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 and peaks that extend in a northeast–southwest direction in the Transantarctic Mountains System, Queen Elizabeth Land region of Antarctica. They comprise the Argentina Range, Forre ...

. Mapped by

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 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 ( ) is the first geological period of the Paleozoic Era, and the Phanerozoic Eon. The Cambrian lasted 51.95 million years from the end of the preceding Ediacaran period 538.8 Ma (million years ago) to the beginning of the Ordov ...

limestone Limestone is a type of carbonate rock, carbonate sedimentary rock which is the main source of the material Lime (material), lime. It is composed mostly of the minerals calcite and aragonite, which are different Polymorphism (materials science) ...

. 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 component, abiotic (non-living) processes such as deposition (geol ...

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 file:Chipmunk-burrow (exits).jpg, 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 Animal lo ...

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