Ruthven Bluff
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. Mapped by United States Geological Survey (USGS) from surveys and U.S. Navy air photos, 1956–67. Named by Advisory Committee on Antarctic Names (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 limestone. This bluff exposes a thick archaeocyathid reef 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-filled burrows up to thick. References Paleontological sites of Antarctica Cliffs of Queen Elizabeth Land