Origin of convoluted laminae

摘要: Comparison of streaked-out “ripples” formed by the drag effects a current passing over watery, yet cohesive sediment bottom with convoluted laminae within beds fine-grained sandstone suggests common origin. Application Bagnold's recent discoveries on behaviour cohesionless in flowing fluids to problem results modification Kuenen's hypothesis origin convolutions. According new interpretation, convolutions arise when formerly sand grains become after deposition and respond increased shearing due higher velocity decollementtype adjustment plane or planes located within, some cases at below base growing bed. Convolute “anticlines” are thought serve same function as that played ripple-marks sand, i.e., they create additional relief order increase restore equilibrium added stress imposed cannot be counterbalanced grain-to-grain encounters.