Emsian

Emsian
407.6 ± 2.6 – 393.3 ± 1.2 Ma
Paleogeography of the Emsian, 400 Ma
Chronology
Etymology
Name formalityFormal
Name ratified1985
Usage information
Celestial bodyEarth
Regional usageGlobal (ICS)
Time scale(s) usedICS Time Scale
Definition
Chronological unitAge
Stratigraphic unitStage
Time span formalityFormal
Lower boundary definitionFAD of the conodont Polygnathus kitabicus
Lower boundary GSSPZinzil'ban Gorge, Uzbekistan
39°12′00″N 67°18′20″E / 39.2000°N 67.3056°E / 39.2000; 67.3056
Lower GSSP ratified1995[5]
Upper boundary definitionFAD of the conodont Polygnathus costatus partitus
Upper boundary GSSPWetteldorf Richtschnitt section, Wetteldorf, Eifel, Germany
50°08′59″N 6°28′18″E / 50.1496°N 6.4716°E / 50.1496; 6.4716
Upper GSSP ratified1985[6]

The Emsian is one of three faunal stages in the Early Devonian Epoch. It lasted from 407.6 ± 2.6 million years ago to 393.3 ± 1.2 million years ago. It was preceded by the Pragian Stage and followed by the Eifelian Stage. It is named after the Ems river in Germany.[7] The GSSP is located in the Zinzil'ban Gorge in the Kitab State Geological Reserve of Uzbekistan, 35 centimetres (14 in) above the contact with the Madmon Formation.

In North America the Emsian Stage is represented by Sawkill or Sawkillian time.

  1. ^ Parry, S. F.; Noble, S. R.; Crowley, Q. G.; Wellman, C. H. (2011). "A high-precision U–Pb age constraint on the Rhynie Chert Konservat-Lagerstätte: time scale and other implications". Journal of the Geological Society. 168 (4). London: Geological Society: 863–872. doi:10.1144/0016-76492010-043.
  2. ^ Kaufmann, B.; Trapp, E.; Mezger, K. (2004). "The numerical age of the Upper Frasnian (Upper Devonian) Kellwasser horizons: A new U-Pb zircon date from Steinbruch Schmidt(Kellerwald, Germany)". The Journal of Geology. 112 (4): 495–501. Bibcode:2004JG....112..495K. doi:10.1086/421077.
  3. ^ Algeo, T. J. (1998). "Terrestrial-marine teleconnections in the Devonian: links between the evolution of land plants, weathering processes, and marine anoxic events". Philosophical Transactions of the Royal Society B: Biological Sciences. 353 (1365): 113–130. doi:10.1098/rstb.1998.0195.
  4. ^ "Chart/Time Scale". www.stratigraphy.org. International Commission on Stratigraphy.
  5. ^ Yolkin, E.; Kim, A.; Weddige, K.; Talent, J.; House, M. (December 1997). "Definition of the Pragian/Emsian Stage boundary". Episodes. 20 (4): 235–240. doi:10.18814/epiiugs/1997/v20i4/005. Retrieved 18 December 2020.
  6. ^ Ziegler, W.; Klapper, G. (June 1985). "Stages of the Devonian System" (PDF). Episodes. 8 (2): 104–109. doi:10.18814/epiiugs/1985/v8i2/006. Retrieved 18 December 2020.
  7. ^ "Emsian stage". Encyclopedia Britannica. Retrieved 2 October 2019.