Geology and Landscape Development
The Margaree Plateau is dissected upland that sweeps southward from the Highlands to Lake Ainslie in the southwest and to the Submerged Lowland (District 560) in the southeast (see Figure 21).
Downfaulted blocks of Windsor Group rocks are found within the folds of resistant Horton strata in several areas. The valleys of the Northeast Margaree, Middle, and Baddeck rivers have all been eroded from Windsor strata (see Figure 8).
The escarpment on the west side of the Northeast Margaree valley is straight for more than 15 km. It is in line with other valleys across the Highlands and with the Aspy Fault valley at Cape North.
When it reaches the Windsor strata, the Northeast Margaree valley widens out, flowing between high hills. The floor of the valley is covered with glacial sands and gravels, and a floodplain with oxbow ponds and terraces has developed. At Emerald the river turns 90° to the west, cuts through a band of Horton strata, and flows to Margaree Forks. Originally it probably flowed southwards to the Middle River and St. Patricks Channel, but this exit was blocked by glacial drift. The old river valley is now occupied by a string of lakes: Harvard Lake, First Lake O'Law, and Second Lake O'Law. Beyond Margaree Forks the river flows through another strip of Windsor strata before entering its drowned estuary at Margaree Harbour.
|Piper's Glen, Inverness County
Click to enlarge
The hilly terrain continues to the Baddeck area. There it is intersected by the Windsor lowland through which the Baddeck River flows to its drowned estuary at Nyanza Bay. Glacial deposits are found along most of the major rivers. At Middle River and Skye River (further south) the gravels contain mastodon teeth and bones.
Much of this Unit falls within a secondary watershed that drains Lake Ainslie into the Margaree Harbour. The Southwest Margaree River dissects the northern portions and is fed by many smaller-order tributaries. There are large grassy fens and wet meadows along the Margaree where it broadens out north of Margaree Forks. Solution lakes occur in the broader areas of the Margaree Valley. This valley also has several large aquifers in the Carboniferous formations.
|Piper's Glen, Inverness County
Click to enlarge
Soils are mapped only as Rough Mountainland. However, the soils are, for the most part, surprisingly deep, with some smooth, compressed silts, supporting the theory that the area was not extensively glaciated. The soils probably share at least some of the characteristics of those described in Unit 584, Ainslie Uplands.
This Unit forms part of Loucks' Sugar Maple, Yellow Birch-Fir Zone. However, while the Ainslie Uplands have a rolling, hilly terrain, the Margaree Plateau is more level. White Spruce is common in old fields and pastures which have been recolonized. On the flatter upland areas, Balsam Fir and Black Spruce are mixed with shade-intolerant species. Better-drained rolling areas have more shade-tolerant hardwoods: Sugar Maple, Yellow Birch, and American Beech, with a mixture of Balsam Fir.
This Unit provides eagle-nesting habitat and an important post-breeding concentration area. Atlantic Salmon and American Eel are found in the Margaree River. Freshwater fish such as White Sucker, sticklebacks, and Brook Trout are found in streams further inland. The Middle River supports four species of salmonids.
Along the Margaree River valley, small mixed farming is the predominant land use. Forestry occurs on the Margaree Plateau. The Margaree is designated as a heritage river and has long been important for salmon fishing. Wildlife and angling attract tourism and recreational use of the area.
Sites of Special Interest
- Northeast Margaree Valley - fault scarp on the west side of the valley, sinkholes in areas of karst topography, river terraces, intervale plants
- Baddeck River (west side, north of Melford) - fossil valley containing Windsor strata
- St. Anns Harbour - gravel and sand bars nearly block the harbour entrance; the narrow gap is crossed by a cable ferry; from Kellys Mountain lookoff (District 220) the old positions of the sand bar can be seen as ridges
- Piper Glen (IBP Proposed Ecological Site 13) - spectacular waterfall, mature mixed forest
- Lake O'Law (IBP Proposed Ecological Site 14) - old growth mixed deciduous forest habitats
Provincial Parks and Park Reserves
- St. Anns
- South West Margaree
- Doyles Bridge
- Lake O'Law
Proposed Parks and Protected Areas System includes Natural Landscape 63 and Candidate Protected Area 8 Trout Brook.
- Cabot Trail (all sections)
- Northeast Margaree valley
- Southwest Margaree valley
- summit of Salt Mountain (views over St. Patricks Channel)
|T2.4 The Carboniferous Basin|
|T3.2 Ancient Drainage Patterns|
|T8.2 Freshwater Environments|
|T11.4 Birds of Prey|
|T11.13 Freshwater Fishes|
|T12.11 Animals and Resources|
|H3.1 Freshwater Open-Water Lotic|
|H3.2 Freshwtaer Open-Water Lentic|
|H3.4 Freshwtaer Bottom Lentic|
|H3.6 Freshwtaer Water's Edge Lentic|
|H6.1 Hardwood Forest (Sugar Maple, Yellow Birch, Beech Association)|
|H6.2 Softwood Forest (Balsam Fir Association)|