Crary Mountains () are a group of ice-covered volcanoes in

Marie Byrd Land Marie Byrd Land (MBL) is an unclaimed region of Antarctica. With an area of , it is the largest unclaimed territory on Earth. It was named after the wife of American naval officer Richard E. Byrd, who explored the region in the early 20th centu ...

Antarctica Antarctica () is Earth's southernmost and least-populated continent. Situated almost entirely south of the Antarctic Circle and surrounded by the Southern Ocean (also known as the Antarctic Ocean), it contains the geographic South Pole. ...

. They consist of two or three

shield volcano A shield volcano is a type of volcano named for its low profile, resembling a shield lying on the ground. It is formed by the eruption of highly fluid (low viscosity) lava, which travels farther and forms thinner flows than the more viscous lava ...

es, named Mount Rees, Mount Steere and

Mount Frakes Crary Mountains () are a group of ice-covered volcanoes in Marie Byrd Land, Antarctica. They consist of two or three shield volcanoes, named Mount Rees, Mount Steere and Mount Frakes, which developed during the course of the Miocene and Plioc ...

, which developed during the course of the

Miocene The Miocene ( ) is the first epoch (geology), geological epoch of the Neogene Period and extends from about (Ma). The Miocene was named by Scottish geologist Charles Lyell; the name comes from the Greek words (', "less") and (', "new") and mea ...

and

Pliocene The Pliocene ( ; also Pleiocene) is the epoch (geology), epoch in the geologic time scale that extends from 5.33 to 2.58cirque A (; from the Latin word ) is an amphitheatre-like valley formed by Glacier#Erosion, glacial erosion. Alternative names for this landform are corrie (from , meaning a pot or cauldron) and ; ). A cirque may also be a similarly shaped landform a ...

s, while Mount Frakes is better preserved and has a wide

caldera A caldera ( ) is a large cauldron-like hollow that forms shortly after the emptying of a magma chamber in a volcanic eruption. An eruption that ejects large volumes of magma over a short period of time can cause significant detriment to the str ...

at its summit.

Boyd Ridge Crary Mountains () are a group of ice-covered volcanoes in Marie Byrd Land, Antarctica. They consist of two or three shield volcanoes, named Mount Rees (Marie Byrd Land), Mount Rees, Mount Steere and Mount Frakes, which developed during the cour ...

is another part of the mountain range and lies southeast of Mount Frakes; it might be the emergent part of a platform that underlies the mountain range. The volcanoes consist mainly of

basalt Basalt (; ) is an aphanite, aphanitic (fine-grained) extrusive igneous rock formed from the rapid cooling of low-viscosity lava rich in magnesium and iron (mafic lava) exposed at or very near the planetary surface, surface of a terrestrial ...

trachyte Trachyte () is an extrusive igneous rock composed mostly of alkali feldspar. It is usually light-colored and aphanite, aphanitic (fine-grained), with minor amounts of mafic minerals, and is formed by the rapid cooling of lava (or shallow intrus ...

and

phonolite Phonolite is an uncommon shallow intrusive or extrusive rock, of intermediate chemical composition between felsic and mafic, with texture ranging from aphanitic (fine-grained) to porphyritic (mixed fine- and coarse-grained). Phonolite is a var ...

in the form of

lava flows Lava is molten or partially molten rock (magma) that has been expelled from the interior of a terrestrial planet (such as Earth) or a moon onto its surface. Lava may be erupted at a volcano or through a fracture in the crust, on land or unde ...

scoria Scoria or cinder is a pyroclastic, highly vesicular, dark-colored volcanic rock formed by ejection from a volcano as a molten blob and cooled in the air to form discrete grains called clasts.Neuendorf, K.K.E., J.P. Mehl, Jr., and J.A. Jackso ...

and hydrovolcanic formations. Volcanic activity here is linked to the

West Antarctic Rift system The West Antarctic Rift System is a series of rift valleys between East and West Antarctica. It encompasses the Ross Embayment, the Ross Sea, the area under the Ross Ice Shelf and a part of Marie Byrd Land in West Antarctica, reaching to th ...

, which is responsible for the formation of a number of volcanoes in the region. During their existence, the range was affected by glaciation and glacial-volcanic interactions.

