Cocoa Crater

Cocoa Crater
Cocoa Cone
Cocoa Crater from the south
Highest point
Elevation2,117 m (6,946 ft)[1]
Coordinates57°39′20″N 130°42′25″W / 57.65556°N 130.70694°W / 57.65556; -130.70694[2]
Geography
Cocoa Crater is located in British Columbia
Cocoa Crater
Cocoa Crater
Location in British Columbia
Map
Location in Mount Edziza Provincial Park
CountryCanada[3]
ProvinceBritish Columbia[3]
DistrictCassiar Land District[2]
Protected areaMount Edziza Provincial Park[2]
Parent rangeTahltan Highland[3]
Topo mapNTS 104G10 Mount Edziza[2]
Geology
Formed byVolcanism[4]
Mountain typeCinder cone[5]
Rock typeHawaiite[6]
Last eruptionHolocene age[5]

Cocoa Crater, sometimes called Cocoa Cone, is a cinder cone in Cassiar Land District of northwestern British Columbia, Canada. It has an elevation of 2,117 metres (6,946 feet) and is one of several volcanic cones in the Snowshoe Lava Field at the southern end of the Big Raven Plateau. The cone is southeast of the community of Telegraph Creek in Mount Edziza Provincial Park, which is one of the largest provincial parks in British Columbia. The climate in the area is characterized by warm summers and cold, snowy winters. However, temperatures can drop below freezing during summer nights, making snow or freezing rain a possibility at any time of the year.

Cocoa Crater is a part of the Mount Edziza volcanic complex, which consists of diverse landforms such as shield volcanoes, stratovolcanoes, lava domes and cinder cones. The cone contains a volcanic crater and was the source of a 2-kilometre-wide (1.2-mile) lava flow that travelled northwest on the Big Raven Plateau into the upper portion of Sezill Creek canyon. Cocoa Crater is surrounded by a number of other volcanic features, including Punch Cone, Koosick Bluff, Coffee Crater, Keda Cone and Hoia Bluff.

Name and etymology

The first recorded use of Cocoa Crater was on a 1929 British Columbia map dubbed 5C. It was then adopted on the National Topographic System map 104G on May 6, 1954.[2] In his 1992 report The Late Cenozoic Mount Edziza Volcanic Complex, British Columbia, Canadian volcanologist Jack Souther gave Cocoa Crater the numeronym SLF-10, SLF being an acronym for the Snowshoe Lava Field.[7] Cocoa Crater is called Cocoa Cone in the Catalogue of Canadian volcanoes, an online database provided by Natural Resources Canada.[5] Cocoa is a reference to the cone's deep colours.[8]

Geography

Cocoa Crater is located in Cassiar Land District of northwestern British Columbia, Canada, immediately southwest of Mount Edziza at the southern end of the Big Raven Plateau.[2][3][9] It has an elevation of 2,117 metres (6,946 feet) and is the largest subaerial cone in the Snowshoe Lava Field, one of the largest areas of Holocene lava flows in the Mount Edziza volcanic complex.[1][6][10] This volcanic complex consists of a group of overlapping shield volcanoes, stratovolcanoes, lava domes and cinder cones that have formed over the last 7.5 million years.[11] As its name suggests, Cocoa Crater contains a volcanic crater; such features are common among cinder cones.[1][12] The cone is near the southwestern end of Tencho Glacier, the largest glacier of the Mount Edziza volcanic complex.[6][13]

Cocoa Crater is surrounded by a number of other landforms within the Mount Edziza volcanic complex. Just northeast of Cocoa Crater is Punch Cone, an older volcanic feature on the western side of Tencho Glacier. Koosick Bluff immediately north of Cocoa Crater is another volcanic feature older than Punch Cone. About 3 kilometres (1.9 miles) southwest and 5 kilometres (3.1 miles) south-southeast of Cocoa Crater are Coffee Crater and Keda Cone, respectively, both of which are also in the Snowshoe Lava Field.[6] Hoia Bluff, about 7 kilometres (4.3 miles) west of Cocoa Crater, is at the southwestern edge of the Big Raven Plateau.[3][6]

