The Windsor Lowlands Unit is divided into two sub-Units:
(a) Shubenacadie River
(b) East Mountain
The Windsor Lowlands cover a very large area south of the Minas Basin, from the Avon River east to the Shubenacadie and Stewiacke river valleys (sub-Unit 511a), and a small area north of Truro (sub-Unit 511b). These two areas are part of the same depositional area and have the same characteristics.
Geology and Landscape Development
The southern boundary of sub-Unit 511a against the Atlantic Interior is essentially identical to the shoreline of the Carboniferous depositional basin in this part of Nova Scotia.
The Horton deposits range in thickness from zero at the margins to nearly 1,000 m near North Mountain. The Wittenburg Ridge was an upland at the time of deposition, and the Horton deposits thin out on its flanks. It is evident that the Rawdon Hills were not uplands because the same thinning does not occur. Good exposures of Horton strata are found at Victoria Park in Truro, and at Horton Bluff, where fossiliferous middle Horton sandstone and shales outcrop. During the period in which deposition was taking place from the Windsor sea, reefs formed near the shoreline. One of these, north of Wittenburg Ridge, is at Gays River; others are found on the Atlantic Coast at East River and Aspotogan, where they developed in another arm of the sea which extended to Sable Island.
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The Windsor Group deposits are about 425 m thick and overall consist of about 50 per cent shales and 25 per cent each of limestone and gypsum. From Windsor to Brooklyn, white cliffs of gypsum can be seen from the road. A wide area of gypsum is preserved in the Cheverie syncline.
The mantle of glacial till attains a thickness of 75 m near Stewiacke. Under the glacial till at Dutch Settlement, spruce branches have been found dating back to the Wisconsinan glaciation 18,000 years ago. The East Milford gypsum quarry has provided much information on glacial tills and the character of interglacial life. There have been many finds of plants and freshwater animals in ancient sinkholes. Remains of mastodon and other animals were discovered in 1991-93 and provisionally dated as 70,000 years old. Sands and gravels are seen in many locations, including the Stewiacke River and its South Branch, and at Hilden, south of Truro.
The landscape generally has low elevations and little relief, and the river system has a rectangular pattern. The rivers tend to be slow-moving mature floodplain rivers with associated intervales. The Kennetcook, Avon, and Shubenacadie are influenced by the tidal actions of the Bay of Fundy. Water flow in the river valleys fluctuates greatly, sometimes flooding extensively. Small lakes are scattered throughout the Unit, including oxbow and solution lakes. An excavated lake occurs at the East Milford quarry in sub-Unit 511a.
Most of sub-Unit 511a falls within two secondary watersheds draining north into Cobequid Bay. The Avon River (see Figure 16) cuts across low ridges whose intervening valleys are occupied by its tributaries. The Halfway and Cogmagun rivers flow into the Avon estuary from the west and east sides, respectively. The Upper Avon, Kennetcook, and St. Croix rivers lie parallel on either side of the estuary. The lower part of the Avon River valley has been drowned, forming a wide estuary which extends into the tributary rivers. The red silt that forms the wide mud banks within the river is derived from erosion of the Triassic deposits and is carried in from the Minas Basin. The upper courses of these rivers meander widely across a lowland bordered by tidal marshes and meadows. The Avon River may occupy a course similar to its ancestral river, which, it is hypothesized, flowed northwards from the southern uplands during the Cretaceous.
The Shubenacadie River, like the Avon, cuts across the fold axes and bands of hard and soft strata, reaching Cobequid Bay west of Truro. At its mouth a narrow band of Horton rocks overlain by Windsor limestone can be seen at Black Rock. For the next five kilometres inland, it cuts through soft red sandstone containing bands of fibrous gypsum (see Figure 11). North of the South Maitland bridge the river cuts a narrow channel through a faulted block of coarse Horton grits. To the south, a cliff of gypsum is exposed at Big Plaster Rock. Further up the river, passing more grits and red sandstone, a fossiliferous limestone containing corals and shells is exposed at Anthonys Nose.
The Stewiacke River, a major tributary of the Shubenacadie River, flows parallel to the fold axes. The relief and altitude in this area are so low that neighbouring streams flow for long distances in opposite directions. For example, the South Branch follows a narrow bed of Windsor Group rocks northeast, while the Stewiacke flows southwest. Many oxbow lakes are associated with the Stewiacke.
The southeastern portion of sub-Unit 511a falls within the Atlantic coast drainage area, and many first- and second-order streams feed into the Musquodoboit River as it meanders towards Musquodoboit Harbour.
Wetlands include flat bogs and fens and large freshwater marshes. Tidal marshes are scattered along the St. Croix, Avon, and Kennetcook rivers.
Surface-water productivity and diversity are generally high, and pH averages 7.5. Groundwater is high in dissolved minerals, particularly around Windsor and in areas associated with karst topography. There are several aquifers along the Stewiacke River.
