458 S. V. WOOD, JTJN., ON THE NEWER 



ford bed. In the former the Eed Crag, gradually losing the oblique 

 character, passes up by a series of horizontally bedded sands with 

 molluscan remains (of which the uppermost part has been known as 

 the Chillesford bed) into the Chillesford Clay. At Walton, however, 

 the bed of sand passing up into laminated clay, with which the Crag 

 s overlain, is not only unconformable to the Crag, but passes over 

 its edge so as to rest on the London Clay. It is not clear to me 

 now whether these beds at Walton represent the Chillesford Clay, 

 or whether they may not represent the Contorted Drift ; but if they 

 do represent the former, then this clay into which the Butley Eed 

 Crag passes uninterruptedly upwards is as unconformable to the 

 Eed Crag of Walton as it is to the Coralline on which, in the neigh- 

 bourhood of Butley, it also rests. Whichever way it may be re- 

 garded, there is no continuation of this southern extremity of the 

 Eed Crag into the Chillesford beds as there is of the northern. 



North of the ridge of Coralline-Crag rock which, occupying the 

 parishes of Sudbourn, Iken, and Orford in the south-east of Sheet 

 50, and of Aldborough in the south of Sheet 49 of the Ord- 

 nance Map (of which a diminutive reduction is given in Map No. 1 

 of the accompanying plate), bounds the marine portion of the 

 Eed Crag, there sets in the fluvio-marine portion, which ranges 

 thence northwards nearly, but not quite, to the north of Norfolk in 

 Sheet 68. This portion, I have for many years contended, is, as 

 regards its lower beds, synchronous with that newer part of the 

 marine accumulations which make up the Eed Crag of Butley 

 in the north-east corner of Sheet 48, and of the neighbouring 

 parishes of Boyton and Chillesford, being altogether newer than the 

 Eed Crag further south, and which occupies the northern centre c" 

 that sheet. Nothing, however, so old as this fluvio-marine portior 

 even the most recent part of it (the Chillesford Clay), occurs in m; 

 view along the North-Norfolk coast-section which extends throng ■ 

 Sheet 68, such fluvio-marine beds as occur there containing Tellin< 

 halthica, a shell unknown from the Crag, and introduced by th 

 commencement of the movements described in Stage II. Th 

 northernmost point at which the beds of this fluvio-marine part c 

 the Crag (and these are the latest even of that part) are to be foun 

 is Aylsham, in the south-east of Sheet 68. 



These facts appear to me to show that during the accumulatio 

 of the Eed Crag there was a gradual movement of elevation in th ; 

 southern part of the area occupied by that Crag, and of depressio i. 

 in the northern. By this the first accumulations represented by th i 

 W^alton bed became land, and then successively the parts immediatel , 

 to the north of it. As this took place the sea encroached at the 

 northern extremity of Sheet 48, so that newer beds of similar fore- 

 shore oblique character formed over the parishes of Butlej^, Chilles- 

 ford, and Boyton, containing a fauna so distinct from that of th"^ 

 Walton bed. These beds of Butley, Chilbsford, and Boyton ar 

 bedded up against the principal remnant of the Coralline Craj- 

 Y/hich has escaped destruction from the waters of the Eed Crag 

 and which destruction furnished so large a spoil of molluscan remains 



