Slide 1: The Discovery and Geology of the Salares Norte Epithermal Gold-Silver Deposit
THE DISCOVERY AND GEOLOGY OF THE SALARES NORTE EPITHERMAL GOLD-SILVER DEPOSIT, NORTHERN CHILE AME ROUNDUP 2017, VANCOUVER Nathan Brewer, Francisco Azevedo, Diego Huete Verdugo, Teresa Guevara, Fernando Rojas, Juanita Rodriguez Melo, Christian Lagos, Claudio Cerda, Constanza Moreno, Regina Baumgartne
Slide 2: Forward looking statements
Forward looking statements Certain statements in this document constitute “forward looking statements” within the meaning of Section 27A of the US Securities Act of 1933 and Section 21E of the US Securities Exchange Act of 1934. In particular, the forward looking statements in this document include
Slide 3: Gold Fields Ltd. - 8 operating mines in 4 countries
Gold Fields Ltd. - 8 operating mines in 4 countries ~2.1 Mozs Au-Eq produced in 2016 (Guidance) The Discovery and Geology of the Salares Norte Epithermal Gold-Silver Deposit, Northern Chile | January 2017 3
Slide 4: Northern Chile / Southern Peru – Main gold belts
Northern Chile / Southern Peru – Main gold belts 80º 70º 60º # Perú # Arequipa La Paz Miocene # Bolívia Paleocene – Oligocene Arica 20º # El Peñon Antofagasta Guanaco Salares Norte # La Coipa Marte-Lobo Maricunga Caspiche Belt Cerro Casale Gold deposits ≥ 2 Moz Pascua Lama-Veladero El Indio El Indio
Slide 5: Regional Settings & Deposits: Maricunga Gold Belt
Salares Norte Regional – Regional Settings Context & Deposits Maricunga Gold Belt Salares Norte Pedernales Salt • Total endowment + 90 Moz AuEq. Lake • All, except La Coipa, Esperanza and Salares Esperanza Norte are porphyry-style Au (Cu) deposits; large La Coipa but low grade. 220 km Cerro Maricung
Slide 6: Maricunga Belt: Porphyry-Epithermal Model
Maricunga Belt: Porphyry-Epithermal Model Steam heated alteration Epithermal level • La Coipa • Esperanza • Salares Norte Porphyry level • Cerro Casale • Lobo-Marte • Refugio • Caspiche • Volcan • Cerro Maricunga Modified from Sillitoe, R.H., 2010 The Discovery and Geology of the Salares Norte Epith
Slide 7: Salares Norte – History of Discovery
Salares Norte – History of Discovery • 2007-2008: Area selection & reconnaissance using La Coipa (Puren) model • 2,500 km2 area selected; minor previous exploration; open ground • Few roads, high elevation (+4,000m); Seasonal exploration (Oct-Apr) • Focus on spectral anomalies within NW-SE structura
Slide 8: Salares Norte – History of Discovery
Salares Norte – History of Discovery • 2008-2009: Initial RC drilling at Pircas, with positive results: 24m @ 4.1 g/t Au, in structurally controlled breccia with oxidised vuggy quartz. • 2009-2010: Follow-up drilling at Pircas, intersections on the order of 100m @ 0.5 g/t Au, in vuggy quartz breccia
Slide 9: District Geology
Salares Norte – District Geology 0 2 4 Km Multiple volcanic events: 21.1 – 1.1 ma Source: SERNAGEOMIN1998- modified by Gold Fields The Discovery and Geology of the Salares Norte Epithermal Gold-Silver Deposit, Northern Chile | January 2017 9
Slide 10: Alunite / Kaolinite Alteration, Aster Data
Salares Norte – Alunite / Kaolinite Alteration, Aster Data Rio Baker Dacite Dome Looking NW Alunite and kaolinite in orange and yellow; steam-heated silica in pale blue; based on Aster data. The Discovery and Geology of the Salares Norte Epithermal Gold-Silver Deposit, Northern Chile | January 2017
Slide 11: Processed AS Ground Mag (100m)
