Early Toarcian
Back to Toarcian (182.7 +/-0.7 Ma)Representation and status
- Color CMYK
- (33%,9%,0%,11%)
- Color RGB
- R: 153 G: 206 B: 227
- Rank
- chronostratigraphic Substage
- Validity
- Unit is in Use
- Status
- valid formal name
- Status discussion
Nomenclature
- Deutsch
- Frühes Toarcien
- Français
- Toarcien précoce
- Italiano
- Primo Toarciano
- English
- Early Toarcian
- Historical Variants
-
Frühes Toarcium, Frühes Toarc
Hierarchy and sequence
- Subordinate units
- Units at roof
- Upper boundary
-
Top just below the first appearance of the ammonite genus Hildoceras.
- Lower boundary
-
Base defined by the first appearance of Eodactylites mirabile (Tethyan Realm), or alternatively by the mass appearance of other dactylioceratids together with Paltarpites paltus.
Age
- Age at top
-
- early Toarcian
- Note about top
-
Serpentinum/Levisoni Zone, Falciferum Subzone
- Age at base
-
- early Toarcian
- Note about base
-
Polymorphum Zone, Mirabile Subzone (Tethyan Realm), approximately equivalent to the Tenuicostatum Zone, Paltum Subzone (NW European Realm)
- Dating Method
-
Ammonite biostratigraphy (mainly dactylioceratids, harpoceratids and early hildoceratids).
-
Toarcian Oceanic Anoxic Event
- Rank
- Oceanic Anoxic Event
- Status
- informal term
- In short
-
Major oceanic anoxic event of the Early Toarcian (around 183 Ma ago), documented by black shale deposits found on all major continents (no oceanic drilling cores have recovered black shales of this age as there is little or no Toarcian ocean crust remaining in the world ocean). This event correlates with a marine extinction event.