Halmahera Arc, North Molucca Islands

Neogene Halmahera island arc
Tract ID 142pCu7202
Country Indonesia
Commodity Cu
Study area name Southeast Asia and Melanesia
Tectonic setting island arc
Deposit type porphyry copper
Grade-tonnage model Porphyry copper, Cu-Au subtype (Singer and others, 2008)
Geologic age
Geologic feature age Neogene through Holocene
Generalized age Tertiary-Neogene
Oldest rocks age 23.03Ma
Youngest rocks age 0Ma
Age range 23.03Ma
Identified Cu resources 250,000metric tons
Known prospects 4
Mean Cu (t/sq km) 392t/sq km
Map scales used 250K, 1M, 2M

Results of the assessment

Assessment date 2010
Estimators Gilpin R. Robinson, Jr., Steve Ludington, Jane M. Hammarstrom, Michael L. Zientek, Arthur A. Bookstrom, Alexander Yan Sze Wah, Bambang Setiabudi, Dwi Sunuhadai
Assessment depth 1km
Quantitative assessment Yes

Estimated number of deposits

Number of deposits Confidence level
1 50%
3 10%
6 5%
6 1%
Mean estimated deposits 1.53 ±1.75 (1.15%)
Probability of mean 0.22
Probability of no copper 0.31

Estimated deposit density

Known
deposits
Total
deposits
Area
(sq km)
Deposit density
per 100,000 sq km
1 2.53 12,245 21

Mean estimated tonnage

Copper 4,800,000
Molybdenum 29,000
Gold 340
Silver 1,600
Ore 970

Undiscovered copper resource

Confidence level 50% 10% 5%
Tonnage 870,000 12,000,000 24,000,000

Economic analysis

Fraser country Indonesia
Fraser type 0.13%
Fraser high 0.88%
Typical cost 0%
High cost 1%
Infrastructure setting High cost
Comments on depth deep
Expected depth distribution
0 - 250m 0.1
250m - 500m 0.3
500m - 1km 0.6
Economically recoverable resources
Copper 2,100,000t
Molybdenum 9,400t
Gold 96t
Silver 720t
Probability no econ recoverable 0.9
Econ NPV 370x $1M
Exp dollars -3.81x $1M/100,000 sq km
Exp value class Very Low

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
Masurung I prospect Maluku Utara Indonesia Occurrence Details
Masurung II prospect Maluku Utara Indonesia Occurrence Details
Payahe prospect Maluku Utara Indonesia Occurrence Details
Sugili prospect Maluku Utara Indonesia Occurrence Details
Matat prospect Maluku Utara Indonesia Prospect Details
Tobobo prospect Maluku Utara Indonesia Prospect Details
Hulu S prospect Maluku Utara Indonesia Prospect Details
Kaputusan P. Bacan prospect Maluku Utara Indonesia Prospect Details
Kaputusan deposit Maluku Utara Indonesia Unknown Details