Usa Copper Prospect


Figure 1: Tenement location map showing the mines and prospects
View enlargement

usa_geo_1006-l
Figure 2: Detailed geology and geochemistry contours showing >700 ppm copper and >0.1 g/t gold
View enlargement

usa_mag_1006-l
Figure 3: Aeromagnetic image showing the first vertical derivative and the geochemistry contours showing >700ppm
copper and >0.1 g/t gold
View enlargement

Usa Copper Prospect

The Usa Copper prospect is predominantly contained within Mineral Production Sharing Agreement application (“APSA”) XIII-00077.

There are indications that the prospect extends eastwards into APSA XIII-00098 which is owned by Mindanao Philcord Mining Corporation which will receive a 1% Net Profits Interest from any production.

Figure 1 shows the Usa prospect location. Figure 2 shows the detailed geology and geochemistry contours and Figure 3 shows an aeromagnetic image overlain by the geochemistry contours.

The Usa prospect is located adjacent to the west side of the Barobo Fault corridor. This fault is parallel to the Philippine Rift Fault located approximately 30 kilometres to the west of the Usa prospect. The Barobo Fault corridor has numerous gold prospects already located along or adjacent to it, including Guinhalinan, Umbon, Matanog, Alikway and Saguisilan.

The Company interprets the Barobo Fault corridor as being prospective for intrusive and structurally controlled styles of copper and gold mineralisation. An old grey limestone and calcareous sedimentary sequence is intruded by multiple phases of dacite, diorite, and andesite porphyry.

Styles of mineralisation exposed along the corridor include pyrite and base metal sulphide bearing hydrothermal and tectonic breccias; skarn related magnetite, pyrite, base metal sulphide and gold bearing veins; pyrite, base metal sulphide gold bearing quartz-carbonate veins and vein breccias; and disseminated, fracture controlled pyrite and base metal sulphide in intrusive bodies and surrounding host rocks. Skarn related magnetite, pyrite, copper and gold mineralisation are also noted.
 

Local Geology and Mineralisation

The geology consists of a mineralised and altered diorite complex which is intruding andesitic volcanics, older limestone and calcareous sediments. The setting and style of mineralisation are very similar to that at the Kamarangan copper-molybdenum porphyry prospect to the north where chalcopyrite and magnetite bearing diorite was intersected over several hundred metres in two holes during a scout diamond drilling completed in late 2008 to early 2009 (see announcement dated 29 May 2009).

The fine- to medium-grained diorite is variably but strongly phyllic altered (white clay, sericite and pyrite) with variably dispersed hairline veinlets of fine-grained magnetite. Chlorite alteration is rare proximal to the diorite, but increases to moderate intensity in volcanic units distal to the diorite. North east trending fractures and veinlets within and on the edges of the diorite are often lined with fine-grained pyrite and magnetite. The diorite has variably distributed weak pervasive grey silica alteration, and is locally stockwork veined with fine 2 to 3 mm thick clear and grey quartz veins; the veins often have fine-grained pyrite, magnetite and occasional bornite disseminated along the selvages.

Mineralisation is predominantly pyrite occurring as fracture filling grains disseminated grains and vein infill. The pyrite is accompanied with bornite, and with occasional chalcopyrite. Malachite stained limestone and calcareous sediments with sphalerite, pyrite and bornite veins, and weakly mineralised pyrite and chalcopyrite magnetite have been noted in drainage float samples to the north of the diorite.

Contouring of the rock chip copper results (>700 ppm Cu) and gold results (>0.1 g/t Au) are shown on Figure 2. The gold and copper contours are in close spatial proximity. The anomalous copper and gold values also overlie three magnetic high features, visible in the 1st vertical derivative of airborne magnetic data shown on Figure 3. The magnetic features appear to reflect zones of strong magnetite alteration in the diorite.

The relationship of the diorite body to the surrounding rocks suggests that it has been recently uncovered and may not be deeply eroded.

Artisanal mining activity is common in the drainages overlying and downstream of the mineralized altered diorite. Less active artisanal mining activity is noted to the north where chlorite and clay altered, sulphide veined andesitic units occur.