Cambrian Stage 4 is the still unnamed fourth stage of the Cambrian and the upper stage of Cambrian Series 2. It follows Cambrian Stage 3 and lies below the Wuliuan. 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.[3] Both proposals will set the lower boundary close to 514 million years ago.[4] The upper boundary corresponds to the beginning of the Wuliuan.
| Cambrian Stage 4 | ||||||||||||||||||||||||||||||||||||||
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| Chronology | ||||||||||||||||||||||||||||||||||||||
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| Etymology | ||||||||||||||||||||||||||||||||||||||
| Name formality | Informal | |||||||||||||||||||||||||||||||||||||
| Usage information | ||||||||||||||||||||||||||||||||||||||
| Celestial body | Earth | |||||||||||||||||||||||||||||||||||||
| Regional usage | Global (ICS) | |||||||||||||||||||||||||||||||||||||
| Time scale(s) used | ICS Time Scale | |||||||||||||||||||||||||||||||||||||
| Definition | ||||||||||||||||||||||||||||||||||||||
| Chronological unit | Age | |||||||||||||||||||||||||||||||||||||
| Stratigraphic unit | Stage | |||||||||||||||||||||||||||||||||||||
| Time span formality | Formal | |||||||||||||||||||||||||||||||||||||
| Lower boundary definition | Not formally defined | |||||||||||||||||||||||||||||||||||||
| Lower boundary definition candidates | FAD of the Trilobite Olenellus or Redlichia | |||||||||||||||||||||||||||||||||||||
| Lower boundary GSSP candidate section(s) | None | |||||||||||||||||||||||||||||||||||||
| Upper boundary definition | FAD of Oryctocephalus indicus. | |||||||||||||||||||||||||||||||||||||
| Upper boundary GSSP | Wuliu-Zengjiayan, Guizhou, China 26°04′51″N 108°24′50″E / 26.0807°N 108.4138°E | |||||||||||||||||||||||||||||||||||||
| Upper GSSP ratified | 2018[2] | |||||||||||||||||||||||||||||||||||||
Naming
editThe International Commission on Stratigraphy has not named the fourth stage of the Cambrian yet. In the widely used Siberian nomenclature stage 4 would overlap with parts of the Botomian and Toyonian.[5]
Biostratigraphy
editThe beginning of Cambrian Stage 4 has been tentatively correlated with the base of the European Leonian faunal stage and the base of the South China Duyunian faunal stage.[6]
During Cambrian Stage 4, three families of trilobites were widely distributed: olenellids, redlichiids, and paradoxidids. At the Stage 4-Wuliuan boundary, the first major trilobite extinction, known as the Olenellid Biomere boundary, occurred. In particular, trilobites of the families Ollenellidae and Redlichiidae have been extinct in Laurentia and South China, respectively.[7]
References
edit- ^ "International Chronostratigraphic Chart" (PDF). International Commission on Stratigraphy. September 2023. Retrieved December 16, 2024.
- ^ Yuanlong Zhao; Jinliang Yuan; Loren E. Babcock; Qingjun Guo; Jin Peng; Leiming Yin; Xinglian Yang; Shanchi Peng; Chunjiang Wang; Robert R. Gaines; Jorge Esteve; Tongsu Tai; Ruidong Yang; Yue Wang; Haijing Sun; Yuning Yang (June 2019). "Global Standard Stratotype-Section and Point (GSSP) for the conterminous base of the Miaolingian Series and Wuliuan Stage (Cambrian) at Balang, Jianhe, Guizhou, China" (PDF). Episodes. 42 (2): 165–184. doi:10.18814/epiiugs/2019/019013. Archived (PDF) from the original on 2022-03-04. Retrieved 2024-04-03.
- ^ 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. Archived from the original (PDF) on 2023-07-16.
- ^ "GSSP Table - Paleozoic Era". Archived from the original on 2023-10-08. Retrieved 2024-03-19.
- ^ "The 13th International Field Conference of the Cambrian Stage Subdivision Working Group" (PDF). Episodes. 31 (4): 440–441. Archived from the original (PDF) on 2014-11-05. Retrieved 2024-04-03.
- ^ 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. 136 (1/2). Geological Society of Sweden: 314–319. Bibcode:2014GFF...136..314Y. doi:10.1080/11035897.2014.898331. S2CID 129488362.
- ^ Jih-Pai Lin, Frederick A. Sundberg, Ganqing Jiang, Isabel P. Montañez, Thomas Wotte (22 November 2019). "Chemostratigraphic correlations across the first major trilobite extinction and faunal turnovers between Laurentia and South China". Scientific Reports. 9 (1): 17392. Bibcode:2019NatSR...917392L. doi:10.1038/s41598-019-53685-2. PMC 6874646. PMID 31758094.
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External links
edit- "ISCS Working Groups: Working Group on the Stage 4 GSSP". International Subcommission on Cambrian Stratigraphy. Archived from the original on 2023-09-26.
- "GSSP Table - Paleozoic Era". Archived from the original on 2023-10-08.