Selandian
Middle Paleocene age (61.66–59.24 Ma), named from Danish marine clays and greensands above the Danian limestones.
Language and route: Danish geographical name through international scientific terminology. Latinised Selandia, the Danish island Zealand (Sjælland) → historical scientific stage-name Selandian. This is a geographical/eponymic formation, not a Greek life-comparison compound.
Literal gloss: of Zealand
The name and its history
Alfred Rosenkrantz · 1924
- What does the word literally mean?
- of Zealand
- What did the original author mean?
- Rosenkrantz distinguished a marine, commonly glauconitic marl-and-clay succession that unconformably overlies Danian limestones in Denmark.
- Why was the name needed?
- A twofold Danian–Thanetian division obscured a distinct younger Danish sedimentary succession and its regional transgressive history.
- What evidence supported the original concept?
- Observed lithological breaks, glauconitic sands, fossiliferous marls and regional North Sea correlations supported the separate interval.
- How has geology changed the concept?
- A depositional hiatus in the Danish type area limits its global utility; the lower GSSP is now at Zumaia, Spain, defined by internationally correlatable markers.
Further historical context
Rosenkrantz distinguished a marine, commonly glauconitic marl-and-clay succession that unconformably overlies Danian limestones in Denmark.
A twofold Danian–Thanetian division obscured a distinct younger Danish sedimentary succession and its regional transgressive history.
Observed lithological breaks, glauconitic sands, fossiliferous marls and regional North Sea correlations supported the separate interval.
A depositional hiatus in the Danish type area limits its global utility; the lower GSSP is now at Zumaia, Spain, defined by internationally correlatable markers.
Editorial qualification
Do not infer the etymology of Sjælland from Selandian, nor identify its Danish unconformity as a globally synchronous boundary.
Related names
Sources
- International Commission on Stratigraphy, International Chronostratigraphic Chart v2026/06 — Primary authority for present unit names, hierarchy and boundary ages, not first coinages
- Schmitz et al. and subsequent review of Selandian stratigraphy, North Sea Basin — Attributes Selandian to Rosenkrantz (1924), the Danish type succession and Spanish GSSP
- Studies of Danian/Selandian contact and Danish unconformity — Original Denmark lithologies compared with revised global boundaries
- Speijer et al. (2020), The Paleogene Period, Geologic Time Scale 2020 — Specialist historical narratives, original regional definitions and modern GSSP revisions