Oxfordium

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system series step ≈ age ( mya )
higher higher higher younger
law Upper Jurassic Tithonium 145
⬍
152.1
Kimmeridgium 152.1
⬍
157.3
Oxfordium 157.3
⬍
163.5
Middle Jurassic Callovium 163.5
⬍
166.1
Bathonium 166.1
⬍
168.3
Bajocium 168.3
⬍
170.3
Aalenium 170.3
⬍
174.1
Lower Jurassic Toarcium 174.1
⬍
182.7
Pliensbachium 182.7
⬍
190.8
Sinemurium 190.8
⬍
199.3
Hettangium 199.3
⬍
201.3
deeper deeper deeper older

The Oxfordium (often shortened to just Oxford, more rarely also Oxfordien) is the lower chronostratigraphic level of the Upper Jurassic series in the Jura in geological history . The stage began geochronologically about 163.5 million years ago and ended about 157.3 million years ago. The Oxfordium follows the Callovium and is replaced by the Kimmeridgium .

Naming and history

The term “Oxfordien” was used by Alexandre Brongniart as early as 1829 , and later by Alcide d'Orbigny . It is the Latinized name of the English city of Oxford .

Definition and GSSP

The beginning of the stage is defined by the first appearance of the ammonite species Brightia thuouxensis . It ends with the first appearance of the ammonite Pictonia baylei in the fossil record. A GSSP (type locality and type profile) has not yet been defined.

Subdivision of the Oxfordium

In the Tethys area, the oxfordium is divided into six ammonite biozones:

Individual evidence

  1. ^ Encyclopedia Universalis

literature

  • Alexandre Brongniart: Tableau théorique de la succession et de la disposition la plus générale on Europa, des terrains et roches, qui composent l'écorce de la terre. 1 sheet, Paris 1829.
  • Felix Gradstein, Jim Ogg, Jim & Alan Smith: A Geologic timescale. Cambridge University Press 2004, ISBN 978-0-521-78673-7
  • Hans Murawski & Wilhelm Meyer: Geological dictionary . 10., rework. u. exp. Ed., 278, Enke Verlag, Stuttgart 1998, ISBN 3-432-84100-0 .

Web links