agnew gold mine · gold fields: agnew gold mine – technical short form report 2011 4 in...

22
2 Agnew Gold Mine Technical Short Form Report 31 December 2011

Upload: others

Post on 21-Apr-2020

2 views

Category:

Documents


0 download

TRANSCRIPT

2

Agnew Gold MineTechnical Short Form Report31 December 2011

Gold Fields: Agnew Gold Mine – Technical Short Form Report 2011 3

Salient features

¨ Mineral Resources at 3.8 Moz.

¨ Mineral Reserves at 1.3 Moz.

¨ Stable Mineral Reserve and Mineral Resource base.

¨ Positive results at Cinderella – potential starter pit.

¨ High grade shoots – Fitzroy, Bengal and Hastings – discovered beneath Main Lode.

¨ Life of Mine extends to 2018 (seven years).

Agnew has a well-funded exploration strategy aimed at extending existing Mineral Reserves from its prospective and relatively unexplored tenements through target testing, new

discovery and new target generation for future definition.

Geographic location

YilgarnCraton

Perth

Kalgoorlie

Leinster

DerbyAgnew

Tenements

Western Australia

Geographic location IFC

1. Overview Page 1

2. Key aspects Page 2

3. Operating statistics Page 3

4. Geological setting and mineralisation Page 4

5. Mining Page 6

6. Projects Page 7

7. Mineral processing Page 7

8. Sustainable development Page 8

9. Mineral Resources and Mineral Reserves Page 9

10. Regulatory codes Page 13

11. Competent Persons Page 13

12. Key technical staff Page 14

13. Brief history Page 17

Res

ourc

e co

nver

sion

dril

ling,

War

oong

a C

omp

lex,

Agn

ew

1. OverviewThe Agnew Gold Mining Company Pty Limited is wholly owned by Gold Fields Limited and currently holds tenements covering an area of approximately 68,138 hectares. Agnew is located some 375 kilometres north of Kalgoorlie in the same geological region as St Ives Gold Mine, and exploits shear-hosted auriferous zones from the highly mineralised Norseman-Wiluna Greenstone Belt.

Agnew represents a solid base for Gold Fields’ growth in the region and is an important contributor to the stated vision, “To be the global leader in sustainable gold mining”, with a target contribution from the Australasia Region of ~1.0 Moz per annum by 2015 in production or development.

Main strategic aims for the company are the discovery of additional Mineral Reserve sources to supplement Waroonga in the short term and the discovery of a significant new ore complex to replace Waroonga in the medium to long term.

Reported Mineral Reserves at Agnew were maintained at 1.3 Moz from December 2010 to December 2011, including the impact of depletion at 224 koz, indicating an effective increase of 205 koz. Changes from December 2010 were dominated by extensions to the main ore body at the Waroonga Underground Complex and the impact of higher gold price assumptions for the December 2011 statement.

This Technical Short Form Report reflects the latest Life of Mine plan input parameters, coupled with an updated Mineral Resource and Mineral Reserve statement as at 31 December 2011. All Mineral Resource and Mineral Reserve figures reported are managed unless otherwise stated and Mineral Resources are inclusive of Mineral Reserves.

Note: For abbreviations refer to page 28 and for glossary of terms refer to page 29 – “Mineral Resources and Mineral Reserves Overview 2011”.

1

Cover image:

CIP processing plant, Agnew Gold Mine

Gold Fields: Agnew Gold Mine – Technical Short Form Report 2011 2

2. Key aspects

Independent audit Figures reported in this declaration are as reviewed by independent external consultants as at 31 December 2011 [Optiro Pty Ltd for Mineral Resources and AMC Consultants (Pty) Ltd for Mineral Reserves]. Gold Fields has been informed that the audit identified no material shortcomings in any process by which the Agnew Mineral Resources and Mineral Reserves were evaluated

Prepared by Gold Fields Limited in compliance with the SAMREC Code (2007 edition)

Effective date 31 December 2011

Source of information This Technical Statement is a summary of the detailed internally sourced document entitled December 2011 Agnew Competent Persons Report

Personal inspection Personal inspection is conducted by the Competent Persons as listed, who are full-time employees of Gold Fields Limited

General location Agnew is situated at latitude 27° 55’ S and longitude 120° 42’ E in the Norseman-Wiluna Greenstone Belt, 23 kilometres west of the town of Leinster in Western Australia, which is approximately 1,100 kilometres north east of Perth. Well-established power, access roads and supporting infrastructure are in place

Licence status and holdings

The Agnew Gold Mining Company Pty Limited (AGMC), ACN 098-385-883, was incorporated in Australia in 2001 as the legal entity holding and conducting mining activity on the Agnew mineral leases. The Gold Fields Limited group holds 100% of the issued shares of AGMC through its 100% holding in the issued shares of Orogen Holding (BVI) Limited. Agnew controls exploration and mineral rights over a total area of 68,138 hectares (total of granted tenements) and has security of tenure for all current exploration and mining leases that contribute to future Mineral Reserves

Operational infrastructure One underground complex mining from three separate ore bodies accessed via declines. Centralised administrative office, engineering workshops and one CIP processing plant (1.3 Mtpa capacity)

Climate No extreme climate conditions are experienced that may affect mining operations

Deposit type Orogenic greenstone gold hosted in a number of different styles of lodes. Although all of the Agnew deposits are broadly hosted by the intersections between structures and stratigraphy, there are subtle differences in alteration and mineralisation controlled in part by the local host rock chemistry

Life of Mine (LoM) Ongoing extensional and brownfields exploration continues which could potentially increase the LoM. It is estimated that the current Mineral Reserve will be depleted in 2018.

