Tags: North Mount Marble Mountain
North Mountain lies on the west side of Bras d'Or Lake between Denys Basin and West Bay. It is about 260 m high and is composed of Precambrian granitic and George River Group rocks. The latter originally contained limestone bands, which have been metamorphosed into marble. Some marble is still quarried at Marble Mountain.
The North Mountain block was outside the early Carboniferous basin where the Horton strata were deposited. Later on, during Windsor time, when the sea covered a wider area, the North Mountain block became an island against which Windsor Group strata accumulated. The block is now almost entirely surrounded by Windsor deposits, which are deeply eroded and give maximum relief on both the north and south sides. The scarp is steepest on the south side and forms cliffs along West Bay. The more gentle dip-slope reaches Denys Basin at a shallower angle. The block is crosscut by a fault, forming a narrow, steep-sided valley.
The valley is occupied by two streams, Kennedys Brook and MacIntyres Brook. Lakes, bogs, and wandering streams are found on the relatively flat crest of North Mountain, but once the marginal slopes are reached, the streams become straight and fast flowing.
North Mountain was well known for its Marble Mountain limestone quarry. The story of this limestone and marble quarry industry of the late 1800s and early 1900s is documented at the Marble Mountain Museum. After limestone was extracted from the quarry, it was crushed, slaked, and shipped to Prince Edward Island, where farmers used it to lime soils. Important Mi'kmaq burial sites are found in North Mountain cliffs bordering the Bras d'Or Lake.