Peru-Ecuador middle–late Miocene La Granja

Assorted middle to late Miocene mainly calc-alkaline plutons.
Tract ID 005pCu1006
Country Ecuador-Peru
Commodity Cu
Study area name Andes
Tectonic setting continental margin
Deposit type porphyry copper
Grade-tonnage model General porphyry copper model (Singer and others, 2005)
Geologic age
Geologic feature age middle-late Miocene
Generalized age Tertiary-Neogene
Oldest rocks age 16Ma
Youngest rocks age 5.3Ma
Age range 10.7Ma
Identified Cu resources 54,000,000metric tons
Known prospects 5
Mean Cu (t/sq km) 921t/sq km
Map scales used 1M

Results of the assessment

Assessment date 2005
Estimators Carlos Mario Celada, Vladimir I. Berger, Charles G. Cunningham, Alejandro Diaz, Mariano Gajardo M., Carlos Portigliati, Alvaro Puig Godoy, Donald A. Singer, David M. Sutphin, Waldo Vivallo S., and Eduardo O. Zappettini
Assessment depth 1km
Quantitative assessment Yes

Estimated number of deposits

Number of deposits Confidence level
8 90%
13 50%
25 10%
25 5%
25 1%
Mean estimated deposits 14.56 ±6.49 (0.45%)
Probability of mean 0.38
Probability of no copper 0.01

Estimated deposit density

(sq km)
Deposit density
per 100,000 sq km
12 26.56 53,190 50

Mean estimated tonnage

Copper 49,000,000
Molybdenum 1,200,000
Gold 1,200
Silver 16,000
Ore 9,700,000,000

Undiscovered copper resource

Confidence level 95% 90% 50% 10% 5%
Tonnage 5,800,000 11,000,000 39,000,000 100,000,000 130,000,000

Economic analysis

Fraser country Peru*
Fraser type 0.44%
Fraser high 0.56%
Typical cost 0.27%
High cost 0.73%
Infrastructure setting Mixed
Comments on depth 70-90% cover; skew deep; lots of Pliocene cover
Expected depth distribution
0 - 250m 0.1
250m - 500m 0.3
500m - 1km 0.6
Economically recoverable resources
Copper 24,000,000t
Molybdenum 440,000t
Gold 380t
Silver 7,600t
Probability no econ recoverable 0.12
Econ NPV 5,100x $1M
Exp dollars 87.55x $1M/100,000 sq km
Exp value class High

Bibliographic references

General Cunningham and others (2008)
Economic Robinson and Menzie (2012)

Deposits and prospects associated with this tract

Name Type State Country Development Details
Alto Dorado prospect La Libertad Peru Occurrence Details
Cañariaco deposit Lambayeque Peru Prospect Details
Cerro Corona deposit Cajamarca Peru Occurrence Details
El Galeno deposit Cajamarca Peru Prospect Details
La Granja deposit Cajamarca Peru Prospect Details
La Vega prospect Cajamarca Peru Prospect Details
Laguna Chamis prospect Cajamarca Peru Occurrence Details
Magistral deposit Ancash Peru Prospect Details
Michiquillay deposit Cajamarca Peru Prospect Details
Minas Conga deposit Cajamarca Peru Prospect Details
Paramo prospect Cajamarca Peru Prospect Details
Pashpap deposit Ancash Peru Prospect Details
Puy-Puy prospect Junín Peru Occurrence Details
Rio Blanco deposit Piura Peru Prospect Details
Tantahuatay deposit Cajamarca Peru Prospect Details
Toromocho deposit Junín Peru Prospect Details
Aguila deposit Ancash Peru Producer Details