Triassic
Oldest period of the Mesozoic, before Jurassic.
Language and route: German geological Trias, ultimately from Greek via Latin. German Trias (‘triad’) from Greek triás, ‘set of three’; Triassic is an English derivation.
Literal gloss: three-part
The name and its history
Friedrich von Alberti · 1834
- What does the word literally mean?
- The ‘three’ is the German lithostratigraphic tripartition, not three Mesozoic periods.
- What did the original author mean?
- Alberti’s ‘threefold’ referred to Buntsandstein, Muschelkalk and Keuper in the Germanic Basin.
- Why was the name needed?
- Previously treated as separate rock units, these three successions could be interpreted as a coherent chronostratigraphic system.
- What evidence supported the original concept?
- Their characteristic alternation of continental and marine facies, stratigraphic superposition and fossil evidence supported Alberti’s 1834 synthesis.
- How has geology changed the concept?
- Modern global Triassic subdivisions and boundaries are not identical with those three regionally variable lithostratigraphic groups.
Further historical context
Friedrich von Alberti’s 1834 Beitrag zu einer Monographie des bunten Sandsteins, Muschelkalks und Keupers brought three formations of the Germanic Basin under the collective designation Trias. The lower Buntsandstein is chiefly variegated continental sandstones, the middle Muschelkalk predominantly marine limestones and dolostones, and upper Keuper a heterogeneous assemblage of sandstones, mudstones and evaporites.
Alberti sought a coherent unit recognised by field succession and fossil relationships, not a new mathematical threefold theory of the Mesozoic. Because the Germanic basin includes terrestrial and marine deposits affected by changing environments, these three units are regional lithostratigraphic bodies and are not equivalent to the modern international Early/Middle/Late Triassic boundaries.
Editorial qualification
German Trias entered scientific vocabulary in a particular stratigraphic sense; assigning the label to global Triassic rocks was an extended use.
Related names
Buntsandstein · Muschelkalk · Keuper · Mesozoic · Jurassic · Cretaceous · Fossil · Stratigraphy · Lithostratigraphy · Superposition · Facies
Sources
- ICS International Chronostratigraphic Chart, 2026/06 — Current name, rank and numerical boundaries
- Alberti (1834), Beitrag zu einer Monographie ... — Digitised 1834 original: Buntsandstein, Muschelkalk and Keuper
- ICS global boundary definitions — Current definition/status of stratigraphic boundaries