- flysch
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/flish/, n. Geol.an association of certain types of marine sedimentary rocks characteristic of deposition in a foredeep.[1845-55; < G < Swiss G flisch referring to such deposits in the Swiss Alps; perh. akin to Swabian dial. flins slate (akin to FLINT)]
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Sequence of shales interbedded with thin, hard, graywacke-like sandstones.Such sequences are usually thousands of yards thick, but the individual beds are only a few inches to a few yards thick. The occasional presence of fossils indicates marine deposition. The term originally was applied to a formation of the Tertiary Period in the northern Alpine region, but it now denotes similar deposits of other ages and places.* * *
▪ rocksequence of shales rhythmically interbedded with thin, hard, graywacke-like sandstones. The total thickness of such sequences is commonly many thousands of metres, but the individual beds are thin, only a few centimetres to a few metres thick. The presence of rare fossils indicates marine deposition. Flysch facies are now generally believed to have accumulated in moderate to deep (up to 2,000 m [6,500 feet]) marine waters. Coarse angular sands probably were deposited from turbidity currents (subaqueous sediment-laden flows); the extraordinary coarse conglomeratic mudstones in some flysch may be a product of submarine mudflows. The term originally was applied to a formation of the Tertiary Period (66.4 to 1.6 million years ago) occurring in the northern Alpine region but now denotes similar deposits of other ages and other places.* * *
Universalium. 2010.
