Exploration and discovery history of copper and gold deposits in Colombia

over the last 50 yearsDr. Stewart D. Redwood

Consulting Economic Geologistwww.sredwood.cominfo@sredwood.com

Redwood Exploration & Discovery

50 years of exploration for bulk tonnage Cu and Au in Colombia

• 20 x Cu deposits discovered• Porphyry Cu, Cu-Mo, Cu-Au, ± skarn, replacement• Only 4 deposits have resources• 6.52 Mt (14.37 Blb) Cu + 7.0 Moz Au

• 16 x Au deposits discovered or expanded with bulk tonnage resources

• Epithermal Au, mesothermal Au, porphyry Au, Au-Cu • 80.3 Moz Au, 155 Moz Ag, 0.36 Mt (800 Mlb) Cu

Cu-Au discoveries 1970-2019N1C1 C2 C3 C4 C5

1No. 2 24 31

3 8 21 25 32 354 6 9 11 14 17 19 22 26 33 36 385 7 10 12 13 15 16 18 20 23 27 28 29 30 34 37 39 40 41

Year

1970

1980

1990

2000

2010

2020

VMS Cu-Au Ni-Fe open pit mineCu-rich porphyry (skarn, replacement) Coal open pit minesAu-rich epithermal, porphyry.Epithermal-mesothermal Au veins

1 El Roble 11 Acandi 21 Cerro Vetas (Titiribi) 31 California (C'jon Blanco, Buenavista) Open Pit Mines2 Los Andes 12 El Sapo 22 Marmato 32 Vetas (El Volcan) N1 Cerro Matoso Ni-Fe3 Infierno-Chili 13 El Pisno 23 Mazamorras (Arboledas) 33 Vetas Gold Project C1 Cerrejon4 Los Guayabos 14 Andagueda (Dojura) 24 Quinchia (La Cumbre) 34 Segovia (Frontino) C2 La Loma5 Puerto Saldana 15 Mocoa 25 Quinchia (Dosquebradas) 35 Marmato Deeps C3 La Francia6 Murindo (Mande Norte) 16 El Alacran 26 Miraflores 36 Buritica C4 Calenturias7 Pantanos-Pegadorcito 17 Rio Amparrado 27 La Mina (La Cantera & Middle) 37 San Matias C5 La Jagua8 Piedrasentada 18 Cobrasco-Comita 28 La Colosa 38 Nueva Chaquira9 Dominical 19 Gramalote 29 La Bodega & La Mascota 39 Mongora

10 Cerro Negro 20 Angostura 30 California 40 San Ramon41 Cisneros

Cu-Au discoveries 1970-2019

• Porphyry Cu: 20 (49%)• Porphyry Au, epithermal Au: 16

(39%)• Epithermal/mesothermal Au

veins: 4 (10%)• VMS Cu-Au: 1 (2%)

La Colosa porphyry Au (AngloGold Ashanti, 2007)

60 year Cu price (US$)

Source: Macrotrends.net

1970-1985Recessions

100 year Au price (US$)

Source: Macrotrends.net

2005-2019

End of gold standard 1971

Price spike 1980

Recessions

Discoverer

N1C1 C2 C3 C4 C5

1No. 2 24 31

3 8 21 25 32 354 6 9 11 14 17 19 22 26 33 36 385 7 10 12 13 15 16 18 20 23 27 28 29 30 34 37 39 40 41

Year

1970

1980

1990

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2010

2020

INGEOMINAS + International Government Agency Ni-Fe open pit mineIndividual geologist/miner Coal open pit minesJunior companyMajor company

