The Osi occurrence is located on the western slope of Razorback Mountain, approximately 23 kilometres north of Germansen Landing (Open File 1990-17). This occurrence has regional geology similar to that of the Biddy occurrence (refer to 093N 114 for the regional geology and a more detailed stratigraphic description of the Echo Lake Group).
Disseminated galena and sphalerite occur within the Siluro-Devonian Echo Lake Group. The mineralization is found in stockwork that is iron-bearing (siderite, hematite). Galena also occurs within quartz veins that cut the Echo Lake carbonates. The carbonates in this area consist of white to grey, coarse dolomite, limestone and limestone breccia. The strata can be thin to thickly bedded or massive and may be partially silicified.
The Osi (Osi South) showing was described by Serem as a dolomite-hosted stockwork of siderite and hematite veinlets with disseminations of coarse galena and patches of fine honey-coloured sphalerite. The showing, in the vicinity of 2006 sample 06B-27R, was reportedly hand-trenched but no results have been published. Northeast of the trenched area, Serem reportedly located a number of oxidized and mineralized float occurrences within a zone measuring 300 metres long by 60 metres wide. In 2006, Bowen took a select grab of a 3-10 centimetre wide seam of siderite with galena that assayed 10.98 per cent lead, 41.25 per cent zinc, 256 grams per tonne silver 0.253 per cent cadmium and 0.039 per cent germanium (Sample 06B-27R, Assessment Report 29107).
The Osi Extension showings area is located about 900 metres east-southeast of Osi South. Serem reported that here, float and altered, rusty outcrops contain blebs of galena and very rare sphalerite.
Exploration activity in the Echo claims area began in the 1920’s and continued sporadically until the early 1970’s when large land positions were acquired by Cominco Limited, Serem Ltd., Canex-Placer Ltd., Imperial Oil Limited and others. This staking activity was in response to a re-mapping program in the region carried out by the Geological Survey of Canada. Concentrated exploration programs were undertaken, especially by Cominco, and included extensive soil geochemical sampling and geological mapping followed by access road construction and bulldozer trenching. Numerous, low-grade lead-zinc-silver prospects were identified.
A joint venture between Equinox Resources Ltd. and Daren Resources Ltd. was initiated in 1986 to further investigate the lead-zinc-silver mineralization discovered earlier by Cominco.
In June 1984, Noranda Exploration Company Limited staked claims in the area to cover a strong lead-zinc-silver silt anomaly which had been identified in a regional government geochemical survey. From the mid to late 1980s, Noranda carried out a program of detailed soil and rock geochemical sampling, IP surveying and limited core drilling in two holes.
In 1993, Cominco carried out geological mapping and reconnaissance soil sampling in the general area previously investigated by Noranda.
During the period July 2005 to March 2007, Barney Bowen staked the Echo claim group to cover known lead-zinc-silver plus/minus germanium mineral occurrences and the host Devonian carbonate strata. In 2006, Bowen completed a 3.8 kilometre long, helicopter-supported prospecting traverse between the Osi and Osi Extension showings areas on his Echo 3, 5 and 8 mineral claims.
Refer also to 093N 011 for further historical details.