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Difference between revisions of "Toney Mountain"
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[[File:MountToneyMap.jpg|thumb|Map of Toney Mountain]] | [[File:MountToneyMap.jpg|thumb|Map of Toney Mountain]] | ||
'''Toney Mountain''' is an elongated snow-covered shield volcano, 60 km (38 mi) long and rising to 3,595 | '''Toney Mountain''' is an elongated snow-covered shield volcano, 60 km (38 mi) long and rising to 3,595 meters at Richmond Peak, located 56 km (35 mi) southwest of [[Kohler Range]] in [[Westarctica]]. | ||
==Geology== | ==Geology== | ||
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An age of 9.1 million years ago has been obtained on a basaltic lava flow beneath the volcano, and it has been inferred that the basal plateau formed between 10.1 and 9.1 million years ago. The massif is younger, with ages ranging from 1 million years in its lower parts to 500,000 years ago. Holocene eruptions may have also occurred at Toney Mountain as indicated by 30 kyr ash layers in ice cores from [[Byrd Station]], although [[Mount Takahe]] and [[Mount Waesche]] are also candidates. During that time period, a number of volcanic eruptions occurred in [[Antarctica]] as recorded by ash layers in ice; this coincides with the coldest period of the Wisconsin glaciation and it is possible that the effects of ash clouds from the Antarctic eruptions caused this period of cold global temperatures. On the other hand, it is also possible that growing ice sheets during this period compressed magma chambers and thus triggered explosive eruptions. | An age of 9.1 million years ago has been obtained on a basaltic lava flow beneath the volcano, and it has been inferred that the basal plateau formed between 10.1 and 9.1 million years ago. The massif is younger, with ages ranging from 1 million years in its lower parts to 500,000 years ago. Holocene eruptions may have also occurred at Toney Mountain as indicated by 30 kyr ash layers in ice cores from [[Byrd Station]], although [[Mount Takahe]] and [[Mount Waesche]] are also candidates. During that time period, a number of volcanic eruptions occurred in [[Antarctica]] as recorded by ash layers in ice; this coincides with the coldest period of the Wisconsin glaciation and it is possible that the effects of ash clouds from the Antarctic eruptions caused this period of cold global temperatures. On the other hand, it is also possible that growing ice sheets during this period compressed magma chambers and thus triggered explosive eruptions. | ||
[[File:Inspecting the GPS antenna at Toney Mountain.jpg|thumb|Inspecting the GPS antenna at Toney Mountain]] | [[File:Inspecting the GPS antenna at Toney Mountain.jpg|thumb|Inspecting the GPS antenna at Toney Mountain]] | ||
Toney Mountain lies in a tectonically and volcanically active region of Antarctica. There, a layer of basaltic rocks up to 5 kilometers (3.1 mi) thick underlie a series of felsic volcanic edifices. These basaltic rocks in turn are emplaced above a Paleozoic basement with granite intrusions of Devonian-Cretaceous, which crops out in some mountain ranges. Beneath Toney Mountain, the basaltic floor rises from an elevation of 3 kilometers (1.9 mi) beneath sea level, and the volcano is situated on the floor of a graben. The region is further characterized by a 500 by 1,200 kilometers (310 mi × 750 mi) large dome-like uplift, part of the West Antarctic Rift, and it may reflect the presence of a stationary hotspot. | Toney Mountain lies in a tectonically and volcanically active region of [[Antarctica]]. There, a layer of basaltic rocks up to 5 kilometers (3.1 mi) thick underlie a series of felsic volcanic edifices. These basaltic rocks in turn are emplaced above a Paleozoic basement with granite intrusions of Devonian-Cretaceous, which crops out in some mountain ranges. Beneath Toney Mountain, the basaltic floor rises from an elevation of 3 kilometers (1.9 mi) beneath sea level, and the volcano is situated on the floor of a graben. The region is further characterized by a 500 by 1,200 kilometers (310 mi × 750 mi) large dome-like uplift, part of the West Antarctic Rift, and it may reflect the presence of a stationary hotspot. | ||
==Discovery and name== | ==Discovery and name== | ||
Toney Mountain was probably among those viewed from a distance by Admiral Byrd and others of the U.S. Antarctic Survey in plane flights from the ship ''Bear'' in February 1940. It was mapped in December 1957 by the oversnow traverse party from Byrd Station to the Sentinel Range, 1957–58, led by C.R. Bentley who proposed the name. | Toney Mountain was probably among those viewed from a distance by Admiral Byrd and others of the U.S. Antarctic Survey in plane flights from the ship ''Bear'' in February 1940. It was mapped in December 1957 by the oversnow traverse party from Byrd Station to the Sentinel Range, 1957–58, led by C.R. Bentley who proposed the name. | ||
Named after George R. Toney, scientific leader at Byrd Station in 1957, a participant in several Antarctic and Arctic operations, serving in both field and administrative capacities. | Named after George R. Toney, scientific leader at [[Byrd Station]] in 1957, a participant in several Antarctic and Arctic operations, serving in both field and administrative capacities. | ||
== | ==Features== | ||
[[ | * [[Creehan Cliff]] | ||
* [[Williamson Ridge]] | |||
[[Category:Geography of Westarctica]] | [[Category:Geography of Westarctica]] | ||
[[Category:Volcanoes]] | [[Category:Volcanoes]] | ||