Manchester Memoirs, Vol. hi. (191 2), No. 10. 7 



water level of about three feet would probably be enough 

 to kill the birches, and allow the reeds, which were 

 probably growing all the time in the pools and water 

 courses of the neighbourhood, to grow over the area. 

 The presence of standing water, such as would be 

 required by the Phragmites, probably did not last long, 

 for we get a fairly thick (1-2 feet) deposit of peat, con- 

 sisting largely of Carex. Following this there must have 

 been a drop in the general land level behind the sea beach. 

 This resulted in a submergence of the area, probably 

 changing it into a fairly still fresh-water lagoon, giving 

 the sandy clay deposits with fresh-water diatoms and 

 sponge spicules. 



So far the account of what probably happened in this 

 small forest area is straightforward. The most difficult 

 deposit to account for is that of the few inches of gravel 

 above the sandy clay. The clay is so friable that it would 

 be thought that any volume of water, sufficiently strong 

 to deposit the stones, would have swept it and the under- 

 lying peat away. The most plausible explanation, which, 

 however, in default of further examination is advanced 

 tentatively, is that there must have been a drop in the 

 land level of some 25 feet below the present low-water or 

 high-tide mark. 



Following this submergence there must have been a 

 rise again to the present level, and after that the area 

 would be left much as it is to-day. The high-water mark 

 was originally much further to seaward than it now is, 

 for stumps of oak trees, about 2 feet in diameter, are to 

 be seen on the alluvial flats. One such, that in August, 

 191 1, showed only a few inches above the pebble ridge, at 

 Easter, 191 2, was fully exposed, while the stump occupying 

 the centre of Fig. 2, PI. I., had been washed away. The 

 general line of the beach has been shifted in some places 

 as much as 8 — 10 yards during the winter of 191 1 -12. 



