Gold Fields

Granny Smith gold mine - Mineral Resources and Mineral Reserves

The Mineral Resources and Mineral Reserves were updated as of December 2017 and used a gold price of A$1,850/oz and A$1,600/oz respectively. The December 2017 Mineral Resources have been stated inclusive of Mineral Reserves. Geological and evaluation models have been updated as at December 2017 to reflect the latest available data sets.

Mineral Resources

The Mineral Resources are classified as Measured, Indicated or Inferred, as described in the SAMREC Code. Mineral Resource categories are assigned with consideration given to geological complexity, grade variance, drill hole intersection spacing and mining development.

Mineral Resource classification

	Tonnes (kt)					Grade (g/t)					Gold (koz)
Classification	Dec 2017	Dec 2016	Dec 2015			Dec 2017	Dec 2016	Dec 2015			Dec 2017	Dec 2016	Dec 2015
Open pit
Measured	—	—	—			—	—	—			—	—	—
Indicated	565	734	—			1.77	1.75	—			32	41	—
Inferred	840	1,456	1,234			1.90	2.10	3.53			51	98	140
Total open pit	1,404	2,190	1,234			1.85	1.98	3.53			84	140	140
Underground
Measured	4,071	3,474	2,524			6.02	5.88	6.58			788	657	534
Indicated	21,606	18,932	16,398			5.94	5.80	5.26			4,129	3,533	2,772
Inferred	11,440	10,500	10,212			5.61	6.43	5.57			2,062	2,172	1,829
Total underground	37,117	32,906	29,133			5.85	6.01	5.48			6,979	6,362	5,135
Total stockpiles	66	93	21			5.58	6.31	6.16			12	19	4
Grand total	38,587	35,189	30,389			5.70	5.76	5.40			7,075	6,520	5,279

Mineral Resource classification per mining area

	Measured					Indicated					Inferred					Total Mineral Resource
Area	Tonnes (kt)	Grade (g/t)	Gold (koz)			Tonnes (kt)	Grade (g/t)	Gold (koz)			Tonnes (kt)	Grade (g/t)	Gold (koz)			Tonnes (kt)	Grade (g/t)	Gold (koz)
Open pit
Granny Smith/Hillside	—	—	—			565	1.77	32			840	1.90	51			1,405	1.85	84
Total open pit	—	—	—			565	1.77	32			840	1.90	51			1,405	1.85	84
Underground
Granny Smith	—	—	—			3,583	3.02	348			1,595	2.70	138			5,178	2.92	486
Wallaby
Zone 70	673	4.83	105			630	4.35	88			184	3.34	20			1,486	4.45	213
Zone 80	545	5.72	100			824	5.14	136			242	5.13	40			1,611	5.33	276
Zone 90	1,656	6.18	329			1,125	4.89	177			528	4.56	77			3,309	5.48	583
Zone 100	1,111	6.77	242			7,000	6.05	1,362			1,741	4.59	257			9,852	5.87	1,860
Zone 110-120	—	—	—			8,311	7.49	2,002			3,050	4.64	455			11,361	6.73	2,457
Zone 135	—	—	—			—	—	—			3,995	8.25	1,060			3,995	8.25	1,060
Other	86	4.5	12			134	3.85	17			105	4.29	14			325	4.17	44
Total underground	4,071	6.02	788			21,606	5.95	4,130			11,440	5.61	2,062			37,117	5.85	6,979
Surface
Surface stockpiles	66	5.58	12			—		—			—		—			66	5.58	12
Grand total	4,137	6.01	800			22,169	5.84	4,162			12,279	5.35	2,113			38,587	5.70	7,075

Modifying factors

• The Measured and Indicated Mineral Resources are inclusive of Mineral Reserves
• Mineral Reserves are quoted in terms of RoM grades and tonnages as delivered to the metallurgical processing facility and are therefore fully diluted
• Mineral Reserve statement includes only Measured and Indicated Mineral Resources, modified to produce Mineral Reserves and contained within the LoM plan
• Mineral Resources and Mineral Reserves undergo regular internal and/or external audits, and any issues identified are rectified at the earliest opportunity – usually during the current reporting cycle

	December
	Units		2017		2016	2015
Mineral Resource parameters
	US$/oz		1,400		1,400	1,500
Mineral Resource gold price	US$/A$		0.76		0.76	0.86
	A$/oz		1,850		1,850	1,750
Cut-off for open pit	g/t		0.57 – 0.63		0.63	0.82
Cut-off for underground	g/t		2.0 – 2.8		2.0 – 2.9	1.7 – 2.8
Mineral Reserve parameters
	US$/oz		1,200		1,200	1,300
Mineral Reserve gold price	US$/A$		0.75		0.75	0.84
	A$/oz		1,600		1,600	1,550
Cut-off for underground	g/t		2.4 – 3.1		2.4 – 3.1	2.6 – 3.2
Mining recovery factor (underground)	%		91		91	91
MCF	%		100		100	100
Dilution underground	%		15		15	10
Plant recovery factor	%		92.8		92.6	92
Processing capacity	Mtpa		3.5		3.5	3.5

The grade tonnage curves for the underground and open pit Mineral Resource are presented below.

