The Leitch and Sandriver mines lie at the heart of the project area. The Leitch mine shaft is 6 km northwest of the town of Beardmore. Beardmore is about 205 km by highway northeast of the airport in Thunder Bay, Ontario. The Leitch mine is a few hundred meters off highway 580. The Sandriver mine shaft is 870 m southwest of the Leitch mine shaft. A bush road provides access to the Sand River mine and continues to the Creek Vein at the west end of the property. Size of Property
10 patented claims, 37 leases, 20 claims; 1,538 hectares (3,800 acres) Ownership
100% Project Overview
The project area includes the past-producing Leitch and Sand River mines and the Creek vein, No. 16 vein, and Boundary Zone prospects.
Both the Leitch and Sand River ore bodies were discovered in 1934-1935. The Leitch mine produced 862,000 ounces (29.6 tonne) of gold from 1936 through mill cleanup in 1968 (Mason and White, 1986). Mining operations eventually reached a depth of 1,380 m (4,525 feet) on the 30th level (Ferguson, 1967). Ore grade mineralization was intersected in drilling below the deepest mine level. Stope grades in the No. 2 vein range from 21.6 g/tonne over 0.27 m to 134 g/tonne over 0.49 m (0.63 oz/st over 0.9 feet to 3.91 oz/st over 1.6 feet) and individual underground samples have a much wider range. Dividing ounces produced by tons milled for the period 1938-1965 gives an average milled grade of 32.6 g/tonne (0.95 oz/st) (Mason and White, 1986), which is affected by both dilution during mining and sorting prior to milling.
The Sandriver mine produced 50,065 ounces (1.7 tonne) gold from 1937 through 1942 (Mason and White, 1986). The Sand River vein is probably continuous with the No. 2 vein in the Leitch mine (Mason and White, 1986). Stopes were mined from surface to a depth of 442 m (1,450 feet. Development continued to a depth of 796 m (2,610 feet) until 1948. Incomplete data suggest stope grades were typically 21 g/tonne (0.6 oz/st) over 40 cm (1.3 feet) in the Sandriver mine. The average milled grade for 1938-1942 is 12 g/tonne (0.32 oz/st) (Mason and White, 1986).
Stope grades reported above are historical data based on mining company documents from the period 1934-1968 and cannot be verified because the underground workings are inaccessible. Widths are presumably measured horizontally and are somewhat greater than true vein widths due to the steep dip of the veins.
The Creek vein prospect occurs in the western part of the project area. Channel assays of the Creek vein collected in 1935 reportedly averaged 7.5 g/tonne (0.218 oz/st) over .46 m (1.5 feet). Resampling of the trench in 1980 yielded only a few samples with more than 3.4 g/tonne (0.1 oz/st). The best intercept of the 1935 drilling (hole #20) is 10.3 g/tonne (0.30 oz/st) over a drilled length of 3 m (10 feet) at a vertical depth of about 15 m (50 feet) (Tough and Gledhill, 1980). 33 holes were drilled in 1987-1988. Holes 87-24, 87-32, and 87-34 yielded samples with grades greater than 10 g/tonne at depths less than 50 m (Rennick, 1988).
The No. 16 vein is a series of quartz veins which were trenched and drilled at surface and developed by an underground drift from the Leitch mine on the 274 m (900 feet) level in 1950-1952. Although some underground samples have multi-ounce grades, such as 133 g/tonne (3.88 oz/st) over 0.2 m (0.67 feet), the vein was generally too thin and the high-grade zones too short for profitable mining. Nonetheless, a small stope produced approximately 68.6 kg (2,000 ounces) of gold (Mason and White, 1986). Subsequent drilling from surface has continued to intersect sporadic high-grade veins (Bevan, 2004).
