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Shotton Snowfield () is a large snowfield between
Herbert Mountains The Herbert Mountains () are a conspicuous group of rock summits on the east side of Gordon Glacier in the Shackleton Range of Antarctica. They were first mapped in 1957 by the Commonwealth Trans-Antarctic Expedition (and named for Sir Edwin S. Her ...
and
Pioneers Escarpment Pioneers Escarpment () is a mostly snow-covered north-facing escarpment, interrupted by occasional bluffs and spurs, between Slessor Glacier on the north and Shotton Snowfield on the south, in the Shackleton Range. The escarpment was photographe ...
on the north and
Read Mountains Read Mountains is a group of rocky summits, the highest Holmes Summit 1,875 m, lying east of Glen Glacier in the south-central part of the Shackleton Range. First mapped in 1957 by the Commonwealth Trans-Antarctic Expedition and named for Profess ...
on the south, in the
Shackleton Range The Shackleton Range is a mountain range in Antarctica. Rising at Holmes Summit to , it extends in an east–west direction for about between the Slessor and Recovery glaciers. The range was named after Sir Ernest Shackleton, leader of the Br ...
of Antarctica.


Location

The Shackleton Range is an ice-covered plateau between high that rises between two large glaciers. It is a rectangular horst rising above major fault zones now under the
Slessor Glacier The Slessor Glacier is a glacier at least 140 km (75 nmi) long and 90 km (50 nmi) wide, flowing west into the Filchner Ice Shelf to the north of the Shackleton Range. First seen from the air and mapped by the Commonwealth Trans-Antarct ...
to the north and
Recovery Glacier The Recovery Glacier () is a glacier flowing west along the southern side of the Shackleton Range in Antarctica. First seen from the air and examined from the ground by the Commonwealth Trans-Antarctic Expedition in 1957, it was so named because ...
glacier to the south. The center of the range is covered by a long ice cap stretching from the Fuchs Dome in the west to Shotton Snowfield in the east, and bounded by cliffs as high as . The Shotton Snowfield extends east from the
Gordon Glacier Gordon Glacier () is an Antarctic glacier of at least in length flowing in a northerly direction beginning in the Crossover Pass, flowing through the Shackleton Range to finally meet the Slessor Glacier. The glacier was first mapped in 1957 by ...
, which separates it from Fuchs Dome. The
Read Mountains Read Mountains is a group of rocky summits, the highest Holmes Summit 1,875 m, lying east of Glen Glacier in the south-central part of the Shackleton Range. First mapped in 1957 by the Commonwealth Trans-Antarctic Expedition and named for Profess ...
separate it from the
Recovery Glacier The Recovery Glacier () is a glacier flowing west along the southern side of the Shackleton Range in Antarctica. First seen from the air and examined from the ground by the Commonwealth Trans-Antarctic Expedition in 1957, it was so named because ...
to the south. The
Herbert Mountains The Herbert Mountains () are a conspicuous group of rock summits on the east side of Gordon Glacier in the Shackleton Range of Antarctica. They were first mapped in 1957 by the Commonwealth Trans-Antarctic Expedition (and named for Sir Edwin S. Her ...
are northwest of the snowfield, and further east the
Pioneers Escarpment Pioneers Escarpment () is a mostly snow-covered north-facing escarpment, interrupted by occasional bluffs and spurs, between Slessor Glacier on the north and Shotton Snowfield on the south, in the Shackleton Range. The escarpment was photographe ...
lies between it and the
Slessor Glacier The Slessor Glacier is a glacier at least 140 km (75 nmi) long and 90 km (50 nmi) wide, flowing west into the Filchner Ice Shelf to the north of the Shackleton Range. First seen from the air and mapped by the Commonwealth Trans-Antarct ...
to the north. The snowfield stretches eastward until it merges into the Antarctic ice sheet. Shotton Snowfield, Fuchs Dome and the table mountains that surround them are the remnants of a
peneplain 390px, Sketch of a hypothetical peneplain formation after an orogeny. In geomorphology and geology, a peneplain is a low-relief plain formed by protracted erosion. This is the definition in the broadest of terms, albeit with frequency the usage ...
. The southern edges of the snowfield have flat rocky areas against cliffs that rise for up to . The ice in most of the snowfield flows north, over the escarpment and into the Slessor Glacier. Ice from a small area in the southwest of the snowfield flows south between the Read Mountains and the
Stephenson Bastion Stephenson Bastion is a mountain massif with steep rock cliffs on its south side, rising to 1,850 m in the south-central part of Shackleton Range. It was first mapped in 1957 by the Commonwealth Trans-Antarctic Expedition, and it was photographe ...
into the Recovery Glacier.


