Ruthven Bluff () is a large rock bluff 1 nautical mile (1.9 km) south of Sosa Bluff in the Schneider Hills portion of the Argentina Range,

Pensacola Mountains The Pensacola Mountains are a large group of mountain ranges of the Transantarctic Mountains System, located in the Queen Elizabeth Land region of Antarctica. Geography They extend 450 km (280 mi) in a NE-SW direction. Subranges of the ...

. Mapped by

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, ...

(USGS) from surveys and U.S. Navy air photos, 1956–67. Named by

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 Richard W. Ruthven, USGS surveyor who visited the bluff in the 1965–66 season.

Geology

Ruthven Bluff is an approximately high bluff of

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 ...

limestone Limestone ( calcium carbonate ) is a type of carbonate sedimentary rock which is the main source of the material lime. It is composed mostly of the minerals calcite and aragonite, which are different crystal forms of . Limestone forms whe ...

. This bluff exposes a thick archaeocyathid

reef A reef is a ridge or shoal of rock, coral or similar relatively stable material, lying beneath the surface of a natural body of water. Many reefs result from natural, abiotic processes— deposition of sand, wave erosion planing down rock out ...

composed of massive boundstone. At this locality, the boundstone contains numerous irregular cavities that are in diameter. These cavities are lined with fibrous cement and filled with either ferroancalcite or internal sediment. At Ruthven Bluff, alternating beds of grainstone and burrowed packstone encase this reef. The packstone beds contain subparallel zones of

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 ...

-filled

burrow An Eastern chipmunk at the entrance of its burrow A burrow is a hole or tunnel excavated into the ground by an animal to construct a space suitable for habitation or temporary refuge, or as a byproduct of locomotion. Burrows provide a form of sh ...

s up to thick.Rowell, A.J., Rees, M.N. and Evans, K.R., 1992. ''Depositional setting of the Lower and Middle Cambrian in the Pensacola Mountains.'' ''Antarctic Journal of the United States'', 25, pp. 40-42. Stilwell, J.D., and Long, J.A., 2011. Frozen in time: prehistoric life in Antarctica.'' Collingwood, Victoria, Australia, CSIRO Publishing. 238 pp.

References

Paleontological sites of Antarctica Cliffs of Queen Elizabeth Land {{QueenElizabethLand-geo-stub