An assemblage of Eocene and Oligocene post-subduction igneous rocks in southwest China
Tract ID 142pCu8711
Country China
Commodity Cu
Study area name Tibetan Plateau
Tectonic setting postconvergence
Deposit type porphyry copper
Grade-tonnage model Porphyry copper, Cu-Au subtype (Singer and others, 2008)
Geologic age
Geologic feature age Eocene and Oligocene
Generalized age Tertiary-Paleogene
Oldest rocks age 55.8Ma
Youngest rocks age 23.03Ma
Age range 32.77Ma
Identified Cu resources 490,000metric tons
Known prospects 9
Mean Cu (t/sq km) 269t/sq km
Map scales used 1M

Results of the assessment

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

Estimated number of deposits

Number of deposits Confidence level
2 90%
6 50%
18 10%
18 5%
18 1%
Mean estimated deposits 8.27 ±5.91 (0.72%)
Probability of mean 0.36
Probability of no copper 0.04

Estimated deposit density

(sq km)
Deposit density
per 100,000 sq km
2 10.27 96,670 11

Mean estimated tonnage

Copper 26,000,000
Molybdenum 150,000
Gold 1,900
Silver 8,600
Ore 5,200

Undiscovered copper resource

Confidence level 95% 90% 50% 10% 5%
Tonnage 200,000 1,300,000 15,000,000 64,000,000 87,000,000

Economic analysis

Fraser country China and Vietnam*
Fraser type 0.18%
Fraser high 0.82%
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 12,000,000t
Molybdenum 53,000t
Gold 620t
Silver 4,100t
Probability no econ recoverable 0.32
Econ NPV 2,400x $1M
Exp dollars 17.85x $1M/100,000 sq km
Exp value class Medium

Bibliographic references

General Ludington, Hammarstrom, and others (2012)
Economic Robinson and Menzie (2012)

Deposits and prospects associated with this tract

Name Type State Country Development Details
Machangqing deposit Yunnan China Prospect Details
Xifanping deposit Yunnan China Prospect Details
Wangdongshan-Hongnitang prospect Yunnan China Prospect Details
Xiaolongtan prospect Yunnan China Prospect Details
Liufang prospect Yunnan China Prospect Details
Habo prospect Yunnan China Prospect Details
Changpingchong prospect Yunnan China Prospect Details
Tongchang prospect Yunnan China Prospect Details