Environmental/Health & Safety

The mine maintained AS4801:2000 Occupational Health and Safety Management System certification and ISO14001:2004, (Environmental Management System) certification. Agnew was certified as fully compliant to the International Cyanide Management Code on 3 June 2009

Reporting codes Gold Fields reports its Mineral Resources and Mineral Reserves in accordance with the South African Code for the Reporting of Exploration Results, Mineral Resources and Mineral Reserves (2007 SAMREC Code), and other relevant international codes such as SEC Industry Guide 7, JORC Code and NI 43-101. The Mineral Resources and Mineral Reserves are underpinned by an appropriate Mineral Resource Management process and protocol to ensure adequate corporate governance in respect of the intent of the Sarbanes-Oxley Act

Ope

n pi

t min

ing

oper

atio

ns

3

3. Operating statistics

UnitsDec

2011Dec

20101 June2010

June2009

June2008

Open pit mining

Total mined kt 1,610 – – – 393

– Waste mined kt 1,024 – – – 191

– Ore mined kt 586 – – – 202

Mined grade g/t 1.6 – – – 3.2

Strip ratio (tonnes) waste : ore 2.1 – – – 1.0

Underground mining

Ore mined kt 621 312 581 737 505

Mined grade g/t 9.7 8.4 8.9 7.9 9.3

Processing

– Mill tonnes kt 935 417 883 1,066 1,315

– Mill head grade g/t 7.0 6.5 6.2 5.8 5.3

– Yield g/t 6.5 5.9 5.8 5.6 4.8

– Plant recovery factor % 94.0 93.7 93.4 92.6 92.9

Gold produced

– Milling koz 194 80 165 192 204

– Heap leach koz N/A N/A N/A N/A N/A

Total gold producedkoz 194 80 165 192 204

kg 6,035 2,258 4,685 5,253 5,873

Gold sold oz 194 80 165 192 204

Financials

Operating cost A$/oz 692 680 614 526 452

Total cash costA$/oz 675 662 611 541 496

US$/oz 696 621 539 401 445

Capital expenditure A$ million 71.8 26.6 62.6 41.6 37.0

Notional cash expenditure (NCE)

A$/oz 1,062 1,013 992 743 632

US$/oz 1,096 951 875 550 567

General

Employees (TEC) number 440 364 375 343 314

Mineral Reserves Mt 7.1 6.9 6.7 2.9 2.5

Mineral Reserve Head Grade g/t 5.7 6.0 5.7 7.7 7.7

Mineral Reserves Moz 1.3 1.3 1.2 0.7 0.6

Expected Life of Mine years 7 7 7 4 31Figures shown represent the six months to 31 December 2010. Rounding off of figures presented in this report may result in minor computational discrepancies. Where this occurs it is not deemed significant.

Agn

ew C

IP p

lant

com

plex

Gold Fields: Agnew Gold Mine – Technical Short Form Report 2011 4

In comparison to other greenstone belts in the Yilgarn Craton, the Norseman-Wiluna Greenstone Belt is highly mineralised, particularly in gold and nickel.

4

Agnew is situated in the northern portion of the Norseman-Wiluna Greenstone Belt, which is part of the Yilgarn Craton, a 2.6 Ga granite greenstone terrain in Western Australia. The rock types in the belt comprise abundant tholeiitic and komatiitic volcanic rocks, chert, sulphidic and albitic sedimentary rocks, and a chain of discrete felsic volcanic centres.

The greenstones of the Agnew area have been metamorphosed to upper greenschist, lower amphibolite metamorphic grades. Gold mineralisation is found in quartz breccia lodes, quartz tensional veining and disseminated arsenopyrite-pyrite-biotite mineralisation developed along the lithological contact between a sandstone and ultramafic conglomerate and on other contacts within the ultramafic conglomerates package. High-grade ore shoots plunge steeply to the north along these contacts. The controls on mineralisation are dilational zones at the intersection of steeply dipping N-S axial planar structures with the stratigraphy. The stronger the contrast in rock competency in these zones, the greater is the potential for mineralisation.

Much of the Yilgarn Craton is deeply weathered and partially covered by Tertiary and Quaternary regolith. Pre-Tertiary lateritic horizons are variably exposed, stripped or buried by later deposits that have in turn been lateritised. The depth of weathering is strongly controlled by original rock types, with mafic rocks generally being more susceptible to weathering than felsic rocks.

Local geologyThe Agnew-Wiluna section of the Norseman-Wiluna Greenstone Belt is bounded by large granitoid bodies and the Ida fault to the west. The Ida fault, locally termed the Waroonga shear, is a major regional scale shear zone that defines the western edge of the Kalgoorlie terrain. The majority of the Agnew ore bodies are on the western limb of the Lawlers anticline, a large open fold, plunging 30° to the north, although economic mineralisation is also formed on the eastern limb (e.g. Vivien), in axial planar positions to the north (e.g. Cams) and in the adjacent Mt White syncline (e.g. Maria).

The Agnew anticline and the Mt White syncline are large-scale folds plunging 30° to the north. The dip of the limbs’ range from moderate at the nose and shoulders of the folds (e.g. at Waroonga) to steep and slightly overturned along the limbs (e.g. at Songvang).

Although all of the Agnew deposits are broadly hosted by the intersections between structures and stratigraphy, there are subtle differences in alteration and mineralisation controlled in part by the local host rock chemistry. Songvang is unusual in its relatively high lead, silver and fluorine content, possibly reflecting input from tonalite and porphyry intrusions. There also appears to have been a slight decline in mineralisation temperatures from south to north through the Agnew area, associated with the north plunge of the Lawlers Anticline and resultant erosion of the overlying lower temperature rocks to the south. This temperature change is reflected in the changing mineralisation styles from south to north, with biotite/garnet assemblages dominating to the south and quartz veining to the north.

