Hettangian

First age of the Early Jurassic

Hettangian

201.4 ± 0.2 – 199.5 ± 0.3 Ma

PreꞒ

Chronology

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Mesozoic

Jurassic

Early

Middle

Late

Rhaetian

Hettangian

Sinemurian

Pliensbachian

Toarcian

Aalenian

Bajocian

Bathonian

Callovian

Oxfordian

Kimmeridgian

Tithonian

Berriasian

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Triassic–Jurassic extinction event

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Subdivision of the Jurassic according to the ICS, as of 2024.[1]
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 Ammonite Psiloceras spelae tirolicum.
Lower boundary GSSP| Kuhjoch section, Karwendel mountains, Northern Calcareous Alps, Austria
47°29′02″N 11°31′50″E﻿ / ﻿47.4839°N 11.5306°E﻿ / 47.4839; 11.5306
Lower GSSP ratified| 2010[2]
Upper boundary definition| FAD of the Ammonites Vermiceras quantoxense and Vermiceras palmeri
Upper boundary GSSP| East Quantoxhead, West Somerset, England, UK
51°11′27″N 3°14′11″W﻿ / ﻿51.1909°N 3.2364°W﻿ / 51.1909; -3.2364
Upper GSSP ratified| 2000[3]

The Hettangian is the earliest age and lowest stage of the Jurassic Period of the geologic timescale. It spans the time between 201.3 ± 0.2 Ma and 199.3 ± 0.3 Ma (million years ago).[4] The Hettangian follows the Rhaetian (part of the Triassic Period) and is followed by the Sinemurian.[5]

In European stratigraphy the Hettangian is a part of the time span in which the Lias was deposited. An example is the British Blue Lias, which has an upper Rhaetian to Sinemurian age. Another example is the lower Lias from the Northern Limestone Alps where well-preserved but very rare ammonites, including Alsatites, have been found.

## Stratigraphic definitions

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The Hettangian was introduced in the literature by Swiss palaeontologist, Eugène Renevier, in 1864. The stage takes its name from Hettange-Grande, a town in north-eastern France, just south of the border with Luxembourg on the main road from Luxembourg City to Metz.

The base of the Hettangian Stage (which is also the base of the Lower Jurassic Series and the entire Jurassic System) is defined as the place in the stratigraphic column where fossils of the ammonite genus Psiloceras first appear. A global reference profile (a GSSP) for the base was defined 2010 for an exposure of the Kendlbach Formation at the Kuhjoch section in the Karwendel Mountains of western Austria.[6] The top of the Hettangian Stage (the base of the Sinemurian) is at the first appearances of ammonite genera Vermiceras and Metophioceras.

### Biostratigraphy

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The Hettangian contains three ammonite biozones in the Tethys domain:

* zone of Schlotheimia angulata
* zone of Alsatites liasicus
* zone of Psiloceras planorbis

## See also

[edit]

* Triassic-Jurassic extinction event

## References

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### Notes

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1. ^ "International Chronostratigraphic Chart" (PDF). International Commission on Stratigraphy. December 2024. Retrieved January 1, 2025.
2. ^ Hillebrandt, A.v.; Krystyn, L.; Kürschner, W.M.; Bonis, N.R.; Ruhl, M.; Richoz, S.; Schobben, M. A. N.; Urlichs, M.; Bown, P.R.; Kment, K.; McRoberts, C.A.; Simms, M.; Tomãsových, A (September 2013). "The Global Stratotype Sections and Point (GSSP) for the base of the Jurassic System at Kuhjoch (Karwendel Mountains, Northern Calcareous Alps, Tyrol, Austria)". Episodes. 36 (3): 162–198\. CiteSeerX 10.1.1.736.9905. doi:10.18814/epiiugs/2013/v36i3/001.
3. ^ Bloos, Gert; Page, Kevin (March 2002). "Global Stratotype Section and Point for base of the Sinemurian Stage (Lower Jurassic)". Episodes. 25 (1): 22–28\. doi:10.18814/epiiugs/2002/v25i1/003. Retrieved 23 December 2020.
4. ^ Benton, Michael J. (2012). Prehistoric Life. Edinburgh, Scotland: Dorling Kindersley. pp. 44–45\. ISBN 978-0-7566-9910-9.
5. ^ For a detailed geologic timescale, see Gradstein et al. (2004)
6. ^ GSSP Table Archived 2012-11-15 at the Wayback Machine

