Ball-and-pillow structures

This shock causes rupturing to occur in the sedimentary rock layer, which induces instability.

Individual lobes caused by this unstable state break off and move downward, settling into the underlying layers.

Both Kuenen (1958) and Owen (1996) have duplicated ball-and-pillow structures in the laboratory, which was done by applying a shock to multilayered strata.

These experiments further conclude that earthquakes, erupting volcanoes, or meteoric impacts can create these formations.

The actual term "ball-and-pillow" came from Potter and Pettijohn (1963), when they cited Smith's work incorrectly.