Middle Miocene
Formal Miocene subepoch: Langhian, Serravallian ages.
Language and route: English ordinal adjective + established geological epoch name. English middle plus scientific Miocene (its root etymology is explained in the Miocene entry). Lower/Upper applies to rock strata; Early/Late applies to time.
Literal gloss: middle part of the Miocene
The name and its history
No single inventor; IUGS ratified formal subseries/subepoch status on 13 October 2021 · 2021 ratification of formal rank (not first use of ordinal words)
- What does the word literally mean?
- middle (relative stratigraphic order) + Miocene
- What did the original author mean?
- This is an ordinal subdivision of the Miocene, not a separate geographic stage invented by a single geologist; in modern formal usage it contains langhian, serravallian.
- Why was the name needed?
- Older regional subdivisions of the Miocene were used inconsistently across basins, and informal Early/Middle/Late labels often lacked an internationally agreed rank.
- What evidence supported the original concept?
- The interval is fixed by the adjoining formal stage GSSPs and internationally correlated biostratigraphic, magnetostratigraphic and astrochronologic records; ordinal words do not imply unique fossil percentages.
- How has geology changed the concept?
- The Middle Miocene is a formally recognised subepoch (its rock equivalent is the Middle Miocene subseries) following IUGS ratification on 13 October 2021; it covers the second of three stages of the Miocene.
Further historical context
This is an ordinal subdivision of the Miocene, not a separate geographic stage invented by a single geologist; in modern formal usage it contains langhian, serravallian.
Older regional subdivisions of the Miocene were used inconsistently across basins, and informal Early/Middle/Late labels often lacked an internationally agreed rank.
The interval is fixed by the adjoining formal stage GSSPs and internationally correlated biostratigraphic, magnetostratigraphic and astrochronologic records; ordinal words do not imply unique fossil percentages.
The Middle Miocene is a formally recognised subepoch (its rock equivalent is the Middle Miocene subseries) following IUGS ratification on 13 October 2021; it covers the second of three stages of the Miocene.
Editorial qualification
2021 is the ratification date, not first use.
Related names
Neogene · Miocene · Langhian · Serravallian · Late Miocene
Sources
- International Commission on Stratigraphy, International Chronostratigraphic Chart v2026/06 — Primary authority for present unit names, hierarchy and boundary ages, not first coinages
- Aubry et al. (2022), Ratification of Neogene subseries as formal units, Episodes — Documents 13 October 2021 ratification of five formal Neogene subepochs/subseries
- ICS Subcommission on Neogene Stratigraphy, objectives and current unfinished GSSP work — Documents the unresolved Burdigalian GSSP and 2021 subepoch formalisation
- ICS, International Stratigraphic Guide: Chronostratigraphic Units — Distinguishes ages from stages and present formal global boundary rules