Olacial Drift 57 



Anglian. These deposits are nearly horizontal and occupy 

 a considerable extent of country, though they have no 

 great thickness. They are mainly composed of sand and 

 gravel ("crag") with very thin bands of clay, and are 

 largely covered with heath of various types. It is doubtful 

 if this part of the country was ever occupied by forest. 

 "The Quaternary deposits form a distinct group 



scattered irregularly over the country, and 

 Quaternary resting indiiferently on any of the rooks 

 Glacial Drift, from the oldest upwards \" Very important 



among these quaternary deposits, just as is 

 the case in Scotland and Ireland, are the extensive sheets 

 of ioe-formed drift dating from the glacial period, and of 

 very variable composition, consisting sometimes of non- 

 calcareous clay (as in many parts of the north of England), 

 sometimes of highly calcareous clay (such as the " chalky 

 boulder-clay" of eastern England), and sometimes, though 

 less frequently, of sandy and gravelly material. These 

 sheets of drift completely cover the older rocks over large 

 tracts of country, particularly in the north, centre, and 

 east, and of course entirely determine the character of 

 the soil, and therefore the vegetation, of these regions. 

 In places the nature of the drift, and therefore of the soil, 

 changes within very short distances. 



In the north of England the Coal Measures of North- 

 umberland and Durham are largely covered by drift 

 (stifE clay or sand and gravel), and the same is true of 

 the Coal Measures and Trias of south Lancashire and 

 Cheshire. In the vale of York there are deposits of 

 boulder clay resting on the Trias, and also extending up 

 the coast from Flamborough Head northwards. Through- 

 out Wales there are deposits of glacial drift in various 

 places, and in the south-west of England there are various 

 deposits of local occurrence which seem to contain evidence 

 of ice-transport. 



1 Woodward, Ihe Geology of England and Wales, p. 26. 



