The Insular Mountains are a range of mountains in the

Pacific Coast Ranges The Pacific Coast Ranges (officially gazetted as the Pacific Mountain System in the United States; ; ) are the series of mountain ranges that stretch along the West Coast of North America from Alaska south to Northern and Central Mexico. Althoug ...

on the Coast of British Columbia, Canada, comprising the Vancouver Island Ranges and Queen Charlotte Mountains. The Insular Mountains are rugged, particularly on Vancouver Island where peaks in Strathcona Provincial Park rise to elevations of more than . The highest of these mountains is Golden Hinde on

Vancouver Island Vancouver Island is an island in the northeastern Pacific Ocean and part of the Canadian province of British Columbia. The island is in length, in width at its widest point, and in total area, while are of land. The island is the largest ...

, which rises to . Although the Coast Mountain Range is usually referred to as the westernmost range of the Pacific Cordillera (since it is the westernmost range on the main landmass at that point), the Insular Mountains are the true westernmost range.

Geological history

These Insular Mountains are not yet fully emerged above

sea level Mean sea level (MSL, often shortened to sea level) is an mean, average surface level of one or more among Earth's coastal Body of water, bodies of water from which heights such as elevation may be measured. The global MSL is a type of vertical ...

, and

and the

Haida Gwaii Haida Gwaii (; / , literally "Islands of the Haida people"), previously known as the Queen Charlotte Islands, is an archipelago located between off the British Columbia Coast, northern Pacific coast in the Canadian province of British Columbia ...

are just the higher elevations of the range, which was in fact fully exposed during the last glacial period (maximum ice extent about 18,000 years ago) when the

continental shelf A continental shelf is a portion of a continent that is submerged under an area of relatively shallow water, known as a shelf sea. Much of these shelves were exposed by drops in sea level during glacial periods. The shelf surrounding an islan ...

in this area was a broad

coastal plain A coastal plain (also coastal plains, coastal lowland, coastal lowlands) is an area of flat, low-lying land adjacent to a sea coast. A fall line commonly marks the border between a coastal plain and an upland area. Formation Coastal plains can f ...

. The Insular Mountains formed when a chain of active

volcanic island Geologically, a volcanic island is an island of volcanic origin. The term high island can be used to distinguish such islands from low islands, which are formed from sedimentation or the uplifting of coral reefs (which have often formed ...

s (the Insular Islands) collided against the

North America North America is a continent in the Northern Hemisphere, Northern and Western Hemisphere, Western hemispheres. North America is bordered to the north by the Arctic Ocean, to the east by the Atlantic Ocean, to the southeast by South Ameri ...

n continent during the mid

Cretaceous The Cretaceous ( ) is a geological period that lasted from about 143.1 to 66 mya (unit), million years ago (Mya). It is the third and final period of the Mesozoic Era (geology), Era, as well as the longest. At around 77.1 million years, it is the ...

period. The type of rocks that form the Insular Mountains are

turbidite A turbidite is the geologic Deposition (geology), deposit of a turbidity current, which is a type of amalgamation of fluidal and sediment gravity flow responsible for distributing vast amounts of clastic sediment into the deep ocean. Sequencing ...

s and

pillow lava Pillow lavas are lavas that contain characteristic pillow-shaped structures that are attributed to the extrusion of the lava underwater, or ''subaqueous extrusion''. Pillow lavas in volcanic rock are characterized by thick sequences of discontinu ...

Granitic A granitoid is a broad term referring to a diverse group of coarse-grained igneous rocks that are widely distributed across the globe, covering a significant portion of the Earth's exposed surface and constituting a large part of the continental ...

plutons seldom occur in the Insular Mountains, unlike the

Coast Mountains The Coast Mountains () are a major mountain range in the Pacific Coast Ranges of western North America, extending from southwestern Yukon through the Alaska Panhandle and virtually all of the British Columbia Coast, Coast of British Columbia sout ...

. The Insular Mountain range covers some 133,879 km² (51,691 sq mi). It experiences frequent

seismic activity An earthquakealso called a quake, tremor, or tembloris the shaking of the Earth's surface resulting from a sudden release of energy in the lithosphere that creates seismic waves. Earthquakes can range in intensity, from those so weak they ...

, with the Pacific Plate and the Juan de Fuca Plate being subducted into the Earth's mantle. Large

earthquake An earthquakealso called a quake, tremor, or tembloris the shaking of the Earth's surface resulting from a sudden release of energy in the lithosphere that creates seismic waves. Earthquakes can range in intensity, from those so weak they ...

s have led to collapsing mountains,

landslide Landslides, also known as landslips, rockslips or rockslides, are several forms of mass wasting that may include a wide range of ground movements, such as rockfalls, mudflows, shallow or deep-seated slope failures and debris flows. Landslides ...

s and

fissure A fissure is a long, narrow crack opening along the surface of Earth. The term is derived from the Latin word , which means 'cleft' or 'crack'. Fissures emerge in Earth's crust, on ice sheets and glaciers, and on volcanoes. Ground fissure A ...

s. During the last glacial period, ice enclosed nearly all of these mountains.