4. Geological setting and mineralisation

Sch

emat

ic o

f gol

d m

iner

alis

atio

n oc

curr

ence

sG

eolo

gy o

f the

Agn

ew L

awle

rs re

gion

sho

win

g th

e A

gnew

ant

iclin

e

The stratigraphy of the Agnew-Wiluna belt appears to be broadly similar to the stratigraphy of the Kalgoorlie region. The following section provides a detailed description of the general stratigraphy for the Agnew mining leases and the stratigraphic location of various ore bodies.

Exploration and drillingAt Agnew there is considerable endowment potential within the current tenement holdings to add significantly to current Mineral Resources and Mineral Reserves, through a combination of on-mine (extensions to known Mineral Resource) and near-mine exploration. In terms of the extent of its tenement holdings and the exploration undertaken

Sandstone

Scotty Creek Sandstone

Ultramafic Conglomerate (North)Mafic Conglomerate (South)

Agnew Ultramafic

Lawlers Basalt

New Holland Genesis

Zone 2/3

Kim/Rajah/Main

Pilgrim

Vivien

Songvang

CrusaderDelivererClaudius

Gold Mineralisation Granite/Porphyry

Cams Camp

Maria North

Maria

Vivien

Lawlers

Songvang

Donegal North

Goldilocks

Miranda Fault

AliceCinderella North

Waroonga Complex

Surprise

Redeemer-Crusader

Endeavour-South

Target 20U

Pinnacles

Pinnacles South 0 5km

N

55

thus far, Agnew cannot yet be considered advanced in exploration terms, and recent geological studies have identified numerous prospective areas yet to be tested effectively.

Mine exploration for the 12 months to December 2011 continued to focus on extensional drilling and reserve delineation at Waroonga, specifically at Main Lode, where a programme of surface drilling below Main North and South was undertaken (exploration triangle below). Directional surface drilling technology was successfully used and a total of 17,446 metres was completed during the year. Drilling, although initially designed to delineate ore for a possible sub-level caving operation at Main North, was soon altered to target the newly interpreted high-grade shoots – Fitzroy, Bengal and Hastings (FBH) – between 700 and 1,200 metres below surface.

Results and interpretation during 2011 have confirmed the continuity of the three shoots down to the 9,300 mRL where they remain open at depth. A fourth high-grade shoot – Yeoman – has also recently been identified beneath Main South with a few boreholes, but the dimensions still need to be determined.

Exploration success in delineating high grade shoots beneath Main Lode will see the Waroonga Complex continue to be the focus of activity during 2012. Significant potential for additional resource ounces exists between the Kim and the Fitzroy shoots (Link target) as well as depth extensions to the Fitzroy, Bengal, Hastings and Yeoman shoots.

In conjunction with the directional drilling programmes at Waroonga, a regional (additional) exploration programme will target the next complex scale discovery as well as smaller high-grade deposits that have the potential to provide supplementary ore feed within a one-to-three-year timeframe (exploration triangle below). A decision on the viability of a small open pit on the Cinderella deposit is expected in early 2012, while encouraging initial drill results from the Alice and Goldilocks prospects will be tested during the first half of 2012.

The success of any exploration project is dependent on the quality of the exploration data. The ability to extract the inherent value in the data is also reliant on new technologies to enhance interpretation and modelling of the data. Agnew maintains rigorous quality assurance and quality control (QA/QC) protocols on all of its exploration programmes, using leading industry practice in data acquisition, reputable laboratories and having sign-off by Competent Persons under the 2007 SAMREC and 2004 JORC Codes.

Agnew’s resource development strategy will continue to focus on the Waroonga Complex where, over the past two years, our understanding of the geology and mineralisation has increased and the resource continues to grow. All of the interpreted mineralised shoots are open at depth and no drill testing south of the Yeoman shoot has been completed to date. Near-mine exploration will focus on initial testing of several targets to the north (Cams) and south (Pinnacles) of the main mine area. New targets are needed to fill the project pipeline to ensure Agnew continues to grow.

Sch

emat

ic o

f gol

d m

iner

alis

atio

n oc

curr

ence

sG

eolo

gy o

f the

Agn

ew L

awle

rs re

gion

sho

win

g th

e A

gnew

ant

iclin

e

Research and developmentThe Research and Development programme undertaken at Agnew over the previous two years has resulted in a vastly improved understanding of the following features of the known gold deposits in the Agnew camp:

¨ Deposit scale structural and temporal controls on the gold mineralisation;

¨ The geochemical signature of the known deposits and importantly, the elements that are intimately associated with gold mineralisation on the micro-scale;

¨ Alteration minerals that are associated with gold mineralisation; and

¨ The stratigraphic architecture of those areas in the Agnew camp where gold mineralisation is known to occur.

Observations stemming from the Research and Development programme are being integrated with exploration targeting and evaluation programmes and it is envisaged that this will greatly improve the effectiveness of exploration in the Agnew gold camp.

Now that the known deposits are understood, the Research and Development programme will focus more on the regional geology to identify new areas that are prospective for gold mineralisation.

