Mud and clay pebbles and cobbles have been observed at many places by different people. They seem to be most common in recent stream deposits and are sometimes seen in eroded alluvial plain sediments. A few geologists have contended that the presence of these mud or clay pebbles in deposits indicates that the deposit as a whole was formed in connection with glaciation and at temperatures near or below freezing. The reason for this conclusion is the belief that balls of mud could not withstand the abrasive and disruptive action of stream transportation unless they were frozen and hard, simulating in that condition a fragment of indurated rock. This may be the history of some mud pebbles in some deposits but it is not a safe criterion on which to date a deposit of sediment.
Proceedings of the Iowa Academy of Science
©1927 Iowa Academy of Science, Inc.
Lugn, A. L.
"An Observed Origin of Some Mud Pebbles,"
Proceedings of the Iowa Academy of Science, 34(1), 249-251.
Available at: https://scholarworks.uni.edu/pias/vol34/iss1/63