Vancouver — Partners Anglo-American (AAUK-Q) and Philex Gold (PGI-V) appear to have intersected a very rare geological event at the Boyongan prospect on the Philippine island of Mindanao. The latest drill holes confirm that the property hosts a copper-gold porphyry which has been overprinted by a high-sulphidation copper-gold event.
“We are very pleased to see the high-grade mineralization repeated,” says Gerard Brimo, Philex’s CEO. “Most of the holes to date have intercepted good-grade mineralization and in a number of instances we have seen exceptional grades.”
Diamond drilling first cut the high-grade core last September, when hole 6 returned an impressive 365-metre intersection grading 0.81% copper and 1.9 grams gold per tonne at the prospect. The latest results continue to yield some very impressive numbers.
Collared 120 metres north of the discovery hole and angled at 85 to the east, hole 13 cut 479 metres of oxide mineralization grading 0.7% copper and 0.94 grams gold per tonne from 85 metres down-hole. Included in this interval was a higher-grade section running 0.98% copper and 1.44 grams gold over 287 metres.
Hole 14 was collared 150 metres north of hole 10 (345 metres grading 0.5% copper and 0.7 grams gold) and inclined at 60 to the north. It cut 388 metres grading 1.07% copper and 2.03 grams gold from 53 metres down-hole. Included in this interval was a section that ran 2.21% copper and 5.11 grams gold over 135 metres.
Driving the higher grades was the occurrence of enargite-bornite veinlets that crosscut the original quartz stockwork. This is a clear indication of a high-sulphidation mineralizing event overprinting an earlier copper porphyry. The base of oxidation was hit at 258 metres down-hole.
Drilled from the same site, but angled at 75 to the south, hole 15 returned 324 metres averaging 1.68% copper and 2.64 grams gold from 61 metres down-hole. Included in this interval was a 187-metre section that ran 2.58% copper and 4.47 grams gold.
“Three drills are being used on the property,” says Brimo. “We expect about 10,000 metres of drilling will be completed this year, which will more accurately define the lateral and vertical extent of the deposit.”
Collared 150 metres west of hole 14, hole 16 is being drilled to the south at an angle of 60. It cut unaltered cover from surface to 175 metres before it hit the mineralized body. From 175 metres to a depth of 420 metres, the hole intersected oxide mineralization (consisting of cuprite, malachite, azurite and limonite) before it hit primary copper mineralization to the current depth of 560 metres.
Hole 17 is being drilled to the south, 150 metres northeast of hole 14. Inclined at a 60 angle, it hit unaltered cover from surface to 108 metres before it intersected a weakly mineralized potassic-altered intrusion breccia to its current depth of 284 metres.
Drilled at the same site as hole 14, hole 18 is being drilled vertically to test the depth extension of the mineralization. This hole hit cover for the first 53 metres. This was followed by strongly altered and mineralized diorite porphyry to the current depth of 73 metres. Anglo-American plans to drill the hole to a depth of 1 km.
Since signing the joint-venture agreement with Philex in September 1999, Anglo-American has outlined four induced-polarization geophysical anomalies on the 5,186-ha project. The company has also initially drill-tested the Bagacay prospect, where the first five holes failed to return any significant mineralization. The major then moved the rig 3 km to the northwest to test for a blind copper-gold porphyry under Quaternary lavas and sediments at Boyongan.
The South African-based major can earn a 40% stake in the North property by spending $2.2 million on exploration over a five-year period. The major can take a 70% interest by completing a bankable feasibility study.
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