30 



be considered as unquestionable Middle Drift; in many places 

 the Boulder Clay can be proved to rest directly upon the Chalk, 

 though there are occasionally patches of gravel and sand at or 

 near its base. 



At Audley End Station, the railway cutting on the North 

 side of the bridge exhibits a succession of clays and loams lying 

 in a hollow scooped out of the chalk and all inclined to the S. at 

 an angle of about 25". The lowest is a grey Boulder Clay full of 

 chalk stones, and contains a thin inter-bedded band of loam ; 

 next succeeds a yellow laminated loam, and then the section 

 becomes obscure, but there are traces of more Boulder Clay, while 

 at the bridge yellowish brown loam is shown on one side the 

 cutting, and gravel on the other. 



Eastward of the station, and barely a mile distant, a good 

 section has been exposed in the railway-cutting on the Saffron 

 Walden branch ; this exhibits an outlying mass of Drift, lying 

 within the general depression of the valley and occupying a 

 hollow in the side of the chalk slope against which the more 

 recent valley beds rest at a lower level. Below the bridge over 

 this cutting the following section is shown : 



1 . Boulder Clay, capping the hill about 1 4 feet. 



2. False-bedded sands and loams with a \ ^^ 



hard calcareous band at the bottom J 



3. Boulder Clay, similar to that above „ 10 ,, 



4. Chalk rising rapidly to the east „ 6 „ 



The calcareous band is about six inches thick near the 

 bridge, and the loamy sand above is also similarly hardened ; 

 this ^infiltration has probably resulted from the presence of 

 the impervious Boulder Clay below, which has stopped the 

 passage of the downward percolating water and allowed the cal- 

 careous material in solution to be deposited. Beyond the bridge 

 the sand and loam are seen to thin out wedge- wise between the 

 two similar Boulder Clays, they can hardly therefore be called 

 Middle Drift, and the whole series, as also that at Audley End, 

 probably belongs to the Upper Glacial beds of Mr Searles 

 Wood. They appear to increase in thickness towards the 

 valley, and at the west end of the cutting the sands pass by 

 contorted and laminated loams into the Boulder Clay above ; but 



