Cajamarca - Regional Overview


Northern Peru - Ecuador Copper - Gold Belt
[Click to Enlarge]Cajamarca region hosts the largest gold mine in South America: Yanacocha, with some 36 million ounces of gold hosted in Miocene-age volcanic rocks. In addition to several other significant epithermal gold deposits, there are also several large porphyry Au-Cu and Cu-Mo deposits of the same age stretching across the region and north into Ecuador, which are called the Northern Peru Cu-Au Porphyry Belt.

The Deborah property (formerly 'La Luminosa') is located in southern Cajamarca region, only one hour east of the city of Cajamarca and with good access via paved and dirt roads. There are several significant deposits nearby: the property is 6 km northeast of the Michiquillay Cu-Au-Mo porphyry deposit (631MT of 0.69% Cu, 0.15 g/t Au, and 0.02% Mo), 6 km southeast of El Galeno porphyry Cu-Au deposit (661MT of 0.50% Cu, 0.12g/t Au, 0.013% Mo), and 12 km southeast of Minas Conga (618MT of 0.3% Cu and 0.8 g/t Au). The geology between all these deposits is similar, with mineralization related to Miocene dacite porphyry stocks intruding Lower to Upper Cretaceous carbonate and sandstone units.

Deborah

Exploration History


Deborah Project - Location and Geology
[Click to Enlarge]There are numerous adits and related dumps on the Deborah property developed over the last 100 years by informal miners, mostly targeting auriferous pyrite-tenantite-chalcocite, and to a lesser extent carboniferous pyrite, occurring as mantos in the nearly vertical, thick-bedded quartzite. Massive pyrite pods within a tectonic breccia in the northeast corner of the concession were also worked. Silver grades are also significant, averaging roughly 10:1 Ag to Au.

Deborah was first formally explored by Newmont Peru in 1992, focusing on the sulphide-bearing breccia target known as the Punrre zone, after the ridge of the same name that connects El Galeno and Deborah. In 1993 they shifted focus north to explore the gold breccias of Hilorico and El Galeno located five kilometres to the northwest, and then returned to Deborah in 2006 to drill 13 holes on the breccias at Deborah, and at least four holes adjacent to the property.

Geology and Mineralization


Deborah Project
[Click to Enlarge]Thick-bedded to massive, densely siliceous quartzite of the Late Jurassic Chicama Formation and/or Lower Cretaceous Chimu Formation is intruded by hornblende granodiorite and dacite porphyry, the latter of which forms a large central stock on the property that weathers slightly more recessively than the resistive quartzite. The intrusions are not mineralized and only weakly argillic in minor fracture zones. Carbonate of the Santa Formation is present in the northeast corner of the concession, apparently in fault contact across a 1-5m wide pyrite-bearing breccia. These units are the same as those hosting mineralization at El Galeno 6km to the northwest, and Michiquillay 12 km to the southwest. The gold breccia at Hilorico, 1 km northeast of Galeno on the adjacent El Molino concession may be the closest analogue to Deborah. At Hilorico, Northern Peru Copper completed about 13,000 metres of drilling by the end of 2007, defining resources of 19.4MT at 0.65 g/t Au and 3.3 g/t Ag in oxides, and 21.3MT at 0.93 g/t Au and 4.8 g/t Ag in sulphides. Northern Peru Copper was bought by China's Minmetals in early 2008.

Gold and silver assay results from Newmont's drilling at Deborah include 51.35m of 0.51 g/t Au and 3.45 g/t Ag, and 44.0 m at 0.73 g/t Au and 12.28 g/t Ag in hole DEB-003, and 47.75m of 0.59 g/t Au and 18.0 g/t Ag in hole DEB-004. Higher grade intersections include 9.2m of 1.26 g/t Au and 2.58 g/t Ag in hole DEB-002 and 4.05m of 1.3 g/t Au and 43.0 g/t Ag in hole DEB-005A. These holes appear to have targeted breccia in quartzite adjacent to the sulphide veins in the southwest corner of the concession, where surface channel samples across outcrops returned the best results.

Exploration Potential


Deborah Project - Cross Section
[Click to Enlarge]The 13 holes drilled by Newmont are concentrated in the area of historic workings, and appear to have targeted the down dip extension of the near-vertical mantos sulphides and related SE trending breccia which host Au-Ag along the western edge of the concession. None were drilled under the much larger recessive zone northeast of the main quartzite hill, and neither was the area covered in the surface rock sampling as it is largely till covered. Part of this area was mapped as dacite porphyry, though it is much more recessive than the dacite porphyry to the south.

Mineralization at the Galeno porphyry deposit is also recessive and forms a low area in the surrounding resistive quartzite. The central recessive zone at Deborah is therefore considered most prospective area, as this is where highly fractured and mineralized zones would be. The recessive zone is in fact on strike with the tectonic breccia related to the regional Punrre fault, which connects Deborah with the Hilorico gold-breccia target east of Galeno, and may represent a splay of the structure. Also, the carbonate could be an important unit in terms of hosting disseminated mineralization in permeable (decalcified) sandy horizons along strike and adjacent to the mineralized breccia. This target has yet to be drill tested.

Work Plan

Work can start immediately on the property as a significant portion of the surface rights is owned by one of the concession holders. In addition to remapping, the property will be resampled from corner to corner with both soil and rock grids, since very little of the historic surface data is available. The recessive area between the two groups of drill holes will be mapped first to determine the depth of overburden and, if it is less than a few metres, trenches and pits will be dug in the area to sample bedrock.