1865.] 



FOSTER AXD TOPLEY MEDWAY GRAVELS. 



453 



In the foregoing description, we have spoken only of those sections 

 especially worthy of notice. It is needless on this occasion to enter 

 more fully into the snbject, as the whole area will be more minutely 

 described in a forthcoming Memoir of the Geological Survey. 



4. Pipes of Gravel and Brick-earth. — Where the gravel and 

 brick-earth rest on the Kentish Rag they are generally let down 

 into " pipes " or " pot-holes," which sometimes attain a very large 

 size. As these pipes not only show the great thickness of the 

 gravel and brick-earth, but also give proof of a considerable lapse 

 of time since the deposition of these old alluvia, we will proceed to 

 describe them in detail. The best sections are seen in some brick- 

 fields to the north of the town of Maidstone. The section (fig. 2, 

 p. 451) will show how the beds occur. The brick-earth is found in 

 long deep pipes, one of which has been proved to go through the 

 entire thickness of the Kentish Eag to the Atherfield Clay beneath. 

 The direction of many of the pipes is a few degrees west of north. 

 They gradually dwindle away and die out at their north and south 

 extremities ; but some can be traced for the distance of a quarter of 

 a mile. 



The largest pit, which is in Mr. Goodwin's brick-field, is 50 yards 

 broad, and is worked to a depth of 40 feet ; it has been dug 10 feet 

 lower, but the running sand which is then met with prevents 

 further working. 



The accompanying section (fig. 3) across the large pit in Mr, 

 GoodAvin's brick-field will show how the brick-earth lies : — 



Fig. 3. — Section across a BricJc-earth pit, Maidstone. 



I I 



Scale. 



I 



I I 



Feet. 



10 20 .30 40 .50 60 70 80 90 100 



1. Kentish Eag. 



2. Clay with angular and weathered lumps of Rag. 



3. Sandgate Beds : fuller's earth interstratified with beds of sand. 



4. Brick-earth distinctly stratified. In the lower part of the pit, the strata are 

 contorted. 



A little gravel is interstratified with the brick-earth. It contains 

 pebbles of Wealden sandstone, angular and rounded fiints, and 

 pieces of chert. Similar pipes are seen in the same brick-field and 

 in another to the south-west ; all are characterized by the lining 

 of Sandgate Beds. 



On the opposite side of the Medway, about half a mile south of 

 Allington Church, there is a small railroad leading from the river 

 to a Rag quarry. Along the cutting which has been made, as many 