Geography and geomorphology

The mountain range lies in eastern

, about from the

Bakutis Coast The Getz Ice Shelf () is an ice shelf over long and from wide, bordering the Hobbs Coast and Bakutis Coast of Marie Byrd Land, Antarctica, between the McDonald Heights and Martin Peninsula. Several large islands are partially or wholly embedded ...

. 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-

IGY Immunoglobulin Y (abbreviated as IgY) is a type of immunoglobulin which is the major antibody in bird, reptile, and lungfish blood. It is also found in high concentrations in chicken egg yolk. As with the other immunoglobulins, IgY is a class of pr ...

Antarctic Program. The Crary Mountains are a chain of three

es long which extends in northwest–southeast direction. The volume of the volcanoes exceeds and the edifices consist of lavas, hydrovolcanic deposits such as

hyaloclastite Hyaloclastite is a volcanoclastic accumulation or breccia consisting of glass (from the Greek ''hyalus'') fragments (clasts) formed by quench fragmentation of lava flow surfaces during submarine or subglacial extrusion. It occurs as thin marg ...

, fragments of

pillow lava Pillow lavas are lavas that contain characteristic pillow-shaped structures that are attributed to the extrusion of the lava underwater, or ''subaqueous extrusion''. Pillow lavas in volcanic rock are characterized by thick sequences of discontinu ...

s and

tuffs Tuff is a type of rock made of volcanic ash ejected from a vent during a volcanic eruption. Following ejection and deposition, the ash is lithified into a solid rock. Rock that contains greater than 75% ash is considered tuff, while rock cont ...

, and

. 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 due to glacial erosion. The Crary Mountains form a

drainage divide A drainage divide, water divide, ridgeline, watershed, water parting or height of land is elevated terrain that separates neighboring drainage basins. On rugged land, the divide lies along topographical ridges, and may be in the form of a single ...

for the

West Antarctic Ice Sheet The West Antarctic Ice Sheet (WAIS) is the segment of the Antarctic ice sheet, continental ice sheet that covers West Antarctica, the portion of Antarctica on the side of the Transantarctic Mountains that lies in the Western Hemisphere. It is cla ...

; they dam it, which is thus higher on the southwestern side of the range. Debris stripes have been observed on the ice near the foot of the mountains. The northeasternmost volcano is Mount Rees, which reaches a summit height of at

Tasch Peak Crary Mountains () are a group of ice-covered volcanoes in Marie Byrd Land, Antarctica. They consist of two or three shield volcanoes, named Mount Rees, Mount Steere and Mount Frakes, which developed during the course of the Miocene and Plioc ...

. Volcanic rocks crop out at

Trabucco Cliff Crary Mountains () are a group of ice-covered volcanoes in Marie Byrd Land, Antarctica. They consist of two or three shield volcanoes, named Mount Rees, Mount Steere and Mount Frakes, which developed during the course of the Miocene and Plioc ...

on its northeastern flank. There is no

. 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 Breccia ( , ; ) is a rock composed of large angular broken fragments of minerals or Rock (geology), rocks cementation (geology), cemented together by a fine-grained matrix (geology), matrix. The word has its origins in the Italian language ...

and lavas, which in one case are intruded by a dike. MountFrakesSteere

In the middle of the chain lies Mount Steere with a summit elevation of and a rectangular summit caldera. Lie Cliff is a volcanic outcrop on the northeastern flank. Mount Steere is heavily dissected, bears evidence of former

glaciation A glacial period (alternatively glacial or glaciation) is an interval of time (thousands of years) within an ice age that is marked by colder temperatures and glacier advances. Interglacials, on the other hand, are periods of warmer climate be ...

in the form of

moraine A moraine is any accumulation of unconsolidated debris (regolith and Rock (geology), rock), sometimes referred to as glacial till, that occurs in both currently and formerly glaciated regions, and that has been previously carried along by a gla ...

s 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. South of Mount Steere is

, with it is the highest peak in the range and the least eroded of the Crary Mountains. It has a wide circular summit caldera and unlike Mount Rees and Mount Steere it bears no evidence of

subglacial eruption Subglacial eruptions, those of ice-covered volcanoes, result in the interaction of magma with ice and snow, leading to meltwater formation, jökulhlaups, and lahars. Flooding associated with meltwater is a significant hazard in some volcanic a ...

