28 TRACES OF THE GREAT ICE AGE IN DERP.VSHIRE. 



These fragments are to be found in abundance at Cromer, and 

 while it is only fair to say that certain geologists explain their 

 presence there in an altogether different manner, the phenomena 

 support the view presented above. Pennine rocks occur in the 

 Great Chalky Boulder-clay, but it seems probable that these were 

 derived from the Older Pleistocene deposits over which the 

 ice passed. 



The deposits of the Newer Pleistocene Epoch indicate the 

 first signs of a return to temperate conditions. " During this 

 stage," says Mr. Deeley, " the rivers cut down their valleys 

 through the older Boulder-clays and sands to within about 

 twenty feet of their present depths, and left their gravels stranded 

 as terraces at various heights above their present courses." 

 Resting upon these interglacial gravels, or the older rocks, is a 

 Boulder-clay, which indicates from its contents a period of cold, 

 when the Scandinavian ice had disappeared, and glaciers from 

 the Pennine Chain once more deposited their moraine matter 

 over the area. There is evidence to show that during this stage 

 glaciers from the Scotch and Cambrian Mountains invaded the 

 western portion of the area. 



It will be seen that, although many of the facts are involved, 

 the subject is one of deep interest. That the problem is difficult — 

 that the deposits have been disturbed again and again is no 

 reason why careful study should not be given to them. Mr. 

 Deeley's paper, quoted above, shows what can be done by careful 

 and persistent work, but much remains to be done. It has only 

 been possible here to give the briefest outline of the facts, and 

 the inferences to be drawn from them. It is desirable that 

 observations should be multiphed. If they support the views 

 held, well ; if they do not, still well ; for men of science ever 

 hold facts to be superior to theories and so-called " laws of 

 nature," and, while they regard a well-established doctrine as a 

 law, ever strive to increase our knowledge o[ fuc/s, and when this 

 fails to harmonise with their doctrines, however cherished these 

 may be, they are readily rehnquished, for the end and aim of all 

 science is a search for truth. 



