Butcher Ridge () is a large, mainly ice-free ridge near the polar plateau in the west part of the

Cook Mountains The Cook Mountains is a group of mountains bounded by the Mulock and Darwin glaciers in Antarctica. Parts of the group were first viewed from the Ross Ice Shelf by the British National Antarctic Expedition (1901–04). Additional portions of th ...

. The ridge is in the form of an arc, extending northwest from Mount Ayres.Faure, G., and Mensing, T. M., 2010. ''The Transantarctic Mountains Rocks, Ice, Meteorites and Water.'' Germany, Heidelberg, Springer Dordrecht. 804 pp. The Ridge peaks at 2,003 meters (6,572 feet). It was named by the

Advisory Committee on Antarctic Names The Advisory Committee on Antarctic Names (ACAN or US-ACAN) is an advisory committee of the United States Board on Geographic Names responsible for recommending commemorative names for features in Antarctica. History The committee was established ...

for Commander H.K. Butcher, U.S. Navy, air operations officer on the Staff of the U.S. Naval Support Force, Antarctica, during U.S. Navy Operation Deepfreeze 1963 and 1964.

Geology

Butcher Ridge is a deeply eroded silicic igneous intrusion. It consists of a hypabyssal intrusion that contains rhythmically layered glassy rocks and plutonic rocks that vary in composition from basaltic andesite to

rhyolite Rhyolite ( ) is the most silica-rich of volcanic rocks. It is generally glassy or fine-grained (aphanitic) in texture, but may be porphyritic, containing larger mineral crystals (phenocrysts) in an otherwise fine-grained groundmass. The mineral ...

." U-Pb dating of

baddeleyite Baddeleyite is a rare zirconium oxide mineral (ZrO2 or zirconia), occurring in a variety of monoclinic prismatic crystal forms. It is transparent to translucent, has high indices of refraction, and ranges from colorless to yellow, green, and dar ...

from the Butcher Ridge yielded an age of about 182.4

Myr The abbreviation Myr, "million years", is a unit of a quantity of (i.e. ) years, or 31.556926 teraseconds. Usage Myr (million years) is in common use in fields such as Earth science and cosmology. Myr is also used with Mya (million years ago). ...

. This age confirms that this igneous complex was emplaced contemporaneously with the Ferrar large igneous province.Nelson, D.A., Cottle, J.M. and Schoene, B., 2019. ''Butcher Ridge igneous complex: A glassy layered silicic magma distribution center in the Ferrar large igneous province, Antarctic.'' ''Antarctica. Bulletin'', 132(5-6), pp.1201-1216. Faure and Mensing argue that the glassy and "pseudo- volcanic" rocks that compose the majority of the Butcher Ridge igneous complex are incompatible with it being a hypabyssal intrusion. Based on this and together with an associated strong magnetic anomaly and other features, they concluded that the Butcher Ridge igneous complex should be seriously investigated as a possible

asteroid An asteroid is a minor planet of the inner Solar System. Sizes and shapes of asteroids vary significantly, ranging from 1-meter rocks to a dwarf planet almost 1000 km in diameter; they are rocky, metallic or icy bodies with no atmosphere. ...

impact structure An impact structure is a generally circular or craterlike geologic structure of deformed bedrock or sediment produced by impact on a planetary surface, whatever the stage of erosion of the structure. In contrast, an impact crater is the surface ...

Features

Gjelsvik Spur

. A rock spur northwest of Mount Ayres on the Butcher Ridge, in the Cook Mountains. It was named after Per Gjelsvik of the University of Wisconsin–Madison aeromagnetic project under John Behrendt, 1963–64. Working from U.S. Navy aircraft, Gjelsvik acquired aeromagnetic profiles over the Transantarctic Mountains bordering the Ross Sea and

Ross Ice Shelf The Ross Ice Shelf is the largest ice shelf of Antarctica (, an area of roughly and about across: about the size of France). It is several hundred metres thick. The nearly vertical ice front to the open sea is more than long, and between hi ...

McCafferty Spur

. A spur on the north face of Butcher Ridge, in the Cook Mountains of Antarctica, northwest of Mount Ayres. It was named after

Anne McCafferty Anne, alternatively spelled Ann, is a form of the Latin female given name Anna. This in turn is a representation of the Hebrew Hannah, which means 'favour' or 'grace'. Related names include Annie. Anne is sometimes used as a male name in the ...

, a geophysicist with the United States Geological Survey (USGS), who in 1991–92 worked on a USGS aeromagnetic survey over the

and, in a cooperative USGS–German project, participated in the first aeromagnetic flight across the Butcher Ridge and Cook Mountains.

References

Sources

* * Ridges of Oates Land {{OatesLand-geo-stub