Geology and Landscape Development
This District extends from Economy to Cape Chignecto along the northern shore of the Minas Basin. The geology and landscape are varied and interesting. Parallel faults and juxtaposed resistant basalts and erodable sandstones create a varied landscape of hills and lowlands, bays, cliffs, and headlands (see Figure 5).
The area has been cut by three major faults into a series of slices which have minor faults within them. At the base of the Cobequids, the east-west trending Cobequid Fault forms the northern boundary of the District and sets Carboniferous strata against the ridge of the Cobequid Hills (Unit 311). Here they form a line of hills from Cape Spencer to the eastern border of the District and beyond. Cliffs have formed along Greville Bay where these strata reach the coast. Further south, the Portapique Mountain Fault (which extends eastwards from Partridge Island) has brought younger erodable Triassic sandstone and resistant basalt into contact with Carboniferous deposits. Within this block, a smaller
east-west fault, the Gerrish Mountain Fault, and other small crosscutting faults further divide the bedrock into small blocks. These have shifted vertically and in some cases have tilted.
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From Economy to Partridge Island the hilly landscape reflects the contrasting resistance to erosion of basalt and Triassic sandstones. The sandstone is very soft and normally forms lowlands. However, where it is capped by basalt, it forms high, steep-sided hills, for example, Portapique Mountain (150 m), an unnamed hill north of Lower Economy (180 m), Economy Mountain (245 m), and Spencers Island (150 m). The high sandstone cliffs at Five Islands Park and on the islands themselves result from the protective effect of basalt. Some of the high basalt-capped blocks have cliffs with columnar jointing; for example, Partridge Island, Cape Sharp, and Spencers Island. Semiprecious stones are found in the amygdaloidal basalts at Partridge Island.
Exposed Triassic sandstone is easily eroded. At Lower Economy a tidal platform more than one mile wide has been cut by wave attack on the coastal exposures of these rocks. The low Triassic area
immediately north of Cape d'Or will presumably eventually be removed completely, leaving the basalt-capped sediments as stacks, similar to Five Islands and Isle Haute (in Unit 810).
|Cape d'Or, Cumberland County
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Near the village of Parrsboro, younger Jurassic sediments which lie on top of the basalt are known to contain dinosaur bones and footprints.
Large glacial outwash deposits are common along the Parrsboro shore. The town of Advocate is built upon an outwash plain. The harbour is enclosed by a bar and cobble beaches derived from gravels eroded from the outwash deposits. In immediate post-glacial time, about 13,000 years ago, a higher sea level created beaches on the hillside north of the present village. These raised beaches are remarkably similar to those in the present Advocate Harbour. At Parrsboro and throughout the District a nearly horizontal wave-cut surface can be seen on the glacial outwash gravels. This surface, eroded at the same time as the Advocate raised beach was being formed, gradually descends eastwards. The sloping nature of the former shoreline is conclusive evidence of differential recovery of the coast since the last glaciation and, hence, of differential crustal loading during the glaciation.
District 710 falls within two secondary watersheds that divide into numerous tertiary drainage areas and direct shoreline drainage into the Minas Channel and Basin. Streams draining this District tend to be straight and fast-flowing, with narrow, steep-sided valleys. There are many waterfalls. The mouths of the Parrsborro and Diligent rivers occur here. Many small bogs and shrub swamps are scattered throughout.
|Diligent River, view of Cape Split
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The principal soils in this area are the Kirkhill and Diligence series. Both are developed on tills from shale of the Riversdale Group. However, Diligence shales are softer and produce clay loam soils, while Kirkhill shales produce shale loam soils. Other soils in the area have formed from extensive deposits of gravel laid down as glacial and post-glacial outwash plains. These soils are mapped as Hebert gravelly loams.
The coastal forest is somewhat modified because the climate moves through a transition from maritime to continental. Spruce, Eastern Hemlock, and pine forests with shade-intolerant birches, maple and aspen are found here, together with the more common spruce, fir and pine forest. Pure stands of pioneer White Spruce are found on oldfields. Blueberry fields are scattered on former farmlands in lowlands and sometimes far up the slopes. The exposed cliffs at Cape d'Or provide habitat for locally rare arctic-alpine plant species.
|Purple Trillium, Cape Split
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Some small salt marshes are found along the shore, but there is generally no Eelgrass. As turbidity of coastal waters diminishes westwards, seaweeds increase, for example Laverbread.
The shore provides wintering habitat for deer coming down from the Cobequid Hills. Deer winter in softwood areas and in spring are often seen in fields. In winter the coastal waters remain open and there
is less accumulation of broken ice than is found further up the Bay of Fundy. Black Duck winter at Advocate Harbour and Parrsboro Harbour, and small numbers of other waterfowl species such as Common
Goldeneye and Bufflehead are sighted along this coast during the winter.
