Coniacian
Third Late Cretaceous age, named by Coquand from Cognac as a subdivision of the older Senonian.
Language and route: Scientific French from French place-name. French place-name: Cognac → French stratigraphic Coniacian (spelling of the scientific formation subsequently anglicised).
Literal gloss: ‘of/from Cognac’ (geographical; not a Greek compound)
The name and its history
Henri Coquand · 1857
- What does the word literally mean?
- ‘of/from Cognac’ (geographical; not a Greek compound)
- What did the original author mean?
- Coquand split his previously broad Upper Chalk sequence and made the Coniacian its lowest new stage, previously within d’Orbigny’s Senonian.
- Why was the name needed?
- The Senonian encompassed several distinct fossil successions; Coquand sought smaller units to align beds in the northern Aquitaine Basin.
- What evidence supported the original concept?
- Local glauconitic and fossil-bearing beds in the Cognac area were compared with other French successions, though the old type boundary has a break.
- How has geology changed the concept?
- The modern Coniacian base has a GSSP at Salzgitter-Salder in Germany, established using inoceramid bivalve evolution, not the old Cognac section.
Further historical context
Coquand split his previously broad Upper Chalk sequence and made the Coniacian its lowest new stage, previously within d’Orbigny’s Senonian.
The Senonian encompassed several distinct fossil successions; Coquand sought smaller units to align beds in the northern Aquitaine Basin.
Local glauconitic and fossil-bearing beds in the Cognac area were compared with other French successions, though the old type boundary has a break.
The modern Coniacian base has a GSSP at Salzgitter-Salder in Germany, established using inoceramid bivalve evolution, not the old Cognac section.
Editorial qualification
The 1857 subdivision is well documented; some origin tables erroneously assign stage authorship to Mayer-Eymar.
Related names
Cretaceous · Late Cretaceous · Turonian · Santonian · Senonian · Biostratigraphy
Sources
- International Commission on Stratigraphy, International Chronostratigraphic Chart v2026/06 — Controlling nomenclature, rank and sequence of internationally recognised ages; not a historical-coinage source
- British Geological Survey, GCR Appendix: Upper Cretaceous stages and substages — Detailed historical type localities, faunal markers and changing stage conceptions
- Kennedy et al., The Global Boundary Stratotype for the Coniacian Stage, Episodes — Historical Coniacian as low division of Senonian; discontinuous Cognac type section
- ICS Subcommission: Coniacian GSSP, Salzgitter-Salder — Modern German GSSP versus old Cognac succession