Geology

As a part of the Mount Edziza volcanic complex, Cocoa Crater lies within a broad area of volcanoes and lava flows called the Northern Cordilleran Volcanic Province, which extends from northwestern British Columbia northwards through Yukon into easternmost Alaska.[6][14] The dominant rocks comprising these volcanoes are alkali basalts and hawaiites, but nephelinite, basanite and peralkaline phonolite, trachyte and comendite are locally abundant. These rocks were deposited by volcanic eruptions from 20 million years ago to as recently as a few hundred years ago. The cause of volcanic activity in the Northern Cordilleran Volcanic Province is thought to be due to rifting of the North American Cordillera driven by changes in relative plate motion between the North American and Pacific plates.[15]

Cocoa Crater is a hawaiitic cinder cone of the Big Raven Formation, the youngest stratigraphic unit of the Mount Edziza volcanic complex.[5][6] The construction of Cocoa Crater took place during the Holocene and was accompanied by the eruption of lava and pyroclastic rocks.[4][6] A 2-kilometre-wide (1.2-mile) lava flow from the cone travelled to the northwest, spread across the Big Raven Plateau and entered the upper portion of Sezill Creek canyon.[16] It was forced to flow around the western end of Koosick Bluff due to the presence of a stagnant valley glacier along the southern margin of the lava flow at the time of eruption.[17] In the steep-sided upper canyon of Sezill Creek, the lava front ends 180 metres (590 feet) above the valley floor where subterranean streams emerge from under the lava flow.[18]

Provincial park

Cocoa Crater covered with snow

Cocoa Crater lies in Mount Edziza Provincial Park southeast of the community of Telegraph Creek.[2] With an area of 266,180 hectares (657,700 acres), Mount Edziza Provincial Park is one of the largest provincial parks in British Columbia and was established in 1972 to showcase the volcanic landscape.[8][19] It includes not only the Mount Edziza area, but also the Spectrum Range to the south, which are separated by Raspberry Pass.[3][8] Mount Edziza Provincial Park is in the Tahltan Highland, a southeast-trending upland area extending along the western side of the Stikine Plateau.[3][20]

Wildlife in the area includes moose, caribou, mountain goats, stone sheep, wolves, bears, squirrels, owls, ptarmigans, ravens, gyrfalcons, grouse and migratory songbirds. The climate is characterized by warm summers and cold, snowy winters; temperatures are warmest in mid-summer during the day when they may hit the 30 degrees Celsius (86 degrees Fahrenheit) range. However, temperatures can drop below freezing during summer nights, making snow or freezing rain a possibility at any time of the year.[8]

See also

References

  1. ^ a b c Global Volcanism Program: Edziza, Synonyms & Subfeatures.
  2. ^ a b c d e f g BC Geographical Names: Cocoa Crater.
  3. ^ a b c d e f g Department of Energy, Mines and Resources 1989.
  4. ^ a b Souther 1992, p. 27.
  5. ^ a b c d Natural Resources Canada: Cocoa Cone.
  6. ^ a b c d e f g h Souther 1988.
  7. ^ Souther 1992, p. 214.
  8. ^ a b c d BC Parks: Mount Edziza Provincial Park.
  9. ^ BC Geographical Names: Cassiar Land District.
  10. ^ Souther 1992, pp. 214, 229.
  11. ^ Souther 1990, pp. 124, 125.
  12. ^ United States Geological Survey 2011.
  13. ^ BC Geographical Names: Tencho Glacier.
  14. ^ Edwards & Russell 2000, pp. 1280, 1281, 1283, 1284.
  15. ^ Edwards & Russell 2000, p. 1280.
  16. ^ Souther 1992, p. 230.
  17. ^ Souther 1992, pp. 232, 233.
  18. ^ Souther 1992, pp. 230, 232.
  19. ^ Holland 1976, p. 49.

Sources