Sitka Gold Corp has a 100% interest in the Alpha Gold Project, a Carlin-type gold prospect located on the southeast projection Cortez Gold Trend, near Nevada Gold Mines’ world class Pipeline, Cortez Hills, and Goldrush mines. The Property is comprised of 239 claims covering 4,938 acres (1999 hectares).
Host rock is a primary control to gold mineralization at the Goldrush mine, and at Alpha. Two host horizons occur at Goldrush, the Horse Canyon Fm to Wenban Fm contact, and the Wenban Unit 5, with the latter hosting most of the ore. Only the upper horizon has been drill tested at Alpha. Testing the lower horizon is a high priority as targets become adequately defined. The stratigraphic section at Alpha is also the same as at the nearby Gold Bar mine complex of McEwen Mining.
Gold mineralization at Alpha occurs along a 7 km section of the north-northwest Alpha anticline, a mineral control structure analogous to the Red Hill anticline at Goldrush. At Alpha NW, 14 drillholes have tested the Horse Canyon Fm confirming gold and Carlin-type alteration along 2.5 kilometers of the anticline trend. At Frazier Creek, 4.5 kilometers south southeast, surface alteration with up to 0.78 g/t gold occurs along 1.5 km of the anticline axis. Sitka’s first hole at Frazier Creek was lost above the target stratigraphy. The Frazier Creek target remains a high priority. An additional anticline target also remains at the original Alpha area about 4 km east of Frazier Creek. AG20-01 was drilled there, encountered a major normal fault. The hole was on the east limb of that anticline and did not reach target stratigraphy.
Alpha NW drilling is delineating an extensive Carlin-type gold system with only the Horse Canyon target horizon tested thus far. A tentative interpretation of the Alpha Anticline axis is highlighted in red. Gold in the drilling generally strengthens to the west toward the interpreted axis. The west limb of the anticline is not drill defined, except by hole 3, leaving an important target zone west of the best holes. Future plans include additional drilling and a soil grid with upgraded geologic mapping. Drill results have emphasized two ENE cross-faults (orange) with the best drill intercepts encountered on the north side of the southern one. A large untested target zone is envisioned on the north side of the northern one. The E-W cross-fault (blue) is of interest for pre-Carlin calc-silicate alteration, lead-zinc mineralization, and structural complexity associated with it.
Cross-sections through holes 8, 10, and 11 illustrate the priority target on the west. The west limb of the Alpha Anticline is not yet defined by drilling. It is anticipated that the fold crest and hingeline will contain the strongest gold. Eocene rhyolite dikes intrude many of the faults along the Alpha Anticline.
Holes 3 and 4 are interpreted to fall on the limbs of the Alpha Anticline. Hole 4, and Hole 16 to the north, have the highest arsenic encountered in the drilling. Arsenic commonly envelopes gold zones at Alpha. This section is located on the north side of an ENE cross-fault, that may focus gold here. The area represents a large high-priority target. The ultimate target is the Wenban Unit 5 host horizon below. Targets along the toothed reverse fault are like those described by Barrick at the deep, high-grade Fourmile deposit north of Goldrush. Reverse faults can produce larger damage zones that transmit gold-bearing fluids.
The long section shows the strongest gold in the Alpha NW drilling lies in the hanging wall of a moderately dipping ENE reverse fault. This hanging wall zone still needs to be tested along strike to the WSW (toward the viewer) to locate its intersection with the Alpha Anticline axis. Testing the underlying Wenban 5 equivalent host will rely on refining and understanding gold distribution around the control structures shown here. Hole 3 indicates a second reverse fault and the hanging wall area east the hole and this cross-section represents another high-priority target zone as shown on the hole 3-4 cross-section.
At Frazier Creek, Carlin-type alteration occurs on surface along 1.5 km of the SSE projection of the Alpha Anticline. This alteration occurs on the north side of a major ENE cross-fault, like the best drill results at Alpha NW. Rock chip sampling returned up to 0.775 g/t gold, greatly exceeding Alpha NW surface sample results. Hole 12 was lost above the target.
Hole 12 encountered a major unrecognized rhyolite dike-filled fault, which contributed to the loss of the hole prior to reaching the target horizon. The hole was mis-targeted because of the unexpected major fault. The re-drill will have an opposite inclination to the WNW. The surface alteration supports the corrected target interpretation.
