THE DISCOVERY AND GEOLOGY OF THE SALARES NORTE EPITHERMAL - - PowerPoint PPT Presentation

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THE DISCOVERY AND GEOLOGY OF THE SALARES NORTE EPITHERMAL - - PowerPoint PPT Presentation

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


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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 Baumgartner, Alex Trueman and Andrew Foley

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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 among others those relating to the Damang Exploration Target Statement; the Far Southeast Exploration Target Statement; commodity prices; demand for gold and other metals and minerals; interest rate expectations; exploration and production costs; levels of expected production; Gold Fields’ growth pipeline; levels and expected benefits of current and planned capital expenditures; future reserve, resource and other mineralisation levels; and the extent of cost efficiencies and savings to be achieved. Such forward looking statements involve known and unknown risks, uncertainties and other important factors that could cause the actual results, performance or achievements of the company to be materially different from the future results, performance or achievements expressed or implied by such forward looking statements. Such risks, uncertainties and other important factors include among others: economic, business and political conditions in South Africa, Ghana, Australia, Peru and elsewhere; the ability to achieve anticipated efficiencies and other cost savings in connection with past and future acquisitions, exploration and development activities; decreases in the market price of gold and/or copper; hazards associated with underground and surface gold mining; labour disruptions; availability terms and deployment of capital or credit; changes in government regulations, particularly taxation and environmental regulations; and new legislation affecting mining and mineral rights; changes in exchange rates; currency devaluations; the availability and cost of raw and finished materials; the cost of energy and water; inflation and other macro-economic factors, industrial action, temporary stoppages of mines for safety and unplanned maintenance reasons; and the impact of the AIDS and other occupational health risks experienced by Gold Fields’ employees. These forward looking statements speak only as of the date of this document. Gold Fields undertakes no obligation to update publicly or release any revisions to these forward looking statements to reflect events or circumstances after the date of this document or to reflect the occurrence of unanticipated events. The Discovery and Geology of the Salares Norte Epithermal Gold-Silver Deposit, Northern Chile | January 2017

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The Discovery and Geology of the Salares Norte Epithermal Gold-Silver Deposit, Northern Chile | January 2017

~2.1 Mozs Au-Eq produced in 2016 (Guidance)

Gold Fields Ltd. - 8 operating mines in 4 countries

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Northern Chile / Southern Peru – Main gold belts

70º 80º 60º

SANTIAGO LaSerena La Paz Arequipa Antofagasta

#

#

# #

Guanaco Cerro Casale Caspiche Pascua Lama-Veladero El Indio-Tambo

Perú Argentina

Marte-Lobo

#

La Coipa

Arica

Bolívia

Paleocene – Oligocene Miocene Gold deposits ≥ 2 Moz Low sulphidation High sulphidation Porphyry

El Peñon

Salares Norte

Alturas

30º 20º Maricunga Belt El Indio Belt

The Discovery and Geology of the Salares Norte Epithermal Gold-Silver Deposit, Northern Chile | January 2017

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Regional Settings & Deposits Salares Norte – Regional Context

  • Total endowment + 90 Moz AuEq.
  • All, except La Coipa, Esperanza and Salares

Norte are porphyry-style Au (Cu) deposits; large but low grade.

  • La Coipa in Care and Maintenance, 2013

~7.5 Moz AuEq production over 25 years.

  • Maricunga (Refugio) suspended, 2016

~3 Mozs Au production over 20 years.

