North of 60 Mining News - The mining newspaper for Alaska and Canada's North

White Rock Minerals Ltd. Aug. 1 reported that its reconnaissance exploration has identified several new volcanogenic massive sulfide prospects across its 35,300-acre Red Mountain property in Interior Alaska. The most exciting of these discoveries is Hunter, where a two-foot massive sulfide outcrop rich in sphalerite (zinc mineralization) and galena (lead mineralization) has been discovered.

White Rock Minerals said the massive sulfide discovered at Hunter extends for more than 500 meters along strike and is hosted within a graphitic schist that can be traced over 1,000 meters.

Portable XRF (X-ray fluorescence analysis) of soil samples returned up to 24.3 percent zinc, 2.4 percent lead, 1.5 percent copper and 249 grams per metric ton silver. Rock chip assays from the VMS outcrop at Hunter are pending.

On-ground geological reconnaissance that has been ongoing since late-May has identified several exploration targets adjacent to the two known deposits of zinc-rich VMS mineralization at Red Mountain – Dry Creek and West Tundra Flats – and four new prospects along a 10,000-meter east-west trend south of Dry Creek – Megan's Draw, Ram, South Platypus and Hunter.

Last year, Australia-based White Rock commissioned a resource calculation for Dry Creek and West Tundra Flats that meets modern reporting standards.

This maiden Australian Joint Ore Reserves Committee- (JORC) compliant calculation outlined 16.7 million metric tons of inferred resource averaging 4.1 percent (1.49 billion pounds) zinc; 1.7 percent (630 million lb) lead; 0.2 percent (57.3 million lb) copper; 99 grams per metric ton (53.5 million oz) silver; and 0.7 g/t (352,000 oz) gold.

This year's drilling has continued to cut high-grade VMS mineralization at both deposits, such as 3.45 meters averaging 15.1 percent zinc, 6.7 percent lead, 518 g/t silver, 2.1 g/t gold and 0.2 percent copper, or 35.2 percent zinc-equivalent in hole WT18-28 at WTF; and 4.8 percent zinc, 2.3 percent lead, 1,435 g/t (46.1 oz/t) silver, 2.2 g/t gold and 0.5 percent copper, or 43.2 percent zinc-equivalent in hole DC18-77 at Dry Creek.

"While a lot of focus and interest is on the diamond drilling we are doing, the background work by the reconnaissance mapping and geochemical sampling crew is key to our next discovery," said White Rock CEO Matt Gill. "To date, this crew has mapped some 30 square kilometers of terrain on foot (out of our 143-square-kilometer tenement package) and taken over 1,000 soil and rock samples."

The reconnaissance work began with an orientation survey carried out over Dry Creek and West Tundra Flats.

This orientation work found that highly conductive anomalies that were easily identifiable with both controlled-source audio-frequency magnetotellurics, or CSAMT, and time-domain electromagnetic surveys carries the high-grade mineralization at Dry Creek.

White Rock selected CSAMT as its preferred geophysical tool due to the quicker acquisition of data.

The geological survey work, along with field inspections of targets to both validate historical mapping and surface sampling at Red Mountain and prioritize previously unknown zones of mineralization has generated seven targets for follow-up exploration and drilling:

• Dry Creek South, where a zone of alteration is associated with historical base metal soil anomalism has been confirmed by portable XRF analyses. Rock chip grab sampling returned assays up to 12.8 percent zinc, 1.1 percent lead, 0.7 percent copper and 34 g/t silver and 0.02 g/t gold.

• Dry Creek East, where soil sampling has confirmed the continuation of an anomalous trend. Portable XRF analysis of soil samples returned anomalous zinc lead and copper.

• West Tundra, where the main VMS horizon exposure at surface, which is less than 100 meters above zinc-rich VMS, shows minimal evidence of massive sulfide mineralization. Two profiles of soil samples were collected across the VMS stratigraphic horizon to provide a geochemical fingerprint with which to assess other favorable VMS horizons identified across the Red Mountain property.

• Ram, a new prospect where massive sulfide float has been discovered and traced back to a proximal source position within a steep talus slope between the Dry Creek South and main Dry Creek massive sulfide lenses. Rock chip grab sampling from Ram returned assays up to 27.1 percent zinc, 152 g/t silver, 8.2 percent lead, 0.3 g/t gold and 0.6 percent copper.

• Megan's Draw, a prospect east of Ram where a zone of alteration is associated with historic base metal soil anomalism that has been confirmed by portable XRF analyses. Rock chip grab sampling returned assays up to 0.3 percent zinc, 8 g/t gold and 0.2 percent lead.

• South Platypus, a prospect west of Ram where a zone alteration including semi-massive sulfide gossan outcrop has been discovered with coincident portable XRF base metal anomalism in soils. The zone has been traced over 1,000 meters along strike with evidence of chalcopyrite (copper) associated with the alteration zone.

• Hunter, the westernmost and most exciting of the prospects discovered so far, where the roughly two-foot-wide zinc- and lead-rich massive sulfide outcrop was discovered.

"Identifying this potentially high-grade massive zinc and lead sulfide rock outcrop is exactly what we are after," Gill said of the Hunter discovery.

White Rock Minerals Ltd.

White Rock has identified four new volcanogenic massive sulfide prospects along a 10,000-meter east-west trend south of the Dry Creek deposit at Red Mountain.

CSAMT geophysics lines have been completed across this favorable horizon at Hunter, with a subtle conductivity anomaly coincident with the massive sulfide found there. This zinc-rich sulfide, however, occurs along a steep talus slope where there is little outcrop. Prospecting along the horizon has mapped out the favorable graphitic host. Subsequent hand trenching has confirmed the presence of massive sulfide, both in place and as float interpreted to be close to the source along a 500-meter stretch of the horizon defined to date.

"Proof of concept of course will be when we test this with the drill bit," said Gill.

White Rock will test the concept this year with drilling now being planned to target below the massive sulfide outcrop at Hunter. The geological information gleaned from this first hole will help the Australian explorer plan for follow-up drilling at this new Red Mountain discovery.

–SHANE LASLEY