148 



MAN AND THE GLACIAL PERIOD. 



period. In the cliffs on the eastern side of the Little 

 Orme's Head, and at several other points along the coast 

 towards the east, a sequence may be observed as follows : 



" 4. Boulder-clay with northern erratics and shells. 



" 3. Sands and gravels with northern erratics and shells, 



" 2. Boulder-clay with northern erratics and shells. 



" 1. Boulder-clay with Welsh erratics and no shells. 



"A similar succession is to be seen in the Vale of 

 Clwyd. The interpretation is clear : In the early stages 

 of glaciation the Welsh ice spread without hindrance to, 

 and laid down, bed ~No. 1 ; then the northern ice came 

 down, bringing its typical erratics and the scourings of 

 the sea-bottom, and laid down the variable series of clays, 

 sands, and gravels which constitute Nos. 2, 3, and 4 of 

 the section. 



" In the Vale of Clwyd an additional interest is imparted 

 to the study of the drift from the circumstance that the 

 remains of man have been found in deposits in caves sealed 

 with drift-beds. The best example is the Cae Gwyn caves, 



Fig. 42.— The Cefn Cave, in Vale of Clwyd. (Trimmer.) a, Entrance ; b, mud 

 with pebbles and wood covered with stalagmite ; c, mud, bones, and angular 

 fragments of limestone ; d, sand and silt, with fragments of marine shells ; 

 e, fissure ; f, northern drift ; g, cave cleared of mud ; h, river Elwy, 100 feet 

 below : i, limestone rock. 



in which flint implements and the bones and teeth of va- 

 rious extinct animals were found embedded in ' cave- 