Geology

The Shackleton Range Metamorphic Complex forms the metamorphic basement of almost the entire Shackleton Range. It seems to be part of the Antarctic Shield. It is formed from sedimentary rocks that have been metamorphosed in some regions, more in the south than the north of the range. The Flett Crags formation, part of the
Turnpike Bluff Turnpike Bluff () is a conspicuous rock formation in Antarctica. First mapped in 1957 by the Commonwealth Trans-Antarctic Expedition, and so named because it marks entry to a crevassed area of Recovery Glacier through which the Expedition's vehicle ...
Group, mainly consists of slate, but contains some bands of quartzite and pebbly conglomerate. It can be seen in the
nunatak A nunatak (from Inuit ''nunataq'') is the summit or ridge of a mountain that protrudes from an ice field or glacier that otherwise covers most of the mountain or ridge. They are also called glacial islands. Examples are natural pyramidal peaks. ...
s north of the Read Mountains escarpment. It is probably over thick, and may be assumed to extend northward under the Shotton Snowfield. The Turnpike Bluff group rests unconformably on the Shackleton Range Metamorphic Complex. It has not been directly dated, but is probably late
Precambrian The Precambrian (or Pre-Cambrian, sometimes abbreviated pꞒ, or Cryptozoic) is the earliest part of Earth's history, set before the current Phanerozoic Eon. The Precambrian is so named because it preceded the Cambrian, the first period of the ...
or perhaps in part
Cambrian The Cambrian Period ( ; sometimes symbolized C with bar, Ꞓ) was the first geological period of the Paleozoic Era, and of the Phanerozoic Eon. The Cambrian lasted 53.4 million years from the end of the preceding Ediacaran Period 538.8 million ...
.


Exploration

The
United States Navy The United States Navy (USN) is the maritime service branch of the United States Armed Forces and one of the eight uniformed services of the United States. It is the largest and most powerful navy in the world, with the estimated tonnage ...
obtained aerial photographs of the feature in 1967 and it was surveyed by
British Antarctic Survey The British Antarctic Survey (BAS) is the United Kingdom's national polar research institute. It has a dual purpose, to conduct polar science, enabling better understanding of global issues, and to provide an active presence in the Antarctic on ...
(BAS), 1968–71. It was named by the
United Kingdom Antarctic Place-Names Committee The UK Antarctic Place-Names Committee (or UK-APC) is a United Kingdom government committee, part of the Foreign and Commonwealth Office, responsible for recommending names of geographical locations within the British Antarctic Territory (BAT) and ...
(UK-APC), 1971, in association with the names of glacial geologists grouped in this area, after
Frederick William Shotton Professor Frederick William Shotton FRS (1906–1990) was a British geologist. He was awarded the Prestwich Medal in 1954. Shotton's research into the geological makeup of Normandy beaches helped allied commanders decide which were the best to u ...
(1906–90), British
Quaternary The Quaternary ( ) is the current and most recent of the three periods of the Cenozoic Era in the geologic time scale of the International Commission on Stratigraphy (ICS). It follows the Neogene Period and spans from 2.58 million years ...
geologist and Professor of Geology, University of Birmingham, 1949–74. Not: Shottonfonna.


