The East Bay Hills
[Geographical Names of Canada - East Bay Hills](_blank)
/ref> refer to a 'fault ridge' of ancient rock on the south side of the East Bay
The East Bay is the eastern region of the San Francisco Bay Area and includes cities along the eastern shores of the San Francisco Bay and San Pablo Bay. The region has grown to include inland communities in Alameda and Contra Costa countie ...
of the Bras d'Or Lake
Bras d'Or Lake (Mi'kmaq language, Mi'kmawi'simk: Pitupaq) is an irregular estuary in the centre of Cape Breton Island in Nova Scotia, Canada. It has a connection to the open sea, and is tidal. It also has inflows of fresh water from rivers, ma ...
, located on Cape Breton Island
Cape Breton Island (french: link=no, île du Cap-Breton, formerly '; gd, Ceap Breatainn or '; mic, Unamaꞌki) is an island on the Atlantic coast of North America and part of the province of Nova Scotia, Canada.
The island accounts for 18. ...
, Canada
Canada is a country in North America. Its ten provinces and three territories extend from the Atlantic Ocean to the Pacific Ocean and northward into the Arctic Ocean, covering over , making it the world's second-largest country by tot ...
, and are an extension of the Appalachian mountain chain. The East Bay Hills lie in Cape Breton County
Cape Breton County is one of eighteen counties in the Canadian province of Nova Scotia. It is located on Cape Breton Island.
From 1879 to 1995, the area of the county excluded from towns and cities was incorporated as the Municipality of th ...
.
The East Bay Hills rise to little more than , forming low ridges in an otherwise lowland landscape. These hill are largely uninhabited (by humans), and include the highest elevation point on Cape Breton Island south of the Bras d'Or Lake at Sgurra Bhreac with a commanding view of the Mira area and Atlantic Ocean
The Atlantic Ocean is the second-largest of the world's five oceans, with an area of about . It covers approximately 20% of Earth's surface and about 29% of its water surface area. It is known to separate the " Old World" of Africa, Europe ...
to the south.
Geology and landscape development
The East Bay Hills are an elongated block of Precambrian
The Precambrian (or Pre-Cambrian, sometimes abbreviated pꞒ, or Cryptozoic) is the earliest part of Earth's history, set before the current Phanerozoic Eon. The Precambrian is so named because it preceded the Cambrian, the first period of the ...
rocks and is composed of two rock types: primarily volcanic
A volcano is a rupture in the crust of a planetary-mass object, such as Earth, that allows hot lava, volcanic ash, and gases to escape from a magma chamber below the surface.
On Earth, volcanoes are most often found where tectonic plates a ...
deposits of the Fourchu Group (ash and lava interleaved with marine sediments), but also granites. They are elongated northeast–southwest in accordance with the same prevailing trend of faults which dominates the geological structures of the North Bras d'Or Uplands. The southeastern margins are also faulted, in this case bringing the resistant Precambrian strata against late Carboniferous
The Carboniferous ( ) is a geologic period and system of the Paleozoic that spans 60 million years from the end of the Devonian Period million years ago ( Mya), to the beginning of the Permian Period, million years ago. The name ''Carbonifero ...
sandstone
Sandstone is a clastic sedimentary rock composed mainly of sand-sized (0.0625 to 2 mm) silicate grains. Sandstones comprise about 20–25% of all sedimentary rocks.
Most sandstone is composed of quartz or feldspar (both silicates) ...
s and siltstone
Siltstone, also known as aleurolite, is a clastic sedimentary rock that is composed mostly of silt. It is a form of mudrock with a low clay mineral content, which can be distinguished from shale by its lack of fissility.Blatt ''et al.'' 1980, p ...
s. On the northeastern side the contact is with easily eroded Carboniferous Windsor Group strata, which were deposited directly against the blocks when they stood as islands in the Carboniferous Sea.
In form and structure the relief and elevations of the East Bay Hills reflect not only their geological setting, surrounded by rocks of varying resistance, but also their position on the low side of the planation surface
In geology and geomorphology a planation surface is a large-scale surface that is almost flat with the possible exception of some residual hills. The processes that form planation surfaces are labelled collectively planation and are exogenic (chi ...
. Precambrian rocks of equivalent resistance have created dominant uplands further north in Cape Breton, but here, where there was little uplift during the Tertiary
Tertiary ( ) is a widely used but obsolete term for the geologic period from 66 million to 2.6 million years ago.
The period began with the demise of the non-avian dinosaurs in the Cretaceous–Paleogene extinction event, at the start ...
, there was also minimal rejuvenation of erosion
Erosion is the action of surface processes (such as water flow or wind) that removes soil, rock, or dissolved material from one location on the Earth's crust, and then transports it to another location where it is deposited. Erosion is distin ...
al action and limited exposure of this hard core of old rocks.
