Geology and Landscape Development
The Sydney Coalfield lies within an area of Pictou-Morien Group sandstones and siltstones which cover an area of about 1300 km2. Within 1,500-2,000 m of strata, about 1,300 m contain coal seams. The strata have been relatively undisturbed and lie in open folds that dip gently seawards at angles of 4-15°.

The area is mantled with sandy to stony till, and the coast offers the best geological exposures,

Englishtown Ferry, as seen from Kelly's Mountain Click to enlarge

although only a few layers can be seen at any one location. From Point Aconi to Port Morien, including the drowned estuary of Sydney River, exposures of sandstone with coal seams are found. One section northwest along the coast from Cranberry Point, which represents a 560-m vertical section, contains 34 coal seams, and fossil trees. A seam of coal one metre thick is exposed in the cliff at Point Aconi, and abundant plant fossils can be found in the shales on the beach. The shales are rich in leaves and other plant parts, but some beds contain only one species, for example, Sphenophyllum in the dark shales at Point Aconi.

The 12 productive seams in the Morien Group average 1-2 m in thickness. They are paralic in character; that is, they tend to be extensive laterally and end abruptly against rock benches rather than merge into shales. The seams also tend to divide laterally. These characteristics reflect their origins on a river floodplain.

Climate
Although rainfall is highest in November and snowfall is highest in January, total precipitation is highest in December when snow and rain occur interchangeably. The annual average fog occurrence is 80 days, with four days per month from December through February, and 11 days per month from May to July. Prevailing winds in fall and winter are from the west or north, and southwest or south-southwest in spring and summer.

Fresh Water
There are no major rivers in this Unit.

Blackett's Lake, Cape Breton County Click to enlarge

Many short streams and brooks form a modified trellis drainage pattern connecting numerous small lakes and ponds. There are four complete tertiary watersheds, parts of two others, and direct shoreline drainage. Streams have pH levels between 6.4 and 7.1, while lakes tend to average between 6.0 and 6.6. Ponds around Point Aconi are soft with shallow anaerobic bottoms. Extensive peat bogs are found in the depressions. Aquifers are confined by the low permeability of the overlying hills.

Soils
The topography in this Unit is fairly level. On the gently undulating areas away from the coast, well-drained Shulie soils have developed on stony, sandy loam tills. Towards the coast where the terrain is flatter, imperfectly drained Springhill and poorly drained Economy soils have developed from the same material.

Over much of the area the bedrock closely approaches the surface and can be readily observed as slabby sandstone outcrops along roadcuts and shorelines. Around Boularderie Island, imperfectly drained Diligence silt clay loams occur, with small areas of well-drained Falmouth soils formed over gypsum (see Unit 511), and some Hebert soils formed on outwash sands and gravels.

Plants
This Unit has a somewhat milder climate than much of the Carboniferous Lowlands, although cold strong winds from the northeast retard springtime warming. A second major factor has been the high degree of disturbance. The Unit lies within Loucks' Sugar Maple-Hemlock, Pine Zone, but repeated disturbance has resulted in a forest dominated by conifers - White Spruce, Black Spruce, Balsam Fir, and Larch. Shade-intolerant species occur on ridges in the coniferous forests, while the maple, aspen, and birch fire association is found on extensive burnt areas.

There are a few salt marsh areas with Eelgrass beds in Lingan Basin, Glace Bay, and Port Morien. Scouring by sea ice in winter limits the growth of marine algae.