  • Salares Norte is the first discovery in the

northern part of the Maricunga gold belt. Maricunga Gold Belt

Salares Norte La Coipa Maricunga (Refugio) Lobo Marte Volcan Caspiche Cerro Casale Cerro Maricunga Esperanza

Pedernales Salt Lake

220 km

The Discovery and Geology of the Salares Norte Epithermal Gold-Silver Deposit, Northern Chile | January 2017

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Modified from Sillitoe, R.H., 2010

Porphyry level

  • Cerro Casale
  • Lobo-Marte
  • Refugio
  • Caspiche
  • Volcan
  • Cerro Maricunga

Maricunga Belt: Porphyry-Epithermal Model

Epithermal level

  • La Coipa
  • Esperanza
  • Salares Norte

Steam heated alteration

The Discovery and Geology of the Salares Norte Epithermal Gold-Silver Deposit, Northern Chile | January 2017

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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 structural corridor
  • 4 of 10 targets selected for detailed follow-up work

10 km

Salares Norte La Coipa

25 km

The Discovery and Geology of the Salares Norte Epithermal Gold-Silver Deposit, Northern Chile | January 2017

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  • 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 with advanced argillic alteration.

  • 2010-2011:

First drill program at Salares Norte, March 2011: 980m RC / 4 holes; Discovery hole: SNRC002, with 96m @ 1.54 g/t Au and 61 g/t Ag Oxidized, good metallurgical response in preliminary leach tests.

  • 2011-2013:

Delineation drilling; Spectacular oxide intercept: 132m @ 53.2 g/t Au and 59.3 g/t Ag (SNDD017). Maiden Resource Declaration (2013)

  • 2014-2015:

Positive Scoping Study; 71,374m completed in 231 holes; Updated Mineral Resource Declaration (December 2015):

  • 2016:

Further drilling and studies.

Salares Norte – History of Discovery

The Discovery and Geology of the Salares Norte Epithermal Gold-Silver Deposit, Northern Chile | January 2017

Tonnes (Mt) Au (g/t) Ag (g/t) Au (Moz) Ag (Moz) Comments 26.8 3.9 48.9 3.3 42.1 30% Indicated; 96% Oxide

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Salares Norte – District Geology

2 4 Km

Source: SERNAGEOMIN1998- modified by Gold Fields

Multiple volcanic events: 21.1 – 1.1 ma

The Discovery and Geology of the Salares Norte Epithermal Gold-Silver Deposit, Northern Chile | January 2017

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Salares Norte – Alunite / Kaolinite Alteration, Aster Data

Looking NW

Dacite Dome Rio Baker

The Discovery and Geology of the Salares Norte Epithermal Gold-Silver Deposit, Northern Chile | January 2017

Alunite and kaolinite in orange and yellow; steam-heated silica in pale blue; based on Aster data.

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Salares Norte - Processed AS Ground Mag (100m)

Looking NW

Dacite Dome Rio Baker

The Discovery and Geology of the Salares Norte Epithermal Gold-Silver Deposit, Northern Chile | January 2017

Low magnetic response (blue-purple colour) coincides with hydrothermal alteration and trace element geochemical anomalies.

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Salares Norte – Discovery hole SNRC002

Andesite Dome Dacite Dome Brecha Principal

NE SW

LOOKING SE

  • Hydrothermal breccia; advanced argillic alteration (silica-alunite-vuggy quartz)
  • Anomalous trace elements in “soil”: As, Sb, Pb, Bi, Hg
  • Low gold (<24 ppb) except one sample with 628 ppb Au below breccia outcrop.
  • Margin of magnetic low; Coincident resistor identified by CSAMT.
  • Model had been proved positive at Pircas.
  • Two RC holes: 1st hole lost @ 85m; 2nd hole successful: 96m @ 1.5 g/t Au from 189m

SNRC002

96m @ 1.54 g/t Au y 61 g/t Ag

The Discovery and Geology of the Salares Norte Epithermal Gold-Silver Deposit, Northern Chile | January 2017

Anomalous gold-in-soil sample site

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Salares Norte – Breccia development

Brecciation Intensity Crackle Jigsaw Mosaic Rubble Monomictic breccia Polymictic breccia “Wispy” juvenile clast

The Discovery and Geology of the Salares Norte Epithermal Gold-Silver Deposit, Northern Chile | January 2017

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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 - Porphyritic Dacite Dome IFAB - Andesite Lava VTBRB - Pyroclastic Tuff VTL - Tuff