The steepest slopes are found on the northwest side of the East Bay Hills, where soft Windsor Group rocks form a narrow band along the shore. The valley of Breac Brook, at the north end of East Bay Hills, appears to be an ancient coastal valley which was filled by Windsor Group deposits and is now being exhumed. The fault line on the southeastern margin can be seen in some areas (e.g., northeast of Oban) but in general does not form a prominent scarp slope.
In this part of Cape Breton south of Bras d'Or Lake, glaciation more than geological structure appears to have influenced drainage patterns. South of East Bay Hills the glacial direction is strongly northeast–southwest, in this case parallel to the fault which defines their southern boundary.[
]
Fresh water
The East Bay Hills have relatively flat plateau-like crests which are poorly drained. Most streams are located on the margins and are aligned northeast, reflecting the glacial direction. The hills contains several lakes and a few scattered raised bogs.
Soils
Heavily podzol
In soil science, podzols are the typical soils of coniferous or boreal forests and also the typical soils of eucalypt forests and heathlands in southern Australia. In Western Europe, podzols develop on heathland, which is often a construct of hum ...
ized Thom soils with a thick iron humate B horizon cover most of the hills. They are associated with Arichat soils (poorly drained, mottled, sandy loam
Loam (in geology and soil science) is soil composed mostly of sand (particle size > ), silt (particle size > ), and a smaller amount of clay (particle size < ). By weight, its mineral composition is about 40–40–20% concentration of sand–sil ...
s), found where the relief is gently undulating or depressional. There are also small areas of peat
Peat (), also known as turf (), is an accumulation of partially decayed vegetation or organic matter. It is unique to natural areas called peatlands, bogs, mires, moors, or muskegs. The peatland ecosystem covers and is the most efficien ...
.
Plants
These hills are somewhat lower than the North Bras d'Or Hills and shade-tolerant hardwoods, although present, are not dominant. The East Bay Hills support instead mixed stands of Red Maple, White Birch, Yellow Birch, American Beech, Balsam Fir, and White Spruce.
Animals
There are few moose
The moose (in North America) or elk (in Eurasia) (''Alces alces'') is a member of the New World deer subfamily and is the only species in the genus ''Alces''. It is the largest and heaviest extant species in the deer family. Most adult mal ...
in this area. Deer
Deer or true deer are hoofed ruminant mammals forming the family Cervidae. The two main groups of deer are the Cervinae, including the muntjac, the elk (wapiti), the red deer, and the fallow deer; and the Capreolinae, including the reindeer ...
are found on side slopes in winter yards. There are a large number of eagle
Eagle is the common name for many large birds of prey of the family Accipitridae. Eagles belong to several groups of genera, some of which are closely related. Most of the 68 species of eagle are from Eurasia and Africa. Outside this area, just ...
nests in stream ravines.
Tourism
The hills offer views north over Bras d'Or Lake, for example, where Highway 4 climbs above shore level near Irish Cove
Irish may refer to:
Common meanings
* Someone or something of, from, or related to:
** Ireland, an island situated off the north-western coast of continental Europe
***Éire, Irish language name for the isle
** Northern Ireland, a constituent unit ...
and Middle Cape
Middle Cape is a community in the Canadian province of Nova Scotia, located in the Cape Breton Regional Municipality on Cape Breton Island
Cape Breton Island (french: link=no, île du Cap-Breton, formerly '; gd, Ceap Breatainn or '; mi ...
. Ben Eoin Provincial Park
Ben Eoin Provincial Park
is a small secluded provincial park on an old farm against hardwood-covered hills in the community of Ben Eoin, Nova Scotia, Canada, on the south side of the East Bay of the Bras d'Or Lake, on Cape Breton Island. This ...
lies along the north edge of the hills. The Ben Eoin Trail (1.7 kilometres (1.1 mi) return) starts at the Ben Eoin Provincial Picnic Park and leads to a well cleared look-off of solid ground and large flat stone on a ridge of the East Bay Hills with a panoramic view of the East Bay of the Bras d'Or Lake 165 metres (541 ft) below.[
]
Cultural environment
Small-scale farming is practised in some areas of the East Bay Hills. Fishing the waters of the Bras d'Or Lake and sporadic forestry have been economic activities in the past. Much of this area is now cottage country, and tourism plays a significant role in the local economy. In the early 1900s the mineral springs at Glengarry in Irish Cove were well known for their perceived healing properties, which drew local people as well as distant travellers.
References
External links
Feature in the ''Natural History of Nova Scotia''
Mountains of Nova Scotia
Landforms of the Cape Breton Regional Municipality
Landforms of Cape Breton County
Mountains of Canada under 1000 metres
{{CapeBretonNS-geo-stub
de:Cape Breton Highlands