Regional (Additional) ExplorationMine (Extensional) Exploration

Cinderella North, Alice, Goldilocks, Maria, Miranda Fault

Porphyry Link,FBH Depth Extensions,

Yeoman

Fitzroy, Bengal, Hastings,Jaws, Papa Bear

Cinderella

15 targets, includingCams, Pinnacles

450 South (deep)Kim South (deep)

Research and development3-D GoCAD & Leapfrog Modelling

Mineral Systems/Prospectivity Mapping

Research and development3-D Leapfrog Modelling

Ongoing Deep Drilling Programmes

Indicated Mineral Resource

Resource Development

Initial Drilling

Target Definition

Advanced Drilling

Gold Fields: Agnew Gold Mine – Technical Short Form Report 2011 6

Dev

elop

ing

ore

driv

eE

xam

ple

of m

ine

desi

gn m

odel

5. Mining

Mining methods Access to the Waroonga underground mine is via a portal and decline located in the previously mined Waroonga open pit. All primary infrastructure, including escape ways and ventilation shafts, are located in the competent sandstone of the hanging wall. The dimensions of the decline are 5 x 5 metres wide by 5.8 metres high with arched backs to allow high capacity trucks to operate.

The Rajah Lode will be mined in 2012 using the modified Avoca Method, which is a variation of bench stoping methodology where the fill typically consists of un-cemented waste rock that is introduced to control wall stability at intervals from 20 to 30 metres. This represents a change from 2011 where conventional long hole, longitudinal retreat open stoping was used with strategic geotechnical pillars left in situ. The Rajah reserve material is narrow vein-style mineralisation paired with a weak footwall. This footwall has demonstrated poor stand-up characteristics over stope strikes greater than 15 metres.

The Main Lode North ore body will be extracted using transverse stoping with mining commencing at the footwall and retreating to the hangingwall. The stopes will be accessed via a tramming drive developed in the hangingwall sandstone.

The cutback of the Songvang pit is mining the northern extent of the existing pit, which was mined between 2004 and 2007. Mining of the Songvang northern cutback will be completed early in February 2012 using conventional open pit truck and excavator methods, with all material mined requiring drilling and blasting.

Mine planning and schedulingThe current mining areas are situated at Waroonga (Kim South, Rajah and Main Lodes) and the Songvang open pit. These form the basis for the 2012 operational plan. The plans, design and schedules are provided and communicated to the mining personnel and contractors, forming the basis of the contract between the parties.

At Waroonga, the stope design takes practical stope layouts into consideration as well as planning for mining losses in pillars or other parts of the resource excluded for technical reasons. Dilution material is included in the stope design. Ore losses can occur when material cannot be practically extracted from the stopes.

Datamine’s Mineable Shape Optimiser was used during the December 2011 Mineral Reserve update. This software optimises the stope shape by using variable cut-off grades.

At Songvang, the pit design for the northern cutback has been optimised using Whittle 4X. The pit design includes a dual lane ramp (23 metres wide to the 10420 level) at a gradient of 1 in 8 to maximise pit production during the pre-strip phase. The ramps are designed to suit 100-tonne capacity rigid dump trucks.

The current mining operations consist of the Waroonga underground complex which includes underground mining at the Kim South, Rajah and Main Lodes. Together with open pit mining

(and stockpiles) at Songvang North, these form the basis for the 2012 Operational Plan.

Rajah

Main North

Kim South

0 100 m

9,600mRL

9,900mRL

7

Dev

elop

ing

ore

driv

e

Cin

dere

lla c

once

pt p

it de

sign

Exa

mpl

e o

f min

e de

sign

mod

el

6. Projects

Underground production from Waroonga does not fully utilise the processing plant capacity. To fully utilise the milling capacity, a cutback of the Songvang pit commenced in January 2011. The mining of the project is scheduled for completion in February 2012 and stockpiled ore will provide supplementary mill feed until Quarter 4, 2012.

The possibility of opportunistically exploiting small-scale open pittable deposits for supplementary mill feed continues to be examined and reviewed. In this regard a small “starter” pit at Cinderella will be assessed early in 2012. Possible cutbacks on existing open pits include New Woman and Redeemer.

Near-mine exploration on the extensive Agnew land holdings will focus on the Scotty Creek sediments and the Alice and Goldilocks prospects. The objective is to discover and bring into production an open pit operation to supplement the Waroonga complex ore, thus fully utilising available processing plant capacity.

Extensional exploration within the Waroonga Complex is targeting known and extrapolated mineralisation trends. Increasing the Mineral Resource and Mineral Reserve will extend the mine life of the Waroonga Complex and increase production flexibility by opening

new areas for exploitation.

7. Mineral processing

The comminution circuit comprises a contractor-owned and operated three-stage crushing plant, feeding a fine ore stockpile, ahead of a two-stage closed circuit ball milling circuit. Milled ore proceeds to a three-stage leaching train feeding the six-stage carbon in pulp (CIP) circuit. Carbon elution is by pressure Zadra with gold being electrowon and smelted. In February 2003 a gravity circuit, comprising a Knelson gravity concentrator in conjunction with an intensive leach reactor (ILR) for intensive cyanidation of the gravity concentrate, was retrofitted. The gravity circuit was upgraded and retrofitted in September 2011 to incorporate a second 26” Knelson gravity concentrator, an Intensive Leach Reactor 2000BA and two Magscreen 1000 units. The processing capacity at the plant is 1.3 Mtpa.

Quantitative analysis of recovery improvements will be evaluated and included in future resources and reserve calculations in accordance with the grade/recovery model currently adapted.

Tailings disposal and impoundment have historically been to a conventional dam constructed using the upstream lift method sourcing wall material from dried tailings. The original tailing storage facility (TSF) was located in an area some 1.5 kilometres southwest of the Agnew plant. Deposition to this facility ceased in early 2004 and a large section of this decommissioned facility has been capped with waste rock. The remaining exposed sections are being harvested for use as underground paste fill. Following

completion of mining activities at the Redeemer Mine, the abandoned pit has been converted to a tailings storage impoundment for tailings arising from the Agnew plant (TSF3). Although situated seven kilometres south of the Agnew plant, the static head is negative, thus pumping of the tailings material is achieved with no additional cost from the previous deposition technique. The pontoon-mounted decant pump recovers water from the supernatant pond, which forms due to liberation of water from the tailings slurry as it settles and consolidates.

