Mudballs on the Beach

Provided by: Martin Ruzek, USRA
Summary authors & editors: Martin Ruzek

Wave action working an offshore mud bank created this field of mud balls on Cassino Beach in Rio Grande, Brazil, following an intense South Atlantic storm in April, 1999. Some are as large as softballs. Sediment from Lagoa dos Patos in southern Brazil has been transported along shore and deposited as a mud suspension, the consistency of yogurt, in the Cassino Beach area. The mud has forced beach goers farther to the south, but provides the raw material for these unique concretions.