flysch
A series of sandstones and schists overlying the true nummulitic formation in the Alps, and included in the Eocene Tertiary.
Most of the structures and textures observed at Ponkapoag section have been noted in turbitite and flysch sequences.
Where it comes from
From German fließen (“to flow, to melt”).
Adapted from the Wiktionary entry flysch (CC BY-SA 4.0).