1. INDONESIA GOLD RESOURCES AND EXPLORATION CHALLENGES
(Source: Prihananto, 2011)
Dr. Arifudin Idrus
Department of Geological Engineering
Gadjah Mada University
address:
Disampaikan pada ‘One-day Course: “Pemanfaatan dan Prospek
Sumberdaya Emas di Indonesia”; HMTG-UGM, 1 Oktober 2011

2. WHY GOLD? Part of human life since ~6,000 years ago
Relatively minor occurrences, but widespread in geographic distribution
Physical properties and valuable deposit
Unique economic behavior (in both small and large scale)

3. GOLD PRODUCTION 1900-1989 (from various sources)
Dutch Colonial Era Independence
Sukarno | Soeharto
Sumatra
CoW
Pacific War
Ertsberg

4. GOLD DISTRICTS 1900-1989 Kalimantan North Sulawesi Alluvials Mangani
Lebong
Ertsberg
Cikotok

6. Total: 1,768 tonnes

7. GOLD PRODUCTION DECREASING ???
Gold deposit potential depleted  No
Decreasing of exploration activities and lack of new discoveries  ???
Technical aspects
Non technical aspects

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

9. DEPOSIT MODEL (Corbett, 2005)

10. REGIONAL GEOLOGY OF INDONESIA

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

12. GOLD RESOURCES + RESERVES 1969 – 2010 (desk study)
Moz (5, tonnes) gold
N: 94

13. GOLD – BY MAGMATIC ARC
Moz (5, tonnes) gold

14. GOLD – BY DEPOSIT TYPE
Moz (5, tonnes) gold

15. GOLD – BY PROJECT STATUS
Moz (5, tonnes) gold

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

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

18. GEOLOGICAL TARGET TYPES
HS EPITHERMAL
Field
SKARN
Field
LS EPITHERMAL
Field
PORPHYRY
Field

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

20. GOLD MINE – LIFE SPANS Porphyry VMS LS Epithermal Sediment hosted90 91 92 93 94 95 96 97 98 99 00 01 02 03 04 05 06 07 08 09 10
Grasberg
Lebong Tandai
Alluvials
Wetar
Kelian
Pongkor
Mt. Muro
Mesel
Rawas
Gosowong
Cikidang
Batu Hijau
Mt. Muro West
Kencana
Cibaliung
Porphyry
VMS
LS Epithermal
Sediment hosted
Alluvial

21. 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 +)

22. 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

23. EXPLORATION CHALLENGES  technical aspects
1. Opportunity to generate/ develop new projects is sliming  Matured Exploration Areas
2. Exploration “going deeper”
Development of new geological/ exploration model
Application of new technology
Advanced exploration techniques and approaches
Higher exploration costs
3. Professional ability and skill of “explorationists”

24. MAJOR GOLD DEPOSIT TYPES IN INDONESIA
Epithermal
Porphyry/ skarn

25. Porphyry vs Epithermal