56 



THE STORY OF THE EARTH. 



sand. Their order ill Nature, as seen in the cliffs 

 and on the surface of the land, is evidence of 



it upward and downward movements both of 

 the floor of the ocean and the dry land, which 

 have been brought about by foldings of the rocks. 



Usbally these rocks, the strata of sand clay 

 and limestone, rest evenly upon each other, for 

 the upward and downward movements are com- 

 monly so gradual, that while the rocks are dis- 

 tinguished from each other by mineral character, 

 and the planes of bedding, which change with 



map "f part <>f Yorkshire, showing the west- 

 ward i from l lamboro 1 Head "t tin- chalk ami Hun- 

 10 l Lmestone, w a- t<» rest unconionnablj upon the 

 Kii . ij . i fOwei ( tolhea and Lias. 



th of the sea-bed, there is no physical break 



in t: m <>f limestone On day or (lay on 



tithe beds in parallel planes of deposit, 