1 El Roble 11 Acandi 21 Cerro Vetas (Titiribi) 31 California (C'jon Blanco, Buenavista) Open Pit Mines2 Los Andes 12 El Sapo 22 Marmato 32 Vetas (El Volcan) N1 Cerro Matoso Ni-Fe3 Infierno-Chili 13 El Pisno 23 Mazamorras (Arboledas) 33 Vetas Gold Project C1 Cerrejon4 Los Guayabos 14 Andagueda (Dojura) 24 Quinchia (La Cumbre) 34 Segovia (Frontino) C2 La Loma5 Puerto Saldana 15 Mocoa 25 Quinchia (Dosquebradas) 35 Marmato Deeps C3 La Francia6 Murindo (Mande Norte) 16 El Alacran 26 Miraflores 36 Buritica C4 Calenturias7 Pantanos-Pegadorcito 17 Rio Amparrado 27 La Mina (La Cantera & Middle) 37 San Matias C5 La Jagua8 Piedrasentada 18 Cobrasco-Comita 28 La Colosa 38 Nueva Chaquira9 Dominical 19 Gramalote 29 La Bodega & La Mascota 39 Mongora

10 Cerro Negro 20 Angostura 30 California 40 San Ramon41 Cisneros

USGS UNDP JICA-MMAJBGR

Cu 1970-1985 Au 2004-2019

Discoverer

• Government 16 (39%)• Majors 7 (17%)• Juniors 16 (39%)• Individuals 2 (5%)

Rio Comita porphyry Cu, Choco, discovered by German Mission (BGR) and INGEOMINAS, 1985

Discovery methodN1C1 C2 C3 C4 C5

1No. 2 24 31

3 8 21 25 32 354 6 9 11 14 17 19 22 26 33 36 385 7 10 12 13 15 16 18 20 23 27 28 29 30 34 37 39 40 41

Year

1970

1980

1990

2000

2010

2020

Regional stream sediment survey Ni-Fe open pit mineGeology Coal open pit minesGeophysicsOld mineArtisanal mineDeep drilling

1 El Roble 11 Acandi 21 Cerro Vetas (Titiribi) 31 California (C'jon Blanco, Buenavista) Open Pit Mines2 Los Andes 12 El Sapo 22 Marmato 32 Vetas (El Volcan) N1 Cerro Matoso Ni-Fe3 Infierno-Chili 13 El Pisno 23 Mazamorras (Arboledas) 33 Vetas Gold Project C1 Cerrejon4 Los Guayabos 14 Andagueda (Dojura) 24 Quinchia (La Cumbre) 34 Segovia (Frontino) C2 La Loma5 Puerto Saldana 15 Mocoa 25 Quinchia (Dosquebradas) 35 Marmato Deeps C3 La Francia6 Murindo (Mande Norte) 16 El Alacran 26 Miraflores 36 Buritica C4 Calenturias7 Pantanos-Pegadorcito 17 Rio Amparrado 27 La Mina (La Cantera & Middle) 37 San Matias C5 La Jagua8 Piedrasentada 18 Cobrasco-Comita 28 La Colosa 38 Nueva Chaquira9 Dominical 19 Gramalote 29 La Bodega & La Mascota 39 Mongora

10 Cerro Negro 20 Angostura 30 California 40 San Ramon41 Cisneros

Discovery method

• Regional stream sediments: 19 (46%)• Geology: 3 (7%)• Geophysics: 1 (2%)• Old mine re-evalution: 11 (27%)• Artisanal mine: 5 (12%)• Deep drilling: 2 (5%)

Regional stream sediment discovery: La Colosa, AngloGold Ashanti (2007)

Discovery method

Porphyry Cu discovery at artisanal Au mine: San Matias (2011)

Re-evaluation of old Au mine: Marmato (1998)

Outcropping or concealed deposit?N1C1 C2 C3 C4 C5

1No. 2 24 31

3 8 21 25 32 354 6 9 11 14 17 19 22 26 33 36 385 7 10 12 13 15 16 18 20 23 27 28 29 30 34 37 39 40 41

Year

1970

1980

1990

2000

2010

2020

Outcropping deposit Ni-Fe open pit mineConcealed by colluvium Coal open pit minesConcealed by lithocapHidden

