The Peña Blanca-001 mining concession (code: 030023706) has a surface area of 700 hectares and it is located in the Piura Department, northern Peru (Fig. 1). This concession is also part of the Celica-Lancones basin, a major mining structural belt located in the north-west of Peru and south of Ecuador. The basin hosts major World class deposits as observed in Fig. 1
The Lancones basin is a belt (90x50 Km) that runs with NE trending; it is located to the northwest of the Peruvian territory, Department of Piura, but also part of Ecuadorian territory called Celica basin in the Loja Province. The magmatic evolution model of the Lancones basin was originated from a "rift" with NNE - SSO orientation under an extensional regime in the middle Jurassic until a marginal basin, product of the separation between Gondwana and Laurasia (Tegart et al., 2000; Ríos 2004). The deformation style of the Lancones basin consists on block tectonics. The E-W fault systems represent the main lineation which limits the Lancones basin as part of the Jubones-Huaypira structural domain in the Huancabamba deflection. In the Upper Cretaceous there are multiple plutonic and sub-volcanic intrusions which gave origin to a magmatic-hydrothermal belt of porphyry copper, skarns and polymetallic veins deposits. In late stages high and low sulphidation epithermal systems were emplaced, especially to the north of the basin. There are five metallogenic provinces: (1) copper-zinc-gold related volcanogenic massive sulphides; (2) lead, zinc and copper related volcanogenic massive sulphides; (3) copper and molybdenum porphyry style mineralization; (4) Iron skarn mineralization; and (5) gold and silver epithermal deposits. They have different lithological, structural and metallogenic characteristics. Three metallogenic events have been identified: (1) An Upper Jurassic – Lower Cretaceous event that corresponds to the Cu-Zn-Au Tambogrande Volcanogenic Massive Sulphide giant deposit, hosted in volcanic sequences of tholeitic affinity of the Ereo Formation; (2) A Cenomanian event, Pb-Zn-Cu Kuroko type Volcanogenic Massive Sulphides hosted in volcano-sedimentary sequences of the La Bocana Formation; and, (3) An Upper Cretaceous (Campanian) event Cu-Mo porphyry style mineralization, iron skarn mineralization and Au-Ag epithermal deposits. Cretaceous-Paleocene intrusions are believed to be responsible for late phases of mineralization.
Access to the area and infrastructure is very acceptable. The zone is crossed by the paved Panamerican high way that joints Peru and Ecuador. The town of Las Lomas (10,000 inhabitants) is located in the area of influence and it counts with the basic services such as local transportation, hotels, banks, phone service, restaurants, gas station, workers, etc. Topography is quite flat with an average elevation of 240 m.a.s.l. Weather is dry subtropical with average temperature of about 19°C. The zone counts with dendritic drainage system and good electrical supply.
This project is located on the west side of the Jurassic-Cretaceous rift developed structure. It is located to the north of the copper-molybdenum+/-gold La Cantera (Chancadora porphyry) and to the south of the Lagartos porphyry (Fig. 1).
The geology of the property corresponds to two lithologies, the first is widespread chloritized outcrops (fresh and weathered) of volcanic rocks (Bocana Formation) such as porphyritic andesitic lavas and tuffs. These rocks also show pervasive chlorite and locally epidote +/- calcite (propylitic hydrothermal alteration). The second corresponds to intermediate to acid coarse grained intrusive showing stockwork development with pervasive phyllic alteration superimposed by argillic and advance argillic hydrothermal alterations.
Northeast-Southwest and Northwest-Southeast structural control have been identified in the zone. These lineaments are controlling the mineralization emplacement as it can be seen in Fig. 3
In 2008 a mining company called Andean carried out a surface geochemical recognition. The result of this short study yielded 17 rock samples (chip and channel). Three samples came from quartz-molybdenite-chalcopyrite veins with thickness ranging 10 and 40 cm. The other fourteen samples were taken in stockwork outcrops with phyllic alteration. Assay results range 33.8 – 383.5 ppm Mo and 0.023 – 0.042 % Cu. Considering that surface rocks shows propylitic and phyllic hydrothermal alterations, it is inferred that mining potential could remain at depth. There are no additional records from other mining companies exploring this property.
In 2013 Gorgona Gold S.A.C. carried out its own exploration works consisting in geological mapping, structural mapping, mapping of hydrothermal alterations and rock geochemistry. The results yielded the discovery of a stockwork system (quartz veinlets extending for about 400 m in length) at UTM coordinates PSAD56 (561235, 9476035) with pervasive phyllic hydrothermal alteration. At UTM coord. PSAD56 (561900, 9465750) a conspicuous outcrop of quartz-molydenite B type veins was observed. Aditionally some porphyry related D type veins were also observed. These porphyry related veining systems let us to infer the existence of a copper-molybdenum+/-gold porphyry deposit. The outcrops rock geochemistry yielded values up to 0.33% Mo, 0.17% Cu, and 0.01 g/t Au in the surface phyllic altered studied rocks.