE ID FROM (m) TO (m) LENGTH (m) Au (g/t) capped Ag (g/t) MT-1445 429.4 668.4 239 1.4 2.3 MT-1455A 491 848.1 357.1 1.4 1.3 MT-1498 204 943.45 739.4 1.47 1.1 MT-1499A 292 816 524 1.72 2.3 MT-1500 394 1,012.1 618.1 1.56 1.5 MND282-01- 17 173.7 383.5 209.8 1.57 3.3 Including 206.0 261.9 55.9 2.79 5.3 MND282-03- 17 137.26 183.0 45.74 3.67 3.58 7 holes drilled for a total of 5,095 meters Deepest drill hole ended in mineralization
  16. 16. 17 >800m ̴150m Inferred top of the DEEPS mineralization THE DEEPS ZONE 3D section using a 1.0 g/t grade shell +1050
  17. 17. 18Summary Section of the Marmato Project, showing areas of potential at depth. MARMATO GOLD DEPOSIT Latest Mineral Resource Estimate SRK Consulting (U.S.), Inc. Veins 13.3 Mt @ 4.6 g/t Au for 1,979 Moz using 1.9 g/t CoG Porphyry 27.0 Mt @ 2.1 g/t Au for 1,858 Moz using 1.9 g/t CoG
  18. 18. 19 SRK Mineral Resource Statement for the Marmato Project, dated June 16, 2017* Category Quantity Grade Metal Au Ag Au Ag Mt g/t g/t 000's oz 000's oz Underground Vein** Measured 2.6 4.7 21.3 396 1,774 Indicated 10.7 4.6 22.3 1,583 7,660 Measured and Indicated 13.3 4.6 22.1 1,979 9,434 Inferred 9.4 4.2 18.9 1,275 5,722 Underground Porphyry*** Measured Indicated 27.0 2.1 14.9 1,858 12,892 Measured and Indicated 27.0 2.1 14.9 1,858 12,892 Inferred 13.5 1.8 15.4 777 6,655 Underground Deeps*** Measured Indicated 0.9 2.0 8.0 60 235 Measured and Indicated 0.9 2.0 8.0 60 235 Inferred 29.3 2.3 2.8 2,142 2,628 Underground Combined Measured 2.6 4.7 21.3 396 1,774 Indicated 38.6 2.8 16.7 3,501 20,787 Measured and Indicated 41.2 2.9 17.0 3,897 22,561 Inferred 52.2 2.5 9.0 4,194 15,005 * Mineral resources are not mineral reserves and do not have demonstrated economic viability. All figures are rounded to reflect the relative accuracy of the estimate. All composites have been capped where appropriate. ** Vein mineral resources are reported at a cut-off grade of 1.9 g/t. Cut-off grades based on a price of US$1,400 per ounce of gold, suitable benchmarked technical and economic parameters and gold recoveries of 90 percent for underground resources, without considering revenues from other metal. *** Porphyry and Deeps mineral resources are reported at a cut-off grade of 1.2 g/t. Cut-off grades based on a price of US$1,400 per ounce of gold, suitable benchmarked technical and economic parameters and gold recoveries of 90 percent for underground resources, without considering revenues from other metal within a limiting pit shell. MARMATO GOLD DEPOSIT Latest Mineral Resources Estimate
  19. 19. 20 THE DEEPS ZONE SPECTRAL INFRARED ANALYSIS OF ALTERATIONS Three (3) sets of alteration associated to the DEEPS mineralization style were identified by Spectral Analysis of 6 drill holes (953 points recorded). 1. Pervasive Propylitic alteration related to iron-magnesium chlorite and epidote with disseminated Pyrrhotite. PoEp
  20. 20. 21 THE DEEPS ZONE SPECTRAL INFRARED ANALYSIS OF ALTERATIONS 2. An event of weak and patchy Potassium alteration, related to secondary biotite hosted in thin veinlets and disseminated in the matrix.