Animals
A large proportion of this Unit is taken up by urban land uses and mammals include those typically found in proximity to developed areas such as deer, coyote, Red Squirrel, Snowshoe Hare, and Red-backed Vole. Elsewhere, mostly scrub or early

Puffin on Bird Island Click to enlarge

successional forest habitats are provided. Some Bald Eagle nesting habitat occurs. A significant faunal component exists along the coast, which includes vertical cliffs that provide seabird nesting sites, and sheltered bays cut off from the open sea by barrier beaches. There are few islands, but two of them, Ciboux and Hertford (Bird Islands), are nationally important nesting areas for Razorbill, Atlantic Puffin, Leach's Storm-petrel, and Black-legged Kittiwakes. Big Glace Bay Lake and Morien Bay provide stopover areas for modest numbers of migratory waterfowl but are of particular interest because a wide variety of species are included. The Piping Plover nests at the Glace Bay Sanctuary. Cormorant breeding colonies occur along the coast.

Cultural Environment
This Unit has been extensively clearcut for forestry and for transmission-line development. Spruce Budworm infestations have been notable.

Sydney boomed at the turn of the century with the building of the Dominion Steel and Coal Company steel plant at Whitney Pier. Coal was also excavated privately, and in a few areas around Glace Bay

Dominion Beach Click to enlarge

the land is unstable due to underground mine tunnels which have caused houses to shift and heave. Sydney Steel and Coal Company (Sysco) is primarily responsible for the creation of the Sydney Tar Ponds, the largest chemical waste site in the country. In 1986, a 10-year Tar Sands Clean Up program was launched - the largest toxic excavation project ever undertaken in Canada. At present, mines extend 8 km from shore under the Cabot Strait, and within the present 10-km economically mineable limit there are 1,000 million tonnes of recoverable coal.

At Coxheath near Sydney, copper occurrences were reported in 1825, with mining production taking place intermittently until 1896. Numerous sand and gravel deposits are commercially exploited in this area. Coal-generated steam turbine power plants at Glace Bay, Lingan, and Point Aconi supply electrical power to the province. Small-scale farming has taken place along the Mira River, and stretches along the river are now cottage country. Outdoor recreational attractions in this area include the Bird Islands, famous for their breeding colonies of Razorbill, Atlantic Puffin, and other seabirds.

Sites of Special Interest

• Coastline northeast of Cranberry Head - 34 coal seams and fossil trees
• New Waterford to Morien Bay - Coastal exposure of the Upper Carboniferous sediments of the Cape Breton coalfield, with plant and animal fossils, including species found nowhere else in North America
• Point Aconi - coastal exposure of Upper Carboniferous sediments with upright tree fossils; plant imprints and fossils in the shales along the beach
• Bird Islands (IBP Proposed Ecological Site 24) - bird nesting site, with rare arctic-alpine plants, one island owned by the Nova Scotia Bird Society, the other by the Department of Natural Resources
• Big Glace Bay Lake Migratory Bird Sanctuary
• Miner's Museum, Glace Bay - outlines aspects of the area's mining history and portrays the life of miners who work the Sydney coalfields in tunnels that stretch miles under the ocean floor

Provincial Parks and Park Reserves

• Groves Point
• Big Bras d'Or
• Dalem Lake
• Dominion Beach
• Lingan

Proposed Parks and Protected Areas System includes Natural Landscape 56.

Scenic Viewpoints

• Dominion cemetery - view over Indian Bay to Lingan power station
• New Waterford, eastern edge - operating coal mine (Lingan) and Lingan power station
• Point Aconi (north end of Highway 162) - operating Prince coal mine and power station

Associated Topics T2.4 The Carboniferous Basin T4.2 Post-glacial Colonization by Plants T6.2 Oceanic Environments T7.3 Oceanic Environments T8.3 Freshwater Wetlands T9.3 Biological Environment T10.1 Vegetation Change T11.6 Shorebirds and Other Birds of Coastal Wetlands T11.7 Seabirds and Birds of Marine Habitats T12.3 Geology and Resources T12.12 Recreational Resources

Associated Habitats H5.3 Cliff and Bank H4.1 Bog H6.1 Hardwood Forest (Maple, Oak, Birch Association) H6.3 Mixedwood Forest (White Spruce, Fir-Maple, Birch Association) Associated Offshore Unit 915 Sydney Bight