The Geode Nunataks () are a group of small
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 on the west side of
Sibelius Glacier
Sibelius Glacier () is a glacier, 12 miles (19 km) long and 6 miles (10 km) wide, flowing south into the Mozart Ice Piedmont 10 miles (16 km) southwest of Mount Stephenson in the northern portion of Alexander Island, Antarctica. T ...
, immediately north of the northern extremity of the
Finlandia Foothills
The Finlandia Foothills () are a rock massif, long and wide, rising to about at the west side of Sibelius Glacier, situated in northern Alexander Island, Antarctica. The massif lies immediately south of the Geode Nunataks, north of the Handel ...
, in northeast
Alexander Island
Alexander Island, which is also known as Alexander I Island, Alexander I Land, Alexander Land, Alexander I Archipelago, and Zemlja Alexandra I, is the largest island of Antarctica. It lies in the Bellingshausen Sea west of Palmer Land, Antarc ...
,
Antarctica
Antarctica () is Earth's southernmost and least-populated continent. Situated almost entirely south of the Antarctic Circle and surrounded by the Southern Ocean, it contains the geographic South Pole. Antarctica is the fifth-largest contine ...
. They were so named by the
UK 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 ...
in 1977; the nunataks are composed of
lava
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 un ...
flows with abundant
geode
A geode (; ) is a geological secondary formation within sedimentary and volcanic rocks. Geodes are hollow, vaguely spherical rocks, in which masses of mineral matter (which may include crystals) are secluded. The crystals are formed by the fill ...
s (cavities within the rock containing
quartz
Quartz is a hard, crystalline mineral composed of silica (silicon dioxide). The atoms are linked in a continuous framework of SiO4 silicon-oxygen tetrahedra, with each oxygen being shared between two tetrahedra, giving an overall chemical form ...
and
calcite
Calcite is a Carbonate minerals, carbonate mineral and the most stable Polymorphism (materials science), polymorph of calcium carbonate (CaCO3). It is a very common mineral, particularly as a component of limestone. Calcite defines hardness 3 on ...
crystals).
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See also
* Appalachia Nunataks
The Appalachia Nunataks () are a group of nunataks rising to about on the west side of the Elgar Uplands, Alexander Island, Antarctica. They are situated 5.62 km southwest of Lyubimets Nunatak, 9 km southwest of Kozhuh Peak and 9.65 ...
* Ceres Nunataks
The Ceres Nunataks () are a group of three nunataks located immediately east of the base of Shostakovich Peninsula in southern Alexander Island, Antarctica. They were mapped by the Directorate of Overseas Surveys from satellite imagery supplied by ...
* Gannon Nunataks
The Gannon Nunataks () are a notable twin-peaked group of nunataks (about high) and several smaller rock outcrops, located between the northern end of the LeMay Range and the Lully Foothills, situated in the west-central portion of Alexander Is ...
References
Nunataks of Alexander Island
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