  21. 21. 22 THE DEEPS ZONE SPECTRAL INFRARED ANALYSIS OF ALTERATIONS 3. Whitish alteration referred to as Albite alteration, due to the presence of albite and muscovite (fine grained) forming an halo along the margins of qtz+pyrrhotite veinlets +bismuth minerals ± chlorite ± epidote. Sm Ab Sm Sm Vns Qtz
  22. 22. 23 THE DEEPS ZONE Alteration overprinting Epidote Albite Smectite qtz vns Illite
  23. 23. 24 P1 dacite porphyry with stockwork of veinlets of quartz-pyrrhotite-minor chalcopyrite with narrow illite halo, overprinting biotite alteration. MT-1498 at 854.0 m. Sample 2.0 m at 17.3 g/t Au, 3.5 g/t Ag and 330 ppm Cu. Veinlet of quartz-pyrrhotite-chalcopyrite with halo of green sericite-smectite in P1 dacite porphyry with weak biotite alteration. MT-1498 at 847.3 m. Sample 2.0 m at 2.88 g/t Au, 0.7 g/t Ag, and 225 ppm Cu. Predominance of native gold, commonly accompanied by bismuth tellurides and bismuth sulphides, strongly associated with silicate (quartz) gangue. (G. Di Prisco, 2012) Fe Po Cpy Maldonite (Au2Bi) Native Bi Tsumoite (BiTe) Au Bi Jonassonite (AuBiS) THE DEEPS ZONE Deeps Mineralization Style
  24. 24. 25 THE DEEPS ZONE Deeps Style High-grade Mineralization MND282-03-17 at 1010 m asl. Sample 1.20 m at 18.06 g/t Au and 2.5 g/t Ag VG
  25. 25. P1 showing Propylitic alteration thin qtz vn+/- Po-Te-Bi-Au 26 VG Po + Bi-sulph THE DEEPS ZONE Deeps Style High-grade Mineralization MT-1500 at 322 m asl. Sample 0.80 m at 133.9 g/t of Au and 26.6 g/t of Ag VG
  26. 26. 27 Phase 2 shows four paragenetic sequences: 2a) coarse Py-Apy-Gn 2b) coarse iron-rich Sp-Po-Gn 2c) fine Py-Ccp 2d) fine Py-Mrc-Ccp-Tetrahedrite Two formation environments: 1. Low sulphidation (LS) state (2a, 2b) with a superimposed 2. Intermediate sulphidation (IS) state (2c,2d) KEEP IN MIND Bi STYLES OF MINERALIZATION Paragenetic Sequences 2a 2b 2c 2d
  27. 27. 28 Legend DRILL HOLES AU PPM Pending 0 0.1 0.1 0.3 0.3 1 1 2.5 > 2.5 BLOCKS AU PPM 0 0.1 0.1 0.3 0.3 1 1 2.5 > 2.5 SW MinerosNacionales U/Gmine L 16 L 17 L 18 L 19 L 20 NEEl Burro Hill Echandia Po, Ccp, Te Au, AuBi, Bi Py, Mrc, Po, Ccp, electrum, Au Py, Apy, Sp, Ad electrum Bi + Bi - Native Bi & Bi minerals Bi in minerals SD43 1224 1223 1211 MARMATO GOLD DEPOSIT Zonation of Mineralization by EDS EPMA
  28. 28. 29 MARMATO GOLD DEPOSIT Microthermometry of Fluid Inclusions Legend DRILL HOLES AU PPM Pending 0 0.1 0.1 0.3 0.3 1 1 2.5 > 2.5 BLOCKS AU PPM 0 0.1 0.1 0.3 0.3 1 1 2.5 > 2.5 SW NEEl Burro Hill Echandia 395.4°C 11.93 wt%NaCl eq 364.9°C, 10.86 wt%NaCl eq 346.05°C, 3.63 wt%NaCl eq 365.8°C, 4.03 wt%NaCl eq 302.7°C, 2.90 wt%NaCl eq 325.2°C 5.11 wt%NaCl eq 305.45°C 4.96 wt%NaCl eq MinerosNacionales U/Gmine L 16 L 17 L 18 L 19 L 20 T° + T° - 1210 SD43 1224 1216 SD101 KEEP IN MIND T°
  29. 29. 30 The Liquid Bismuth Collector Model Douglas et al. 2000
  30. 30. 31 THE DEEPS ZONE Conclusions Mineralization• extends vertically at least 900 m below the limit of the current underground operation. The• Deeps Zone has been drilled along strike for about 500 m and over a width of >100 m. The• Deeps mineralization is related to veinlets of Qtz-Po±Ccp±Bi-sulph±Tellurides and VG. Cu grades are very low and are not of economic interest. The veinlets have a narrow halo of intermediate argillic alteration. Pyrrhotite and chalcopyrite increase downwards. The• high-grade areas within the Deeps Zone are commonly related to the presence of visible Au scattered throughout the thin quartz veinlets. The• Deeps mineralization is structurally controlled, which is confirmed by a strong control of the general disposition of the thin veinlets that host the mineralization. This structural control possibly depends on the same stress field that generated the fault system that hosts the epithermal events in the middle and upper areas of the deposit. The• thin veinlets that characterized the Deeps Zone resemble a system of tension fractures developed in a compressive regime, within an envelope generated by a sinistral transpressional shearing system related to WNW-ESE compression, which could be assimilated to a Dilational jog. The• alteration associated to the Deeps mineralization is generally weak, and does not match with any type of alteration related to a porphyry type deposit.
  31. 31. Detailed➢ Petrography program to gain a better understanding of the Deeps mineralization. Planning➢ and execution of an infill drilling program aimed to convert and further develop the Inferred resources and, to further develop the geologic knowledge of the Deeps Zone. Run➢ a Conceptual Metallurgical Test program. Run➢ a Geotechnical Testwork program. Study➢ the potential to develop the new Deeps Zone into the overall business plan for Marmato through a PEA. 32 THE DEEPS ZONE Work in progress
  32. 32. 33 THANKS

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