Slumping structures caused by organically derived gases in sediments.
The interstitial waters of many sediments are saturated with methane derived from the decay of included organic material. Further generation of methane or local pressure reduction resuilts in sediment dilation and loss of sediment stability. The grains of sediment separated by gas behave in toto as an elastic fluid, and typical " slumping structures " result.
Monroe
J N
JN