Carnium

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system series step ≈ age ( mya )
higher higher higher younger
Triad Upper Triassic Rhaetium 201.3
⬍
208.5
Norium 208.5
⬍
228
Carnium 228
⬍
235
Middle Triassic Ladinium 235
⬍
242
Anisium 242
⬍
247.2
Lower Triassic Olenekium 247.2
⬍
251.2
Indusium 251.2
⬍
251.9
deeper deeper deeper older

The Karnium , (almost always shortened to Karn in German usage ) is the oldest (lowest) chronostratigraphic level of the Upper Triassic in the history of the earth , which geochronologically corresponds to the period about 235 to about 228 million years ago and thus lasted about 7 million years. The previous stage is the Ladinium of the Middle Triassic, the following stage the Norium .

Naming and history

Edmund von Mojsisovics introduced the name in 1869 as the "Carnic Step". It is not entirely clear whether the name is derived from the Carnic Alps (Austria) or rather from the Latin name for Carinthia (= Carinthia).

Definition and GSSP

The beginning of the stage is defined with the first appearance of the ammonite species Daxatina canadensis . The official GSSP (global type locality and type profile) is the profile in the Stuores meadows near Badia (Province of Bozen , South Tyrol ). The end of the stage is defined by the base of the ammonite zone Klamathites macrolobatus or Stikinoceras kerri and the conodonts zones Metapolygnathus communisti or Metapolygnathus primitius . The final demarcation (or the GSSP for the norium) has not yet been ratified.

Breakdown

The carnium is divided into five ammonite zones:

Regionally, the Karn is divided into the lower levels Cordevol ( Cordevolium ), Jul ( Julium ) and Tuval ( Tuvalium ), which roughly corresponds to Unter-, Mittel- and Oberkarn.

See also

  • Raibl event (also: Reingrabener Wende, Carnian Pluvial Event , Carnian Wet Intermezzo )

Individual evidence

  1. ↑ Edmund von Mojsisovics: About the structure of the upper Triassic formations of the eastern Alps. Yearbook of the Imperial and Royal Geological Institute Vienna, 19: 91–150, Vienna 1869 Online at archive.org (p. 127).

literature

  • Peter Brack, Hans Rieber, Alda Nicora and Roland Mundil: 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): 233-244, Beijing 2005 ISSN  0705-3797 .
  • C. Broglio Loriga, S. Cirilli, V. De Zanche, D. Di Bari, P. Gianolla, G. Laghi, S. Manfrin, A. Mastandrea, P. Mietto, G. Muttoni, C. Neri, R. Posenato , MC Rechichi, R. Rettori and G. Roghi: The Prati di Stuores / Stuores Wiesen section (Dolomites, Italy): a candidate Global Stratotype section and Point for the base of the Carnian stage. Rivista Italiana di Paleontologia e Stratigrafia, 105: 37-78, Milan 1999 ISSN  0035-6883 .
  • Felix Gradstein, Jim Ogg, Jim & Alan Smith: A Geologic timescale . Cambridge University Press 2005 ISBN 978-0-521-78673-7
  • P. Mietto, N. Buratti, S. Cirilli, V. De Zanche, P. Gianolla, S. Manfrin, A. Nicora, N. Preto, M. Rigo and G. Roghi (2007): New constraints for the Ladinian- Carnian boundary in the Southern Alps: Suggestions for global correlations In: "The Global Triassic" - Bulletin 41, Pages 275–281 PDF document (3.1 MB)

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