s, probably due to lack of erosion that could have exposed them. Volcanic rocks crop out both on the southern and western flank, at Morrison Rocks and English Rock respectively. These outcrops are

cinder cone A cinder cone or scoria cone is a steep, volcanic cone, conical landform of loose pyroclastic rock, pyroclastic fragments, such as volcanic ash, clinkers, or scoria that has been built around a volcanic vent. The pyroclastic fragments are forme ...

s that formed on the slopes of Mount Frakes. Volcanic and nonvolcanic boulders on the slopes of Mount Frakes may either be

xenolith A xenolith ("foreign rock") is a rock (geology), rock fragment (Country rock (geology), country rock) that becomes enveloped in a larger rock during the latter's development and solidification. In geology, the term ''xenolith'' is almost exclusi ...

s or

glacial erratic A glacial erratic is a glacially deposited rock (geology), rock differing from the type of country rock (geology), rock native to the area in which it rests. Erratics, which take their name from the Latin word ' ("to wander"), are carried by gla ...

is smaller than the other three volcanoes and located southeast of Mount Frakes and reaches an elevation of . Runyon Rock crops out to its east and is the only area of Boyd Ridge not covered by ice. Cinders and a cliff of

are found there. The volcanoes rise from a platform formed by lava flows and

pyroclastic rocks Pyroclastic rocks are clastic rocks composed of rock fragments produced and ejected by explosive volcanic eruptions. The individual rock fragments are known as pyroclasts. Pyroclastic rocks are a type of volcaniclastic deposit, which are deposit ...

. This platform lies at about 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 faulting.

Echo In audio signal processing and acoustics, an echo is a reflection of sound that arrives at the listener with a delay after the direct sound. The delay is directly proportional to the distance of the reflecting surface from the source and the lis ...

and

magnetic Magnetism is the class of physical attributes that occur through a magnetic field, which allows objects to attract or repel each other. Because both electric currents and magnetic moments of elementary particles give rise to a magnetic field, m ...

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. The mountains are associated with a strong

magnetic anomaly In geophysics, a magnetic anomaly is a local variation in the Earth's magnetic field resulting from variations in the chemistry or magnetism of the rocks. Mapping of variation over an area is valuable in detecting structures obscured by overlying ...

that may reflect subglacial rocks containing

magnetite Magnetite is a mineral and one of the main iron ores, with the chemical formula . It is one of the iron oxide, oxides of iron, and is ferrimagnetism, ferrimagnetic; it is attracted to a magnet and can be magnetization, magnetized to become a ...

Geology

Cenozoic The Cenozoic Era ( ; ) is Earth's current geological era, representing the last 66million years of Earth's history. It is characterized by the dominance of mammals, insects, birds and angiosperms (flowering plants). It is the latest of three g ...

volcanism in Marie Byrd Land is related to the West Antarctic Rift and has been explained by the activity of a

mantle plume A mantle plume is a proposed mechanism of convection within the Earth's mantle, hypothesized to explain anomalous volcanism. Because the plume head partially melts on reaching shallow depths, a plume is often invoked as the cause of volcanic ho ...

. This plume either underlies Marie Byrd Land and its volcanoes, or it rose to the surface before Antarctica separated from

New Zealand New Zealand () is an island country in the southwestern Pacific Ocean. It consists of two main landmasses—the North Island () and the South Island ()—and List of islands of New Zealand, over 600 smaller islands. It is the List of isla ...

during the middle

Cretaceous The Cretaceous ( ) is a geological period that lasted from about 143.1 to 66 mya (unit), million years ago (Mya). It is the third and final period of the Mesozoic Era (geology), Era, as well as the longest. At around 77.1 million years, it is the ...

and induced volcanism across the continental borderlands of the

Southwest Pacific The points of the compass are a set of horizontal, radially arrayed compass directions (or azimuths) used in navigation and cartography. A ''compass rose'' is primarily composed of four cardinal directions—north, east, south, and west—each ...

