Wordium

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system series step ≈ age ( mya )
higher higher higher younger
Perm Lopingium Changhsingium 251.9
⬍
254.2
Wuchiapingium 254.2
⬍
259.9
Guadalupium Capitanium 259.9
⬍
265.1
Wordium 265.1
⬍
268.8
Roadium 268.8
⬍
272.3
Cisuralium Kungurium 272.3
⬍
279.3
Artinskium 279.3
⬍
290.1
Sacmarium 290.1
⬍
295.5
Asselium 295.5
⬍
298.9
deeper deeper deeper older

The Wordium is the middle chronostratigraphic level (or geochronological age) of Middle Perm or the Guadalupium series. The stage covers the period from approximately 268.8 million years to 265.1 million years. The Wordium follows the Roadium and is overlaid by the Capitanium .

Naming and history

The Wordium was first developed by Johan August Udden a. a. Retired as a stratigraphic unit in 1916. It is named after the word formation in the North American Permian Basin . In 1961 Brian F. Glenister and William Madison Furnish defined the wordium as the chronostratigraphic lower level of their, then still regional, level of the Guadalupium. In 2001 the Wordium was ratified by the IUGS as a global chronostratigraphic level .

Definition and GSSP

The basis of the wordium is defined by the first appearance of the conodont species Jinogondolella aserrata . The end of the stage is marked with the first appearance of the conodont species Jinogondolella postserrata . The reference profile GSSP of the Wordium is located at Getaway Ledge in the Guadalupe Mountains in Texas , USA .

Breakdown

The wordium corresponds to the entire Jinogondolella aserrata -Conodontenbiozone. The fusulins allow a subdivision into two bio-zones:

  • Afganella tereshkovae
  • Neoschwagerina tenuis

correlation

In Central Europe, the wordium is contained in the upper part of the lithostratigraphic unit of the Rotliegend . It corresponds here with part of the regional level of the saxonium . In Russia, the regional level of Urzhumium is about the same age as Wordium . In Tethysbereich the wordian corresponds to the lower part of the regional Murgabium stage.

literature

  • Brian F. Glenister, Bruce R. Wardlaw, Lance L. Lambert, Claude Spinosa, SA Bowring, DH Erwin, Manfred Menning and Garner L. Wilde: Proposal of Guadalupian and Component Roadian, Wordian and Capitanian Stages as International Standards for the Middle Permian Series. Permophiles, 34: 3-11, 1999 PDF
  • Felix Gradstein, Jim Ogg, Jim & Alan Smith: A Geologic timescale. Cambridge University Press 2005, ISBN 978-0-521-78673-7

Web links