Pinnacle Island at Five Islands and Spencers Island provide breeding areas for Double-crested Cormorant, Common Eider, Great Blue Heron, Herring Gull, and Black-backed Gull. Black Guillemot nest
at Spencers Island. There are a few other breeding sites for gulls and cormorants.
In summer, large flocks of mostly male Common Eider are observed along the coast. Scoters and second-year loons are also seen. Cape d'Or and Five Islands have been release sites for a Peregrine Falcon reintroduction program. Blomidon is another release site (District 720). Bald Eagle nest near Five Islands.
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The tidal flats and salt marshes at Advocate Harbour attract some migratory shorebirds, but not the huge numbers found in the larger mud-flat areas of the Bay of Fundy. Smaller numbers of varied species are seen, for example, Ruddy Turnstone and Black-bellied Plover. Willet and Sharp-tailed Sparrow are also seen, and Vesper Sparrow occurs in blueberry fields.
The shoreline is mostly gravel with considerable silt. The marine fauna is characteristic of rocky, cobbly, and muddy shores but with limited diversity because of the silty water. Shells of Slipper Limpets, sponges, and Hornwrack are commonly found washed ashore.
The varied relief of this District allows a frequently changing scene. Basalt-capped hills jut out into the bay as cliff-lined headlands (and sometimes as islands). Behind them, a band of lowland is backed inland by the fault scarp of the Cobequid Hills. Panoramas across the bay are seen at some points, while at others one finds intimate scenes along small inland valleys (e.g., along the Diligent and Parrsboro rivers). Settlement is light, but sufficient to create interest. Overall, this small District is one of the most scenic in mainland Nova Scotia.
At the beginning of the seventeenth century, Champlain reported the presence of native copper on this shoreline. As a result he called this site "Cap des Mines," referring to an attempt to mine copper. Later it became known by the French as Cape d'Or (Golden Cape), even though copper is the principal mineral found here. Many interesting legends surround the great cliffs, beaches, and masses of rocks at Five Islands. According to one, these islands were great pieces of earth which Kluskap (Glooscap), the divine warrior, threw in a rage at his ancient enemy, the beaver. Fishing has always been economically important to communities on the Basalt Headlands. In the distinctive weir-fishing methods of this area, fish are trapped in walled nets with the rise and fall of the Fundy tide. A fleet of small boats works out of Advocate Harbour mainly for scallop, lobster, and Winter Flounder. Clamdigging has been commercially important here, but overexploitation led to the development of clamdigging regulations in 1993. Kelp is picked at extreme low tide near Cape d'Or. In the nineteenth century, communities on the Basalt Headlands were well known for shipbuilding, using local timber. Forestry and farming have been characteristic land uses. Fossil-bearing cliffs are distinctive in this area, and fossil finds on the Basalt Headlands include some of the earliest dinosaurs.
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Sites of Special Interest
- Parrsboro Shore, Five Islands to West Bay - long coastal section of basalt lavas and sediments across the Triassic-Jurassic boundary, fossils include fishes, and bones and trackways of dinosaurs and
other reptiles; the site is protected under the Special Places Protection Act
- Cape d'Or (IBP Proposed Ecological Site 1) - windswept headland providing arctic-alpine habitat; plants include two species of Milk-vetch
- Moose River (IBP Proposed Ecological Site 7) - mature Red Spruce forest
- Economy Mountain Lookoff - to north and west, the steep escarpment of Cobequid Fault; in the foreground, low-lying Carboniferous and Triassic sediments
- Moose Island - agate and basalt sea stacks
- Partridge Island - semiprecious minerals
- West Bay - angular unconformity; fossil rain prints, ripple marks, mud cracks, channel
- Advocate - raised beaches 35 m above high water; spit across harbour
- Isle Haute - an island of Jurrasic basalt is clearly visible from Cape d'Or; included in Unit 810 because of its open coastal character, with White Spruce forests, even though the main part of the Unit
is some distance away on Digby Neck; the fauna is poorly known but includes nesting Common Eider and Black Guillemot
- Wasson Bluff - important exposed Triassic-Jurassic boundary with trackways and fossils, including those of early dinosaurs and other reptiles; site protected under the Special Places Protection
Act; information available at the Fundy Geological Museum at Parrsboro
Provincial Parks and Park Reserves
- Five Islands Provincial Park - dinosaur bones and footprints below park; geological and estuary interpretation trails
- Economy Mountain Lookoff (view northwards)
- Five Islands Provincial Park (view west to Five Islands)
- Clarke Head Trail
- Highway 209, Greville Bay shore
- Cape d'Or Trail
|T2.6 The Triassic Basalts and Continental Rifting|
| Terrestrial Glacial Deposits and Landscape Features|
|T4.2 Post-glacial Colonization by Plants|
|H5.3 Cliff and Bank|
|H6.2 Softwood Forest (Spruce, Hemlock, Pine Association)|
|Associated Offshore Units|
|912 Outer Fundy|
|913a Minas Basin|