Investtgation of Flaser and Wavy Bedding

Flume experiments simulating a 12.5 hour tidal cycle were performed to test the hypothesis that flaser and wavy bedding can be produced in shallow subtidal areas by tidal activity. The effects of clay composition, sand size, total amount of sediment deposited, compaction time, and peak current velocity were investigated. It was found that the resistance of a recently-deposited mud bed to subsequent.erosion is determined primarily by the amount of overburden. The effect of a rippled sand bed on the erosion of an overlying mud bed is profound, causing erosion to occur at mean flow velocities substantially less than those required for erosion of a planar bed. The results indicate that successive deposition of thin mud layers during several consecutive slack-water periods cannot occur since the deposited mud will always be resuspended during the intervening high-velocity episodes. Although thick mud layers may accumulate during a single slack-water period, these beds are unlikely to be preserved due to the high rate of subsequent