The Lexington Mountain region is underlain by a series of metamorphosed Cambrian to Devonian sedimentary and volcanic rocks of the Lardeau Group which overlies the Lower Cambrian Badshot Formation in the east. The predominant structural features in the area are northwest trending and plunging overturned folds and regional semiconcordant to concordant faults. The strata within these structures are steeply east dipping with a variable plunge to the northwest.
Three distinct northwest striking limestone-chlorite schist contact zones spaced at roughly 1 kilometre intervals cross the property. The Index Formation (Lardeau Group) hosts similar mineralization within these zones and may represent either folded repetitions of the same contact or stratigraphic repetitions of similar depositional environments. The mineralization occurs as both disseminated and massive zones of galena, pyrite and sphalerite associated with dolomitized limestone and silicification invariably developed with siderite-rich zones containing hematite and magnetite localized along the limestone-chlorite schist contacts.
The mineralization at the Nellie showing consists of disseminations, lenses and bands of galena, pyrite and sphalerite in a siliceous gangue. Hostrocks are a bleached limestone and sericitized chlorite schist. A rock sample from an adit dump analysed 0.97 per cent lead, 3.08 per cent zinc and 24.6 grams per tonne silver (Assessment Report 20480). Historic workings consist of an incline and a crosscut at the foot of the incline, a total of 18 metres (ca. 1898).
Mineralization in a series of occurrences along strike to the southeast (Kitsap, 082KNW148; Alma, 082KNW124; Banner, 082KNW163; and Daffodil, 082KNW197) consists of intermittent lenses of galena-sphalerite in crosscutting fractures and quartz-carbonate veins within siderite or ankerite alteration zones. Alteration consists of sericitization of phyllite, ankerite-siderite alteration of dolomite and dolomite alteration of limestone.
This area was originally explored in the late 1800s and early 1900s when prospectors discovered widespread precious and base metal mineralization. The Nellie property claims were staked in 1985 for Lardeau Development Corporation and sold to L. Mikulic in 1987. Kosa Resources Ltd. acquired its right to purchase the claims in 1987. In 1987, Ram Explorations Ltd. conducted a ground VLF-EM and magnetic survey and geochemical sampling. In 1989-90, Kosa Resources Ltd. conducted rock, soil and silt sampling, geological mapping, grid extension and ground VLF-EM and magnetic surveys.
