Rhaetian
Final Triassic age, named for the Rhaetian Alps; historically contested transitional beds between Keuper and Lias.
Language and route: International scientific terminology from Latin geographical ethnonym. Classical Latin Raetia/Rhaetia → Rhaetian Alps → German geological Rhät / scientific Rhaetian; variant spelling Raetian.
Literal gloss: of/from Raetia
The name and its history
Carl Wilhelm von Gümbel · 1859–1861 (conflicting publication-year attributions)
- What does the word literally mean?
- ‘of/from Raetia’, referring to the Rhaetian (Raetian) Alps and classical region Raetia.
- What did the original author mean?
- Gümbel recognised a transitional uppermost Triassic succession in the Alpine region; the word initially belonged to regional rock mapping rather than a universally delimited age.
- Why was the name needed?
- The beds near the Triassic–Jurassic transition were variously attributed to the Keuper, Lias and intervening Rhaetic divisions; marine fossils exposed shortcomings of rigid Germanic rock-unit correlation.
- What evidence supported the original concept?
- Alpine strata, marine invertebrates and later ammonoid and conodont studies were used to seek a coherent position of these disputed beds.
- How has geology changed the concept?
- The Rhaetian is today the last Triassic age immediately beneath the globally defined Hettangian. Its name does not fix the Triassic–Jurassic boundary at a Swiss locality.
Further historical context
The name invokes the Rhaetian (Raetian) Alps and classical region Raetia. Gümbel recognised a transitional uppermost Triassic succession in the Alpine region; the word initially belonged to regional rock mapping rather than a universally delimited age.
The beds near the Triassic–Jurassic transition were variously attributed to the Keuper, Lias and intervening Rhaetic divisions; marine fossils exposed shortcomings of rigid Germanic rock-unit correlation. Alpine strata, marine invertebrates and later ammonoid and conodont studies were used to seek a coherent position of these disputed beds.
The Rhaetian is today the last Triassic age immediately beneath the globally defined Hettangian. Its name does not fix the Triassic–Jurassic boundary at a Swiss locality.
Editorial qualification
Histories quote 1859 and 1861; primary bibliographical work is required before one can assert a unique first naming date.
Related names
Triassic · Norian · Hettangian · Lias
Sources
- ICS International Chronostratigraphic Chart, 2026/06 — Official current ranks and names; ages are subject to revision
- USGS Geolex, Rhaetian — Qualified attribution Gümbel (1861) and Alpine toponym
- Dictionary of Greek and Roman Geography (1854), Rhaetia — Classical Latin geographical name and orthographic distinction
- P. Fauré, Le Jurassique: divisions et étages, histoire de la géologie — French historiographical account; some first-year claims conflict with other accounts
- ICS ratified boundary GSSP register — Ratified GSSPs; check status separately from naming history