Southern California Batholith

Jurassic-Early Cretaceous island arc(s) of western Baja California, including the western part of the Cretaceous Peninsular Ranges batholith and associated volcanic rocks
Tract ID 003pCu3001x
Country Mexico-United States of America
Commodity Cu
Study area name Mexico and US revised
Tectonic setting island arc
Deposit type porphyry copper
Grade-tonnage model General porphyry copper model (Singer and others, 2008)
Geologic age
Geologic feature age Jurassic
Generalized age Mesozoic
Oldest rocks age 199.6Ma
Youngest rocks age 145.5Ma
Age range 54.1Ma
Identified Cu resources 5,300,000metric tons
Known prospects 1
Mean Cu (t/sq km) 82t/sq km
Map scales used 500K

Results of the assessment

Assessment date 2008
Estimators Francisco Cendejas-Cruz, Enrique Espinosa, Floyd Gray, Jane M. Hammarstrom, Steve Ludington, Gilpin R. Robinson, Jr., Efren Pérez-Segura, Martín Valencia-Morena, José Luis Rodríguez-Castañeda, Lukas Zürcher
Assessment depth 1km
Quantitative assessment Yes

Estimated number of deposits

Number of deposits Confidence level
2 10%
5 5%
7 1%
Mean estimated deposits 0.89 ±1.71 (1.94%)
Probability of mean 0.18
Probability of no copper 0.6

Estimated deposit density

(sq km)
Deposit density
per 100,000 sq km
1 1.89 40,240 5

Mean estimated tonnage

Copper 3,300,000
Molybdenum 91,000
Gold 82
Silver 960
Ore 670

Undiscovered copper resource

Confidence level 10% 5%
Tonnage 8,100,000 17,000,000

Economic analysis

Fraser country Mexico
Fraser type 0.68%
Fraser high 0.32%
Typical cost 1%
High cost 0%
Infrastructure setting Typical
Comments on depth 40% cover; skew shallow
Expected depth distribution
0 - 250m 0.35
250m - 500m 0.25
500m - 1km 0.4
Economically recoverable resources
Copper 2,300,000t
Molybdenum 45,000t
Gold 45t
Silver 600t
Probability no econ recoverable 0.87
Econ NPV 690x $1M
Exp dollars 2.67x $1M/100,000 sq km
Exp value class Low

Bibliographic references

General Hammarstrom and others (2010) and U.S. Geological Survey National Mineral Resource Assessment Team (2002)
Economic Robinson and Menzie (2012)

Deposits and prospects associated with this tract

Name Type State Country Development Details
Arco Sur prospect Baja California Sur Mexico Occurrence Details
El Arco deposit Baja California Mexico Prospect Details