The Snow Nunataks (or Ashley Snow Nunataks) are a line of four widely separated

nunatak A nunatak (from Inuit language, Inuit ) 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 often form natural pyramidal peaks. Isolated nunataks are also cal ...

s on the coast of

Palmer Land Palmer Land () is the portion of the Antarctic Peninsula, Antarctica that lies south of a line joining Cape Jeremy and Cape Agassiz. This application of Palmer Land is consistent with the 1964 agreement between the Advisory Committee on Antarctic N ...

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. ...

, trending east–west for southward of Case Island. They consist of volcanic

outcrop An outcrop or rocky outcrop is a visible exposure of bedrock or ancient superficial deposits on the surface of the Earth and other terrestrial planets. Features Outcrops do not cover the majority of the Earth's land surface because in most p ...

s that probably represent several small

subglacial volcano A subglacial volcano, also known as a glaciovolcano, is a volcanic form produced by subglacial eruptions or eruptions beneath the surface of a glacier or ice sheet which is then melted into a lake by the rising lava. Today they are most common i ...

es. Most of the nunataks are mounds 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 ...

overlain by

lapilli Lapilli (: lapillus) is a size classification of tephra, which is material that falls out of the air during a volcanic eruption or during some meteorite impacts. ''Lapilli'' is Latin for "little stones". By definition lapilli range from in dia ...

tuff 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 co ...

s. However, two of them may be

tuya A tuya is a flat-topped, steep-sided volcano formed when lava erupts through a thick glacier or ice sheet. They are rare worldwide, being confined to regions which were covered by glaciers and had active volcanism during the same period. As lava ...

s due to the existence of subaerially-chilled caprocks. The Snow Nunataks are uncertain in age but they probably formed in the

Late Miocene The Late Miocene (also known as Upper Miocene) is a sub-epoch of the Miocene epoch (geology), Epoch made up of two faunal stage, stages. The Tortonian and Messinian stages comprise the Late Miocene sub-epoch, which lasted from 11.63 Ma (million ye ...

or later. The nunataks were discovered by the

United States Antarctic Service 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 ...

(USAS) (1939–41) and named for Ashley C. Snow, aviation pilot on the expedition.

References

Nunataks of Palmer Land Volcanoes of Palmer Land Subglacial volcanoes {{coord, 73, 35, S, 77, 15, W, display=title