TSF3 is projected to last until 2015 based on deposition rates of 1.3 million tonnes per annum and historical deposition levels from December 2004 to February 2011.

Upgrade of the gravity recovery circuit was completed in September 2011.

Agn

ew p

lant

and

set

tler

dam

s

Gold Fields: Agnew Gold Mine – Technical Short Form Report 2011 8

8. Sustainable development

In Australia, large advances in safety have been made over the last 20 years by concentrating primarily on the practices (policies and procedures, rules, training etc.) and the environment (equipment, tools, machines etc.). By focusing on the person aspect of safety, emphasis is placed on the individual to question their contribution to a positive safety culture.

In regards to our full compliance to a Health and Safety Management System, Agnew has been certified OHSAS18001:2004, through the Australian Standard AS/NZ4801:2001

Although Gold Fields has developed a Group environmental policy, the Australian operations are currently guided by their own individual policies. These policies have been developed within the Group policy framework, but are tailored to suit the site-specific environmental conditions. Agnew has developed and implemented an environmental management system, certified to the international standard ISO14001, and the site

Agnew manages risk to mitigate and, where possible, eliminate hazards in the working environment. Maintenance of outstanding health and safety performance through the participation of all employees and the application of safe, innovative processes and

technologies, within a framework of full legislative and best practice compliance.

Env

ironm

enta

l mon

itorin

gS

ongv

ang

cree

k re

habi

litat

ion

policies conform to the standards requirements. If non-compliances are observed in terms of environmental legislation and approval documentation commitments, management are made aware of the issues and take appropriate measures to address the situation in line with site policies.

Safety statisticsClass Units June 2007 June 2008 June 2009 Dec 20101 Dec 2011

Fatalities (No) 0 0 0 0 0

Fatality rate (per mmhrs) 0 0 0 0 0

LDIFR (per mmhrs) 0.9 0 4.6 1.1 2.71 For six months to December 2010.

9

Env

ironm

enta

l mon

itorin

gS

ongv

ang

cree

k re

habi

litat

ion

Agn

ew M

ine

gold

pou

r

Mineral Resourceclassification

Tonnes (Mt) Grade (g/t) Gold (’000 oz)

Dec 2011

Dec 2010

June 2010

Dec 2011

Dec 2010

June 2010

Dec 2011

Dec 2010

June 2010

Open pit and underground

Measured 3.5 4.5 4.4 4.7 4.1 4.1 540 597 584

Indicated 12.9 13.6 14.7 5.3 5.2 5.0 2,199 2,265 2,368

Inferred 7.5 7.4 7.7 4.5 4.1 4.3 1,082 981 1,075

Total open pit and underground 23.9 25.5 26.8 5.0 4.7 4.7 3,820 3,843 4,027

Surface stockpiles

Measured 0.3 0.0 0.0 1.7 6.3 6.1 17 2 2

Total surface stockpiles 0.3 0.0 0.0 1.7 6.3 6.1 17 2 2

Grand total 24.2 25.5 26.8 4.9 4.7 4.7 3,838 3,845 4,028

9. Mineral Resources and Mineral Reserves

Mineral ResourcesThe Mineral Resources are classified as Measured, Indicated or Inferred, as described in the 2007 SAMREC Code. Mineral Resource categories are assigned with consideration given to geological complexity, grade variance, drill hole intersection spacing, and mining development. Kriging neighbourhood analysis is also used to assist with classification. The impacts of year-on-year changes are covered in the reconciliation section. The following factors apply to the Mineral Resources presented in this report:

¨ All Mineral Resources are declared using a cut-off grade calculated for the individual deposit; ¨ The declared Mineral Resources are further tested by the application of modifying factors to ensure that there is a reasonable

prospect of eventual economic extraction; ¨ Open pit Mineral Resources comprise the undiluted material above the nominated cut-off within a diluted optimised pit shell; ¨ Underground Mineral Resources are selected using a minimum mining width and minimum stope size; and ¨ Mineral Resources are quoted at an appropriate in situ economic cut-off grade with tonnages and grades based on the

relevant resource block models. They also include estimates of any material below the cut-off grade required to be mined to extract the complete pay portion of the Mineral Resource.

Geological and evaluation models have been updated as at December 2011 to reflect the latest available data sets. An integrated mine design and schedule based on current performance levels takes cognisance of the inherent risks associated with mining operations at Agnew.

DATA TO COME

Gold Fields: Agnew Gold Mine – Technical Short Form Report 2011 10

Modifying factors ¨ The Measured and Indicated Mineral Resources are

inclusive of those Mineral Resources modified to produce Mineral Reserves;

¨ All quoted Mineral Resources and Mineral Reserves are 100% Agnew ownership;

¨ Mineral Reserves are quoted in terms of run-of-mine (RoM) grades and tonnages as delivered to the metallurgical processing facility and are therefore fully diluted;

¨ Mineral Reserve statements include only Measured and Indicated Mineral Resources, modified to produce Mineral Reserves and contained within the LoM plan; and

¨ Mineral Resource and Mineral Reserve undergo both internal and external audits annually. Any issues identified are rectified at the earliest opportunity.

