TEUNK OF AN OAK IN THE BOULDEK CLAY. 383 



It struck me then that it must have been buried in the Boulder 

 Clay at the time of the deposition of that formation. 



I was not able to examine it carefully at the time, and being 

 anxious to have the opinion of a more experienced geologist 

 than myself, and of one who had been much occupied in a dis- 

 trict where such superficial beds predominate, I asked Mr. 

 Topley (of the Geological Survey) to come and examine it 

 with me, which he did on the 10th of July, and again on the 

 12th, when, with the assistance of Mr. Holmer (the engineer 

 of the line), it was carefully dug out, and we then found it to 

 be part of the trunk of an old oak tree, about four feet long, 

 and 8-50 feet in girth. The lower end appears fractured, as if 

 broken off in a storm ; but it bore scarcely any, or very slight, 

 marks of attrition, and on the part which was still protected 

 by the clay the bark was well preserved. The other parts 

 which had been exposed in the cutting for more than two 

 years were stripped of the bark, but the wood, looking like 

 "bog-oak," is hard and sound, evidently owing to the imper- 

 vious nature of the stiff clay in which it was imbedded. This 

 clay contains many boulders, principally of neighbouring sand- 

 stones, but they are not much rolled, though occasionally there 

 occur also some of limestone bearing marks of glacial action. 



From the appearance of the log I do not think it can have 

 been washed from any great distance, but that it was probably 

 broken from a tree growing in the neighbourhood and dropped 

 on the mud, and this probably before the modification of the 

 drift into its present slopes and valleys. 



The presence in the " Boulder Clay" of this portion of a tree 

 in so perfect a state (if it is of the glacial period) is an indica- 

 tion, I think, that the wliole of the country had not been covered 

 with ice, as has been supposed by some geologists, but that 

 there were parts free from it, on one of which this tree was 

 growing ; and the contents of the bed, principally derived from 

 the neighbouring rocks, and not much waterworn, show that 

 the present appearance of the valleys and hill- sides is greatly 

 due to the action of the water supplied by the gradual melting 

 of the snow and ice in the warmer temperature of the period 



