Transantarctic Mountains
Geology

The Transantarctic Mountains are considerably older than other mountain ranges of the continent, which are mainly volcanic in origin. The range was uplifted during the opening of the West Antarctic Rift System to the east, beginning about 65 million years ago in the early Cenozoic, and soon after became occupied by glaciers.

The mountains consist of sedimentary layers lying upon a basement of granites and gneisses. The sedimentary layers include the Beacon Supergroup sandstones, siltstones, and coal deposited beginning in the Silurian period and continuing into the Jurassic. In many places, the Beacon Supergroup has been intruded by dikes and sills of Jurassic age Ferrar Dolerite. Many of the fossils found in Antarctica are from locations within these sedimentary formations.

Ice from the East Antarctic Ice Sheet flows through the Transantarctic Mountains via a series of outlet glaciers into the Ross Sea, Ross Ice Shelf, and West Antarctic Ice Sheet. These glaciers generally flow perpendicular to the orientation of the range and define subranges and peak groups. It has been thought that many of these outlet glaciers follow the traces of large-scale geologic faults. However, the ice flow theories will be re-evaluated in light of new data from recent ice-penetrating radar surveys which revealed the presence of three previously unknown deep subglacial valleys affecting the "mountainous subglacial topography beneath the ice divide". These geographic features are likely to have a significant impact on models and calculations related to ice flow through the Transantarctic Mountain region.
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