This document discusses gold resources and exploration challenges in Indonesia. It provides an overview of major gold deposit types and styles found in Indonesia, including porphyry, epithermal, and skarn deposits. Statistics on Indonesia's gold production and reserves since 1990 are presented, showing the majority coming from porphyry and skarn deposits in the Papuan magmatic arc. Challenges to the mining industry in Indonesia include uncertainty regarding mineral tenure and overlapping forestry regulations.

1. INTRODUCTION: STYLES & GOLD
RESOURCES
Dr.rer.nat. Arifudin Idrus
Associate Professor in Economic Geology
Department of Geological Engineering
Gadjah Mada University, Yogyakarta
E-mail: arifidrus@ugm.ac.id
In-House Training
UNHAS Makassar, 25-27 September 2014
INTRODUCTION: STYLES & GOLD
RESOURCES
Dr.rer.nat. Arifudin Idrus
Associate Professor in Economic Geology
Department of Geological Engineering
Gadjah Mada University, Yogyakarta
E-mail: arifidrus@ugm.ac.id
In-House Training
UNHAS Makassar, 25-27 September 2014

2. Porgera, Zone 7
Papua New Guinea
Sleeper
Nevada, USA

3. Crustal environment in which major gold deposit styles from
Robert et al., 2007 (in Lipson, 2014)
Crustal environment in which major gold deposit styles from
Robert et al., 2007 (in Lipson, 2014)

6. Global porphyry Cu-Au depositsGlobal porphyry Cu-Au deposits

7. Global Tectonic Setting vs Gold DepositsGlobal Tectonic Setting vs Gold Deposits
}Different classes
of epithermal deposits

8. Relative Amounts of Gold
(>5 Moz deposits, 1997)
50% Witwatersrand
12% Epithermal
10% Porphyry (+ intrusion hosted)
12% Sediment hosted (incl. 4% “Carlin”)
9% Greenstone lode (“orogenic”)
7% Other (Fe Fm, VHMS, etc.)
50% Witwatersrand
12% Epithermal
10% Porphyry (+ intrusion hosted)
12% Sediment hosted (incl. 4% “Carlin”)
9% Greenstone lode (“orogenic”)
7% Other (Fe Fm, VHMS, etc.)
Arribas, 2000
Relative Amounts of Gold
(>5 Moz deposits, 1997)
50% Witwatersrand
12% Epithermal
10% Porphyry (+ intrusion hosted)
12% Sediment hosted (incl. 4% “Carlin”)
9% Greenstone lode (“orogenic”)
7% Other (Fe Fm, VHMS, etc.)
50% Witwatersrand
12% Epithermal
10% Porphyry (+ intrusion hosted)
12% Sediment hosted (incl. 4% “Carlin”)
9% Greenstone lode (“orogenic”)
7% Other (Fe Fm, VHMS, etc.)

9. INDONESIAN GOLD RESOURCES AND
EXPLORATION CHALLENGES
Reference: Prihatmoko, 2010
INDONESIAN GOLD RESOURCES AND
EXPLORATION CHALLENGES
Reference: Prihatmoko, 2010

10. 133.0
130.0
150.0
170.0
190.0
210.0
230.0
250.0
GoldProduction
(Tonnes)
INDONESIA GOLD PRODUCTION (1990-2010)
Source: ESDM (2011); KITCO (2011)
1990 1991 1992 1993 1994 1995 1996 1997 1998 1999
Gold Production
(Tonnes) 11.7 16.0 38.2 43.3 42.6 62.8 83.6 90.0 124.0 133.0
Gold Price (USD) 385.5 362.1 343.8 359.7 384.0 383.7 387.8 331.0 294.2 278.9
11.7
16.0
38.2
43.3 42.6
62.8
83.6
90.0
124.0
10.0
30.0
50.0
70.0
90.0
110.0
130.0
GoldProduction
(Tonnes)
133.0
224.7
187.1
172.1
127.8
163.1
159.3
900.00
1,000.00
1,100.00
1,200.00
1,300.00
1,400.00
1,500.00
Gold
Price
(USD)
INDONESIA GOLD PRODUCTION (1990-2010)
Source: ESDM (2011); KITCO (2011)
1999 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010
133.0 124.0 224.7 187.1 172.1 127.8 163.1 116.3 159.3 29.1 97.7 109.8
278.9 279.1 271.0 309.7 363.3 409.7 444.7 603.4 695.3 871.9 972.3 1,224
124.0
127.8
116.3
29.1
97.7
109.8
100.00
200.00
300.00
400.00
500.00
600.00
700.00
800.00
Year

