Ongoing chip sampling is enabling
The program is aimed at expanding the Northeast, Central and South prospects. The company recently collected 746 additional continuous chip samples, targeting a 250-metre-wide, north-to-northeasterly trending mineralized structural corridor that extends over a strike length of 1,850 metres. To date, Pacific Rim has collected 5,502 samples, the average grade of which is 1.56 grams gold per tonne.
“We have made great progress toward our objective of eliminating as much risk as possible, as quickly as possible, on our Luicho project,” says Pacific Rim’s CEO, Thomas Shrake.
The 10-sq.-km property, 540 km southeast of Lima, represents a low-sulphidation epithermal prospect. Hosted in sandstone, the mineralization occurs as stockwork quartz veining below an impermeable shale unit. An independent petrographic report has concluded that the gold is hosted in late-stage fracture fillings as free grains associated with quartz and iron oxides.
The corridor is related to a complex series of converging north-southerly and northeast-southwesterly trending right-lateral slip faults. The faults have produced a large, fractured and brecciated zone.
At the Northeast zone, 948 chip samples have been collected over a 700-by-400-metre area. They returned an average of 1.19 grams gold, with 67% exceeding 0.31 gram gold at an average grade of 1.71 grams gold. The zone remains open to the north.
A total of 1,812 chip samples was collected over the 550-by-250-metre Central zone. These returned an average of 3.27 grams gold, with 71% exceeding the 0.31-gram mark. The average grade was 4.52 grams gold.
At the Southeast zone, 602 chip samples were collected over an area measuring 650 by 250 metres. The average grade was 1.34 grams gold, with 53% exceeding 0.31 gram gold, returning an average grade of 2.38 grams gold.
The recent sampling included the underground sampling from 16-year-old tunnels that extend for 5 to 30 metres on the western slope prospect. The weighted average of the tunnel samples, which represent a total combined length of 258 metres, is 7.35 grams gold.
“Sampling tunnels has indicated a strong correlation between surface and underground mineralization,” Shrake says.
The company has also collected and shipped 500 kg of underground rock samples, which will be subjected to metallurgical tests. Initial procedures will include bottle-roll tests to narrow down an optimal crush size range. The company plans to conduct narrow-diameter column leach tests on a larger bulk sample.
Pacific Rim is completing a geological and structural map in anticipation of a 12,000-metre program of reverse-circulation drilling, scheduled for the spring.
The company will continue with cliff chip sampling and underground rock channel sampling of old tunnels. Construction has started on a 6.5-km access road in preparation for the drilling.
Pacific Rim acquired the property in October 1999 by agreeing to certain exploration expenditures over the first two years and making a cash payment of US$24.2 million after the third year. At production, a maximum 3% royalty will be payable to the vendor, a private Peruvian company.
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