Mount Sidley, Executive Committee Range, Marie Byrd Land, Western Antarctica, Antarcticai

Regional Level Types
Mount Sidley	Mountain
Executive Committee Range	Mountain Range
Marie Byrd Land	Area
Western Antarctica	Region
Antarctica	Continent

Mount Sidley is the highest dormant volcano in Antarctica, a member of the Volcanic Seven Summits, with a summit elevation of 4,181–4,285 metres (13,717–14,058 ft). It is a massive, mainly snow-covered shield volcano which is the highest of the five volcanic mountains that comprise the Executive Committee Range of Marie Byrd Land. The feature is marked by a 5 km wide caldera on the southern side and stands NE of Mount Waesche in the southern part of the range.

The mountain was discovered by Rear Admiral Richard E. Byrd on an airplane flight, November 18, 1934, and named by him for Mabelle E. Sidley, the daughter of William Horlick who was a contributor to the 1933–35 Byrd Antarctic Expedition. Despite its height, the volcano's extremely remote location means that it is little known even in the mountaineering world compared to the much more accessible Mount Erebus, the second-highest Antarctic volcano which is located near the U.S. and New Zealand bases on Ross Island.

The first recorded ascent of Mount Sidley was by New Zealander Bill Atkinson on January 11, 1990, whilst working in support of a United States Antarctic Program scientific field party. [Wikipedia]

Lower crustal pyroxenite xenoliths in a phonolite.

The xenoliths have suffered localized breakdown reactions during their residence in a shallow magmatic chamber below the volcano.

Geochronology

Mineralization age: Neogene : 5.68 ± 0.06 Ma to 4.18 ± 0.04 Ma

Important note: This table is based only on rock and mineral ages recorded on mindat.org for this locality and is not necessarily a complete representation of the geochronology, but does give an indication of possible mineralization events relevant to this locality. As more age information is added this table may expand in the future. A break in the table simply indicates a lack of data entered here, not necessarily a break in the geologic sequence. Grey background entries are from different, related, localities.

Geologic Time				Rocks, Minerals and Events
Phanerozoic
	Cenozoic
		Neogene
			Pliocene	ⓘ Basanite (youngest age) 4.18 ± 0.04 Ma
			Miocene	ⓘ Basanite (oldest age) 5.68 ± 0.06 Ma

Other Databases

Wikipedia:	https://en.wikipedia.org/wiki/Mount_Sidley
Wikidata ID:	Q924312

Other Regions, Features and Areas containing this locality

References