. In the latter theory, the Marie Byrd Land volcanism is caused by a remnant plume head underneath the continent. The

basement A basement is any Storey, floor of a building that is not above the grade plane. Especially in residential buildings, it often is used as a utility space for a building, where such items as the Furnace (house heating), furnace, water heating, ...

crops out along the coast and consists of

granitoid A granitoid is a broad term referring to a diverse group of coarse-grained igneous rocks that are widely distributed across the globe, covering a significant portion of the Earth's exposed surface and constituting a large part of the continental ...

s and

metamorphic Metamorphic rocks arise from the transformation of existing rock to new types of rock in a process called metamorphism. The original rock (protolith) is subjected to temperatures greater than and, often, elevated pressure of or more, causi ...

sediments left by a

Devonian The Devonian ( ) is a period (geology), geologic period and system (stratigraphy), system of the Paleozoic era (geology), era during the Phanerozoic eon (geology), eon, spanning 60.3 million years from the end of the preceding Silurian per ...

volcanic arc A volcanic arc (also known as a magmatic arc) is a belt of volcanoes formed above a subducting oceanic tectonic plate, with the belt arranged in an arc shape as seen from above. Volcanic arcs typically parallel an oceanic trench, with the arc ...

. This volcanism manifests itself with 18 large and numerous smaller volcanoes, which occur in groups, rows or as solitary systems in Marie Byrd Land. The larger centres have produced phonolite,

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

, trachyte and rocks with intermediate compositions, and reach heights of over above sea level. The smaller centres are found at the foot of the larger centres, as

parasitic vent A parasitic cone (also adventive cone, satellite cone, satellitic cone or lateral cone) is the cone-shaped accumulation of volcanic material not part of the central vent of a volcano. It forms from eruptions from fractures on the flank of the ...

s on their slopes or along the coast. These vents have produced

alkali basalt Alkali basalt or alkali olivine basalt is a dark-colored, porphyritic volcanic rock usually found in oceanic and continental areas associated with volcanic activity, such as oceanic islands, continental rifts and volcanic fields. Alkali basalt i ...

basanite Basanite () is an igneous, volcanic ( extrusive) rock with aphanitic to porphyritic texture. It is composed mostly of feldspathoids, pyroxenes, olivine, and calcic plagioclase and forms from magma low in silica and enriched in alkali metal ox ...

and

hawaiite Hawaiite is an olivine basalt with a composition between alkali basalt and mugearite. It was first used as a name for some lavas found on the island of Hawaii. It occurs during the later stages of volcanic activity on oceanic islands such as Ha ...

Composition

Basalt Basalt (; ) is an aphanite, aphanitic (fine-grained) extrusive igneous rock formed from the rapid cooling of low-viscosity lava rich in magnesium and iron (mafic lava) exposed at or very near the planetary surface, surface of a terrestrial ...

occurs at all four volcanoes. Phonolite and trachyte are found at Mount Rees and Mount Steere, the former also at Mount Frakes; Mount Rees also features rhyolite.

Phenocryst image:montblanc granite phenocrysts.JPG, 300px, Granites often have large feldspar, feldspathic phenocrysts. This granite, from the Switzerland, Swiss side of the Mont Blanc massif, has large white phenocrysts of plagioclase (that have trapezoid sh ...

s include

clinopyroxene The pyroxenes (commonly abbreviated Px) are a group of important rock-forming inosilicate minerals found in many igneous and metamorphic rocks. Pyroxenes have the general formula , where X represents ions of calcium (Ca), sodium (Na), iron (Fe ...

olivine The mineral olivine () is a magnesium iron Silicate minerals, silicate with the chemical formula . It is a type of Nesosilicates, nesosilicate or orthosilicate. The primary component of the Earth's upper mantle (Earth), upper mantle, it is a com ...

and

plagioclase Plagioclase ( ) is a series of Silicate minerals#Tectosilicates, tectosilicate (framework silicate) minerals within the feldspar group. Rather than referring to a particular mineral with a specific chemical composition, plagioclase is a continu ...

. The magma erupted in the Crary Mountains originated in the mantle and underwent

fractional crystallization Fractional crystallization may refer to: * Fractional crystallization (chemistry), a process to separate different solutes from a solution * Fractional crystallization (geology) Fractional crystallization, or crystal fractionation, is one of the ...

after formation.

