On the Westleton Beds of Norfolk and Suffolk. 281 



the Glacial Deposits, proceeded in the present contribution to con- 

 sider the extension of the Westleton Beds beyond the area of the 

 Crag, and described their range inland through Suffolk, East, West, 

 and South Essex, Middlesex, North and South Hertfordshire, South 

 Buckinghamshire, and North and South Berkshire, noticing their 

 relationship to the overlying Glacial beds, where these were deve- 

 loped, and the manner in which they reposed upon older deposits. 

 He gave an account of the heights of the various exposures above 

 Ordnance Datum, and mentioned the relative proportion of the 

 different constituents in various sections, thus showing that in their 

 southerly and westerly extension they differed both in composition 

 and in mode of distribution from the Glacial deposits. Distinction 

 was also made between the Westleton Beds and the ^Brentwood 

 Beds. 



Attention was next directed to the occurrence of the Westleton 

 Series, south of the Thames, in Kent, Surrey, and Hampshire, and 

 their possible extension into Somersetshire was inferred from the 

 character of the deposits on Kingsdown and near Clevedon. 



In tracing the deposits from the east coast to the Berkshire 

 Downs it was noticed that at the former place the beds lay at sea- 

 level, but ranging inland, they gradually rose to heights of from 500 

 to 600 feet ; that in the first instance they underlay all the Glacial 

 deposits, and in the second they rose high above them, and their 

 seeming subordination to the Glacial series altogether disappeared ; 

 thus at Braintree, where the Westleton Beds were largely developed, 

 they stood up through the Boulder-clay and gravel which wrapped 

 round their base, whilst further west, where they became diminished 

 to mere shingle-beds, they attained heights of from 350 to 400 feet, 

 capping London-clay hills, where the Boulder-clay lay from 80 to 100 

 feet lower down the slopes, the difference of level between the two 

 deposits becoming still greater in a westerly direction, until finally 

 the Boulder-clay disappeared. 



The origin of the component pebbles of the beds was discussed, 

 and their derivation traced (1) to the beds of Woolwich age in Kent, 

 N. Erance and Belgium, and possibly to some Diestian beds, (2) to 

 the older rocks of the Ardennes, (3) to the Chalk and older drifts, 

 and (4) to the Lower Greensand of Kent and Surrey, or in part to 

 the Southern drift. 



The marine nature of the beds was inferred from the included 

 fossils of the type-area, and the absence of these elsewhere accounted 

 for by decalcification. 



The southward extension of the beds was shown to be limited by 

 the anticlinal of the Ardennes and the Weald, and the scanty pala> 

 ontological evidence of the nature of that land was noted, and the 

 possible existence of the Scandinavian ice-sheet to the north was 

 referred to in connexion with the disappearance of the beds in that 

 direction. 



Erom the uniform character of the Westleton shingles the author 

 Phil. Mag. S. 5. Vol. 29. No. 178. March 1890. Y 



