Seismite

thumb|Seismites in the Upper Ordovician of northern Kentucky. thumb|Seismite in Holocene sediments of the Dead Sea basin, Israel. thumb|Seismite in the Borden Formation, Ohio, demonstrating "flow rolls".

Seismites are sedimentary beds and structures deformed by seismic shaking. The German paleontologist Adolf Seilacher first used the term in 1969 to describe earthquake-deformed layers. Today, the term is applied to both sedimentary layers and soft sediment deformation structures formed by shaking. This subtle change in usage accommodates structures that may not remain within a layer (i.e., clastic dikes or sand volcanos).