Bajocian

Bajocian
170.9 ± 0.8 – 168.2 ± 1.2 Ma
Chronology
Etymology
Name formalityFormal
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 Ammonites Hyperlioceras mundum, Hyperlioceras furcatum, Braunsina aspera, and Braunsina elegantula
Lower boundary GSSPCabo Mondego, Portugal
40°11′57″N 8°54′15″W / 40.1992°N 8.9042°W / 40.1992; -8.9042
Lower GSSP ratified1996[2]
Upper boundary definitionFAD of the Ammonite Gonolkites convergen
Upper boundary GSSPRavin du Bès, Bas-Auran, Alpes de Haute, France
43°57′38″N 6°18′55″E / 43.9606°N 6.3153°E / 43.9606; 6.3153
Upper GSSP ratifiedJuly 2008[3]

In the geologic timescale, the Bajocian is an age and stage in the Middle Jurassic. It lasted from approximately 170.9 ±0.8 Ma to around 168.2 ±1.2 Ma (million years ago). The Bajocian Age succeeds the Aalenian Age and precedes the Bathonian Age.[4]

  1. ^ "International Chronostratigraphic Chart" (PDF). International Commission on Stratigraphy.
  2. ^ Pavia, G.; Enay, R. (March 1997). "Definition of the Aalenian-Bajocian Stage boundary". Episodes. 20 (1): 16–22. doi:10.18814/epiiugs/1997/v20i1/004. Retrieved 23 December 2020.
  3. ^ Fernández-López, Sixto Rafael; Pavia, Giulio; Erba, Elisabetta; Guiomar, Myette; Maria Helena Henriques; Lanza, Roberto; Mangold, Charles; Morton, Nicol; Olivero, Davide; Daniele Tiraboschi (2009). "The Global Boundary Stratotype Section and Point (GSSP) for base of the Bathonian Stage (Middle Jurassic), Ravin du Bès Section, SE France" (PDF). Episodes. 32 (4): 222–248. doi:10.18814/epiiugs/2009/v32i4/001.
  4. ^ See for a detailed geologic timescale Gradstein et al. (2004)