### Literature

[edit]

* Gradstein, F.M.; Ogg, J.G. & Smith, A.G.; 2004: A Geologic Time Scale 2004, Cambridge University Press.
* Renevier, E.: Notices géologiques et paléontologiques sur les Alpes Vaudoises, et les régions environnantes. I. Infralias et Zone à Avicula contorta (Étage Rhaetien) des Alpes Vaudoises Bulletin de la Société Vaudoise des Sciences Naturelles 8, p. 39–97. (in French)

## External links

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* GeoWhen Database - Hettangian
* Lower Jurassic timescale, at the website of the subcommission for stratigraphic information of the ICS
* Stratigraphic chart of the Lower Jurassic, at the website of Norges Network of offshore records of geology and stratigraphy

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Jurassic Period

| Lower/Early Jurassic| Middle Jurassic| Upper/Late Jurassic

|
|

* Hettangian
* Sinemurian
* Pliensbachian
* Toarcian

* Aalenian
* Bajocian
* Bathonian
* Callovian

* Oxfordian
* Kimmeridgian
* Tithonian

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Geological history of Earth

Cenozoic Era
(present–66.0 Ma)|

| Quaternary (present–2.58 Ma)|

* Holocene (present–11.7 ka)
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Neogene (2.58–23.0 Ma)|

* Pliocene (2.59–5.33 Ma)
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Paleogene (23.0–66.0 Ma)|

* Oligocene (23.0–33.9 Ma)
* Eocene (33.9–56.0 Ma)
* Paleocene (56.0–66.0 Ma)

Mesozoic Era
(66.0–252 Ma)|

| Cretaceous (66.0–145 Ma)|

* Late (66.0–100 Ma)
* Early (100–145 Ma)

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Jurassic (145–201 Ma)|

* Late (145–164 Ma)
* Middle (164–174 Ma)
* Early (174–201 Ma)

Triassic (201–252 Ma)|

* Late (201–237 Ma)
* Middle (237–247 Ma)
* Early (247–252 Ma)

Paleozoic Era
(252–539 Ma)|

| Permian (252–299 Ma)|

* Lopingian (252–260 Ma)
* Guadalupian (260–272 Ma)
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* Late (444–458 Ma)
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Cambrian (485–539 Ma)|

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* Terreneuvian (521–539 Ma)

Proterozoic Eon
(539 Ma–2.5 Ga)|

| Neoproterozoic (539 Ma–1 Ga)|

* Ediacaran (539–635 Ma)
* Cryogenian (635–720 Ma)
* Tonian (720 Ma–1 Ga)

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Mesoproterozoic (1–1.6 Ga)|

* Stenian (1–1.2 Ga)
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* Calymmian (1.4–1.6 Ga)

Paleoproterozoic (1.6–2.5 Ga)|

* Statherian (1.6–1.8 Ga)
* Orosirian (1.8–2.05 Ga)
* Rhyacian (2.05–2.3 Ga)
* Siderian (2.3–2.5 Ga)

Archean Eon (2.5–4 Ga)|

* Neoarchean (2.5–2.8 Ga)
* Mesoarchean (2.8–3.2 Ga)
* Paleoarchean (3.2–3.6 Ga)
* Eoarchean (3.6–4 Ga)

Hadean Eon (4–4.6 Ga)|

ka = kiloannum (thousand years ago); Ma = megaannum (million years ago); Ga = gigaannum (billion years ago).
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