11. China South Africa United States Australia Indonesia
2007
Gold (Tonnes) 276 272 255 251
276 272
255 251
-
50
100
150
200
250
300
350
400
GoldProduction
(Tonnes)
TOP TENS GOLD PRODUCERS (2007)
Source: USGS 2007 Mineral Year Book
China Australia United States South Africa Russia
2010
Gold (Tonnes) 341 266 240 190
341
266
240
190
-
50
100
150
200
250
300
350
400
GoldProduction
(Tonnes)
TOP TENS GOLD PRODUCERS (2010)
Source: Gold Mining Journal 2011
Indonesia Peru Russia Canada PNG Ghana
171 167 153 93 67 63
171 167
153
93
67 63
Total: 1,768 tonnes
Russia Peru Indonesia Ghana Canada Uzbekistan
190 170 120 100 90 90
190
170
120
100 90 90
Total: 1,797 tonnes

12. GOLD DEPOSIT TYPES
• Witwatersrand
• Greenstone Belt
• Epithermal including Carlin (sediment hosted)
• Porphyry/ skarn
• Orogenic Gold
• Volcanogenic Massive Sulfide (VMS)
• Others
• Witwatersrand
• Greenstone Belt
• Epithermal including Carlin (sediment hosted)
• Porphyry/ skarn
• Orogenic Gold
• Volcanogenic Massive Sulfide (VMS)
• Others
GOLD DEPOSIT TYPES
• Witwatersrand
• Greenstone Belt
• Epithermal including Carlin (sediment hosted)
• Porphyry/ skarn
• Orogenic Gold
• Volcanogenic Massive Sulfide (VMS)
• Others
• Witwatersrand
• Greenstone Belt
• Epithermal including Carlin (sediment hosted)
• Porphyry/ skarn
• Orogenic Gold
• Volcanogenic Massive Sulfide (VMS)
• Others

13. DEPOSIT MODEL (Corbett, 2005)DEPOSIT MODEL (Corbett, 2005)

14. REGIONAL GEOLOGY OF INDONESIAREGIONAL GEOLOGY OF INDONESIA

15. MAGMATIC ARCS OF INDONESIA
(Carlile ane Mitchel, 1994)
MAGMATIC ARCS OF INDONESIA
(Carlile ane Mitchel, 1994)

16. GOLD RESOURCES + RESERVES 1969 – 2010 (desk study)
 167.66 Moz (5,214.38 tonnes) gold
News Release
15.84 moz
Unpublished
Report
4.34 moz
Published Paper
147.48 moz
GOLD RESOURCES + RESERVES 1969 – 2010 (desk study)
 167.66 Moz (5,214.38 tonnes) gold
News Release
15.84 moz
News Release
N: 94
News Release
Published Paper
Unpublished
Report

17. GOLD – BY MAGMATIC ARC
 167.66 Moz (5,214.38 tonnes) gold
Halmahera
3.83 moz
Other
0.90 moz
Papua
100.15 moz
GOLD – BY MAGMATIC ARC
 167.66 Moz (5,214.38 tonnes) gold
Sunda-Banda
35.59 moz
Kalimantan
11.40 moz
Sunda-
Banda
KalimantanKalimantan
11.40 moz
Sulawesi
15.80 moz
Kalimantan
Sulawesi
Papua

18. GOLD – BY DEPOSIT TYPE
 167.66 Moz (5,214.38 tonnes) gold
HS Epithermal
9.41 moz
VMS
0.97 moz
Mesothermal
2.87 moz
Sediment Hosted
3.08 moz
Alluvial
1.18 moz
Skarn
47.78 moz
HS Epithermal
9.41 moz
LS Epithermal
31.07 moz
GOLD – BY DEPOSIT TYPE
 167.66 Moz (5,214.38 tonnes) gold
Porphyry
71.3 moz
Alluvial
1.18 moz
Deposit Type
Porphyry
Skarn
HS Epithermal
LS Epithermal
VMS
Mesothermal

19. GOLD – BY PROJECT STATUS
 167.66 Moz (5,214.38 tonnes) gold
Mined Out
20.00 mozExploration
37.52 moz
Unknown
1.13 moz
GOLD – BY PROJECT STATUS
 167.66 Moz (5,214.38 tonnes) gold
Mined Out
20.00 moz
Project Status
Mined Out
Being Mined
109.02 moz
Mined Out
Being Mined
Exploration
Unknown

20. GOLD MINES 1990-2010
Mt. Muro
Buduk
Mt. Muro
Kelian
Cikidang
Batu Hijau
Rawas
Pongkor
Lb Tandai Mt. Muro West
Cibaliung
Buduk Mesel
Gosowong
Active
Closed
Sediment Hosted
LS Epithermal
Porphyry/ Skarn
VMS
…….
…….
…….
…….
Mesel
Kelian
Grasberg
Batu Hijau
Wetar
Kencana