1 El Roble 11 Acandi 21 Cerro Vetas (Titiribi) 31 California (C'jon Blanco, Buenavista) Open Pit Mines2 Los Andes 12 El Sapo 22 Marmato 32 Vetas (El Volcan) N1 Cerro Matoso Ni-Fe3 Infierno-Chili 13 El Pisno 23 Mazamorras (Arboledas) 33 Vetas Gold Project C1 Cerrejon4 Los Guayabos 14 Andagueda (Dojura) 24 Quinchia (La Cumbre) 34 Segovia (Frontino) C2 La Loma5 Puerto Saldana 15 Mocoa 25 Quinchia (Dosquebradas) 35 Marmato Deeps C3 La Francia6 Murindo (Mande Norte) 16 El Alacran 26 Miraflores 36 Buritica C4 Calenturias7 Pantanos-Pegadorcito 17 Rio Amparrado 27 La Mina (La Cantera & Middle) 37 San Matias C5 La Jagua8 Piedrasentada 18 Cobrasco-Comita 28 La Colosa 38 Nueva Chaquira9 Dominical 19 Gramalote 29 La Bodega & La Mascota 39 Mongora

10 Cerro Negro 20 Angostura 30 California 40 San Ramon41 Cisneros

Hidden deposit: Marmato Deeps (2011)

47.6 Mt @ 2.2 g/t ind + inf (Gran Colombia, 2019)Discovery holes, 2011 (Gran Colombia)

Discovery holes 2013 (AngloGold Ashanti)

Concealed by lithocap: Nuevo Chaquiro (2012-13)

605 Mt @ 0.65% Cu, 0.32 g/t Au (maiden inf resource, 2014, AGA)0.3% Cu starts at 250-400 m depth

Economic statusN1C1 C2 C3 C4 C5

1No. 2 24 31

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Year

1970

1980

1990

2000

2010

2020

Not drilled Ni-Fe open pit mineDrilled phase 1 Coal open pit minesResourcePEA-PFS-FSProduction

1 El Roble 11 Acandi 21 Cerro Vetas (Titiribi) 31 California (C'jon Blanco, Buenavista) Open Pit Mines2 Los Andes 12 El Sapo 22 Marmato 32 Vetas (El Volcan) N1 Cerro Matoso Ni-Fe3 Infierno-Chili 13 El Pisno 23 Mazamorras (Arboledas) 33 Vetas Gold Project C1 Cerrejon4 Los Guayabos 14 Andagueda (Dojura) 24 Quinchia (La Cumbre) 34 Segovia (Frontino) C2 La Loma5 Puerto Saldana 15 Mocoa 25 Quinchia (Dosquebradas) 35 Marmato Deeps C3 La Francia6 Murindo (Mande Norte) 16 El Alacran 26 Miraflores 36 Buritica C4 Calenturias7 Pantanos-Pegadorcito 17 Rio Amparrado 27 La Mina (La Cantera & Middle) 37 San Matias C5 La Jagua8 Piedrasentada 18 Cobrasco-Comita 28 La Colosa 38 Nueva Chaquira9 Dominical 19 Gramalote 29 La Bodega & La Mascota 39 Mongora

10 Cerro Negro 20 Angostura 30 California 40 San Ramon41 Cisneros

Economic status

Buritica gold production 2020 (Continental Gold) Gramalote open pit approval 2015, feasibility study 2020 (B2Gold / AngloGold Ashanti)

Deposit modelsN1C1 C2 C3 C4 C5

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Year

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1980

1990

2000

2010

2020

VMS Cu-Au Ni-Fe open pit minePorphyry Cu-Mo, Cu-Au Coal open pit minesPorphyry Au-Cu, AuSkarn /replacement Cu-AuOxidised intrusion Au veins/veinletsReduced intrusion Au veinletsIS epithermal AuHS epithermal Au

