MAN AND THE GLACIAL PERIOD. 



67 



most every section, from Norfolk into Surrey. It is everywhere seen 

 in the Thames Valley lying on the top of the lowland gravels, and is 

 shown* in great perfection in the long section now (March, 1876) ex- 

 posed between Acton and Hanwell, on the Great Western Railway. 





Fig. 1. Scale twelve feet to oneinch. 1. Sandy clay, or "trail.'' with patches of sand (S) and scat- 

 tered flints, mostly in nests, at the irregular base of the deposit. 3. Sands and grave), false- 

 bedded with lenticular beds of sand (S), and in the lowest seams rounded pebbles of chalk. 



It generally, if not always, rests upon an irregular surface of the beds 

 below it, and contains stones derived from some other source. 



On the south side of the Waveney, at Syleham, there are good 

 sections on both sides of the turnpike, and these exhibit similar false- 

 bedded sands and gravels, which are, however, covered by the upper 

 bowlder-clay instead of by " trail." Fig. 2 shows a section exposed 



Fig. 2 Brown howlder-clav. with many whole flints, and with angular patches of red sand (B\ 

 marly clay with small stones (A), and red bowlder-clay ( C). 3. Sands aud subangular flint, 

 gravel with rounded pebble of quartz, and (in the lowest seams) of chalk. 



on the south side of the turnpike. A little farther west, on the north 

 side of the turnpike, is another gravel-pit, showing a similar succes- 

 sion, but with the beds of sand and gravel strongly false-bedded. In 

 all these sections small pebbles of chalk are very abundant in the 

 lowest beds. The most remarkable feature in the upper bowlder-clay 

 is the numerous angular patches of material quite different from the 

 matrix of brown clay. The angular patches of red sand are very pe- 

 culiar and difficult to explain. 



In a large gravel-pit a little north of Oakley Church there is a long 



