Unit 583 is divided into two sub-Units:
(a) South River
Geology and Landscape Development
South and north of the town of Antigonish are two areas of upland underlain by Devonian to Middle Carboniferous strata of varying character. They include resistant Horton strata, easily eroded Windsor deposits, and slightly more resistant Canso and Riversdale strata. Some volcanic rocks also occur. The areas are cut by faults and are elevated and dissected. They represent a transitional zone between the coastal lowland and the uplands to the west and south.
In the South River area, a valley extends southwards through Lochaber Lake across the southern uplands to the St. Marys River estuary. This may have been the course of an ancestral river that flowed northwards from the Scotian Shelf and was superimposed upon the resistant rocks that the valley now crosscuts.
This Unit is divided into a number of tertiary watersheds, most of which drain into St. Georges Bay (see Figure 17). Surface water is dominated by tributaries that flow in a modified trellis pattern into first-order streams draining either into the harbours or directly into the bay. Floodplains occur along many of the Antigonish area streams and rivers in sub-Unit 583a.
|Woodland along stream, Frankville, Antigonish County
Click to enlarge
South River (sub-Unit 583a)
To the west of this sub-Unit, Millbrook soils predominate. These soils have developed from gravelly clay loam tills of mixed origin - sandstones, shales, and metamorphic rocks. In the centre, well-drained Woodbourne soils have developed from shales and sandstones of the Windsor Formation. Woodbourne soils are stony to shaly loams. Stewiacke and Hebert soils are common on water-deposited materials along stream and river valleys, the former having developed from alluvium and the latter from glaciofluvial deposits.
Lakevale (sub-Unit 583b)
The soils in this sub-Unit tend to be imperfectly drained, either because of fine-textured impermeable subsoil, or because they are underlain by flat-lying bedrock. The finest textured soils are Queens (sandy clay loam) and Millbrook (gravelly clay loam). Hansford soils are coarser but also imperfectly drained. The better-drained Thom soils are derived from a mixture of sandstones and metamorphic rocks. Westbrook soils are found on tills derived from conglomerate.
This Unit falls within Loucks' Sugar Maple-Hemlock, Pine Zone, at the boundary between two ecoregions: a northerly one in which conifers predominate among scattered deciduous stands, and a more southerly one in which shade-tolerant species are found on a wider range of sites. In the western part of the Unit, Sugar Maple, Yellow Birch, and American Beech are common, with spruce, Eastern Hemlock, pine, Red Maple, and birch on less well-drained sites. Oldfields regenerating in White Spruce are common. As one approaches Cape Breton, softwoods became more prevalent.
This Unit provides mainly forested habitats, with cliffs along St. Georges Bay. There is virtually no information on small mammals in this Unit, but diversity is probably moderately high. Typical freshwater fish species include White Suckers, perch, shiners, Brown Bullhead, Brook Trout, American Eel and Gaspereau. Three isolated populations of Yellow Perch exist in Lochaber Lake.
Forestry exploitation and small farming in valley intervales characterize much of the land use in this area. In the South River area (sub-Unit 583a), limestone is quarried at Antigonish. The Fraser Mills Fish Hatchery raises small fish for lake stocking programs throughout the province and an exhibition centre at the operation provides information on the hatchery and local angling. At Lakevale (sub-Unit 583b), commercial fishing provides an economic base.
Provincial Parks and Park Reserves
Proposed Parks and Protected Areas System includes Natural Landscape 45.
|T2.4 The Carboniferous Basin|
|T3.2 Ancient Drainage Patterns|
|T8.1 Freshwater Hydrology|
|T9.1 Soil-forming Factors|
|T11.3 Freshwater Fishes|
|T12.11 Animals and Resources|
|H3.1 Freshwater Open-Water Lotic|
|H3.3 Freshwater Bottom Lotic|
|H3.5 Freshwater Water's Edge Lotic|
|H6.1 Hardwood Forest (Sugar Maple, Yellow Birch, Beech Association)|
|H6.2 Softwood Forest (White Spruce Association)|
|H6.3 Mixedwood Forest (Spruce, Fir, Pine-Maple, Birch Association)|
|Associated Offshore Unit|
|Sub-Unit 583b: 914 Northumberland Strait|