COLE : PHYSICAL GEOGEAPHY OF THE EAST RIDING. 
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low-lying swampy districts, covered with thick forests, which 
afforded hunting-grounds for the people who lived on the hill tops. 
The vast entrenchments on the Wolds, and the great number of 
tumuli show that in ancient British days the high grounds were 
thickly populated, whilst even in later days the same fact is borne 
witness to by the number of sites of extinct villages. 
The following Geological Formations occur in the East-Riding : — 
Sand Dunes 
Warp 
Chalk Gravels 
Peat 
Sands 
Boulder Clavs and Gravels 
Recent 
and 
Post-glacial. 
Glacial. 
Poet Tertiary. 
Upper Chalk 
Middle „ 
Lower „ 
Speeton Clays 
Kimeridge Clay 
Upper Cretaceous 
Lower Cretaceous 
Upper Oolite. 
Cretaceous, 
Upper Calcareous Grit 
Coral Rag 
Coralline Oolite 
Lower Calcareous Grit 
Oxford Clay 
Kelloway 
Millepore 
Estuarine Sandstones 
Dogger 
Upper Lias 
Middle Lias 
Lower Lias 
Rhsetic 
Middle Oolite. 
Lower Oolite. 
Jurassic. 
Keuper 
Upper New Red Sandstone. 
Triassic. 