Nunataks

Isolated
nunatak A nunatak (from Inuit ''nunataq'') is the summit or ridge of a mountain that protrudes from an ice field or glacier that otherwise covers most of the mountain or ridge. They are also called glacial islands. Examples are natural pyramidal peaks. ...
s in the snowfield that are named on the 1983
United States Geological Survey The United States Geological Survey (USGS), formerly simply known as the Geological Survey, is a scientific agency of the United States government. The scientists of the USGS study the landscape of the United States, its natural resources, ...
map are (west to east):


Freshfield Nunatak

. An isolated nunatak rising to c. to the southeast of Herbert Mountains in the Shackleton Range. Photographed from the air by the U.S. Navy, 1967, and surveyed by BAS, 1968-71. In association with the names of pioneers of polar life and exploration grouped in this area, named by the UK-APC in 1971 after Douglas W. Freshfield (1845-1934), English geographer and mountaineer in the Caucasus Mountains and the Himalayas. Freshfield Nunatak should perhaps be seen as part of the
Herbert Mountains The Herbert Mountains () are a conspicuous group of rock summits on the east side of Gordon Glacier in the Shackleton Range of Antarctica. They were first mapped in 1957 by the Commonwealth Trans-Antarctic Expedition (and named for Sir Edwin S. Her ...
. Rocks include
biotite Biotite is a common group of phyllosilicate minerals within the mica group, with the approximate chemical formula . It is primarily a solid-solution series between the iron-endmember annite, and the magnesium-endmember phlogopite; more alumino ...
schist Schist ( ) is a medium-grained metamorphic rock showing pronounced schistosity. This means that the rock is composed of mineral grains easily seen with a low-power hand lens, oriented in such a way that the rock is easily split into thin flakes o ...
s and biotite
quartzite Quartzite is a hard, non- foliated metamorphic rock which was originally pure quartz sandstone.Essentials of Geology, 3rd Edition, Stephen Marshak, p 182 Sandstone is converted into quartzite through heating and pressure usually related to tect ...
.


Bergan Castle

. A castlelike nunatak rising to to the southwest of Mount Dewar in Shotton Snowfield, Shackleton Range. Photographed from the air by the U.S. Navy, 1967. Surveyed by BAS, 1968-71. In association with the names of pioneers of polar life and travel grouped in this area, named by the UK-APC in 1971 after Ole Ferdinand Bergan (1876-1956), Norwegian inventor who designed Bergan's "meis" (carrying frames) and rucksacks, patented in Norway in 1909. Bergan Castle contains an intensely folded
sericite Sericite is the name given to very fine, ragged grains and aggregates of white (colourless) micas, typically made of muscovite, illite, or paragonite. Sericite is produced by the alteration of orthoclase or plagioclase feldspars in areas that hav ...
quartzite or
muscovite Muscovite (also known as common mica, isinglass, or potash mica) is a hydrated phyllosilicate mineral of aluminium and potassium with formula K Al2(Al Si3 O10)( F,O H)2, or ( KF)2( Al2O3)3( SiO2)6( H2O). It has a highly perfect basal cleavage ...
quartzite, partly blastomylonitic.


Lindqvist Nunatak

. A nunatak south of Chevreul Cliffs, rising to in the east part of Shotton Snowfield, Shackleton Range. Photographed from the air by the U.S. Navy in 1967 and surveyed by BAS, 1968-71. In association with the names of pioneers of polar life and travel grouped in this area, named by the UK-APC after Frans W. Lindqvist (1862-1931), Swedish inventor of the Primus pressure stove in 1892. Not: Lindquist Nunatak, Lindqvist Island. Lindqvist Nunatak contains a plagioclase-microcline gneiss and a quartzitic gneiss with cataclastic and/or blastomylonitic texture. An amphibolite has also been found there that contained light-brown biotite with incIusions of zircon and rutile.


References


Sources

* * * * * * {{refend Snow fields of Antarctica Bodies of ice of Coats Land