| Nor'Wester Mountains | |
| Range | |
|
Mount McKay
|
|
| Country | Canada |
|---|---|
| Province | Ontario |
| Highest point | Mount McKay |
| - elevation | 483 m (1,585 ft) |
| - coordinates | |
The Nor'Wester Mountains are a group of mountains immediately south of Thunder Bay, Ontario, Canada, located on the southern limits of the City of Thunder Bay and south of the Kaministiquia River.[1]:32,33
Mount McKay is the highest, most northern and best known of these mountains; it is 270 m (890 ft) above Lake Superior and 442 m (1,450 ft) above sea level.[1]:31,32 It is a flat-topped hill flanked by steep cliffs on three sides.[1] Mount McKay is composed of shale and greywackes – the Rove Formation – which is covered by the hard, protective 60 m (200 ft) thick diabase cap.[1]:iii,2 The Rove Formation is part of the Animikie Group.[1]:32 The Rove sedimentary layers in the Nor'Wester Mountains are overlain by a 60 m (200 ft) cap of diabase;[1]:32 this Logan diabase is 1115 ± 1 million years old.[2] This diabase cap is the erosional remnant of a sill that once extended over the entire area.[1]:32 Most of it is covered by a thick layer of mineral soil.[1]:32
The north face of Mount McKay shows evidence that below this cap is another 7.2 m (24 ft) thick sill of very hard diabase.[1]:32 This sill is also an erosional remnant and is 96 m (315 ft) below the first cap and 190 m (620 ft) below the top of the hill – or 242 m (794 ft) above sea level.[1]:32
Loch Lomond, 287 m (942 ft) above sea level, collects most of the runoff within the Nor’Wester Mountains; Loch Lomond is drained by the Lomond River.[1]:5 A few square kilometers of mountain slope south of Mount McKay are drained by Whiskeyjack Creek.[1]:5