The Sil occurrence is situated on the northwest side of Blind Creek, about 7 kilometres east of Keremeos.
This marble prospect is hosted in the Carboniferous Blind Creek Formation, comprised largely of medium bedded grey limestone and calcareous argillite. The unit underlies a 1.4 by 1 kilometre area situated largely between Blind Creek and Manuel Creek on the northeast side of the Similkameen River.
At the Sil prospect, the rocks have been divided into three units: upper volcanic, marble and calcareous argillite, and lower volcanic and metasediments. The upper volcanic units consists of greyish green porphyritic andesite, possibly of the Triassic Old Tom Formation. The lower contact with marble and calcareous argillite is not exposed but is inferred to be sharp from drillholes. The underlying marble and calcareous argillite unit has a measured thickness of approximately 200 metres. More massive cliff-forming marble outcrops are underlain by well bedded, competent, calcareous argillite. The lower contact of the marble unit is well exposed and is sharply underlain by volcanic rocks.
A major northwest-trending fault is expressed topographically by a canyon in the northeast corner of the prospect. Changes in bedding orientations in the marble indicate gentle folding with a northwest plunging fold axis. Regular parallel joints occur in zones several metres thick. The joints trend northeast with variable dips.
The Sil prospect covers discontinuous outcrops over 400 metres and subsurface extensions of marble. Exposures are common and the weathered surface has a pitted, grey pattern a few millimetres thick. Fresh marble is dull grey to black. A poorly developed bedding is locally present. Some horizons of black marble contain crinoid, brachipods, belemnites and rugose coral fossils. Irregular white or yellow calcite veinlets occur within the marble. The veinlets are composed of white scapolite, garnet, magnetite and humite in a scattered mosaic of calcite and brucite. More massive, fine-grained marble is micritic textured. On the eastern half of the prospect the marble dips northward about 32 degrees. To the west the marble changes dip to 30 to 50 degrees to the west.
Diamond drilling on the Sil 1 claim and mapping in 1991 has defined a area containing 200,000 square metres of marble ranging from 50 to 200 metres thick. Based on an assumed average thickness of 150 metres and a specific gravity of 2.69 this zone is calculated to containing possible reserves of 80.7 million tonnes of black to grey marble (Assessment Report 21293). Based on the limited diamond drilling, 44 per cent of the marble is suitable for dimension stone and 50 per cent for marble mosaic. Therefore, 35.5 million tonnes possible reserves of dimension stone and 23 million tonnes possible reserves marble mosaic were determined (Assessment Report 21293). An undetermined amount of additional marble occurs to the north under volcanics. Further drilling is required to determine the total depth and lateral extent of fractures, thickness of the marble and presence of structural discontinuities.
The prospect is owned by F.G. Ramsey. In 1982 and 1983, Weymark Engineering Ltd. was contracted to examine the prospect. The limestone was explored as a source of marble by R.G. International Imports Ltd. in 1990. Six holes were drilled for a total of 180 metres.
