134 ON SOME PLATEAU DEPOSITS AT FELSTKAD AND STEKP.INO. 



take Glacial Gravel for Boulder Clay derivatives.'' The members of 

 one are enclosed in a matrix of sand or sandy loam, and in the other 

 of clay or chalky clay. In one the stones are much water-worn and 

 abraded, and in the other the flints are often entire or sharply 

 splintered, and seldom show any signs of water-wearing. Pieces of 

 Oolitic rock, with fossils, are frequent in the Boulder Clay, but never 

 occur in the (ilacial Gravels hereabouts. Precisely the same may 

 l)e said of the Post-Glacial Gravels under consideration. 



When we consider the position of this gravel, occupying practi- 

 cally the highest land within nearly a mile radius, and remember that 

 it belongs to the closing scenes of the glacial disturbance, we shall 

 have a better apprehension of the work of denudation which has 

 since been in progress, and of the great changes in contour which 

 have occurred. This single instance, in fact, demonstrates the exist- 

 ence of Plateau Gravels which are now reduced to a remnant. 



At Blewitt's Pit, Stebbing, about a mile N.N.E. of the church 

 (old one-inch map, sheet 47), there is a deposit of very sandy loam, 

 with large boulders, overlying Westleton Gravel, which is only to be 

 accounted for on the supposition that this friable loam is the repre- 

 sentative of a deposit now almost vanished. The loam is much 

 too sandy and friable to be mistaken for weathered Boulder Clay. 

 At any rate, I have not seen any weathered Boulder Clay at all like 

 this deposit.^ It has a faint tinge of purple, and were it not for the 

 large boulders entombed, I should say it was a rain-wash derived 

 from the Westleton Gravel. The loam occupies a considerable- 

 elevation, say sixty to seventy feet above the Stebbing Brook, but 

 it is surrounded on three sides by rather higher land. These higher 

 eminences now consist of Westleton Gravel or Boulder Clay. 



There are other sandy loams in the vicinities of Willows (ireen, 

 Fairwood Common, and Rayne, which appear to stand on the 

 same footing as that at Stebbing ; but we cannot in these cases 

 separate so clearly the influence of surrounding beds. 



These Plateau Gravels (in the sense that they overlie Boulder 

 Clay) have been called Post-Glacial ; but they have no other claim 

 to that epithet, as evidence exists of arctic conditions obtaining 

 jjosterior to the format on of those gravels. This is to be fountl 



3 " But there are sometimes beds of Boulder Clay in this Gravel — not in the tract described 

 perhaps and also there are beds of Gravel in Boulder Clay." -W. W'hit.akek. 



(see 



4 " In Suffolk I have seen, in section, Boulder Clay passing laterallv into sandy stony loam 

 l! Southwold Memoir). Some Boulder Clay is very sandy."- W. VVmitakkk. 



