Sun shines brightly over Pirquitas silver play

In northwestern Argentina, Sunshine Mining & Refining (SSC-N) will double its efforts at the Pirquitas silver deposit for the second half of the year.

The company spent US$1.3 million on drilling, assaying and dewatering the underground workings during the first half of 1996. A total of 14,300 ft. of RC drilling, as well as nearly 3,000 ft. of core drilling, were completed, allowing the company to establish a resource of 47.5 million tons grading 6.5 oz. silver per ton and 0.49% tin.

Sunshine plans to spend another US$2.8 million — more than twice the amount spent in the first part of the year — on an expanded program of drilling and metallurgical testing. Before the year is over, the company will conduct another 25,000 ft. of core drilling, as well as 34,000 ft. of RC drilling.

The increased density of the drilling is meant to upgrade the deposit into the proven and probable category. Additional stepout drilling, to proceed in 1997, is planned to expand the size of the resource.

Dewatering has exposed the deposit to below the third level, and is expected to be completed by the end of August. Metallurgical testwork is expected to be complete by the end of the third quarter. Sunshine expects to make a development decision and proceed with a bankable feasibility study by late this year or early 1997.

Also in Argentina, the company has expanded the size of the epithermal gold system at the Cerro Choique gold property in Rio Negro province. Trenching has indicated the dimensions of the system are 2,600 by 6,600 ft. The system is characterized by stockworks, quartz veins and hydrothermal breccias within volcanics.

Meanwhile, in the southern province of Chubut, Sunshine has terminated its 50% interest option on the Huemules gold property. Although the company identified a 400,000-oz. gold resource there, the property did not meet the company’s minimum requirements for further exploration.

Back in the U.S., Sunshine has entered into a joint-venture agreement to explore and develop the Grizzly Bear property near Ouray, Colo. The company believes the high-grade gold-silver mine has the potential for significant mineralization in an unexplored vein system. Sunshine can obtain a half interest in the property by spending US$5 million over the next five years.