Geologic history

The Crary Mountains were active between 9.3 and 0.04 million years ago during the Miocene and

Pliocene The Pliocene ( ; also Pleiocene) is the epoch (geology), epoch in the geologic time scale that extends from 5.33 to 2.58argon-argon dating on Mount Frakes, and imply an eruption 35,000±10,000–32,000±10,000 years ago. These ages were obtained on English Rock, which has also yielded ages of 826,000±79,000–851,000±36,000 and 1.62±0.02 million years ago.

Tephra Tephra is fragmental material produced by a Volcano, volcanic eruption regardless of composition, fragment size, or emplacement mechanism. Volcanologists also refer to airborne fragments as pyroclasts. Once clasts have fallen to the ground, ...

deposits in

ice core An ice core is a core sample that is typically removed from an ice sheet or a high mountain glacier A glacier (; or ) is a persistent body of dense ice, a form of rock, that is constantly moving downhill under its own weight. A glacier ...

s recovered at

Byrd Station The Byrd Station is a former research station established by the United States during the International Geophysical Year by U.S. Navy Seabees during Operation Deep Freeze II in West Antarctica. It was a year-round base until 1972, and then se ...

may have originated at Marie Byrd Land volcanoes such as these of the Crary Mountains. The maximum age of each volcano decreases in southeastward direction, from 9.34±0.24 million years old Mount Rees to 2.67±0.39 million years old Boyd Ridge. The pattern of volcanism migrating along the chain has been observed at other mountain ranges such as the

Executive Committee Range The Executive Committee Range () is a range consisting of five major volcanoes, which trends north-south for along the 126th meridian west, in Marie Byrd Land, Antarctica. Location The Executive Committee Range is south of the eastern end of ...

, where it takes place at a pace of like at the Crary Mountains. It is directed away from the centre of the Marie Byrd Land volcanic province and may reflect the propagation of a fracture in the crust.

West Antarctica West Antarctica, or Lesser Antarctica, one of the two major regions of Antarctica, is the part of that continent that lies within the Western Hemisphere, and includes the Antarctic Peninsula. It is separated from East Antarctica by the Transan ...

has been subject to glaciation since the

Oligocene The Oligocene ( ) is a geologic epoch (geology), epoch of the Paleogene Geologic time scale, Period that extends from about 33.9 million to 23 million years before the present ( to ). As with other older geologic periods, the rock beds that defin ...

, where a perhaps local

ice cap In glaciology, an ice cap is a mass of ice that covers less than of land area (usually covering a highland area). Larger ice masses covering more than are termed ice sheets. Description By definition, ice caps are not constrained by topogra ...

or snow deposit existed at Mount Petras. Volcanoes erupting through ice leave specific geologic structures which can be used to reconstruct the timing and extent of past glaciations. Geologic evidence at the Crary Mountains implies that a substantial West Antarctic Ice Sheet existed during the Miocene, and that fluctuations in its size may have stressed the crust and modulated the activity of volcanoes in its area. Before its formation the Crary Mountains might have been islands. In the Crary Mountains, ice occurred either in the form of slope ice when the mountains were erupting or as a thick continental

ice sheet In glaciology, an ice sheet, also known as a continental glacier, is a mass of glacier, glacial ice that covers surrounding terrain and is greater than . The only current ice sheets are the Antarctic ice sheet and the Greenland ice sheet. Ice s ...

. The glaciers were cold-based and thus did not produce

tillite image:Geschiebemergel.JPG, Closeup of glacial till. Note that the larger grains (pebbles and gravel) in the till are completely surrounded by the matrix of finer material (silt and sand), and this characteristic, known as ''matrix support'', is d ...

s or glacial surfaces, and were probably thin. Glacial erosion took place mainly between 8.55 and 4.17 million years ago; it formed the cirques in Mount Rees and Mount Steere and transported

s on the mountains.

Named features

Named features, from northwest to southeast, include Trabucco Cliff, Mount Rees, Tasch Peak, White Valley, Mount Steere, Lie Cliff, Mount Frakes, English Rock, Morrison Rocks, Campbell Valley, Boyd Ridge and Runyon Rock. The features were all mapped by the

United States Geological Survey The United States Geological Survey (USGS), founded as the Geological Survey, is an agency of the U.S. Department of the Interior whose work spans the disciplines of biology, geography, geology, and hydrology. The agency was founded on Mar ...

