MINING NEWS: Spring drilling for diamonds at Shulin Lake property completed

Patricia Liles

Mining News editor

Calgary-based Golconda Resources Ltd., operator of the Shulin Lake diamond exploration joint venture, has concluded a spring drilling program conducted in March at the Southcentral Alaska property.

About 25 miles due west of the Parks Highway and about 80 miles north of Anchorage, the Shulin Lake project is targeting a volcanic occurrence that has previously yielded micro-diamonds and diamond indicator minerals. It’s the first known discovery of diamonds from a bedrock source in Alaska, according to joint venture partner Shear Minerals.

Golconda conducted drilling this March, although no results or detailed information about that work was available from the company. According to a Feb. 4 press release, the joint venture planned to drill 10 holes for a total of 3,000 feet to test different areas of a circular structure, visible on a satellite photo of the property.

Winter drilling involves access from Trapper Creek, involving traveling about 10 miles by winter trails, according to Kevin Adler, vice president of On-Line Exploration Services, an Anchorage-based geological consultant on the property since 1999.

Drilling work depends on “how long the snow lasts,” Adler told Mining News in mid-March. In September 2003, the joint venture drilled two holes into the circular structure, which has a diameter of about two kilometers, according to Golconda’s press release.

The holes intersected a volcanic sequence of sandy tuffs and fine ash, “indicating that this feature is most likely a volcanic center and the source of the diamond indicator minerals and micro-diamonds found in earlier programs,” the press release said. Indicator minerals show a chemical composition similar to eclogitic minerals found in lamproitic environments elsewhere, the release said.

Placer miners prospecting for gold initially discovered the diamond indicator minerals, according to Adler and to property information on Shear Minerals’ website.

Core drilling in the spring of 2002 yielded samples that contained 15 micro-diamonds, less than 0.5 millimeter in one direction with a minimum of 0.1 millimeter in one dimension. A macro-diamond, measuring 0.71 by 0.57 by 0.47 millimeters was also found, in the same hole, at a depth of 574 to 609 feet, according to Shear.

The micro-diamonds were characterized by consultant Lakefield Research as generally being white, transparent, mostly fragments, some with crystal faces, frosted surfaces and graphic coatings.