Grade tonnage curve - Surface		Grade tonnage curve - Underground

Mineral Reserves

The Mineral Reserve estimate for Granny Smith is based on a detailed and engineered LoM plan. All design and scheduling work is undertaken by experienced engineers using appropriate mine planning software. The planning process incorporates realistic modifying factors and the use of appropriate cut-off grades, geotechnical criteria, mining fleet productivities and other techno-economic investigations.

The Mineral Reserves are derived from the LoM plan, which is supported by a detailed design and schedule that takes account of cut-off grades, prevailing geotechnical factors directing optimal sequencing and incorporates appropriate modifying factors.

Capital requirements are accommodated in the cash-flow model to ensure sustainable operations over the LoM.

Mineral Reserve classification

	Tonnes (kt)					Grade (g/t)					Gold (koz)
Classification	Dec 2017	Dec 2016	Dec 2015			Dec 2017	Dec 2016	Dec 2015			Dec 2017	Dec 2016	Dec 2015
Underground
Proved	1,498	1,383	758			4.97	5.38	6.90			239	239	168
Probable	10,865	8,457	6,173			5.59	5.28	5.73			1,951	1,435	1,137
Total underground	12,363	9,840	6,931			5.51	5.29	5.86			2,191	1,674	1,305
Surface
Proved	66	93	21			5.58	6.31	6.16			12	19	4
Total surface	66	93	21			5.58	6.31	6.16			12	19	4
Grand total	12,430	9,933	6,952			5.51	5.30	5.86			2,203	1,693	1,310

Mineral Reserves classification per mining area

	Proved				Probable				Total Mineral Reserve
Area	Tonnes (kt)	Grade (g/t)	Gold (koz)		Tonnes (kt)	Grade (g/t)	Gold (koz)		Tonnes (kt)	Grade (g/t)	Gold (koz)
Underground
Other (Z70 + Z80)	192	4.05	25		454	4.04	59		646	4.04	84
Z90	631	5.19	105		241	4.13	32		872	4.89	137
Z100	675	5.02	109		3,372	5.49	596		4,047	5.42	705
Z110/120					6,799	5.79	1,265		6,799	5.79	1,265
Total underground	1,498	4.97	239		10,865	5.59	1,951		12,363	5.51	2,191
Surface
Surface stockpiles	66	5.58	12			—			66	5.58	12
Grand total	1,564	5.00	251		10,865	5.59	1,951		12,430	5.51	2,203

Mineral Resource and Mineral Reserve reconciliation year-on-year

Factors that affected Mineral Resource reconciliation year-on-year		Factors that affected Mineral Reserve reconciliation year-on-year
Mining depletion from Zones 70, 80, 90 and 100 in the Wallaby underground (-301koz).		Mining depletion from Zones 70, 80, 90 and 100 in the Wallaby underground (-301koz).
Increase of 535koz to the Wallaby underground Mineral Resource from resource extension discoveries and remodelling primarily in Zone 110-120 and Zone 135.		Strong growth from deeper lodes at Zone 110/120 (518koz) due to conversion of new Indicated Mineral Resources and resource extension discoveries.
Minor overall change to the Granny Smith Resource; Goanna OP -77koz (updated mining parameters); Granny Smith UG +83koz (updated resource modelling); and inclusion of the Hillside Inferred Resource (21koz).		New Mineral Reserve additions to Zone 100 (163koz) and to Z60-90 (136koz).

Mineral Resource reconciliation (Gold – koz)		Mineral Reserves reconciliation (Gold – koz)

Mineral Reserve sensitivity

To illustrate the impact of fluctuations in gold price and exchange rates on the current declaration, Granny Smith has generated sensitivities with respect to Mineral Reserves. The following graph indicates the Managed Mineral Reserve sensitivity at -15%, -10%, -5%, +5%, +10% and +15% to the base (A$1,600/oz) reserve gold price.

These sensitivities (other than for the base case) are not supported by detailed plans and depletion schedules. They should only be considered on an indicative basis; specifically as such sensitivities assume 100% selectivity, without any operating cost increases.

Mineral Reserve sensitivity (Gold – Moz)