Drilling at Mindoro Resources Calo prospect within the compay"s Batangas project on Luzon Island in the Philippines has encountered porphyry-related alteration.

The results of the first two reconnaissance drill holes encountered hydrothermal alteration, consistent with the outer pyritic halo of a porphyry copper-gold system. A third hole, a further 2km distance from the first two holes, is starting and is targeting an area of advanced argillic alteration, with associated copper showings.

Due to the very large size of the target, this initial program of 3500 metres in six drill holes will be widely-spaced; up to two kilometres apart.

Mindoro president Tony Climie says: "We are pleased with these results, as the first two holes ever drilled into Calo, and 2km apart, both encountered porphyry-related alteration.

"These results support our surface indications of a large porphyry copper-gold system. We will continue our program of wide spaced drilling with the objective of vectoring into the mineralization centres."

One hole was drilled in the southern part of the target and intersected loosely consolidated young cover sediments and pyroclastic materials from collar to 162 metres depth. Volcanic breccias, flows and tuffs were then intersected to hole bottom at 502 metres. Zones of opaline silicification, pyritization and clay alteration were encountered, with intensity of hydrothermal alteration increasing with depth. Pyrite content (up to 15%) and fracture frequency both increase towards hole bottom. Anomalous zinc (to 960 parts per million) and copper (to 200 parts per million), gold and arsenic are associated with the pyritic zones. The hole was terminated prematurely due to operational problems.

The second hole was drilled 2km to the north. It intersected volcanic breccias, flow and tuffs, with zones of opaline and chalcedonic silica alteration, chloritization and barite. Sericite alteration occurs in structural zones. Geochemical results have not yet been received.

The alteration is strongest in the more permeable volcanics units, indicating lateral flow of hydrothermal fluids. The opaline and chalcedonic silica and barite are interpreted to be associated with epithermal mineralization events, both low and high sulphidation, which frequently overprint porphyry copper-gold systems in the Philippines. The high temperature sericite alteration in this hole is interpreted as porphyry-related. The high pyrite contents are consistent with the outer pyrite halo associated with porphyry copper-gold systems.

A third hole is starting in a further two kilometre step-out and will be drilled in an area of advanced argillic alteration on the western part of Calo. Copper and copper-gold showings are associated with the argillic alteration, and skarn copper mineralization was located nearby in newly acquired ground not yet covered by geophysical (IP) surveys.

Mindoro's Batangas projects covers more than 30,000 hectares in a well-mineralized copper-gold belt and include the Kay Tanda epithermal gold-silver prospect, where resource delineation is in progress, and the promising Calo, El Paso and Archangel porphyry copper-gold prospects, each with multiple targets. Phelps Dodge's (now Freeport McMoRan) Taysan porphyry copper-gold deposit is approximately 9km north of Calo.