Flysch
“Deep-sea sediment from colliding continents”
Flysch is a sequence of deep-marine sedimentary rocks — alternating layers of sandstone, siltstone, and shale — deposited by turbidity currents in front of advancing mountain belts. These rhythmic layers record the erosion of rising mountains into adjacent ocean basins during continental collisions.
quartz, feldspar, clay minerals, calcite, rock fragments, mica
Alps (Switzerland, Austria), Carpathians, Pyrenees, Apennines (Italy), Basque Coast (Spain), Himalayas
3-6 (varies by layer)
The dramatic striped cliffs of the Basque Coast UNESCO Geopark in Spain are flysch sequences that captured the exact moment of the asteroid impact that killed the dinosaurs — the K-Pg boundary is visible as a thin clay layer.
Test Your Knowledge
What type of deep-sea sediment transport process creates the characteristic graded bedding in flysch?
Photo Attribution
Related Specimens
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