The Crow-Fledgling occurrence is located at an elevation of approximately 970 metres, near the east bank of Krao Creek and west of Loon Lake.
Regionally, the area is underlain by hornblende schists, limestone and banded quartzite of the Upper Mississippian to Permian Milford Formation and basaltic volcanic rocks of the Carboniferous to Permian Kaslo Group. To the west granodioritic intrusive rocks of the Middle Jurassic Nelson Batholith are exposed.
The Krao (MINFILE 082FNE076) and Crow-Fledgling Crown grants are underlain by hornblende schists, limestone and banded quartzite of the Mississippian to Lower Permian Milford Group. Calcite, siderite and quartz with galena and sphalerite occur in a fissure in the limestone. Wire silver occurs in solution cavities and joint planes within the mineralized zone.
The Crow-Fledgling has recorded production for 4 years, from 1937 to 1960, when 169 tonnes was shipped. From this, 25 913 grams of silver, 13 394 kilograms of lead and 10 039 kilograms of zinc and 22 kilograms of cadmium were recovered.
Work History
The Krao and Crow-Fledgling claims were Crown granted to A.D. Wheeler in 1890. During the first period of major development work, which lasted through 1908, the deposit was stripped over an 18 by 46 metre area. A shaft, dipping west at 75 degrees, was sunk on the hangingwall to a depth of 30 metres. A tunnel, located several hundred metres east of the shaft on the Hamburg Crown-granted claim, was driven for 259 metres to intersect the Krao limestone approximately 91 metres below the surface. Several hundred feet of drift along a limestone band at the end of the crosscut failed to turn up any ore. In 1906, the property was sold to the Krao Silver-Lead Mining Co. and a program of stripping and stoping for small amounts of high-grade ore was carried out. The following year the shaft was deepened to 78 metres and 152 metres of drifting and crosscutting was completed. Water courses were encountered in sinking.
Active production ceased soon after 1908 and, except for small amounts of very rich silver ore mined by leasers, there was little change up to 1952. In 1949, Yale Lead & Zinc Mines Ltd. acquired these claims. The Krao dump, amounting to 173 tonnes, was milled in 1952. In 1953 and 1954 stoping was completed adjacent to the shaft at the 30-metre level. The following year stoping was carried out above the 61-metre level.
In 1979, David Minerals Ltd. conducted a program of geochemical (stream and silt) sampling on the area as the Peanut Butter claims of the Ainsworth property. The following year, nine diamond drill holes, totalling 926 metres, were completed on the Crow-Fledgling and Black Chief claims. Drilling on the west side Krao Creek yielded intercepts of up to 0.33 per cent zinc, 0.12 per cent lead, 60.3 grams per tonne silver and 4.11 grams per tonne gold over 0.28 metre (77.57 to 77.85 metres down hole) in hole 80-4 and 0.96 per cent zinc, 1.96 per cent lead and 63.8 grams per tonne silver over 0.55 metre (85.27 to 85.82 metres down hole) in hole 80-6 (Assessment Report 8254).
In 1989, South Kootenay Goldfields Inc., on behalf of Dragoon Resources Ltd., conducted a program of prospecting, geological mapping and rock sampling on the area as the Peanut Butter property. Two samples (E49711 and E49712) from the main vein, as exposed near Krao Creek, yielded an average of 4.99 per cent lead, 13.30 per cent zinc and 60.9 grams per tonne silver, and two dump samples (E49721 and E49722) from the adit mouth on the Hamburg claim to the east yielded an average of 9.98 per cent lead, 2.47 per cent zinc and 69.9 grams per tonne silver (Assessment Report 19130).
In 2012, David Wallach prospected and rock sampled the area as the Ainsworth property. Two undescribed rock samples (1986626 and 1986627) from the occurrence area both yielded greater than 1.00 per cent zinc and lead, each, and greater than 100 grams per tonne silver (Assessment Report 33426).
In 2019, a minor program of soil sampling was conducted by Taylor Lorenzen near the south end of Loon Lake. In 2022, a 72.0 line-kilometre airborne (drone) magnetic survey was conducted on the area as the Ainsworth Mill property.
