This report describes an investigation by means of laboratory tests of the critical shear stress and bed erosion as a function of time and bed shear stress for a sediment consisting of alternating sand and clay layers 0.1–3 cm thick (sand-clay laminae). This type of deposit occurs quite frequently in estuaries and tidal inlets. The tests were carried out on an original bed deposited in an estuary.
The critical shear stress and the degree of erosion in relation to time for the sand-clay lamination were found to agree in order of magnitude with those for clay layers. The resistance to erosion of the sand-clay lamination is therefore comparable with that of clay layers.