Cambrian Stage 10

Source: Wikipedia, the free encyclopedia.
Cambrian Stage 10
~489.5 – 485.4 ± 1.9 Ma
↓
Chronology
←
←
Dresbachian extinction
Subdivision of the Cambrian according to the
Newfoundland, Canada
49°40′58″N 57°57′55″W / 49.6829°N 57.9653°W / 49.6829; -57.9653
Upper GSSP ratified2000[2]

Stage 10 of the Cambrian is the still unnamed third and final stage of the Furongian series.[3] It follows the Jiangshanian and precedes the Ordovician Tremadocian Stage.[4] The proposed lower boundary is the first appearance of the trilobite Lotagnostus americanus around 489.5 million years ago, but other fossils are also being discussed (see below). The upper boundary is defined as the appearance of the conodont Iapetognathus fluctivagus which marks the beginning of the Tremadocian and is radiometrically dated as 485.4 million years ago.[5]

Naming

The 10th stage of the Cambrian has not been formally named by the

Yakutia, was also proposed in 2011.[9]

Stratotype

The ICS is still discussing which geological section and biostratigraphic marker will be used to define the base of the 10th Cambrian stage.[10][11]

Likely candidates for the section are still investigated. A first proposal was a section near

GSSP, e.g. in Australia, Kazakhstan and Canada.[6]

Candidates for the biostratigraphic marker are the

Eoconodontus notchpeakensis is favored by many authors because it is globally widespread and is independent of facies (known from continental rise to peritidal environments).[6]

The Eoconodontus notchpeakensis proposal would also incorporate a non-biostratigraphic marker to correlate the beginning of stage 10 globally. A carbon isotope excursion (the HERB-event) occurs in the lower part of the E. notchpeakensis range.[6]

Subdivisions

Cambrian Stage 10 can be subdivided using different biostratigraphic zones. Several conodont zone and subzones can be distinguished. The same is true for trilobites.[6]

References

  1. ^ "Chart/Time Scale". stratigraphy.org. International Commission on Stratigraphy.
  2. doi:10.18814/epiiugs/2001/v24i1/005. Archived
    (PDF) from the original on 2023-11-27. Retrieved 2024-03-25.
  3. ^ a b "Latest version of international chronostratigraphic chart". International Commission on Stratigraphy. Retrieved 2024-03-25.
  4. ^ "Stratigraphic Chart". International Commission on Stratigraphy. Archived from the original on 2012-10-30. Retrieved 2024-03-25.
  5. ^ "GSSP Table - Paleozoic Era". Geologic Timescale Foundation. Archived from the original on 2023-10-08. Retrieved 2024-03-25.
  6. ^
    doi:10.3140/bull.geosci.1251. Archived from the original
    (PDF) on 2023-08-29.
  7. doi:10.3140/bull.geosci.1255
    .
  8. S2CID 134012657
    .
  9. doi:10.3140/bull.geosci.1270.{{cite journal}}: CS1 maint: multiple names: authors list (link
    )
  10. ^ "ISCS Working Groups: Working Group on the Stage 10 GSSP". International Subcommission on Cambrian Stratigraphy. Archived from the original on 2023-09-26.
  11. doi:10.31857/S0869592X20020064. Archived (PDF) from the original on 2024-01-30.{{cite journal}}: CS1 maint: multiple names: authors list (link
    )
  12. doi:10.1016/j.palwor.2006.10.017
    .

External links
Retrieved from "https://en.wikipedia.org/w/index.php?title=Cambrian_Stage_10&oldid=1218866285"