Mineral Resource parameters

Dec 2010

Dec 2011

Mineral Resource gold priceUS$/ozUS$/A$

A$/oz

1,1001.23

1,350

1,4501.07

1,550

Cut-off for mill feed g/t 0.3 0.3

Cut-off for open pit g/t 0.3 – 0.4 0.3

Cut-off for underground g/t 1.5 – 4.0 0.3 – 4.0

Mineral Reserve parameters

Mineral Reserve gold priceUS$/ozUS$/A$

A$/oz

1,0001.23

1,225

1,3001.07

1,400

Cut-off for mill feed underground g/t 1.5 – 4.4 3.1 – 4.4

Cut-off for mill feed open pit g/t 0.4 0.4

MCF % 100 100

Dilution % 26 26

Plant recovery factor % 94.5 94.5

Processing capacity Mtpa 1.3 1.3

Grade tonnage curvesGrade tonnage curves for the total and open pit Mineral Resource is presented. The total chart illustrates the relatively high-grade characteristic of the Agnew camp where historical grades have been in the region of 5 to 6 g/t.

25

20

15

10

5

0

16

14

12

10

8

6

4

2

00 1 2 3 4 5 96 7 8

Cut-off grade (g/t)

— A

vera

ge g

rade

abo

ve c

ut-o

ff (g

/t)

— T

onne

s (m

illio

ns)

Underground

Total (underground and open pits)

32

28

24

20

16

12

8

4

0

16

14

12

10

8

6

4

2

00 1 2 3 4 5 6 7 98

Cut-off grade (g/t)

— A

vera

ge g

rade

abo

ve c

ut-o

ff (g

/t)

— T

onne

s (m

illio

ns)

Son

gvan

g cu

t-ba

ck

11

Mineral ReservesThe Mineral Reserve estimate for Agnew is based on an appropriately detailed and engineered LoM plan. All design and scheduling work is undertaken to an appropriate level of detail by experienced engineers using appropriate mine planning software. The planning process incorporates appropriate modifying factors and the use of cut-off grades and other technical-economic investigations.

The table in this section summarises the Agnew statement of Mineral Reserves. The terms and definitions are those given in the 2007 SAMREC Code prepared by the South African Mineral Resource Committee under the auspices of the South African Institute of Mining and Metallurgy. The current Operational Plan has mining occurring in the Kim South, Rajah and Main Lode at the Waroonga Complex.

The Mineral Reserves are derived following the production of the LoM plan by incorporating modifying factors into the resource model.

Mineral Reserveclassification

Tonnes (Mt) Grade (g/t) Gold (’000 oz)

Dec 2011

Dec 2010

June 2010

Dec 2011

Dec 2010

June 2010

Dec 2011

Dec 2010

June 2010

Open pit and underground

Proved 1.4 1.3 0.7 5.5 4.8 6.9 239 195 166

Probable 5.4 5.6 6.0 6.0 6.2 5.5 1,046 1,126 1,061

Total open pit and underground 6.8 6.9 6.7 5.9 6.0 5.7 1,285 1,321 1,227

Surface stockpiles

Proved low-grade stockpiles 0.3 – – 1.7 – – 17 – –

Total surface stockpiles 0.3 – – 1.7 – – 17 – –

Grand total 7.1 6.9 6.7 5.7 6.0 5.7 1,302 1,321 1,227

Mineral Reserve classified per mining area

Proved Probable Total Mineral Reserve

Tonnes(kt)

Grade(g/t)

Gold(koz)

Tonnes(kt)

Grade(g/t)

Gold(koz)

Tonnes(kt)

Grade(g/t)

Gold(koz)

Underground

Waroonga - Kim Lode 294 13.4 127 2,831 7.4 677 3,125 8.0 804

Waroonga - Rajah Lode 179 4.2 24 265 3.7 32 444 3.9 56

Waroonga - Main Lode 671 3.7 79 2,351 4.5 338 3,022 4.3 417

Total underground 1,144 6.2 230 5,447 6.0 1,046 6,591 6.0 1,276

Surface

Songvang open pit 208 1.4 9 – – – 208 1.4 9

Surface stockpiles 306 1.7 17 – – – 306 1.7 17

Total surface 514 1.6 26 – – – 514 1.6 26

Grand total 1,658 4.8 255 5,447 6.0 1,046 7,105 5.7 1,302

Son

gvan

g cu

t-ba

ck

Pan

oram

ic v

iew

of C

IP p

lant

Gold Fields: Agnew Gold Mine – Technical Short Form Report 2011 12

Factors that affected Mineral Resource reconciliation:

¨ Changes from December 2010 were dominated by extensions to the Main ore body;

¨ An increase in the Mineral Resource gold price from A$1,350 to A$1,550 mitigated by rise in costs; and

¨ Depletion by mining occurred in the Kim, Main, Rajah and Songvang ore bodies.

5.0

4.0

3.0

2.0

1.0

0

Change in Mineral Resources December 2010 to December 2011

Gol

d (M

oz)

Res

ourc

em

odel

ling

Incl

usio

ns/

Exc

lusi

ons

Gol

d pr

ice

Cos

ts

Dep

letio

n

Dis

cove

ry

Dec

embe

r 20

10

Dec

embe

r 20

11

3,845

0.193.8 3.8

3,652

0.23 0.00

0.60 0.14

0.32

3,838

Factors that affected Mineral Reserve reconciliation:

¨ Depletion by mining (-1,207 kt and -224 koz);

¨ Improvements in the definition of additional high-grade Mineral Resources primarily at Main Lode from the surface diamond drilling programme and grade control definition in Kim Lode; and

¨ The use of the Mineable Stope Optimiser software (MSO) resulted in an increase that included lower grade “halo” material into the Mineral Reserves.