21. PRIMARY GOLD DEPOSITS/ OCCURENCES
Seruyung TombulilatoPungkut
Martabe
Seruyung Tombulilato
Way Linggo
Elang
Pungkut
Mirah
Bukit Tujuh
Palu
Jelai-Mewet
Pangulir
Ojolali
PRIMARY GOLD DEPOSITS/ OCCURENCES
Toka TindungTombulilato
Active
Closed
Sediment Hosted
LS Epithermal
HS Epithermal
Porphyry/ Skarn
Mesothermal Vein
…….
…….
…….
…….
…….
Toka TindungTombulilato
Wabu
Awak Mas
Motomboto
Palu
Pangulir

22. 0.010
0.100
1.000
10.000
100.000
1000.000
0.100 1.000 10.000 100.000 1000.000
Deposite Size (Mt)
Grade(g/tAu)
Porphyry Skarn VMS Sedimen Hosted LS Epithermal Mesothermal Vein HS Epithermal
GEOLOGICAL TARGET TYPES
0.010
0.100
1.000
10.000
100.000
1000.000
0.100 1.000 10.000 100.000 1000.000
Deposite Size (Mt)
Grade(g/tAu)
Porphyry Skarn VMS Sedimen Hosted LS Epithermal Mesothermal Vein HS Epithermal
LS EPITHERMAL
Field
0.010
0.100
1.000
10.000
100.000
1000.000
0.100 1.000 10.000 100.000 1000.000
Deposite Size (Mt)
Grade(g/tAu)
Porphyry Skarn VMS Sedimen Hosted LS Epithermal Mesothermal Vein HS Epithermal
GEOLOGICAL TARGET TYPES
HS EPITHERMAL
Field
SKARN
Field
0.010
0.100
1.000
10.000
100.000
1000.000
0.100 1.000 10.000 100.000 1000.000
Deposite Size (Mt)
Grade(g/tAu)
Porphyry Skarn VMS Sedimen Hosted LS Epithermal Mesothermal Vein HS Epithermal
SKARN
Field
PORPHYRY
Field

23. GOLD MINE – LAPSE TIMES
Mine Owner Status
Lebong Tandai Billiton (CSR) Closed
Gosowong Newcrest Closed
Wetar Billiton Closed
Ertsberg Freeport Closed
Pongkor Antam Production
Kelian Riotinto Closed
Mt. Muro Aurora ClosedMt. Muro Aurora Closed
Kencana Newcrest Production
Mesel Newmont Closed
Rawas Laverton Closed
Cibaliung Austindo/ Antam Production
Batu Hijau Newmont Production
Mt. Muro West Straits Production
Grasberg Freeport Production
Average Lapse Time (Years)
GOLD MINE – LAPSE TIMES
Status
Contract
Signed Production Lapse
Closed 1985 1986 1
Closed 1997 1999 2
Closed 1986 1991 5
Closed 1967 1973 6
Production 1988 1994 6
Closed 1985 1992 7
Closed 1985 1994 9Closed 1985 1994 9
Production 1997 2006 9
Closed 1986 1996 10
Closed 1986 1997 11
Production 1998 2010 12
Production 1986 1999 13
Production 1985 2004 19
Production 1967 1989 22
9.5

24. GOLD MINE – LIFE SPANS
Mine 90 91 92 93 94 95 96 97 98
Grasberg
Lebong Tandai
Alluvials
Wetar
Kelian
Pongkor
Mt. Muro
Mesel
RawasRawas
Gosowong
Cikidang
Batu Hijau
Mt. Muro West
Kencana
Cibaliung
Porphyry
LS Epithermal
Alluvial
GOLD MINE – LIFE SPANS
98 99 00 01 02 03 04 05 06 07 08 09 10
VMS
Sediment hosted

25. FACTORS AFFECTING INDUSTRY’S FUTURE
 Geological Prospectiveness (++)
 Country Stability (+)
 Gold Price (++)
 Legal/Commercial Basis ( - )
New Mining Law, lack of implementing regulations
 Intensity of Exploration Efforts (– to +)
 Geological Prospectiveness (++)
 Country Stability (+)
 Gold Price (++)
 Legal/Commercial Basis ( - )
New Mining Law, lack of implementing regulations
 Intensity of Exploration Efforts (– to +)
FACTORS AFFECTING INDUSTRY’S FUTURE
 Geological Prospectiveness (++)
 Country Stability (+)
 Gold Price (++)
 Legal/Commercial Basis ( - )
New Mining Law, lack of implementing regulations
 Intensity of Exploration Efforts (– to +)
 Geological Prospectiveness (++)
 Country Stability (+)
 Gold Price (++)
 Legal/Commercial Basis ( - )
New Mining Law, lack of implementing regulations
 Intensity of Exploration Efforts (– to +)

