Silver Islet mine, Silver Islet, Sibley Township, Thunder Bay District, Ontario, Canada
|Latitude & Longitude (WGS84):||48° 19' 16'' North , 88° 48' 40'' West|
|Latitude & Longitude (decimal):||48.32111,-88.81111|
|Köppen climate type:||Dfb : Warm-summer humid continental climate|
A tiny island in Lake Superior.
The Silver Islet mine was located on a very small, rocky islet just off shore in Lake Superior. To accommodate the workings the islet's size had to be increased with bulkheads and fill. The Silver islet ore deposit was the most productive in the Thunder Bay District and was in the “Island Group”, one of three groups of metalliferous vein ore deposits (Franklin, et al, 1986). The veins of the “Mainland” and “Port Coldwell” groups contain quite simple mineral assemblages including the common sulphides, silver, acanthite, quartz, calcite, barite and fluorite. However, the Silver Islet and Edwards Island deposits are characterized by a five element mineral assemblage, ie. Ag-Co-Ni-As-Bi. The mineral assemblages present in other ore deposits in the Island group appear simple and similar to those of the Mianland group. However, Franklin, et al (1986) note that the other ore deposits are poorly known and that the Silver Islet vein system contains significant areas of simple mineralogy.
28 valid minerals.
This geological map and associated information on rock units at or nearby to the coordinates given for this locality is based on relatively small scale geological maps provided by various national Geological Surveys. This does not necessarily represent the complete geology at this locality but it gives a background for the region in which it is found.
Click on geological units on the map for more information. Click here to view full-screen map on Macrostrat.org
1000 - 1600 Ma
|Sibley Gp. (circa 1.34 Ga)|
Age: Mesoproterozoic (1000 - 1600 Ma)
Stratigraphic Name: Sibley Gp. (circa 1.34 Ga)
Comments: Southern and Superior Province
Reference: Ontario Geological Survey. 1:250 000 scale bedrock geology of Ontario. ISBN 978-1-4435-5705-4. Miscellaneous Release–Data 126 - Revision 1. 
Wilson, W.E. (1986). Famous mineral localities: the Silver Islet mine, Ontario. Mineralogical Record, 17, 49-60.