The Boundary Zone was tested by a series of drill holes in the late 1980s by Teck. Several quartz vein intercepts have grades of 1-5 g/tonne (0.3-0.15 oz/st) over drilled lengths of 0.9-4 m (3-13 feet). The best intercept had visible gold and a grade of 217 g/tonne (6.33 oz/st) over a drilled length of 1.04 m (3.4 feet). Teck found insufficient continuity of the quartz veins to justify further work. Geology
The Leitch - Sandriver project is located within the Beardmore-Geraldton greenstone belt of the Wabigoon subprovince of the Superior province. The project area is underlain by metagreywacke of the southern metasedimentary sub-belt of the Beardmore-Geraldton greenstone belt. The metagreywacke is part of a turbidite sequence which faces south. It generally strikes 70-90o and dips greater than 70o north or south and is cut by a spaced cleavage striking 50-80o and dipping steeply northwest. The area is north of the Standingstone/Watson Lake fault and on the south limb of a major anticline with a wavelength greater than 1 km (LaFrance, DeWolfe, and Stott, 2004; Hart, terMeer, and Jolette, 2002).
Iron formations occur at lower stratigraphic levels north of the mines. They include well banded units of chert and hematite and/or magnetite as well as argillite with abundant hematite (Mason and White, 1986). The northeastern part of the property has metavolcanic rocks of the central metavolcanic sub-belt.
Metagreywacke has been intruded by minor gabbro and diorite bodies which are locally foliated and by Proterozoic diabase dikes and sills. A thick sill cuts the gold veins in the Leitch mine at depths of 570-750 m (1,870-2,460 feet) and in the Sandriver mine at depths of 485-670 m (1,585-2,220 feet). Mineralization
Gold mineralization is hosted by quartz veins in metagreywacke. The quartz veins have very minor carbonate, greenish sericite and/or chlorite, and sparse pyrite, arsenopyrite, and tetrahedrite. Sphalerite and scheelite were also reported in the veins in the Leitch mine (Mason and White, 1986). The Leitch No. 2 -- Sand River vein cuts bedding at a low angle and has been interpreted to occupy an S3 axial planar cleavage (LaFrance, DeWolfe, and Stott, 2004). It is locally folded in a right-stepping "z" pattern. The Leitch No. 6 vein is subparallel to, and south of, the No. 2 vein. The Leitch No. 1 and No. 3 veins are approximately perpendicular to the No. 2 vein and intensely folded. The Leitch No. 4 vein has an intermediate orientation and is also strongly folded. The No. 2 vein was mined continuously to the deepest mine level and the No. 4 and No. 3 veins were mined to at least depths of 1,110 m (3,325 feet) (Ferguson, 1967).
At the Creek vein prospect, gold mineralization occurs in quartz-carbonate veins in pyritic, carbonate-altered metadiorite (Rennick, 1988). References
Bevan, P.A., 2004, Qualifying report on the Sand River/Leitch mines with specific reference to the #16 vein systems, Beardmore area, northwestern Ontario, Canada, for Roxmark Mines Limited.
Ferguson, S.A., 1967, Leitch Gold Mines Limited, subsurface No. 1, 900-foot level, subsurface No. 2, 4525 foot level, parts of Eva and Summers townships, District of Thunder Bay: Ontario Department of Mines, Preliminary Map P.485.
Hart, T.R., terMeer, M., and Jolette, C., 2002, Precambrian geology of Kitto, Eva, Summers, Dorothea and Sandra townships, northwestern Ontario: Phoenix bedrock mapping project: Ontario Geological Survey, Open File Report 6095, 206 p.
LaFrance, B., DeWolfe, J.C., and Stott, G.M., 2004, A structural reappraisal of the Beardmore-Geraldton belt at the southern boundary of the Wabigoon subprovince, Ontario, and implications for gold mineralization: Canadian Journal of Earth Science, v. 41, p. 217-235.
Mason, J. and White, G., 1986, Gold occurrences, prospects, and deposits of the Beardmore-Geraldton area, districts of Thunder Bay and Cochrane: Ontario Geological Survey, Open File Report 5630.
Rennick, M.W., 1988, Report on the Cryderman Gold, Inc., Sand River property, Eva Township, Thunder Bay Mining Division, District of Thunder Bay, Ontario: Company Report.
Tough, S. and Gledhill, T., 1980, Progress report, Sand River property: Memorandum to Elcamber Resources, Ltd.