Agua Amarga Brecha Principal

Salares Norte – Geological Map

The Discovery and Geology of the Salares Norte Epithermal Gold-Silver Deposit, Northern Chile | January 2017

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< 0.05 0.05 – 0.25 0.25 – 0.50 1.00 – 2.50 2.50 – 5.00 > 5.00 0.50 – 1.00 Monomictic Hydrothermal Breccia Monomictic Breccia Polymictic Hydrothermal Breccia Polymictic Breccia Porphyritic Andesite - Basal Porphyritic Andesite - Dome Porphyritic Dacite - Dome Basaltic Andesite Lava

Salares Norte – 4000NW Section

132m @ 53.2 g/t Au, 59.3 g/t Ag 67.5m @ 10.4 g/t Au, 43.9 g/t Ag 120m @ 2.9 g/t Au, 48.0 g/t Ag 50.4m @ 1.6 g/t Au, 81.3 g/t Ag 60.95m @ 4.8 g/t Au, 58.3 g/t Ag 166m @ 10.6 g/t Au, 101.0 g/t Ag

SW NE

4,370 Looking Northwest

The Discovery and Geology of the Salares Norte Epithermal Gold-Silver Deposit, Northern Chile | January 2017

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Salares Norte – Alteration model

Alteration facies typical of a high sulphidation epithermal system

AAA

Quartz-Alunite

AKD

Kaolinite -/- Dickite

ARI

Illite

ARS

Illite/smectite

PR

Propylitic

PO

Potassic

STH

Steam Heated

UNA

Unaltered rock

SI

Massive and cream silica

SIC

Chalcedonic silica

ARM

Smectite

STH AAA AKD SIC

UNA

ARM

UNA

N

LEGEND

SIC

Brecha Principal Agua Amarga

The Discovery and Geology of the Salares Norte Epithermal Gold-Silver Deposit, Northern Chile | January 2017

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Salares Norte - Brecha Principal – Alteration Model

Section 4,000NW – Looking NW

AAA AKD ARI ARS PR PO STH UNA

LEGEND

SI SIC ARM

STH

AAA AKD ARS

SIC ARM

STH AAA ARI

Oxidation limit

SW NE

SI Steam Heated Massive and cream silica Chalcedonic silica Quartz - Alunite Kaolinite - Dickite Illite Illite/smectite Propylitic Potassic Unaltered Rock Smectite (Argillic)

4,370

The Discovery and Geology of the Salares Norte Epithermal Gold-Silver Deposit, Northern Chile | January 2017

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Salares Norte – Mineralisation examples in HQ drill core

The Discovery and Geology of the Salares Norte Epithermal Gold-Silver Deposit, Northern Chile | January 2017

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Salares Norte – Gold Grade Shells

500 m

Brecha Principal Agua Amarga

Grade Shells Gold

≥ 1 g/t ≥ 5 g/t

The Discovery and Geology of the Salares Norte Epithermal Gold-Silver Deposit, Northern Chile | January 2017

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Salares Norte – Gold Grade Shell

NW SE LONGITUDINAL SECTION LOOKING TO NE Top of mineralisation ~4370 1 Top of mineralisation ~4310

Agua Amarga - 700m

Gold (g/t)

0 - 0.05 0.05 - 0.25 0.25 - 0.5 0.5 - 1 1 – 2.5 2.5 – 5 5 – 2,850

Brecha Principal - 700m

The Discovery and Geology of the Salares Norte Epithermal Gold-Silver Deposit, Northern Chile | January 2017

Open

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Salares Norte - Final remarks

Thank you!!

  • 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
  • Geophysical surveys (ground magnetics and CSAMT)
  • Early validation of the exploration model at Pircas
  • Persistence, systematics and perhaps some serendipity!
  • Supportive management, consistent budgets and local autonomy.

Key factors which led to the discovery

Gracias!

The Discovery and Geology of the Salares Norte Epithermal Gold-Silver Deposit, Northern Chile | January 2017