Central Kalimantan

A dispersed belt of Tertiary intermediate intrusive and volcanic rocks that postdate pre-Eocene subduction and deformation, uplift, and erosion of pre-Miocene rocks and continental basement in Kalimantan
Tract ID 142pCu7019
Country Indonesia
Commodity Cu
Study area name Southeast Asia and Melanesia
Tectonic setting postconvergence
Deposit type porphyry copper
Grade-tonnage model Porphyry copper, Cu-Au subtype (Singer and others, 2008)
Geologic age
Geologic feature age late Oligocene through Pliocene
Generalized age Tertiary-Neogene
Oldest rocks age 28.4Ma
Youngest rocks age 2.6Ma
Age range 25.8Ma
Identified Cu resources 940,000metric tons
Known prospects 9
Mean Cu (t/sq km) 277t/sq km
Map scales used 500K, 1M

Results of the assessment

Assessment date 2010
Estimators Arthur A. Bookstrom, Jane M. Hammarstrom, Steve Ludington, Gilpin R. Robinson, Jr, and Michael L. Zientek
Assessment depth 1km
Quantitative assessment Yes

Estimated number of deposits

Number of deposits Confidence level
3 90%
8 50%
30 10%
30 5%
30 1%
Mean estimated deposits 12.9 ±10.04 (0.78%)
Probability of mean 0.38
Probability of no copper 0.03

Estimated deposit density

(sq km)
Deposit density
per 100,000 sq km
1 13.9 144,580 10

Mean estimated tonnage

Copper 40,000,000
Molybdenum 230,000
Gold 2,900
Silver 13,000
Ore 8,100

Undiscovered copper resource

Confidence level 95% 90% 50% 10% 5%
Tonnage 1,000,000 2,800,000 25,000,000 100,000,000 130,000,000

Economic analysis

Fraser country Indonesia and Sabah and Sarawak, Malaysia
Fraser type 0.13%
Fraser high 0.88%
Typical cost 0%
High cost 1%
Infrastructure setting High cost
Comments on depth default
Expected depth distribution
0 - 250m 0.25
250m - 500m 0.25
500m - 1km 0.5
Economically recoverable resources
Copper 19,000,000t
Molybdenum 81,000t
Gold 950t
Silver 6,200t
Probability no econ recoverable 0.17
Econ NPV 3,700x $1M
Exp dollars 21.48x $1M/100,000 sq km
Exp value class Medium

Bibliographic references

General Hammarstrom and others (2013)
Economic Robinson and Menzie (2012)

Deposits and prospects associated with this tract

Name Type State Country Development Details
Ruwai prospect Kalimantan Barat Indonesia Occurrence Details
Sungai Imbak prospect Sabah Malaysia Occurrence Details
Baroi Gold prospect Kalimantan Tengah Indonesia Prospect Details
Ibu prospect Kalimantan Barat Indonesia Prospect Details
Mansur prospect Kalimantan Tengah Indonesia Prospect Details
Mamut deposit Sabah Malaysia Prospect Details
Bongkud prospect Sabah Malaysia Prospect Details
Kalimantan Gold prospect Kalimantan Tengah Indonesia Prospect Details
Masuparia prospect Kalimantan Tengah Indonesia Prospect Details
Nungkok prospect Sabah Malaysia Prospect Details