Editing Cape Breton Island (section)

== Geography ==
[[File:Cape Breton Island.png|thumb|upright=1.35|Map of select municipalities on Cape Breton Island]]
[[File:Cape Breton Island map.png|thumb|300px|Travel map of Cape Breton Island, with major highways and freeways marked]]
The irregularly-shaped rectangular island is about 100&nbsp;km wide and 150 long, for a total of {{convert|10311|km2|0}} in area.<ref>{{Cite web |title=Cape Breton Island {{!}} The Canadian Encyclopedia |url=https://www.thecanadianencyclopedia.ca/en/article/cape-breton-island |access-date=2021-08-11 |website=www.thecanadianencyclopedia.ca |archive-date=28 July 2021 |archive-url=https://web.archive.org/web/20210728034414/https://www.thecanadianencyclopedia.ca/en/article/cape-breton-island |url-status=live}}</ref>

It lies in the southeastern extremity of the [[Gulf of St. Lawrence]]. Cape Breton is separated from the [[Nova Scotia peninsula]] by the very deep [[Strait of Canso]]. The island is joined to the mainland by the [[Canso Causeway]].

Cape Breton Island is composed of rocky shores, rolling farmland, glacial valleys, barren headlands, highlands, woods and plateaus.

=== Geology ===
The island is characterized by a number of elevations of ancient [[crystal]]line and [[metamorphic rock]] rising up from the south to the north, and contrasted with eroded lowlands. The bedrock of blocks that developed in different places around the globe, at different times, and then were fused together via [[tectonics]].<ref name="roland">{{cite book |last1=Roland |first1=Albert E. |title=Geological background and physiography of Nova Scotia |date=1982 |publisher=Nova Scotian Institute of Science |location=Halifax, N.S. |isbn=0-919680-19-4 |pages=248–284}}</ref>

Cape Breton is formed from three [[terrane]]s. These are fragments of the Earth's [[Crust (geology)|crust]] formed on a [[tectonic plate]] and attached by [[Accretion (geology)|accretion]] or [[Suture (geology)|suture]] to crust lying on another plate. Each of these has its own distinctive geologic history, which is different from that of the surrounding areas. The southern half of the island formed from the [[Avalonia|Avalon terrane]], which was once a [[microcontinent]] in the [[Paleozoic]] era. It is made up of [[volcanic rock]] that formed near what is now called Africa.<ref name=":0">{{Cite web |last=Parks Canada Agency |first=Government of Canada |date=2018-01-05 |title=The formation of Cape Breton Island - Cape Breton Highlands National Park |url=https://www.pc.gc.ca/en/pn-np/ns/cbreton/decouvrir-discover/environ/geologie-geology/ile-island |access-date=2021-08-11 |website=www.pc.gc.ca |archive-date=11 August 2021 |archive-url=https://web.archive.org/web/20210811193158/https://www.pc.gc.ca/en/pn-np/ns/cbreton/decouvrir-discover/environ/geologie-geology/ile-island |url-status=live}}</ref> Most of the northern half of the island is on the Bras d'Or terrane (part of the [[Ganderia]] terrane). It contains volcanic and [[sedimentary rock]] formed off the coast of what is now [[South America]].<ref name=":0" /> The third terrane is the relatively small Blair River [[Inliers and outliers (geology)|inlier]] on the far northwestern tip. It contains the oldest rock in the Maritimes, formed up to 1.6 billion years ago.<ref name=":0" /> These rocks, which can be seen in the Polletts Cove - Aspy Fault Wilderness Area north of [[Pleasant Bay, Nova Scotia|Pleasant Bay]], are likely part of the [[Canadian Shield]], a large area of [[Precambrian]] [[Igneous rock|igneous]] and [[metamorphic rock]] that forms the core of the [[North America]]n continent.

The Avalon and Bras d'Or terranes were pushed together about 500 million years ago when the supercontinent [[Gondwana]] was formed. The Blair River inlier was sandwiched in between the two when [[Laurasia|Laurussia]] was formed 450-360 million years ago, at which time the land was found in the [[tropics]]. This collision also formed the [[Appalachian Mountains]]. Associated [[rift]]ing and [[Fault (geology)|faulting]] is now visible as the canyons of the [[Cape Breton Highlands]].<ref name=":1">{{Cite web |last=Parks Canada Agency |first=Government of Canada |date=2018-01-05 |title=The formation of the Cape Breton Plateau - Cape Breton Highlands National Park |url=https://www.pc.gc.ca/en/pn-np/ns/cbreton/decouvrir-discover/environ/geologie-geology/plateau |access-date=2021-08-11 |website=www.pc.gc.ca |archive-date=11 August 2021 |archive-url=https://web.archive.org/web/20210811212218/https://www.pc.gc.ca/en/pn-np/ns/cbreton/decouvrir-discover/environ/geologie-geology/plateau |url-status=live}}</ref> Then, during the [[Carboniferous]] period, the area was flooded, which created [[sedimentary rock]] layers such as [[sandstone]], [[shale]], [[gypsum]], and [[Conglomerate (geology)|conglomerate]]. Later, most of the island was tropical forest which later formed coal deposits.