Change in Mineral Reserves December 2010 to December 2011

1.4

1.2

1.0

0.8

0.6

0.4

0.2

0

Res

ourc

em

odel

ling

Exc

lusi

ons/

Incl

usio

ns

Gol

d pr

ice

Cos

ts

Dis

cove

ry

Min

ed d

eple

tion

Dec

embe

r 20

10

Dec

embe

r 20

11

1.3

0.22

0.060.08

0.060.03

0.041.3

Gol

d (M

oz)

Mineral Reserve SensitivityThe graph below illustrates the sensitivity of the Mineral Reserve to incremental changes in the gold price.

The sensitivities are not based on detailed depletion schedules and should be considered on a relative and indicative basis only.

(-10%) (-5%) (+5%) (+10%) (+25%)(Base)1,400

Managed Mineral Reserve Sensitivity

Gol

d (M

oz)

1.161.24 1.30

1.35 1.40

1.61

Gold price (A$/oz)

2.0

1.5

1.0

0.5

0

Sur

face

wor

ksho

p –

mai

nten

ance

on

drilli

ng r

ig

Mineral Resources and Mineral Reserves reconciliation year-on-year

13

10. Regulatory codes

SAMRECThis technical statement has been prepared in compliance with the South Africa Code for the Reporting of Exploration Results, Mineral Resources and Mineral Reserves (2007 SAMREC Code).

JSEThis technical statement has been prepared in compliance with the Listings Requirements of the JSE Limited, South Africa (JSE), specifically Section 12.

Sarbanes-Oxley ActThe Mineral Resources and Mineral Reserves are underpinned by an appropriate Mineral Resource management process and protocol to ensure adequate corporate governance in respect of the intent of the Sarbanes-Oxley Act.

EnvironmentalAgnew has an environmental management team that is supported by specialists from the regional office in Perth. The systems, procedures, training etc. are at international leading practice levels.

11. Competent Persons

Competent Persons

Peter Johansen: Mineral Resource Manager BSc (Hons) Geology. AusIMM membership number 108674. Industry experience: 23 years in exploration and mining in Australia and PNG. Commodities: gold, iron ore. 5 years at Agnew.

Alan Pedersen: Resource Modelling ManagerGraduate Certificate in Geostatistics. MAusIMM membership number: 222422. Industry experience: 29 years in mining and exploration in Australia, PNG and Ghana. Commodities: gold, nickel and copper. 14 years at Agnew.

Jason Sander: Mine Planning Manager BEng (Hons) Mining Engineering. LoM strategic planning, reserve estimation and LoM planning. MAusIMM membership number: 111818. Industry experience: 16 years in mining in Australia. Commodities: gold, copper, iron ore. 6 years at Agnew.

James Emslie: Technical Services ManagerBSc (Hons) Geology. AusIMM membership number 205418. Industry experience: 15 years in mining in Australia Commodities: gold, iron ore. 3 years at Agnew.

Internal technical reviews have been conducted by the Competent Persons as listed, who are full-time employees of Gold Fields Limited.

Aer

ial v

iew

of L

eins

ter

Sur

face

wor

ksho

p –

mai

nten

ance

on

drilli

ng r

ig

Gold Fields: Agnew Gold Mine – Technical Short Form Report 2011 14

Post Incumbent Qualifications Years Key responsibilities

General Manager Timothy Gilbert BEng (Hons) Mining Engineering 24 Responsible for overall strategic direction, leadership and management of the mine site

Mining Manager (Underground and Open Pit Mining)

David Vemer B App Sci (Hons) Extractive Metallurgy 16 Management of mining operations

Financial Management and Accounting Commercial Manager

Eric Asubonteng BSc Administration (Accounting) ACCA

8 Financial management, reporting and compliance

Sustainable Development Manager

Greg Yarrick B App Sci (Environmental Health) Post-grad Diploma (Health Sciences – OHS)

24 Management of health, safety environmental and community

Human Resources Manager

Sean Redmond MBa 15 Human resources management

Metallurgy and Engineering Manager

Alex Kraan BBa 4 Engineering, logistics and infrastructure management. Mineral Processing and Metallurgy CIL and Tailings management.

Mineral Resources Manager: Mine Planning and Resource Management

Peter Johansen BSc (Hons) Geology 23 Mineral Resources and Mineral Reserves and compilation of CPR

12. Key technical staff

Fine

ore

sto

ckpi

le

Agn

ew G

old

Min

eP

lan

show

ing

min

e in

frast

ruct

ure

as a

t 31

Dec

embe

r 201

1

6915

000N

6900

000N

6885

000N

6915

000N

6900

000N

6885

000N

6915

000N

6900

000N

6885

000N

270000E

255000E

22

23

1G

enes

is P

it

2N

ew H

olla

nd P

it

3H

idde

n S

ecre

t Pit

4W

aroo

nga

Com

plex

5W

aroo

nga

Pit

6U

nder

grou

nd O

pera

tions

7Em

u Ta

iling

s S

tora

ge

8R

edee

mer

Offi

ce

9R

edee

mer

Pit

10S

tock

pile

s

11C

rusa

der C

ompl

ex

12C

laud

ius

Pit

13P

ilgrim

’s P

it

14D

eliv

erer

Pit

15C

rusa

der

Pit

16C

rusa

der

Offi

ce

17S

ongv

ang

Pit

18G

reat

Eas

tern

Pit

19N

orth

Pit

20W

eigh

t H

ill P

it

21Tu

ret

Pit

22E

mu

Offi

ce

23W

aroo

nga

Offi

ce

24V

ivie

n P

it

25M

aria

Sou

th P

it

26M

aria

Nor

th P

it

Ref

eren

ce

Agn

ew M

inin

g Le

ase .

......

......

......

......

...

