Cambrian Stage 4

Key events in the Cambrian

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Ediacaran

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Ordovician

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Fortunian

"Stage 2"

"Stage 3"

"Stage 4"

"Stage 5"

Drumian

Guzhangian

Paibian

Jiangshanian

"Stage 10"

 

 

 

 

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Baykonurian glaciation

Baykonurian glaciation

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Orsten Fauna

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Burgess Shale

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Kaili biota

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Archaeocyatha extinction

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Emu Bay Shale

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Sirius Passet biota

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Chengjiang biota

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First Trilobites

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SSF diversification, first brachiopods & archaeocyatha

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First halkieriids, mollusсs, hyoliths SSF

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Treptichnus pedum trace
Large negative peak δ 13C_carb excursion

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First Cloudina & Namacalathus mineral tubular fossils

Stratigraphic scale of the ICS subdivisions and Precambrian/Cambrian boundary.

Cambrian Stage 4 is the still unnamed 4th stage of the Cambrian and the upper stage of the 2nd Cambrian series. It follows the 3rd stage and lies below the Cambrian Stage 5. The lower boundary has not been formally defined by the International Commission on Stratigraphy. One proposal is the first appearance of two trilobite genera, Olenellus or Redlichia. Another proposal is the first appearance of the trilobite species Arthricocephalus chauveaui.^[1] Both proposals will set the lower boundary close to 514 million years ago.^[2] The upper boundary corresponds to the beginning of Cambrian Stage 5 which also has not been formally defined yet. Proposals are the first appearances of the trilobite species Oryctocephalus indicus or Ovatoryctocara granulata, dated at approximately 509 million years ago.^[3]

Naming

The International Commission on Stratigraphy has not named the 4th stage of the Cambrian yet. In the widely used Siberian nomenclature stage 4 would overlap with parts of the Botomian and Toyonian.^[4]

Biostratigraphy

The beginning of Cambrian Stage 4 has been tentatively correlated with the base of the European Duyunian faunal stage and the base of the South China Leonian faunal stage.^[5]

References

1. Peng, S.C.; Babcock, L.E. (21 September 2011). "Continuing progress on chronostratigraphic subdivision of the Cambrian System" (PDF). Bulletin of Geosciences: 391–396. doi:10.3140/bull.geosci.1273. Retrieved 21 November 2012.
2. "GSSP Table - Paleozoic Era". Retrieved 18 November 2012.
3. Gozalo, Rodolfo; Álvarez, María Eugenia Dies; Vintaned, José Antonio Gámez; Zhuravlev, Andrey Yu.; Bauluz, Blanca; Subías, Ignacio; Chirivella Martorell, Juan B.; Mayoral, Eduardo; Gursky, Hans-Jürgen; Andrés, José Antonio; Liñán, Eladio (1 December 2011). "Proposal of a reference section and point for the Cambrian Series 2-3 boundary in the Mediterranean subprovince in Murero (NE Spain) and its intercontinental correlation". Geological Journal: n/a–n/a. doi:10.1002/gj.1330.
4. "The 13th International Field Conference of the Cambrian Stage Subdivision Working Group" (PDF). Episodes. 31 (4): 440–441.
5. Yuan, Jinliang; Ng, Tin-Wai (2014). "Tentative correlation of the Duyunian (Cambrian Series 2, Stage 4) and the Taijiangian (Cambrian Series 3, Stage 5) between South China and the Mediterranean region". GFF. Geological Society of Sweden. 136 (1/2): 314–319. doi:10.1080/11035897.2014.898331.

Preceded by Proterozoic Eon	Phanerozoic Eon
	Paleozoic Era						Mesozoic Era			Cenozoic Era
	Cambrian	Ordovician	Silurian	Devonian	Carboniferous	Permian	Triassic	Jurassic	Cretaceous	Paleogene	Neogene	4ry