Weeks Formation

Last updated
Weeks Formation
Stratigraphic range: Cambrian Stage 3
Beckwithia cephalon collection Paul Hille.jpg
Fossil from the Weeks Formation
Type Formation
Location
Region Utah
CountryFlag of the United States.svg  United States

The Weeks Formation is a geologic formation in Utah. It preserves fossils dating back to the Cambrian period and more specifically the Guzhangian stage. Its upper part has yielded a diverse fauna dominated by trilobites and brachiopods, but also comprising various soft-bodied organisms, such as Falcatamacaris . [1] As such, it is regarded as a Konservat-Lagerstätte.

See also

Related Research Articles

Wheeler Shale Geologic formation in Utah notable for trilobite fossils

The Wheeler Shale is a Cambrian (c. 507 Ma) fossil locality world-famous for prolific agnostid and Elrathia kingii trilobite remains and represents a Konzentrat-Lagerstätte. Varied soft bodied organisms are locally preserved, a fauna and preservation style normally associated with the more famous Burgess Shale. As such, the Wheeler Shale also represents a Konservat-Lagerstätten.

Kinzers Formation

The Kinzers Formation is a geologic formation in Pennsylvania. It preserves fossils dating back to the Cambrian Period.

The Dotsero Formation is a geologic formation in Colorado. It preserves fossils dating back to the Cambrian period.

Spence Shale

The Spence Shale is the middle member of the Langston Formation in southeastern Idaho and northeastern Utah. It is exposed in the Bear River Range, the Wasatch Range and the Wellsville Mountains. It is known for its abundant Cambrian trilobites and the preservation of Burgess Shale-type fossils.

Langston Formation

The Langston Formation is a geologic formation in Idaho and Utah. It preserves fossils dating back to the Cambrian period. The formation is composed of bluish-gray limestone, weathering to a buff color, often with rounded edges.

The Nopah Formation is a geologic formation in Utah. It preserves fossils dating back to the Cambrian period.

Notch Peak Formation Geologic formation in Utah, United States

The Notch Peak Formation is a geologic formation in Utah. It preserves fossils dating back to the Cambrian period.

Orr Formation

The Orr Formation is a geologic formation in Utah. It preserves fossils dating back to the Cambrian period.

The Pioche Formation is a geologic formation in Utah and Nevada. It preserves fossils dating back to the Cambrian period.

The Ute Limestone is a geologic formation in Utah. It preserves fossils dating back to the Cambrian period.

The Marjum Limestone is a geologic formation in Utah. It preserves fossils dating back to the Cambrian period.

The Chisholm Formation is a geologic formation in Utah. It preserves fossils dating back to the Cambrian period.

The Dunderberg Shale is a geologic formation in Nevada and Utah.

The Swasey Formation is a geologic formation in Utah. It preserves fossils dating back to the Cambrian period.

The Swasey Limestone is a geologic formation in Utah. It preserves fossils dating back to the Cambrian period.

The Whiteaves Formation is a geologic formation in British Columbia. It preserves fossils dating back to the Jurassic period.

The Agua Nueva Formation is a geologic formation in Mexico. It preserves fossils dating back to the upper part of the Cenomanian stage of the Cretaceous period. It consists "predominantly of alternating fossiliferous, organic matter-rich, laminated, dark gray limestone and non-laminated, organic matter-poor limestone in decimeter-thick beds with occasional centimetric beds of brown shale that show no apparent internal structures." The formation is noted for its qualities as a Konservat-Lagerstätte, with notable finds including the plesiosaur Mauriciosaurus and shark Aquilolamna.

Menat Formation

The Menat Formation is a geologic formation in France. It preserves fossils dating back to the Paleocene. It is a maar deposit located on top of an ancient volcano, the extent is very localised with the outcropping area being around 600 by 1000 metres. Numerous species of fossil insects, plants and fish are known, as well as some isolated mammals, including the primate Plesiadapis insignis, the choristodere reptile Lazarussuchus, and birds, including members of Halcyornithidae and Messelasturidae and relatives of Songziidae.

Khankaspis is a poorly preserved arthropod genus that contains one species, K. bazhanovi, recovered from the Snegurovka Formation of Siberia, Russia. Some authors have placed Khankaspis within the order Strabopida, but poorly preserved material precludes detailed comparisons with other Cambrian arthropods.

Falcatamacaris is an extinct genus of Cambrian artiopodan arthropod, only known from the type species F. bellua described in 2014, from the Guzhangian aged Weeks Formation in Utah. The holotype specimen is over 10 cm long. The trunk consists of 11 tergites, with crescent shaped pleural spines. Its placement within the Artiopoda was unresolved.

References

  1. Lerosey-Aubril, Rudy; Gaines, Robert R.; Hegna, Thomas A.; Ortega-Hernández, Javier; Van Roy, Peter; Kier, Carlo; Bonino, Enrico (2018). "The Weeks Formation Konservat-Lagerstätte and the evolutionary transition of Cambrian marine life". Journal of the Geological Society. 175: 705–715. doi:10.1144/jgs2018-042.