Английская Википедия:Curtis Formation

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Шаблон:Infobox rockunit

Файл:Curtis over Slickrock.jpg
Light-colored beds of the Curtis Formation in abrupt contact with the underlying Entrada Formation. This contact marks the J3 unconformity,

The Curtis Formation is a geologic formation in Utah. It preserves fossils dating back to the Callovian age of the Jurassic period.

Файл:Curtis Point type locality of the Curtis Formation.jpg
Curtis Point, namesake for the Curtis Formation visible as the light gray strata.

Description

Файл:Wild Horse Butte detail.jpg
Lightly-colored Curtis Formation at Wild Horse Butte

The Curtis Formation is composed of shallow marine sandstone, with thin beds of mudstone and minor limestone and gypsum. The sandstone is grayish-green in color and flat bedded or cross bedded. The presence of glauconite and marine invertebrate fossils indicates it was laid down in a shallow marine environment that became hypersaline towards the end of deposition. It represents a high stand of the Sundance Sea in the Callovian.[1]

History of investigation

The formation was first described by Gilluly and Reeside in 1928 and named for exposures in the northeast San Rafael Reef at Curtis Point (Шаблон:Coord). Pipiringos and Imlay reassigned the Curtis as a member of the Stump Formation in 1979,[2] but this was rejected by Peterson in 1988.[3]

Footnotes

Шаблон:Reflist

See also

Шаблон:Portal

References

Шаблон:Chronostratigraphy of Colorado

  1. Lucas and Anderson 1992
  2. Pipiringos and Imlay 1979
  3. Peterson 1988