Anisian

Coordinates: 45°04′27″N 28°48′08″E / 45.0742°N 28.8022°E / 45.0742; 28.8022
Source: Wikipedia, the free encyclopedia.
Anisian
247.2 – ~242 Ma
Age
Stratigraphic unitStage
Time span formalityFormal
Lower boundary definitionNot formally defined
Lower boundary definition candidates
Lower boundary GSSP candidate section(s)
Upper boundary definitionFAD of the
Upper boundary GSSPBagolino, Lombardian pre-Alps, Italy
45°49′09″N 10°28′16″E / 45.8193°N 10.4710°E / 45.8193; 10.4710
Upper GSSP ratified2005[6]

In the

Lower Triassic Epoch) and precedes the Ladinian
Age.

Stratigraphic definitions

The stage and its name were established by

.

The base of the Anisian Stage (also the base of the Middle Triassic series) is sometimes laid at the first appearance of

GSSP or golden spike) was proposed at a flank of the mountain Deşli Caira in the Romanian Dobruja.[8]

The top of the Anisian (the base of the Ladinian) is at the first appearance of

appears at the same level.

Especially in Central Europe the Anisian Stage is sometimes subdivided into four substages: Aegean, Bythinian, Pelsonian and Illyrian.

The Anisian contains six ammonite biozones:

Selected formations

* Tentatively assigned to the Anisian; age estimated primarily via terrestrial tetrapod biostratigraphy (see Triassic land vertebrate faunachrons)

References

  1. .
  2. .
  3. ^ Retallack, G. J.; . Retrieved 2007-09-29.
  4. .
  5. .
  6. . Retrieved 23 December 2020.
  7. ^ According to Gradstein et al. (2004); Brack et al. (2005) give 248 to 241 Ma
  8. ^ The GSSP was proposed by Grădinaru et al. (2007)

Sources

  • Brack, P.; Rieber, H.; Nicora, A. & Mundil, R.; 2005: The Global boundary Stratotype Section and Point (GSSP) of the Ladinian Stage (Middle Triassic) at Bagolino (Southern Alps, Northern Italy) and its implications for the Triassic time scale, Episodes 28(4), pp. 233–244.
  • Grădinaru, E.; Orchard, M.J.; Nicora, A.; Gallet, Y.; Besse, J.; Krystyn, L.; Sobolev, E.S.; Atudorei, N.-V. & Ivanova, D.; 2007: The Global Boundary Stratotype Section and Point (GSSP) for the base of the Anisian Stage: Deşli Caira Hill, North Dobrogea, Romania, Albertiana 36, pp. 54–71.
  • Gradstein, F.M.; Ogg, J.G. & Smith, A.G.; 2004: A Geologic Time Scale 2004, Cambridge University Press.

External links

45°04′27″N 28°48′08″E / 45.0742°N 28.8022°E / 45.0742; 28.8022