Colton Formation
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The Colton Formation is a
geologic formation A geological formation, or simply formation, is a body of rock having a consistent set of physical characteristics ( lithology) that distinguishes it from adjacent bodies of rock, and which occupies a particular position in the layers of rock exp ...
in
Utah Utah ( , ) is a state in the Mountain West subregion of the Western United States. Utah is a landlocked U.S. state bordered to its east by Colorado, to its northeast by Wyoming, to its north by Idaho, to its south by Arizona, and to it ...
. Its age is based on its position between the Upper Cretaceous-Paleocene North Horn Formation and overlying Green River Formation. The name was first used by P.T. Walton in 1944 for strata below the Green River Formation at the base of the Roan Cliffs, Utah. However, the type section was first given by E.M. Spieker in 1946. for exposures near the town of Colton on Soldier Summit, Utah County, Utah. Previously, the strata were assigned to the Wasatch Formation, which had become a rather generic name by the US Geological Survey for mudstone-sandstone strata of Eocene age. The formation is composed of reddish-brown to green beds of mudstone and shaly siltstone, interlayered with yellowish- to grayish-orange and grayish-brown, thin, fine- to medium-grained quartzose sandstone beds. The mudstones are locally variegated in shades of red and gray. Many sandstones are cross-bedded in large and small trough sets and the thicker samdstones are interpreted as deltaic deposits growing into Lake Flagstaff and Lake Uinta. Root structures and mudcracks are common in the mudstone beds. The only fossil described to date is a fragmentary skeleton of the aquatic bird ''Presbyornis recurvirostrus''J. W. Hardy. 1959. A previously undescribed recurvirostrid from the Eocene of Utah. ''Auk'' 76(1):106-108 ype of ''Coltonia recurvirostra'', now ''Presbyornis recurvirostrus''/ref> from a lacustrine limestone.


See also

* California River *
List of fossiliferous stratigraphic units in Utah This article contains a list of fossil-bearing stratigraphic units in the state of Utah, U.S. Sites See also * Paleontology in Utah References * {{DEFAULTSORT:Fossiliferous stratigraphic units in Utah Utah Stratigraphic units A strat ...
*
Paleontology in Utah The location of the state of Utah Paleontology in Utah refers to paleontological research occurring within or conducted by people from the U.S. state of Utah. Utah has a rich fossil record spanning almost all of the geologic column. During the P ...


References

* Paleogene geology of Utah {{Paleogene-stub