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Hettangian

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). The Hettangian follows the Rhaetian (part of the Triassic Period) and is followed by the Sinemurian.

Key facts

Geologic timespan.name: Hettangian
Geologic timespan.color: Hettangian
Geologic timespan.time_start: 201.4
Geologic timespan.time_start_uncertainty: 0.2
Geologic timespan.time_end: 199.5
Geologic timespan.time_end_uncertainty: 0.3
Geologic timespan.image_map: File:200Ma Mollweide.png
Geologic timespan.caption_map: Mollweide map of Earth 200 million years ago, with black outlines depicting countries in their locations
Geologic timespan.timeline: Jurassic
Geologic timespan.name_formality: Formal
Geologic timespan.celestial_body: earth
Geologic timespan.usage: Global (ICS)
Geologic timespan.timescales_used: ICS Time Scale
Geologic timespan.chrono_unit: Age
Geologic timespan.strat_unit: Stage
Geologic timespan.timespan_formality: Formal
Geologic timespan.lower_boundary_def: FAD of the Ammonite Psiloceras spelae tirolicum.
Geologic timespan.lower_gssp_location: Kuhjoch section, Karwendel mountains, Northern Calcareous Alps, Austria

via Wikipedia infobox

Article

7 sections

Contents

Stratigraphic definitions
Biostratigraphy
See also
References
Notes
Literature
External links

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.