Much later, the land was shaped by repeated [[ice age]]s which left [[Striation (geology)|striations]], [[till]], [[U-shaped valley]]s, and carved the Bras d'Or Lake from the [[bedrock]].<ref name=":1" /> Examples of U-shaped valleys are those of the [[Chéticamp River|Chéticamp]], [[Grande-Anse River|Grande Anse]], and Clyburn River valleys. Other valleys have been eroded by water, forming V-shaped valleys and [[canyon]]s. Cape Breton has many fault lines but few earthquakes. Since the North American continent is moving westward, earthquakes tend to occur on the western edge of the continent.

=== Climate ===
{{climate chart
| Sydney
|-9.6 | −1.1 | 152.5
|-10.3 | −1.5 | 128.1
|-6.7 | 1.5 | 130.0
|-1.6 | 6.6 | 133.3
|2.7 | 13.1 | 103.2
|7.7 | 18.6 | 96.9
|12.6 | 23.1 | 88.5
|13.1 | 22.9 | 100.2
|9.1 | 18.8 | 118.7
|4.3 | 12.6 | 142.9
|0.2 | 7.3 | 156.0
|-5.0 | 2.1 | 167.0
| float = right
| clear = none
| source = [[Environment Canada]]<ref name="CCN Sydney">{{cite web |url=http://climate.weather.gc.ca/climate_normals/results_1981_2010_e.html?stnID=6486&lang=e&amp;StationName=Sydney&amp;SearchType=Contains&amp;stnNameSubmit=go&dCode=1&dispBack=1 |title=Sydney NS |work=Canadian Climate Normals 1981–2010 |date=25 September 2013 |publisher=Environment Canada |language=English, French |accessdate=28 September 2015 |archive-date=4 March 2016 |archive-url=https://web.archive.org/web/20160304111843/http://climate.weather.gc.ca/climate_normals/results_1981_2010_e.html?stnID=6486&lang=e&StationName=Sydney&SearchType=Contains&stnNameSubmit=go&dCode=1&dispBack=1 |url-status=live}}</ref>}}

The warm summer [[humid continental climate]] is moderated by the proximity of the cold, oftentimes polar [[Labrador Current]] and its warmer counterpart the [[Gulf Stream]], both being dominant currents in the North Atlantic Ocean.

=== Ecology ===
==== Lowlands ====
There are lowland areas in along the western shore, around Lake Ainslie, the Bras d'Or watershed, [[Boularderie Island]], and the Sydney coalfield. They include salt marshes, coastal beaches, and freshwater wetlands.<ref name="eco" />

Starting in the 1800s, many areas were cleared for farming or timber. Many farms were abandoned from the 1920s to the 1950s with fields being reclaimed by [[Picea glauca|white spruce]], [[Acer rubrum|red maple]], [[Betula papyrifera|white birch]], and [[Abies balsamea|balsam fir]].<ref name="eco" /> Higher slopes are dominated by [[Betula alleghaniensis|yellow birch]] and [[Acer saccharum|sugar maple]]. In sheltered areas with sun and drainage, [[New England–Acadian forests|Acadian forest]] is found. Wetter areas have [[Larix laricina|tamarack]], and [[Picea mariana|black spruce]]. The weather station at Ingonish records more rain than anywhere else in Nova Scotia.<ref name="eco">{{cite web |last1=Neily |first1=Peter |last2=Basquill |first2=Sean |last3=Quigley |first3=Eugene |last4=Keys |first4=Kevin |title=Ecological Land Classification |url=https://novascotia.ca/natr/forestry/ecological/pdf/Ecological-Land-Classification-guide.pdf |access-date=12 August 2021 |publisher=Nova Scotia Department of Natural Resources |archive-date=12 August 2021 |archive-url=https://web.archive.org/web/20210812040653/https://novascotia.ca/natr/forestry/ecological/pdf/Ecological-Land-Classification-guide.pdf |url-status=live}}</ref>

Behind barrier beaches and dunes at [[Aspy Bay]] are [[salt marsh]]es. The Aspy, Clyburn, and Ingonish rivers have all created [[floodplain]]s which support populations of black ash, [[Fiddlehead|fiddle head]] fern, [[Decodon verticillatus|swamp loosestrife]], [[Asclepias incarnata|swamp milkweed]], [[Neottia bifolia|southern twayblade]], and [[Sanguinaria|bloodroot]].