26. CONCERNS IN INDONESIA
(non technical aspects)
 Uncertainty in mineral tenement system (Mining Law
No.4/ 2009 with lack of implementing regulations)
 Forestry overlapping issues
 Pains of regional autonomy
 Illegal mining
 Local community / NGOs
 Uncertainty in mineral tenement system (Mining Law
No.4/ 2009 with lack of implementing regulations)
 Forestry overlapping issues
 Pains of regional autonomy
 Illegal mining
 Local community / NGOs
CONCERNS IN INDONESIA
(non technical aspects)
 Uncertainty in mineral tenement system (Mining Law
No.4/ 2009 with lack of implementing regulations)
 Forestry overlapping issues
 Pains of regional autonomy
 Illegal mining
 Local community / NGOs
 Uncertainty in mineral tenement system (Mining Law
No.4/ 2009 with lack of implementing regulations)
 Forestry overlapping issues
 Pains of regional autonomy
 Illegal mining
 Local community / NGOs

27. EXPLORATION CHALLENGES  technical aspects
2. Exploration “going deeper”
 Development of new geological/ exploration model
 Application of new technology
 Advanced exploration techniques and approaches
 Higher exploration costs
1. Generate/ develop new projects
2. Exploration “going deeper”
 Development of new geological/ exploration model
 Application of new technology
 Advanced exploration techniques and approaches
 Higher exploration costs
EXPLORATION CHALLENGES  technical aspects
2. Exploration “going deeper”
 Development of new geological/ exploration model
 Application of new technology
 Advanced exploration techniques and approaches
 Higher exploration costs
1. Generate/ develop new projects
2. Exploration “going deeper”
 Development of new geological/ exploration model
 Application of new technology
 Advanced exploration techniques and approaches
 Higher exploration costs

28. GOING DEEPER EXAMPLEGOING DEEPER EXAMPLE
(GOSOWONG(GOSOWONG –– KENCANA)KENCANA)
GOING DEEPER EXAMPLEGOING DEEPER EXAMPLE
(GOSOWONG(GOSOWONG –– KENCANA)KENCANA)

29. GOING DEEPER EXAMPLE (GOSOWONGGOING DEEPER EXAMPLE (GOSOWONG –– KENCANA)KENCANA)GOING DEEPER EXAMPLE (GOSOWONGGOING DEEPER EXAMPLE (GOSOWONG –– KENCANA)KENCANA) Richards et al (2005)

30. GOING DEEPER EXAMPLE (GOSOWONGGOING DEEPER EXAMPLE (GOSOWONG –– KENCANA)KENCANA)GOING DEEPER EXAMPLE (GOSOWONGGOING DEEPER EXAMPLE (GOSOWONG –– KENCANA)KENCANA) Richards et al (2005)

31. GOING DEEPER EXAMPLE (GOSOWONGGOING DEEPER EXAMPLE (GOSOWONG –– KENCANA)KENCANA)GOING DEEPER EXAMPLE (GOSOWONGGOING DEEPER EXAMPLE (GOSOWONG –– KENCANA)KENCANA) Richards et al (2005)

32. GOING DEEPER EXAMPLE (FRUTA DEL NORTEGOING DEEPER EXAMPLE (FRUTA DEL NORTE -- ECUADOR)ECUADOR)GOING DEEPER EXAMPLE (FRUTA DEL NORTEGOING DEEPER EXAMPLE (FRUTA DEL NORTE -- ECUADOR)ECUADOR)

33. GOING DEEPER EXAMPLE (FRUTA DEL NORTEGOING DEEPER EXAMPLE (FRUTA DEL NORTE -- ECUADOR)ECUADOR) Leary (2007)GOING DEEPER EXAMPLE (FRUTA DEL NORTEGOING DEEPER EXAMPLE (FRUTA DEL NORTE -- ECUADOR)ECUADOR)
237.25m @ 4.14g/t Au

34. Conglomerate
Late Andesite
GOING DEEPER EXAMPLE (FRUTA DEL NORTEGOING DEEPER EXAMPLE (FRUTA DEL NORTE -- ECUADOR)ECUADOR)
58.9mt @ 7.23 g/t Au (13.7 moz)
Andesite
Conglomerate
GOING DEEPER EXAMPLE (FRUTA DEL NORTEGOING DEEPER EXAMPLE (FRUTA DEL NORTE -- ECUADOR)ECUADOR) Leary (2007)
58.9mt @ 7.23 g/t Au (13.7 moz)
Andesite

35. Serujan East Wall-Mt. MuroSerujan East Wall-Mt. Muro

36. LET’S LEARN ABOUT DEPOSIT MODELS !!!LET’S LEARN ABOUT DEPOSIT MODELS !!!LET’S LEARN ABOUT DEPOSIT MODELS !!!LET’S LEARN ABOUT DEPOSIT MODELS !!!