Mount Andrus () is a peak southeast of Mount Boennighausen in the southeast extremity of the

Ames Range The Ames Range () is a range of snow-covered, flat-topped, steep-sided mountains, extending in a north–south direction for and forming a right angle with the eastern end of the Flood Range in Marie Byrd Land, Antarctica. Location The Ames R ...

, 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.

Mapping and name

Mount Andrus was 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 air photographs, 1964–68. It was 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 Lt. Carl H. Andrus, United States Navy, medical officer and Officer-in-Charge of

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 ...

in 1964.

Geology

Mount Andrus is the youngest of the

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 in the Ames Range, which formed during 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 ...

. Late-stage volcanic activity resumed at Mount Andrus in the late

Pleistocene The Pleistocene ( ; referred to colloquially as the ''ice age, Ice Age'') is the geological epoch (geology), epoch that lasted from to 11,700 years ago, spanning the Earth's most recent period of repeated glaciations. Before a change was fin ...

or the

Holocene The Holocene () is the current geologic time scale, geological epoch, beginning approximately 11,700 years ago. It follows the Last Glacial Period, which concluded with the Holocene glacial retreat. The Holocene and the preceding Pleistocene to ...

. Its 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. While the age of Mt. Andrus is not well known it is one of the oldest trachytic shield volcanoes in Marie Byrd Land, similar in age to Mount Hampton. The westward face of the mountain is drained by the Coleman Glacier, with significant crevassing present.

References

Sources

* * * {{DEFAULTSORT:Andrus, Mount Polygenetic shield volcanoes Calderas of Antarctica Volcanoes of Marie Byrd Land Ames Range Miocene shield volcanoes Shield volcanoes of Antarctica