Sheinwoodian
The age of the Wenlock interval (Silurian), approximately 432.9–430.6 Ma according to the ICS June 2026 chart.
Language and route: English locality. English locality → international English. Named after Sheinwood village / Hughley Brook region, Shropshire.
Literal gloss: named for Sheinwood
The name and its history
International Wenlock stage scheme; GSSP ratified 1980 · See attributed dates and cited original / standardisation works; first-use priority qualified where noted
- What does the word literally mean?
- Named for sheinwood. Immediate scientific language-route: English locality → international English. This is a locality-based or geographical term, not a description of a universal geological event.
- What did the original author mean?
- The earlier part of the historically mapped Wenlock succession, now treated as a formal age/stage with a defined lower boundary.
- Why was the name needed?
- A formal lower Wenlock stage was established so the historically recognised Wenlock succession could be split into boundary-based internationally comparable units.
- What evidence supported the original concept?
- The Hughley Brook reference section at the base of the Buildwas Formation was chosen using graptolite and conodont correlation arguments.
- How has geology changed the concept?
- ICS documentation itself cautions that the selected boundary does not precisely coincide with the graptolite zone once believed to mark it; revision has been discussed.
Further historical context
*Naming and context.* A formal lower Wenlock stage was established so the historically recognised Wenlock succession could be split into boundary-based internationally comparable units.
*Evidence and later scope.* The Hughley Brook reference section at the base of the Buildwas Formation was chosen using graptolite and conodont correlation arguments. ICS documentation itself cautions that the selected boundary does not precisely coincide with the graptolite zone once believed to mark it; revision has been discussed.
Editorial qualification
Formal GSSP documentation notes marker-correlation problems: do not present the fossil proxy as infallible.
Related names
Silurian · Wenlock · Homerian · Fossil · Graptolite · Conodont
Sources
- ICS International Chronostratigraphic Chart (June 2026) — Current formal unit, order, rank and numerical age
- ICS international GSSPs: Silurian stages and boundary issues — Modern formal references, rank, locations and correlation
- British Silurian Stratigraphy, Wenlock Series chapter — Stratigraphic history, evidence and original usage of Wenlock