Shubenacadie River (sub-Unit 511a)
A considerable variety of soils is found in this area, but the dominant series is Queens, an imperfectly drained, sandy clay loam developed on clay loam till derived from shale and sandstones. Well-drained Hansford sandy loams have developed on Horton sandstone in the Hantsport-Walton area. Mottled Hantsport soils, also from shales and sandstones, are found in low-lying areas and close to the coast. Drumlinoid features are common from Brookfield to Enfield, and lacustrine deposits often occur on the till plain. Alluvial soils such as Stewiacke, Cumberland, and Chaswood often occur along stream and river valleys. These range in texture from gravelly sandy loams to silty clay loams.
East Mountain (sub-Unit 511b)
The main soil series in this sub-Unit is Diligence, an imperfectly drained clay loam over clay till derived from grey shales. Along North River, Cumberland gravelly sandy loams occur.
The main factors influencing the vegetation of this Unit are the gentle relief, poor drainage, and the repeated cutting and burning of the forests. The spruces, fir, White Birch, Red Maple, Eastern Hemlock, and White Pine are the major species, with scattered Sugar Maple, American Beech, and Yellow Birch occurring on better-drained low ridges. Abandoned farmlands are common and have usually been recolonized by White Spruce, Red Spruce, and Balsam Fir. In other areas, repeated burning has encouraged Wire Birch, White Pine, Red Pine, and Black Spruce. Repeated disturbance sometimes leads to the development of semi-permanent shrub cover. American Elm, Black Ash, the occasional Sugar Maple and American Beech may be found along the rivers.
C.D. Howe made the following observations on the soil-forest relationships of this area in 1912: Along the coast, the ridges
are capped with hardwoods and the depressions support a mixed forest in which either red spruce or hemlock prevails; and frequently, the conifers occur in pure stands. The mixed forest is very luxuriant on the broad gentle slopes where the composition is from one-half to three-fourths red spruce and usually about 15 percent is yellow birch and five percent beech. The soil is deep and consists mostly of silt and fine sand. When the top of the ridges are narrow, they are crowned with hardwoods, otherwise the mixed type extends over them.
|Smileys Provincial Park, Hants County
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This Unit offers a mix of lowland, disturbed forest habitats, scattered farmlands, some dykelands, tidal marshes, and fertile river valleys. The mix of land types and fertility provides habitat for a great variety of Nova Scotia wildlife. Deer, which are creatures of edge habitat, thrive in the Windsor Lowlands. Some deer are concentrated in the upper basin of the Stewiacke, but because of the low topography throughout this Unit, there are no huge winter concentrations like those which occur at the foot of the Cobequid Hills (Unit 311). Moose are occasionally seen, but for the most part are absent.
There are few lakes, but the rivers and streams are comparatively productive and the freshwater fauna is diverse. The Unit provides good habitat for raccoon, muskrat, and mink, and diverse breeding habitats for waterfowl. Significant wetland habitats occur at South Branch and Otter Brook. Wood Turtles are abundant in the Musquodoboit Valley and in the Kennetcook and Five Mile Rivers. River Otter find good habitat associated with the major rivers, and beaver are common. Beaver dams do not persist and lodges are often built into riverbanks. Shallow, eutrophic Lake Egmont and its associated freshwater marsh provide one of the richest freshwater plant and animal localities in the province.
The tidal waters of the Shubenacadie and Stewiacke rivers allow anadromous fish species to reach fresh water for spawning, and allow their offspring access to the ocean, where they mature. Striped Bass occur in both rivers, and many thousands of American Shad spawn in the Stewiacke. Faster-flowing streams that feed the Stewiacke River are important spawning and nursery areas for Atlantic Salmon. Brown Trout, which is an introduced species, and Brook Trout also inhabit the Stewiacke River.
The anadromous Atlantic Tomcod spawns in the Shubenacadie River in January, attracting concentrations of 50-100 Bald Eagles. The greatest concentrations of eagles occur in the Riverside area. Besides winter visitors, Bald Eagles are seen around roughly 10 or more nesting sites in this Unit in summer. Common Mergansers and Black Ducks overwinter here.
Ospreys have recently become more numerous, and Canada Geese also nest in this Unit. Ring-necked Pheasant can be found here, but in much smaller numbers than in the Triassic Lowlands (Region 600).
A cave near South Maitland is a significant bat hibernation site.
Many parts of the Windsor Lowlands were favourite spots of the Mikmaq for hunting and fishing, and many place names in this area are of Mikmaq origin. The name Shubenacadie is derived from the Mikmaq word meaning place where groundnuts grow. It has long been a Mikmaq settlement and today features one of the largest Mikmaq communities in the province. The name Stewiacke is also derived from Mikmaq and means flowing out in small streams and whimpering or whining as it goes.
In the seventeenth century the Acadians settled in the Windsor Lowlands, including along the St. Croix River, the Avon River (which the Acadians called the Pisiquid), and the Kennetcook River (known to the Acadians as the Quenetcou). Dyking significantly altered the coastal and estuarine landscape.
After 1760, New England Planters settled on vacant dykelands and employed remaining Acadians to maintain them. Soon Germans, Yorkshiremen, and a huge influx of Loyalists came to the Windsor Lowlands to farm its fertile soils. Parts of the Windsor Lowlands are today some of the most productive farming areas in Nova Scotia. Much of this area has also been logged for its timber, and many lumbering and sawmill operations are found here.
