21. The landscape is dominated by deposits of till, boulder clays and glacial lake clays. 22. The dam was constructed with the boulder clay and alluvium excavated from the reservoir bed. 23. The underlying rocks are the coal measures of the Manchester Coalfield covered with boulder clay . 24. He found a five-metre thickness of boulder clay overlaid by sand and gravel. 25. The Holderness landscape is dominated by deposits of till, boulder clays and glacial lake clays. 26. Glacial drumlins of boulder clay lie in the vales of the Dee, Cree and Urr. 27. Subsequently, during the same or a later Britain by the older name of boulder clay . 28. When the glacier finally retreated they left deep deposits of boulder clay and glacial alluvium behind. 29. :: : We are on real Suffolk clay ( chalky boulder clay to geologists ). 30. When the ice finally retreated it left deep deposits of boulder clay ( or till ) behind.