Red sandstone and white gypsum cliffs can be observed throughout this area. Bedrock is Carboniferous sedimentary with [[limestone]], shale, and sandstone. Many [[Fluvial processes|fluvial]] remains from are glaciation found here. Mining has been ongoing for centuries, and more than 500 mine openings can be found, mainly in the east.<ref name="eco" />

[[Karst]] topography is found in Dingwall, South Harbour, Plaster Provincial Park, along the Margaree and Middle Rivers, and along the north shore of Lake Ainslie. The presence of gypsum and limestone increases soil [[pH]] and produces some rich wetlands which support [[Calliergon giganteum|giant spear]], [[Paludella squarrosa|tufted fen]], and other [[moss]]es, as well as vascular plants like [[Cyperaceae|sedges]].<ref name="eco" />

==== Cape Breton Hills ====
This ecosystem is spread throughout Cape Breton and is defined as hills and slopes 150-300m above sea level, typically covered with Acadian forest.<ref name="eco" />

It includes [[North Mountain (Nova Scotia)|North Mountain]], [[Kellys Mountain]], and [[East Bay Hills (Nova Scotia)|East Bay Hills]].

Forests in this area were cleared for timber and agriculture and are now a mosaic of habitats depending on the local terrain, soils and [[microclimate]]. Typical species include ironwood, white ash, beech, sugar maple, red maple, and yellow birch. The understory can include striped maple, [[Corylus cornuta|beaked hazelnut]], fly [[honeysuckle]], club mosses and [[fern]]s. Ephemerals are visible in the spring, such as [[Dicentra cucullaria|Dutchman's breeches]] and [[Claytonia|spring beauty]].<ref name="eco" />

In ravines, shade tolerant trees like [[Tsuga canadensis|hemlock]], white pine, [[Picea rubens|red spruce]] are found. Less well-drained areas are forested with balsam fir and black spruce.

==== Highlands and the Northern Plateau ====
The Highlands comprise a [[Table (landform)|tableland]] in the northern portions of [[Municipality of the County of Inverness|Inverness]] and [[Municipality of the County of Victoria|Victoria]] counties.

An extension of the [[Appalachian Mountains|Appalachian mountain chain]], elevations average 350 metres at the edges of the plateau and rise to more than 500 metres at the centre. The area has broad, gently rolling hills bisected with deep valleys and steep-walled canyons. A majority of the land is a [[taiga]] of balsam fir, with some white birch, white spruce, mountain ash, and heart-leaf birch.<ref name="eco" />

The northern and western edges of the plateau, particularly at high elevations, resemble arctic [[tundra]]. Trees 30–90 high, overgrown with [[Cladonia rangiferina|reindeer lichens]], can be 150 years old. At very high elevations some areas are exposed bedrock without any vegetation apart from [[Cladonia]] lichens. There are many barrens, or [[heath]]s, dominated by bushy species of the [[Ericaceae]] family.

[[Spruce]], killed by [[Choristoneura|spruce budworm]] in the late 1970s, has reestablished at lower elevations, but not at higher elevations due to moose [[Browsing (herbivory)|browsing]]. [[Decomposition]] is slow, leaving thick layers of [[plant litter]]. [[Groundcover|Ground cover]] includes [[Oclemena acuminata|wood aster]], [[Linnaea|twinflower]], [[Marchantiophyta|liverworts]], wood [[sorrel]], [[Clintonia borealis|bluebead lily]], [[Coptis|goldthread]], various ferns, and [[Lily of the valley|lily-of-the-valley]], with [[bryophyte]] and [[Solidago macrophylla|large-leaved goldenrod]] at higher elevations. The [[understory]] can include [[Acer pensylvanicum|striped maple]], mountain ash, ferns, and [[Acer spicatum|mountain maple]].<ref name="eco" />

Near water, [[Betula pumila|bog birch]], [[alder]], and [[Rowan|mountain-ash]] are found. There are many open [[wetland]]s populated with stunted [[Larix laricina|tamarack]] and black spruce. Poor drainage has led to the formation of [[Mire|peatlands]] which can support [[Trichophorum cespitosum|tufted clubrush]], [[Amelanchier bartramiana|Bartram's serviceberry]], [[Carex exilis|coastal sedge]], and [[Rubus chamaemorus|bakeapple]].<ref name="eco" />

==== Cape Breton coastal ====
The eastern shore is unique in that while not at a high elevation, it has a cool climate with much rain and fog, strong winds, and low summer temperatures. It is dominated by a boreal forest of black spruce and balsam fir. Sheltered areas support tolerant hardwoods such as white birch and red maple. Many salt marshes, fens, and bogs are found there.<ref name="eco" />

There are many beaches on the highly crenelated coastline. Unlike elsewhere on the island, these are rocky and support plants unlike those of sandy beaches. The coast provides habitat for common coast bird species like [[common eider]], [[Black-legged kittiwake|black legged kittiwake]], [[black guillemot]], whimbrel, and [[great cormorant]].

=== Hydrology ===
Land is drained into the [[Gulf of Saint Lawrence]] via the rivers [[Aspy River|Aspy]], [[Sydney River|Sydney]], [[Mira River (Nova Scotia)|Mira]], [[Framboise River|Framboise]], [[Margaree River|Margaree]], and [[Chéticamp River|Chéticamp]]. The largest freshwater lake is [[Lake Ainslie]].