Bajocian

Bajocian
Bajocian
170.9 ± 0.8 – 168.2 ± 1.2 Ma PreꞒ Ꞓ O S D C P T J K Pg N ↓
Chronology
←	Triassic–Jurassic extinction event
	Subdivision of the Jurassic according to the ICS, as of 2023.; Vertical axis scale: millions of years ago.;
Etymology
Name formality	Formal
Usage information
Celestial body	Earth
Regional usage	Global (ICS)
Time scale(s) used	ICS Time Scale
Definition
Chronological unit	Age
Stratigraphic unit	Stage
Time span formality	Formal
Lower boundary definition	FAD of the Ammonites Hyperlioceras mundum, Hyperlioceras furcatum, Braunsina aspera, and Braunsina elegantula
Lower boundary GSSP	Cabo Mondego, Portugal; 40°11′57″N 8°54′15″W / 40.1992°N 8.9042°W
Lower GSSP ratified	1996
Upper boundary definition	FAD of the Ammonite Gonolkites convergen
Upper boundary GSSP	Ravin du Bès, Bas-Auran, Alpes de Haute, France; 43°57′38″N 6°18′55″E / 43.9606°N 6.3153°E
Upper GSSP ratified	July 2008

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]

^ "International Chronostratigraphic Chart" (PDF). International Commission on Stratigraphy.
^ 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.
^ 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.
^ See for a detailed geologic timescale Gradstein et al. (2004)

[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)

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