(USGS) from surveys and

United States Navy The United States Navy (USN) is the naval warfare, maritime military branch, service branch of the United States Department of Defense. It is the world's most powerful navy with the largest Displacement (ship), displacement, at 4.5 millio ...

aerial photography in 1959–66.

Trabucco Cliff

. A cliff at the tip of the broad spur which forms the northeast extremity of Mount Rees. Named by the United States

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 ...

(US-ACAN) for William J. Trabucco,

United States Antarctic Research Program The United States Antarctic Program (or USAP; formerly known as the United States Antarctic Research Program or USARP and the United States Antarctic Service or USAS) is an organization of the United States government which has a presence in the ...

(USARP) ionospheric physicist at

McMurdo Station McMurdo Station is an American Antarctic research station on the southern tip of Ross Island. It is operated by the United States through the United States Antarctic Program (USAP), a branch of the National Science Foundation. The station is ...

, 1969, and

Siple Station Siple Station ( )was a research station in Antarctica (), established in 1973 by Stanford's STAR Lab, to perform experiments that actively probed the magnetosphere using very low frequency (VLF) waves. Its location was selected to be near the Ear ...

, 1973.

Mount Rees

. Mountain located northwest of Mount Steere in the north end of Crary Mountains. Named by US-ACAN for Manfred H. Rees, aurora scientist at Byrd Station, 1965–66 season.

Tasch Peak

. A rocky peak in the southeast portion of Mount Rees. Named by US-ACAN for Paul Tasch, USARP geologist in the Sentinel Range and Ohio Range, summer 1966–67, and Coalsack Bluff, 1969–70.

White Valley

. A broad ice-covered valley that indents the northern part of Crary Mountains between Trabucco Cliff and Lie Cliff. Named by US-ACAN for Franklin E. White, USARP ionospheric physicist at Byrd Station in four summer seasons, 1966–71.

Mount Steere

. Prominent mountain high standing north-northwest of Mount Frakes. Named by US-ACAN for William C. Steere, biologist at McMurdo Station, 1964–65 season.

Lie Cliff

. A prominent rock cliff at the eastern foot of Mount Steere. Named by US-ACAN for Hans P. Lie, USARP ionospheric physicist at Siple Station in the 1970–71 and 1973-74 summer seasons.

Mount Frakes

. A prominent mountain high marking the highest elevation in the Crary Mountains. Named by US-AC AN for Lawrence A. Frakes, USARP geologist who worked three summer seasons in the Falkland Islands and Antarctica, 1964-65 through 1967–68.

English Rock

. A rock outcrop near the foot of the western slope of Mount Frakes. Named by US-ACAN for Claude L. English Jr., United States Navy, helicopter crewman with Squadron VXE-6 during Deep Freeze 1970; he also deployed with the Squadron during Deep Freeze 1961, 1962 and 1965.

Morrison Rocks

. A group of rocks which outcrop along the southern slope of Mount Frakes. Named by US-ACAN for Paul W. Morrison, United States Navy, hospital corpsman at the South Pole Station in 1974.

Campbell Valley

. An ice-filled valley, or pass, extending east–west between the main group of peaks of the Crary Mountains and Boyd Ridge. Named by US-ACAN for Wallace H. Campbell, ionospheric physicist at McMurdo Station in the 1964–65 season; Macquarie Island, 1961–62.

Boyd Ridge

. An ice-covered ridge, long, which extends in an east–west direction and forms the south end of the Crary Mountains. It is separated from the main peaks of the group by Campbell Valley. Named by US-ACAN for John C. Boyd, USARP biologist at McMurdo Station, 1965–66 and 1966–67 seasons.

Runyon Rock

. A prominent rock along the northern side of Boyd Ridge. Named by US-ACAN for William E. Runyon, United States Navy, construction electrician at the South Pole Station in 1969 and 1974.

References

Sources

* * * * * * * * * * * * * * * *

External links

* {{gnis, id=3276, type=antarid Crary Mountains Volcanoes of Marie Byrd Land Miocene shield volcanoes Pliocene shield volcanoes Pleistocene shield volcanoes Shield volcanoes of Antarctica