Boulder Clay

 The lower and upper boulder clays of Teesside were regarded by Smith (1981) as products of Late Devensian ice sheets. The first deposited lodgement till and outwash as it retreated and these deposits subsequently were overridden by the second ice sheet, which left behind its own lodgement till and outwash. The lower boulder clay is brown in colour and contains clasts from the western southern uplands and the Lake District as well as southern Scandinavia.

The geotechnical properties of some till deposits occuring along the coastal areas of eastern England. F.G. Bell. Engineering Geology 63 (2002)