Editing Crary Mountains (section)

== Geography and geomorphology ==

The mountain range lies in eastern [[Marie Byrd Land]], [[Antarctica]],{{sfn|Panter|Hart|Kyle|Blusztanjn|2000|p=216}} about {{convert|250|km}}{{sfn|Wilch|McIntosh|2002|p=247}} from the [[Bakutis Coast]].{{sfn|LeMasurier|Thomson|Baker|Kyle|1990|p=180}} It was first visited in 1959–1960, and several accessible outcrops were sampled. The name refers to [[Albert P. Crary]], who was then Deputy Chief Scientist for the US-[[International Geophysical Year|IGY]] Antarctic Program.{{sfn|LeMasurier|Thomson|Baker|Kyle|1990|p=184}}

The Crary Mountains are a chain of three{{sfn|Wilch|McIntosh|Panter|2021|p=539}} [[shield volcano]]es{{sfn|LeMasurier|Thomson|Baker|Kyle|1990|p=180}} {{convert|50|km}} long{{sfn|Panter|Hart|Kyle|Blusztanjn|2000|p=216}} which extends in northwest–southeast direction.{{sfn|Panter|Hart|Kyle|Blusztanjn|2000|p=218}} The volume of the volcanoes exceeds {{convert|400|km3}} and the edifices consist of lavas, [[Hydrovolcanic eruption|hydrovolcanic]] deposits such as [[hyaloclastite]], fragments of [[pillow lava]]s and [[tuffs]], and [[scoria]].{{sfn|Chakraborty|2010|p=103}} Unlike many other mountains in Marie Byrd Land, which owing to a lack of erosion display only their highest and youngest parts, in the Crary Mountains the internal structure of the volcanoes are well exposed{{sfn|Haywood|Smellie|Ashworth|Cantrill|2008|p=422}} due to glacial erosion.{{sfn|Wilch|McIntosh|Panter|2021|p=539}} The Crary Mountains form a [[drainage divide]] for the [[West Antarctic Ice Sheet]];{{sfn|Kovach|Faure|1977|p=1018}} they dam it, which is thus higher on the southwestern side of the range.{{sfn|Wilch|McIntosh|Panter|2021|p=539}} Debris stripes have been observed on the ice near the foot of the mountains.{{sfn|Ford|Andersen|1967|p=731}}

The northeasternmost volcano is [[Mount Rees (Marie Byrd Land)|Mount Rees]], which reaches a summit height of {{convert|2709|m}} at [[Tasch Peak]]. Volcanic rocks crop out at [[Trabucco Cliff]] on its northeastern flank.{{sfn|Panter|Hart|Kyle|Blusztanjn|2000|p=218}} There is no [[caldera]].{{sfn|Wilch|McIntosh|Panter|2021|p=522}} Glacial erosion has cut deep cirques into the eastern flank of Mount Rees, and volcanic outcrops indicate that volcanic rocks alternate between subglacial formations and subaerial formations. Outcrops consist of [[breccia]] and lavas, which in one case are intruded by a [[Dike (geology)|dike]].{{sfn|Wilch|McIntosh|2002|p=247}}

[[File:MountFrakesSteere.jpg|thumb|Mount Frakes and Mount Steere]]
In the middle of the chain lies [[Mount Steere]] with a summit elevation of {{convert|3558|m}} and a rectangular summit caldera. [[Lie Cliff]] is a volcanic outcrop on the northeastern flank.{{sfn|Panter|Hart|Kyle|Blusztanjn|2000|p=218}} Mount Steere is heavily dissected,{{sfn|Panter|Hart|Kyle|Blusztanjn|2000|p=219}} bears evidence of former [[glaciation]] in the form of [[moraine]]s{{sfn|Wilch|McIntosh|Panter|Dunbar|1993|p=8}} and cirques have been eroded into its northern and northeastern flanks. As with Mount Rees, volcanic rocks alternate between these that formed subglacially and these formed subaerially. Outcrops feature breccias and lava with numerous intruded dikes.{{sfn|Wilch|McIntosh|2002|p=247}}

South of Mount Steere is [[Mount Frakes]], with {{convert|3654|m}} it is the highest peak in the range{{sfn|Panter|Hart|Kyle|Blusztanjn|2000|p=218}} and the least eroded of the Crary Mountains.{{sfn|Panter|Hart|Kyle|Blusztanjn|2000|p=219}} It has a {{convert|4|km}} wide circular summit caldera and unlike Mount Rees and Mount Steere it bears no evidence of [[subglacial eruption]]s, probably due to lack of erosion that could have exposed them.{{sfn|Wilch|McIntosh|2002|p=249}} Volcanic rocks crop out both on the southern and western flank, at [[Morrison Rocks]] and [[English Rock]] respectively.{{sfn|Panter|Hart|Kyle|Blusztanjn|2000|p=218}} These outcrops are [[cinder cone]]s that formed on the slopes of Mount Frakes.{{sfn|Wilch|McIntosh|2002|pp=249, 251}} Volcanic and nonvolcanic boulders on the slopes of Mount Frakes may either be [[xenolith]]s or [[glacial erratic]]s.{{sfn|Wilch|McIntosh|Panter|Dunbar|1993|p=9}}

[[Boyd Ridge]] is smaller than the other three volcanoes{{sfn|Wilch|McIntosh|Panter|2021|p=539}} and located southeast of Mount Frakes and reaches an elevation of {{convert|2375|m}}.{{sfn|Panter|Hart|Kyle|Blusztanjn|2000|p=218}} [[Runyon Rock]] crops out to its east{{sfn|Wilch|McIntosh|Panter|2021|p=542}} and is the only area of Boyd Ridge not covered by ice. Cinders and a cliff of [[hyaloclastite]] are found there.{{sfn|Panter|Hart|Kyle|Blusztanjn|2000|p=219}}

The volcanoes rise from a platform formed by lava flows and [[pyroclastic rocks]].{{sfn|LeMasurier|Thomson|Baker|Kyle|1990|p=180}} This platform lies at about {{convert|2700|-|2800|m}} elevation and the Boyd Ridge may be a southeastward extension thereof. It appears that the platform — which crops out only on the eastern side of the Crary Mountains — was tilted westward by [[fault (geology)|fault]]ing.{{sfn|LeMasurier|Thomson|Baker|Kyle|1990|p=181}} [[Echo]] and [[magnetic]] sounding have imaged the root of the Crary Mountains in the West Antarctic Ice Sheet, finding that the underlying terrain is steep and flanked by narrow troughs.{{sfn|Jankowski|Drewry|1981|p=19}} The mountains are associated with a strong [[magnetic anomaly]] that may reflect subglacial rocks containing [[magnetite]].{{sfn|American Geophysical Union|1971|p=31}}