48°50′11″N 113°39′14″W / 48.8363690°N 113.6539971°W[1]
Appekunny Formation is a thick series of rock strata located in the Lewis Range within Glacier National Park, in the U.S. state of Montana. The formation is primarily mudstone and siltstone deposited in a shallow sea during the Proterozoic. Not far from the eastern entrance to the Going-to-the-Sun Road at St. Mary, Montana, the formation can be easily seen on the slopes of Singleshot Mountain.[2] The Appekunny Formation contains bedding structures which may include the remains of the oldest metazoan (animal) on Earth known by the species name Horodyskia moniliformis.[3]
The Appekunny Formation is named after Apikuni Mountain and averages 1,970 feet (600 m) thick. The rock strata have been dated at between 1.2–1.4 billion years old.
References
edit- ^ "Apikuni Mountain". Geographic Names Information System. United States Geological Survey, United States Department of the Interior. Retrieved May 27, 2018.
- ^ Dyson, James. "The Belt Formations". The Geologic Story of Glacier National Park. National Park Service. Retrieved May 27, 2018.
- ^ Fedonkin, Mikhail A.; Yochelson, Ellis L. (2002). "Middle Proterozoic (1.5 Ga) Horodyskia moniliformis Yochelson and Fedonkin, the Oldest Known Tissue-Grade Colonial Eucaryote". Smithsonian Contributions to Paleobiology (94): 1–29. doi:10.5479/si.00810266.94.1.
Further reading
edit- Raup, Omar; Robert L. Earhart; James W. Whipple; Paul E. Carrara (1983). Geology Along Going-to-the-Sun Road, Glacier National Park, Montana. West Glacier, Montana: Glacier Natural History Association. ISBN 0-934318-11-5.
- Price, Mike (January–March 2006). "Virtual Geomorphology" (PDF). Archived (PDF) from the original on 15 May 2006. Retrieved 2006-04-29.
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