Regional geology in this area has been relatively sparse, and the current property-scale interpretation has been derived from mapping completed by the Alaska Division of Geologic and Geophysical Surveys summarized in the Hyder Ketchikan Department of Mines Open-File 011 report by Maas et al released in 1995. Property geology is dominated by the Lower Jurassic Lower Hazelton Group andesitic to dacitic volcanic, volcaniclastics, and associated sedimentary rocks, trending broadly east-west across the property. Mid-way down the north face of the ridge towards the West Fork of Texas Creek, this Lower Hazelton volcanic package contacts with the coeval Texas Creek Stock, a granodiorite to quartz diorite to quartz monzonite. This Lower Hazelton package and coeval intrusive bodies are a regionally prospective stratigraphic horizon that plays host to the majority of large high-grade gold and silver deposits in the Golden Triangle.
Casey Glacier Sphalerite
The Casey Glacier Sphalerite occurrence is comprised of mineralized boulders up to 1m in diameter spanning a roughly 1000m by 2000m wide zone. Mineralization is hosted in massive bands and veinlets of sphalerite with lesser galena, silver, and trace gold with associated intense silica and carbonate alteration associated with mineralization and brecciation. Outcrop associated with these subcrop samples was never located in historic exploration work, suggesting the likely source of these boulders was underneath the summit icefield located between the Ferguson and Casey Glaciers. This previously 1km long icefield has almost entirely receded since the 1992 and 1995 sampling programs took place (see Figure 2).
Of 35 historic float, subcrop, grab, and channel samples taken on the property, 17 assayed over 1% zinc, including 8 which assayed over 10% zinc, often associated with high base and precious metal counts. Individual high-grade samples include: 5.0 g/t Au, 62.4 g/t Ag, 0.1% Cu and 29.5% Zn; 195.4 g/t Ag, 2.0% Cu, 2.6% Zn, 300.3 g/t Ag, and 0.3% Cu.
The Engineer Mine is consistent with polymetallic quartz veining up to 1.2m wide exposed over 100m along strike. The vein is hosted in a granodiorite unit of the Texas Creek Suite and Hazelton volcanosediments with local blocks of volcanosediments included in the vein. Mineralization occurs in narrow shoots of massive pyrite chalcopyrite and galena.
Of 20 grab and channel samples collected historically, samples ranged from trace to 26.3 g/t Au and trace to 366.9 g/t Ag. 11 samples assayed over 1.0 g/t Au with individual samples including 14.5 g/t Au and 366.9 g/t Ag; 26.3 g/t Au and 63.42 g/t Ag; 12.62 g/t Au and 47.3 g/t Ag, and 14.7 g/t Au and 168 g/t Ag.