Midcarpiennes

Midcarpiennes is a regional geological term used in some Francophone and Western European stratigraphic literature to designate the middle portion of the Carboniferous period. It is not an International Commission on Stratigraphy (ICS) formal stage, and its exact boundaries vary by locality and author. In practice, the midcarpiennes refers to the middle interval within the Carboniferous, commonly associated with the Viséan to Serpukhovian subdivisions in regional schemes.

Age and scope

The midcarpiennes generally cover the middle part of the Carboniferous, lying between the early and late portions of the period. In regional frameworks, this interval is often linked to rocks of Viséan and Serpukhovian affinities, corresponding roughly to a mid‑Carboniferous chronostratigraphic position. Because it is a regional construct rather than a globally standardized stage, its absolute ages and boundaries are not fixed across all areas.

usage and geography

The term has historical usage chiefly in France and parts of Western Europe, where local stratigraphic charts employed midcarpiennes to describe suites of rocks with particular lithologies and fossil assemblages. With the wider adoption of ICS subdivisions, the midcarpiennes has become less common in formal contexts, though it may still appear in older literature, regional syntheses, or museum labels.

Lithology and fossils

Midcarpien sequences are typically represented by marine to marginal marine sediments, including limestones, shales, and sandstones, deposited during the middle Carboniferous. Fossil content often includes marine invertebrates such as brachiopods and crinoids, with faunal assemblages that help distinguish regional midcarpienne facies.

Current status

Today, the midcarpiennes is primarily of historical or regional interest. In formal, global stratigraphy, the corresponding horizons are usually described in terms of Viséan and Serpukhovian intervals, rather than as a standalone midcarpienne stage.