100 PROF. J. PRESTWICH ON THE RELATION OF THE 



same structure in the Forest Series at Trimlingham and other 

 places. He remarks that the carbonaceous clay and overlying 

 sand are apparently contorted together, and that the contortions 

 are cut off by the overlying evenly bedded freshwater clays, and 

 he suggests that this contorted structure may be due either to the 

 treading of some of the large Mammalia in shallow waters, or else 

 to the lateral thrust caused by alternate freezing and thawing of the 

 beds in winter (p. 33). 



In one of my note-books, I have the following sketch (fig. 3) of a 

 similar contortion, but it was there, as at Covehithe and Easton 

 Bavant, immediately under the Westleton Beds 6. 



Pig. 3. — Section at the base of the Cliff near Trimlingham. 



b 



feet. 

 a. Boulder-clay (base of) — 



h. White sand in horizontal layers, with indents in c 3 



c. Laminated black clay and white sand 8 



May not these small contortions be due to floes of river- or 

 shore-ice impinging on beds of soft clay ? just as at St. Acheul 

 (Amiens), where there is reason to attribute the contortions (which 

 are, however, on a larger scale) to the action of the river-ice * at 

 the high-level period. 



Another section exhibiting similar intermediate characters as at 

 North Bavant, but still without anything definite, was formerly to 

 be seen in a pit one mile W.S.AY. of South Cove Church. It was as 

 follows : — 



feet. 



a. Westleton Shingle 4 to 5 



b. Light-coloured, sand 4 



c. Light-coloured laminated clay 3 



d. Dark grey clay 3 



The clay was underlain by loam and then (it was said) by Crag 

 (?). At the Frostenden brick-pit the same dark clay, also without 

 fossils or pebbles, was worked under the Boulder-clay. 



The coast-section resumes again, after a break of 1| mile, at the 

 south end of Kessiugland cliff (fig. 4), but it is often obscured, and 

 owing to encroachment of the sea varies considerably from time to 

 time. On the occasion of one of my early visits traces of the 

 Westleton Shingle were to be seen resting on grey clay and sand, 

 showing similar contortions to those before noticed at Covehithe and 

 * Phil. Trans, for 1860, p. 299, and 1864, p. 269. 



