The Cañariaco Project comprises a total area of 10,189.50 ha in 15 concessions. Three porphyry copper targets, Cañariaco Norte, Cañariaco Sur, and Quebrada Verde, have been identified. Candente Copper, through its Peruvian subsidiary Cañariaco Copper Perú S.A (CCPSA), and others holds a 100% interest in the Cañariaco Project.
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Summary:
The Cañariaco Norte and Cañariaco Sur deposits are considered to be examples of porphyry-copper systems. The Cañariaco Norte deposit is a large, near surface, bulk mineable porphyry copper deposit located in the Lambeyeque region of northern Peru.
The Cañariaco Norte deposit is hosted within a multiphase intrusive–breccia complex approximately 1.7 km in strike extent and 1.1 km wide. The deposit has been drill-tested to a depth of approximately 770 m and remains open at depth. The majority of the copper–gold mineralization is hosted within the intrusive and breccia units, but locally extends for variable distances into the enclosing volcanic units. Intrusive units comprise approximately 55 to 60% of the deposit, breccias approximately 30 to 35%, and pre-mineral volcanic rocks approximately 5 to 10%.
The intrusive units are nested and collectively roughly oval in shape, with older intrusive rocks being cut by successively younger intrusive bodies. In general, the intrusive units are north–south-trending, steeply-dipping bodies. The breccia units cut the intrusive units, are oval to circular in shape, and are steeply plunging. The dykes generally strike northwest–southeast with a steep southwesterly dip. The shape and positioning of the intrusive, breccias, and dyke units was largely controlled by northwest–southeast- and northeast–southwest-trending faults (Casselman et al., 2008).
In general, the highest copper grades (>0.5% Cu) occur in the biotite–feldspar porphyry and polymictic breccia units. Intermediate copper grades (0.35 to 0.5% Cu) are most common in the hydrothermal breccia and the coarse quartz porphyry, and the lowest grades (0.2 to 0.35% Cu) are found in the crowded quartz feldspar porphyry, tourmaline breccias, and volcanic host rocks. The feldspar porphyry dykes typically do not contain copper grades unless the dykes have been fractured, brecciated, or cracklebrecciated near the south margin of the hydrothermal breccia, where they have been weakly mineralized (average copper grade range of 0.1 to 0.2% Cu).
The Cañariaco Sur deposit is at an earlier stage of exploration than Cañariaco Norte. Fifteen holes were drilled into Cañariaco Sur and although it is only partially drilled off it is understood to be a simpler porphyry system than Cañariaco Norte. Cañariaco Sur lacks the later stage brecciation event that introduced arsenic into Cañariaco Norte and does not have the other breccias that complicated the copper grade controls at Cañariaco Norte.
Cañariaco Sur also has a higher gold content than Cañariaco Norte. The Cañariaco Sur deposit is located approximately 2 km southwest of Cañariaco Norte. The deposit consists of a large area of potassic alteration with a coincident copper–gold–molybdenum soil geochemical anomaly with approximate dimensions of 1,400 x 900 m. A large, coincident magnetic high, IP/resistivity low, and chargeability high was identified coincident with the soil geochemical anomaly and area of potassic alteration. Candente Copper has interpreted the prospect as a porphyry-copper-gold centre dominated by potassic alteration with chalcopyrite–bornite–molybdenite mineralization and anomalous copper–gold–molybdenum grades.
The host rocks to the mineralized intrusions are Calipuy Group andesite volcanic rocks. Two main intrusions were noted from geological mapping, an early 750 x 500 m quartz monzonite stock, and a later diorite stock with an area of approximately 100 x 50 m. A third intrusive phase may also exist (Stillitoe, 1999).
Mineralization at Cañariaco Sur is predominantly chalcopyrite and bornite with minor pyrite. The depth of oxidation averages 40 m to 50 m and contains copper oxides in the form of copper wads. Meter-scale supergene enrichment is present in some drillholes.
Quebrada Verde Prospect
The Quebrada Verde prospect is 3.2 km south of Cañariaco Norte and 1.5 km south of Cañariaco Sur. Strongly anomalous levels of copper and gold in soil samples cover an area of 0.7 x 0.9 km. A large IP chargeability high centred on a resistivity anomaly and magnetic high, and covering an area of 0.8 x 2.0 km, occurs coincident with the soil geochemical anomalies. Candente Copper staff have interpreted the prospect as a porphyry copper–gold centre. The one historic drill hole did not test the geochemical/geophysical target.
Quebrada Verde host rocks consist of a 1 km x 750 m diorite porphyry stock that intruded Calipuy Group andesite volcanic rocks (Wilson, 1999). A satellite stock of the same diorite porphyry measuring 400 m x 400 m is located 200 m to the northeast. An east–west striking, post-mineralization granodiorite dyke, with dimensions of approximately 1 km x 100 m, intruded the volcanic rocks and the larger diorite porphyry stock.