Salares Norte - Processed AS Ground Mag (100m) Rio Baker Dacite Dome Looking NW Low magnetic response (blue-purple colour) coincides with hydrothermal alteration and trace element geochemical anomalies. The Discovery and Geology of the Salares Norte Epithermal Gold-Silver Deposit, Northern Chile | J
Slide 12: Discovery hole SNRC002
Salares Norte – Discovery hole SNRC002 NE LOOKING SE SW Andesite Dacite Dome Dome Brecha Principal SNRC002 96m @ 1.54 g/t Au y 61 g/t Ag • Hydrothermal breccia; advanced argillic alteration (silica-alunite-vuggy quartz) • Anomalous trace elements in “soil”: As, Sb, Pb, Bi, Hg Anomalous gold-in-soil
Slide 13: Breccia development
Salares Norte – Breccia development Crackle Jigsaw Mosaic Rubble Brecciation Intensity Polymictic breccia “Wispy” juvenile clast Monomictic breccia The Discovery and Geology of the Salares Norte Epithermal Gold-Silver Deposit, Northern Chile | January 2017 13
Slide 14: Geological Map
Salares Norte – Geological Map Agua Amarga Brecha Principal Lithology Surface RC - Alluvial/colluvial deposit STH - Steam Heated Alteration BXP - Polymictic Breccia (Diatreme) BXPH - Hydrotermal Breccia (polymictic) ICPA_D - Porphyritic Andesite Dome BXMPA - Monomictic Andesite Breccia ICPD_D - Porp
Slide 15: 4000NW Section
Salares Norte – 4000NW Section SW Looking Northwest NE 60.95m @ 4.8 g/t 67.5m @ 10.4 g/t Au, 58.3 g/t Ag Au, 43.9 g/t Ag Monomictic Hydrothermal Breccia Monomictic Breccia 4,370 Polymictic Hydrothermal Breccia Polymictic Breccia Porphyritic Andesite - Basal 120m @ 2.9 g/t Porphyritic Andesite - Dome
Slide 16: Alteration model
Salares Norte – Alteration model Alteration facies typical of a high sulphidation epithermal system LEGEND N STH Steam Heated UNA SIC Chalcedonic silica Agua Massive and Amarga SI cream silica SIC AAA Quartz-Alunite STH Kaolinite -/- AKD Dickite AAA Brecha ARI Illite UNA Principal SIC AKD ARS Illite
Slide 17: Brecha Principal – Alteration Model
Salares Norte - Brecha Principal – Alteration Model Section 4,000NW – Looking NW SW NE STH STH AAA Oxidation limit SIC SI 4,370 ARM AAA AKD ARS ARI Steam Quartz - LEGEND STH AAA ARS Illite/smectite ARM Smectite (Argillic) Heated Alunite Chalcedonic Kaolinite - SIC AKD PO Potassic Unaltered silica Di
Slide 18: Mineralisation examples in HQ drill core
Salares Norte – Mineralisation examples in HQ drill core The Discovery and Geology of the Salares Norte Epithermal Gold-Silver Deposit, Northern Chile | January 2017 18
Slide 19: Gold Grade Shells
Salares Norte – Gold Grade Shells Agua Amarga Grade Shells Gold ≥ 1 g/t Brecha Principal ≥ 5 g/t 500 m The Discovery and Geology of the Salares Norte Epithermal Gold-Silver Deposit, Northern Chile | January 2017 19
Slide 20: Gold Grade Shell
Salares Norte – Gold Grade Shell NW LONGITUDINAL SECTION LOOKING TO NE SE Top of mineralisation ~4370 Top of mineralisation ~4310 1 Open Agua Amarga - 700m Gold (g/t) 0 - 0.05 0.05 - 0.25 Brecha Principal - 700m 0.25 - 0.5 0.5 - 1 1 – 2.5 2.5 – 5 5 – 2,850 The Discovery and Geology of the Salares No
Slide 21: Final remarks – Thank you!!
Salares Norte - Final remarks Key factors which led to the discovery ● Understanding of Andean high sulphidation Au-Ag systems ● Effective Aster image processing & targeting ● Geological mapping and recognition of key alteration facies ● Geochemical sampling and pathfinder element anomalism ● Geophy