Scotfact: Scottish valleys are not as deep as they once were but they are gradually getting deeper again. At the end of the ice age, melting ice sheets meant that there was a great deal of rock and soil debris carried downstream and gradually dumped in the river valleys. In many Scottish valleys you will now see flat or gently sloping benches or steps high above the current valley bottom. These represent the levels of the valley bottom in previous times, before rivers had cut through the debris and carried it further seawards. This process is continuing. The debris was often carried out to sea and helped to provide the material to form many of our present sand and shingle beaches and dune systems.
Venlaw