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Sierra Pintada Property


Exploration Target

20 - 100 million tonne IOCG type oxide Cu-Au deposit
200 - 300 million tonne porphyry Cu-Au deposit

The Sierra Pintada property, consisting of fourteen exploration claims totaling approximately 3300 hectares, is located in the Chilean Coastal cordilleran copper-gold belt 650 kilometers north of Santiago and is readily accessible from the town of Vallenar 30 km to the east. The property covers a 15 kilometer strike length of a several hundred kilometer long major structure zone along which there are numerous centers of past high grade copper, gold, silver and cobalt mining e.g. Carrizal Alto District passed production approximately 450,000 tonnes of copper and 1.5 million ounces of gold. The high grade copper-gold veins, mantos and stock works previously worked on the Sierra Pintada property are most probably within the Early Cretaceous Metallogenic Belt which includes the Andacollo and Los Mantos de Punitaqui Mines.


All claims are owned 100% by Minera IPBX Limitada, the whole owned Chilean exploration arm of International PBX Ventures Limited.

Geology and Mineralisation
The property covers 15 kilometers of the structural contact between late Paleozoic meta-volcanic and meta-sedimentary rocks which form the Coastal Metamorphic complex to the west and Late Cretaceous diorites to granodiorites of the Franja Central to the east. This NNE trending zone is up to 100 metres wide with northerly trending splays and wherever it emerges from beneath overburden is the center of numerous prospect pits, adits and workings to depths of 50 metres on high grade Cu-Au (Ag, +/- Co) and Au-Cu (Ag) fissure veins from 1-5 metres width. The material previously mined typically graded 3-5% Cu + 1-5 gpt Au for the former and 10-50 gpt Au + 1-5% Cu for the later.

There are at least four mining districts of from 2-4 km strike length occur along the 25 km of strike of the structure zone identifiable south of Freirina. The northern most La Gloria and Totora districts are covered by the Sierra Pintada project claims.

These claims cover two strongly mineralised zones within the main structure zone. The western most Viña zone consist of a 50 - 100 metre wide zone of shearing and brecciation within strongly hematite-clay-limonite +/- quartz altered volcanics and dioritic intrusives with wide spread CuOx mineralisation. This zone has been extensively worked along approximately 1500 m of strike and vertical range of 150 metres. The workings consist of trenches, adits and open cuts from 1-10 metres wide on multi-directional high-grade zones visibly grading 5% or more green copper minerals. The workings concentrate in several high grade cores from 15-20 m wide. At a 2.75 gpcc density this worked section of the core has a tonnage potential of about 10 million metric tonnes. The structure is strong where it heads under pediment gravels in both strike directions. The eastern most Gloria zone is similar in all aspects to the Viña zone with the exception that it shows weak green copper mineralisation in the surface workings which according to local miners are on 'veins' grading 15-30 gpt gold.

Scattered old workings and hematite/clay rich soils indicates that at least the Gloria gold-copper zone probably does continue to the southwest beneath pediment cover to the Totora district were a repeat situation of high grade fissure and shear veins has been worked.

There are no published records of production from the old mines or prior exploration activity. Reconnaissance scale Government geological for the area suggest that most of the mining activity occurred during the 1820's to 1890's i.e. during the main mining period at Carrizal Alto. Hand cobbed ore grading 5-10% copper and 15-50 gpt gold reportedly being shipped to the Carrizal Bajo smelters.

During evaluation and acquisition of the project claims a series of 33 representative chip and dump samples were collected by Minera IPBX Limitada personnel. The results area as follows:
Gloria Zone: Au 1.03 - 5.1 gpt (av. 2.58 gpt.) plus 0.02 - 1.59% Cu (av. 0.36%)
Viña Zone: Cu 0.92 - 8.00% (av. 2.59%) plus 0.12 - 1.82 gpt Au (av. 0.48 gpt)
These results are in line with verbal reports from local miners of shipped grades of 15+ gpt gold from the Gloria Zone and 5%+ copper from the Viña Zone when the hand cobbing reduction ratio of from 3-5:1 is taken in to account. The locals also state that much of the gold was coarse free gold.

As mentioned above in the La Gloria mining district one section of the Viña zone has been worked over a length of 1500 metres and vertical range of at least 150 metres. Considering the two core sections of about 35 metres thickness and average density of 2.75 gpcc, this section alone has an open ended open pit tonnage potential of about 20 million tonnes. In this same district the Gloria zone is exposed for at least 1700 metres and averages about 50 metres wide hence its near surface open pit tonnage potential at this point is also about 20-30 million tonnes.

On a larger scale repeat deposits of similar size may be encountered in the southern Totora district and the overburden areas between the two districts. Also it is possible that these districts are centered above deeper Andacollo style porphyry systems as has been suggested for Carrizal Alto to the north.