Geology and Landscape Development
The Ainslie Uplands cover a large area of southwestern Cape Breton from St. Georges Bay to Lake Ainslie. The geology is dominated by Horton Group deposits which have been thrown into broad folds trending northeast to southwest.

Krummholz, Martinique Beach Islands Click to enlarge

The area is on the uptilted side of the planation surface and has been deeply eroded. Almost all strata younger than Windsor age have been stripped off. The remaining Windsor Group strata, which still attain a total thickness of 750 m, are preserved in long synclines and fault blocks southwest of Lake Ainslie and east of the Mabou Highlands (Unit 314). In this area, on the southern end of the highlands, volcanic rocks of Devonian to Carboniferous age are found.

The Ainslie Uplands are hilly and fairly rugged, with the hills forming a visual continuum from the Creignish Hills to Lake Ainslie. All the major rivers - the Mabou, Southwest Mabou, Mull, and Black - exploit the bands of Windsor strata lying between the long ridges of Horton rocks and form a roughly rectangular drainage pattern. The Mabou River flows in a faulted block of Windsor strata and reaches the Northumberland Strait through a drowned estuary.

Glacial deposits brought down from the Cape Breton highlands by glaciers and glacial streams mantle the area. Lake Ainslie has been dammed by glacial gravels, which can be seen as ridges near Strathlorne. The westward extension of the lake, Loch Ban, is shallow and bordered with peat deposits, which can be found far up Black River along a flat, low belt of Windsor strata. Coarse glacial gravels can be seen on the lower slopes of the Mabou Hills. Inland, fine sandy deposits in a valley between Loch Ban and the sea ascend to more than 150 m above sea level.

Fresh Water
The northeastern portion of this Unit is dominated by Lake Ainslie, the largest lake in Cape Breton, draining north through the Margaree into the Northumberland Strait. The southern portions are dominated

Some of the Province's best salmon rivers are in this region Click to enlarge

by the trellised drainage patterns of the Mabou River and its many tributaries. The headwaters of the Skye River occur in this Unit. Most of the streams are shallow and fast-flowing, with pH levels averaging 6.0. Lake Ainslie has a pH of 7.8, and conductivity is 105 micromhos/cm.

Soils
On the higher elevations - up to 200 m - Diligence, Woodbourne, and Westbrook soils predominate. Diligence soils have developed from grey shales, and Woodbourne soils have developed from reddish-brown sandstones and conglomerates. Falmouth and Queens soils are chiefly found on low-lying areas below 30 m and overlying or adjacent to gypsum deposits. All of these soils, with the exception of Westbrook, are imperfectly drained loams or clay loams over relatively impermeable clay loam tills. The large area of sand between Lake Ainslie and the sea is an interesting feature. Coarse, well-drained Canning soils have developed on this sand plug.

Plants
As the highest and one of the most northerly units in the Carboniferous Lowlands Region, the Ainslie Uplands are part of the Sugar Maple, Yellow Birch-Fir Zone which encompasses many of the uplands in Nova Scotia (Region 300). This zone is distinguished by predominantly hardwood forest, in which Sugar Maple, American Beech, Yellow Birch, and Mountain Maple occupy the upper slopes and high ridges. Balsam Fir and White Spruce cover the upland flats and valley slopes. Black Spruce and Larch are found on the extensive clay soils throughout this area. Oldfields regenerating in White Spruce are common.

Animals
Small-mammal diversity is relatively high. Brook Trout and White Perch are typical freshwater species. Lake Ainslie has a rich and diverse aquatic fauna. Snails carry the larvae of the trematode parasites that affect people as "swimmers' itch."

Cultural Environment
Farming and forestry characterize land use. Coal was once mined at Mabou Mines. Barite was formerly mined at Lake Ainslie and continues to be extracted at other sites in this area.

Sites of Special Interest

• Strathlorne (Route 19) - a hummocky ridge of sand that dammed a river formerly flowing to Inverness and thus created Lake Ainslie; the lake now drains northward into the Margaree River
• Mabou Harbour mouth to West Mabou Harbour - gypsum area
• Black River (IBP Proposed Ecological Site 12) - alkaline sphagnum bog, including a number of rare plants such as Rhynchospora capillacea; Carex gynocrates; Eleocharis pauciflora, var. fernaldii; Salix candida; and Galium tinctorium

Ecological Park Reserves

• McFarlane Woods - old deciduous forest

Provincial Parks and Park Reserves

• North Ainslie
• Long Point
• Mabou
• Ainslie Point

Proposed Parks and Protected Areas System includes Natural Landscape 58.

Scenic Viewpoints

• Highway 395 (east shore of Lake Ainslie)
• Skye River Valley (Highway 252)

Associated Topics T2.4 The Carboniferous Basin T3.1 Development of the Ancient Landscape T3.3 Glaciation, Deglaciation and Sea-level Changes T3.4 Terrestrial Glacial Deposits and Landscape Features T8.1 Freshwater Hydrology T11.11 Small Mammals T12.3 Geology and Resources

Associated Habitats H3.1 Freshwater Open-Water Lotic H3.3 Freshwater Bottom Lotic H5.2 Oldfield H6.1 Hardwood Forest (Sugar Maple, Yellow Birch, Beech Association) H6.2 Softwood Forest (Spruce, Fir Association; Black Spruce, Larch Association) Associated Offshore Unit 914 Northumberland Strait