1 El Roble 11 Acandi 21 Cerro Vetas (Titiribi) 31 California (C'jon Blanco, Buenavista) Open Pit Mines2 Los Andes 12 El Sapo 22 Marmato 32 Vetas (El Volcan) N1 Cerro Matoso Ni-Fe3 Infierno-Chili 13 El Pisno 23 Mazamorras (Arboledas) 33 Vetas Gold Project C1 Cerrejon4 Los Guayabos 14 Andagueda (Dojura) 24 Quinchia (La Cumbre) 34 Segovia (Frontino) C2 La Loma5 Puerto Saldana 15 Mocoa 25 Quinchia (Dosquebradas) 35 Marmato Deeps C3 La Francia6 Murindo (Mande Norte) 16 El Alacran 26 Miraflores 36 Buritica C4 Calenturias7 Pantanos-Pegadorcito 17 Rio Amparrado 27 La Mina (La Cantera & Middle) 37 San Matias C5 La Jagua8 Piedrasentada 18 Cobrasco-Comita 28 La Colosa 38 Nueva Chaquira9 Dominical 19 Gramalote 29 La Bodega & La Mascota 39 Mongora

10 Cerro Negro 20 Angostura 30 California 40 San Ramon41 Cisneros

Deposit models

• Cu-rich porphyry: 17 (41%)• IS epithermal-mesothermal Au: 9 (22%)• Au-rich porphyry: 5 (12%)• Oxidised intrusion Au veins: 4 (10%)• Skarn/replacement Cu-Au: 3 (7%)• HS epithermal Au: 1 (2%)• Reduced intrusion Au: 1 (2%)• VMS Cu-Au: 1 (2%)

Porphyry Cu-Au (San Matias) Porphyry Au-(Cu) (La Mina)

Metallogenic beltsN1C1 C2 C3 C4 C5

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Year

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Jurassic-Cretaceous Segovia, Antioquia + Ibague Batholiths Ni-Fe open pit mineLate Cretaceous Canasgordas terrane Coal open pit minesLate Cretaceous arcEocene Mande-Acandi BatholithMiocene Upper Cauca-Patia beltLate Miocene Middle Cauca beltLate Mio-Pliocene California-Vetas belt

1 El Roble 11 Acandi 21 Cerro Vetas (Titiribi) 31 California (C'jon Blanco, Buenavista) Open Pit Mines2 Los Andes 12 El Sapo 22 Marmato 32 Vetas (El Volcan) N1 Cerro Matoso Ni-Fe3 Infierno-Chili 13 El Pisno 23 Mazamorras (Arboledas) 33 Vetas Gold Project C1 Cerrejon4 Los Guayabos 14 Andagueda (Dojura) 24 Quinchia (La Cumbre) 34 Segovia (Frontino) C2 La Loma5 Puerto Saldana 15 Mocoa 25 Quinchia (Dosquebradas) 35 Marmato Deeps C3 La Francia6 Murindo (Mande Norte) 16 El Alacran 26 Miraflores 36 Buritica C4 Calenturias7 Pantanos-Pegadorcito 17 Rio Amparrado 27 La Mina (La Cantera & Middle) 37 San Matias C5 La Jagua8 Piedrasentada 18 Cobrasco-Comita 28 La Colosa 38 Nueva Chaquira9 Dominical 19 Gramalote 29 La Bodega & La Mascota 39 Mongora

10 Cerro Negro 20 Angostura 30 California 40 San Ramon41 Cisneros

Metallogenic belts

Conclusions

• Exploration methods• Stream sediment geochemistry• Soil geochemistry follow-up• Geology• Artisanal mines

• Future • Regional geophysics• Property geophysics

• Challenges• Public security • Social license• Environmental permitting• Bureaucratic delays • Logistics• Topography• Tropical vegetation• Deep weathering

• Immature exploration play• Outcropping mineralization• Maturity varies by belt

Future exploration trends

• Surface exploration of areas as they open up with improved security and social-environmental permitting

• E.g. Choco, Sur de Bolivar, Nariño

• Deep exploration for concealed targets in more mature belts

• Model-driven• Geophysics• Deep, directional drilling

Deep, directional drilling at Segovia