The mineral resources of the Windsor Lowlands have long attracted mining operations. In 1876, manganese was first mined in Tennycape and the mineral was produced intermittently for the next three decades. Mining operations at Milford, Miller Creek, and Wentworth Creek, among others, exploit the large deposits of gypsum and anhydrite. At Dutch Settlement (Hants County) the gypsum beds are 60 m thick. One billion tonnes have been blocked out and another four billion are in reserve. A large barite deposit near Walton was mined for 30 years, but the mine closed in 1971. Clay and shale deposits at Lantz, Milford, and Shubenacadie are exploited to produce virtually all the provinces supplies of brick. Dolomite is quarried for agricultural purposes at Upper Musquodoboit.
A large outwash deposit known as the Hardwoodlands Aquifer is found south of the Shubenacadie Indian Reserve. It is a significant freshwater resource in an area of saline groundwater.
Sites of Special Interest
Avon River Area
- Horton Bluff (north of Hantsport) - fossil plants, invertebrates, fish, amphibian bones, and tracks (including the largest footprints of Horton Group age ever reported)
- Blue Beach, Hants County - Early Carboniferous strata with bones and footprints of early amphibians and reptiles
- Newport Landing (northeast of wharf) - good exposure of early Windsor Group fossiliferous limestone containing brachiopods, gastropods, bryozoans, cephalopods, and pelecypods; this is underlain by gypsum, limestone, shale, sandstone; fossil corals outcrop on the shore
- Cheverie (near Mutton Cove) - late Horton-age tree stumps 10-20 cm high and 10-30 cm in diameter, karst topography
- Cheverie Point to Summerville - Horton-age soil beds with rootlets
- Wolfville to Windsor (along Highway 101) - road runs along the Wolfville Ridge anticline with the Gaspereau syncline to the south
- Hantsport - road descends into the syncline of Halfway River and up the slope of the next anticline (Grey Mountain)
- Brooklyn - in a gypsum area to the west, Yellow Ladys-slipper, Shepherdia, and Carex flacca are found
|View from Shand House
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- Gypsum areas (karst topography) - Cheverie, Walton through Goshen to Lower Burlington, Mount Denson to Windsor Forks to Newport Corner; gypsum cliffs along the St. Croix River; sinkhole behind Kings-Edgehill School
- St. Croix River (IBP Proposed Ecological Site 66) - mixed forest on karst topography harbouring rare orchids
- Shand House Museum, Windsor - products of the former Windsor Furniture Company
Shubenacadie River Area
- Black Rock (mouth of Shubenacadie) - Horton strata overlain by Windsor limestone
- Eagles Nest (Shubenacadie River) - Horton sandstone
- Big Plaster (Whites) Rock - gypsum cliff
- Anthonys Nose (Shubenacadie River) - fossiliferous limestone, 15 m thick, containing shells and corals
- Victoria Park (Truro) - steeply inclined Horton sandstone and siltstone
- Gypsum areas (karst topography) - Urbania (south of Maitland), South Maitland (Hayes Cave), East Milford (large working gypsum quarry, site of mastodon finds), Dutch Settlement
- East Milford quarry, Halifax County - removal of the overburden of glacial till as part of gypsum mining operations frequently uncovers fossiliferous interglacial deposits. Fossils of plants, insects, molluscs, and vertebrates, including mastodon remains, are found, particularly in deposits in sinkholes
- Lantz - clay for brickmaking
- Shubenacadie (IBP Proposed Ecological Site 68) - clearcut in mixedwoods, regenerated with Leatherwood; Carex aurea; Milium effusum, var. cisatlanticum; Bulblet Fern; and Alder-leaved Buckthorn
- South Maitland (IBP Proposed Ecological Site 69) - river intervale, gypsum cliffs, mixed forest, and cave system
- Lawrence House Museum, Maitland - shipbuilding history
- Creighton Forest Environment Centre, entrance of Shubenacadie Wildlife Park - documents historical aspects of forestry and wildlife in Nova Scotia
- Lake Egmont - diverse freshwater community
Provincial Parks and Park Reserves
- Shubenacadie Wildlife Park
- Musquodoboit Valley
- St. Croix
- South Maitland
Proposed Parks and Protected Areas System includes Natural Landscape 28
- Avon area - Highway 101 near exit 4 (view of St. Croix floodplain, gypsum cliffs); Highway 101 south of Hantsport, looking north (view of Minas Basin)
- Shubenacadie area - Highway 102 north of exit 9, looking east (view of large dairy farms); Highway 102 north of exit 11 (view of tidal Stewiacke River)
- Caddell Rapids - lookoff
The Carboniferous Basin
Ancient Drainage Patterns
Terrestrial Glacial Deposits and Landscape Features
Rare and Endangered Plants
Birds of Prey
Amphibians and Reptiles
Geology and Resources
Plants and Resources
Cliff and Bank
Hardwood Forest (Sugar Maple, Elm Association)
Softwood Forest (White Spruce Association; Pine Association)
Mixedwood Forest (Spruce, Fir, Pine-Maple, Birch Association)