The Collaborative International Dictionary
Flysch \Flysch\ (fl[=e]sh), n. [A Swiss word, fr. G. fliessen to flow, melt.] (Geol.) A name given to the series of sandstones and schists overlying the true nummulitic formation in the Alps, and included in the Eocene Tertiary.
Wiktionary
n. (context geology English) A series of sandstones and schists overlying the true nummulitic formation in the Alps, and included in the Eocene Tertiary.
Wikipedia
Flysch is a sequence of sedimentary rocks that is deposited in a deep marine facies in the foreland basin of a developing orogen. Flysch is typically deposited during an early stage of the orogenesis. When the orogen evolves, the foreland basin becomes shallower and molasse is deposited on top of the flysch. It is therefore called a syn-orogenic sediment (deposited contemporaneously with mountain building).
Usage examples of "flysch".
Where the eastern-most alpine foreland of the first range met the flysch foothills at the northwestern end of the second, the river broke through a rocky barrier and turned abruptly south.
Between the river and the mountains was a landscape of dormant vegetation overlaying a flysch zone of sandstone.