Agn

ew P

rosp

ectin

g Li

cenc

e ....

......

...

Agn

ew E

xplo

ratio

n Li

cenc

e ...

......

.....

Taili

ngs .

......

......

......

......

......

......

......

......

......

..

Ope

n P

it ....

......

......

......

......

......

......

......

......

..

Was

te D

ump

......

......

......

......

......

......

......

...

Roa

ds ...

......

......

......

......

......

......

......

......

......

..

Tow

ns ..

......

......

......

......

......

......

......

......

......

...

6915

000N

6900

000N

6885

000N

6915

000N

6900

000N

6885

000N

6915

000N

6900

000N

6885

000N

270000E

255000E

17

16

1920

21

Gold Fields: Agnew Gold Mine – Technical Short Form Report 2011 17

13. Brief history

The history of Agnew

1895: Gold discovered at Lawlers, 10 kilometres south of Agnew Township.

1895 – 1912:The Waroonga mine developed, tramming ore 10 kilometres to the existing Great Eastern mine. Closed due to poor performance.

1934:East Murchison United Limited (EMU) purchased Waroonga lease and constructed a treatment plant in 1936.

1937 – 1948:The Waroonga mine now known as Emu is operated until closure due to high groundwater inflows and ‘company problems’.

1948 – 1975:Despite further exploration by the Kim syndicate, WA Mines department and Western Mining Corporation (WMC), including the sinking of a 63-metre shaft, funds to develop the ore bodies could not be raised.

1976:WMC exercised an option to purchase the Emu mine after intersecting mineralisation below the old workings.

1984:Percussion and diamond drilling undertaken by WMC to test open-pit potential of the area. This was followed by test pitting in 1985 and full scale open-pit mining from 1986.

1985:WMC enters a joint venture with Nord Australex Pty Limited to explore for Emu style mineralisation leading to the discovery of the Redeemer and Deliverer ore bodies.

1987:The Cox-Crusader ore body discovered 400 metres south of the Deliverer ore body by Asarco Australia Limited (Asarco).

1989: Exploratory underground development undertaken at Emu from which production was maintained.

1990: Underground operations commenced at Redeemer.

1992:All operations around Emu ceased and Emu mine allowed to flood. WMC purchases Cox leases from Asarco as ore body extends into WMC tenements to north and Cox pit extended.

1994: Cox pit mined out and a decline developed on the Crusader ore body.

2001:New phase of drilling undertaken in Emu area leading to recommencement of open-pit operations and renaming from Emu to Waroonga.

Gold Fields Australia acquired the operations from WMC and formed Agnew Gold Mining Company.

2002: Decline developed to access the Kim and Main Lodes. Redeemer underground mine closed.

2005:Ore production from Songvang commenced. Ore development and trial stoping undertaken in Main Lode. 100% of the gold rights to the Miranda and Vivien joint venture leases obtained.

2006 – 2010: Exploration of the Claudius and Vivien complexes continues. Drilling at Waroonga continues to extend the known limits of the Kim and Main ore bodies.

2011:Ore production from Songvang cutback commenced. High-grade shoots – Fitzroy, Bengal and Hastings – discovered beneath Main Lode

Gold Fields: Agnew Gold Mine – Technical Short Form Report 2011 18

Agnew Mineral Resource and Mineral Reserve Classification

Drilling into Waroonga ore body extensions

EXPLORATIONRESULTS

MINERALRESERVES

MINERALRESOURCES

Reported as in situmineralisation estimates

Consideration of mining, metallurgical, economic, marketing, legal,environmental, social and governmental factors (the ‘modifying factors’)

24.2 Mt @ 4.9 g/t3.8 Moz

7.1 Mt @ 5.7 g/t1.3 Moz

5.4 Mt @ 6.0 g/t1.0 Moz

1.7 Mt @ 4.8 g/t0.3 Moz

7.5 Mt @ 4.5 g/t1.1 Moz

12.9 Mt @ 5.3 g/t2.2 Moz

3.8 Mt @ 4.5 g/t0.6 Moz

Reported as mineableproduction estimates

Incr

easi

ng le

vel o

f geo

scie

ntifi

c kn

owle

dge

and

confi

denc

e

MEASURED PROVED

PROBABLEINDICATED

INFERRED

1,400 mbs

Waroonga Pit

Main NorthMain South

Kim Lode

Reserve Stopes Completed Stopes

Hastings Shoot

Bengal Shoot

Fitzroy Shoot

Rajah Lode

19

Notes

Res

ourc

e co

nver

sion

dril

ling

at W

aroo

nga

Com

plex

This Technical Short Form Report (“the Report”) contains information as at 31 December 2011 (“the Effective Date of this Report”). The statements and information set out in this Report speak only as of the Effective Date of this Report. Shareholders and other interested and affected parties are therefore urged to review all public disclosures made by Gold Fields after the Effective Date of this Report, as some of the information contained in the Report may have changed or have been updated. Gold Fields does not undertake any obligation to update publicly or release any revisions to statements and information set out in this Report to reflect events or circumstances after the Effective Date of this Report or to reflect the occurrence of unanticipated events, unless obliged to do so pursuant to law or regulation. In such event, Gold Fields does not undertake to refer back to any information contained in this Report.

Gold Fields: Agnew Gold Mine – Technical Short Form Report 2011 1

Registered Office South Africa:150 Helen RoadSandownSandton, 2196 JohannesburgGautengPrivate Bag X30500Houghton, 2041 South Africa

Website: http://www.goldfields.co.za Telephone: +27 (0) 11 562 9700Facsimile: +27 (0) 11 562 9838

“If we cannot mine safely, we will not mine”

Gold Fields Safety Value