Glacier A glacier (; or ) is a persistent body of dense ice, a form of rock, that is constantly moving downhill under its own weight. A glacier forms where the accumulation of snow exceeds its ablation over many years, often centuries. It acquires ...

s that ran down to the

Pacific Ocean The Pacific Ocean is the largest and deepest of Earth's five Borders of the oceans, oceanic divisions. It extends from the Arctic Ocean in the north to the Southern Ocean, or, depending on the definition, to Antarctica in the south, and is ...

sharpened the

valley A valley is an elongated low area often running between hills or mountains and typically containing a river or stream running from one end to the other. Most valleys are formed by erosion of the land surface by rivers or streams over ...

faces and

eroded 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 disti ...

their bottoms. These valleys were transformed into

fjord In physical geography, a fjord (also spelled fiord in New Zealand English; ) is a long, narrow sea inlet with steep sides or cliffs, created by a glacier. Fjords exist on the coasts of Antarctica, the Arctic, and surrounding landmasses of the n ...

s when the ice melted and the

rose. Ice Age remnants may still be noted, such as the Comox Glacier in the Vancouver Island Ranges.

Sub-ranges

Haida Gwaii

* Queen Charlotte Mountains, on

: # Cameron Range: On the western side of Graham Island # Crease Range: On north-central Graham Island # McKay Range: On the south coast of Graham Island # San Christoval Range: On the western side of

Moresby Island Moresby Island () is a large island () that forms part of the Haida Gwaii archipelago (formerly known as Queen Charlotte Islands) in British Columbia, Canada, located at It is separated by the narrow Skidegate Channel from the other princip ...

Vancouver Island

* Vancouver Island Ranges, on

: #

Refugium Range The Refugium Range is a low, small mountain range comprising the mountains/hills of the Brooks Peninsula on northern Vancouver Island, British Columbia, Canada. It has an area of and is a subrange of the Vancouver Island Ranges which in turn for ...

: On the Brooks Peninsula # Sophia Range: On Nootka Island, on the peninsula between Esperanza Inlet and Nuchatlitz Inlet # Genevieve Range: Nootka Island # Karmutzen Range: Between Nimpkish Lake, Tlakwa Creek and Karmuzten Creek # Hankin Range: Between Nimpkish Lake and Bonanza Lake #

Franklin Range The Franklin Range is a small mountain range on Vancouver Island, British Columbia, Canada, located just southwest of Robson Bight and Johnstone Strait. It has an area of 200 km2 and is a subrange of the Vancouver Island Ranges which in ...

: Near Robson Bight on the Johnstone Strait between the Tsitika River and Kokish River # Bonanza Range: Between the Nimpkish River and the Tsitika River by Bonanza Lake # Sutton Range: Between Nimpkish River, White River, Oktwanch River, Gold River # Newcastle Range: Johnstone Strait, west of Sayward-Kelsey Bay and east/north of Adams River # Prince of Wales Range: East coast of Vancouver Island 40 km (25 mi) north of Campbell River # Halifax Range: Along Johnstone Strait between Amor de Cosmos Creek and Pye Creek # Beaufort Range: North of Port Alberni and west of Qualicum Beach # Pelham Range: Between the Sarita River and Alberni Inlet # Somerset Range: Between The Pacheena-Sarita River basins and the Klanawa River (between Nitinat Lake and Imperial Eagle Channel) # Seymour Range: Between the valley of Cowichan Lake, San Juan River and Gordon River # Gowlland Range: Near Victoria between Saanich Inlet and Brentwood Bay. Includes Mount Work Regional Park #

Pierce Range The Pierce Range is a small very steep-sided mountain range on central Vancouver Island, British Columbia, Canada. It has an area of 94 km2 and is a subrange of the Vancouver Island Ranges which in turn form part of the Insular Mountains.

: South of Gold River between the Jacklah River and the Burman River # Haihte Range: Between Tashsis River, the Nomash River, Zeballos Lake and Woss Lake The Elk River Mountains, located in Strathcona Provincial Park, are sometimes classified as a range.Philips

References

{{Reflist Pacific Coast Ranges Mountain ranges of British Columbia South Coast of British Columbia Landforms of Vancouver Island Landforms of Haida Gwaii

Geological history

Sub-ranges

Haida Gwaii

Vancouver Island

See also

References