302 Sheppard : Section in the Boulder-clay near Withernsea. 



sigTiificance of these separate divisions is being" denionstrated,. 

 by the researches of Stather and others, any light that can be 

 thrown upon the nature of the junction of the various divisions 

 should be recorded — hence the present note. 



As a rule the actual dividing line between the different 

 boulder-clays consists of a thin layer of sand or gravel — 

 through which small quantities of water trickle down on to the 

 sands. Occasionally quite a massive bed of gravel occurs at 

 the junction, whilst at other times the difference in the colour 

 of the two clays has to be the principal guide — an occasional 

 large boulder or pebble occurring along the line of division 

 between the two. 



Owing to the rapid rate of the erosion, and the soft nature- 

 of the clays, it does not often happen that a section is visible 

 show^ing the upper surface of either of the lower beds of clay. 



Fig. I. 



a. Beach. 



1). Purple boulder-claj- (15 feet). 



c. Stoneless laminated clay (2 feet). 



d. Fine gravel (5 feet). 



e. Hessle clay — much weathered (5 feet). 



In 'Geological Rambles in East Yorkshire' (1903), p. 22^ 

 I described a ' boulder pavement ' which was exposed after 

 a heavy wind on the beach a little to the south of what was 

 then existing of the Withernsea pier. That section admirably 

 showed a number of boulders and pebbles — embedded in the 

 upper part of the Middle or Purple Boulder-clay — which were 

 all on the same level, in nearly every instance striated on their 

 upper surfaces. They were also orientated. The opinion was 

 then, expressed that this purple boulder-clay, with its embedded 



Naturalist. 



