Clay, High-level Derwent Gravel, and 

 post-Glacial Derwent Gravel. An exca- 

 vation on Sinfin Moor showed 



feet, inches. 



Black peat 1 2 



Disintegrated shells 3 



Stiff yellow clay 2 



Shells 2 



Quicksand , 3 



8 5 



Excavations showing the Allenton 

 gravel are not very numerous. The 

 best now open is situated a little to the 

 east of Alvaston Church. The deposit 

 is a red sand or sandy gravel, with beds 

 of sandy clay containing pebbles. The 

 pit is close to the edge of the escarp- 

 ment. There is, consequently, very 

 little left of the ' trail ' at this point, 

 denudation having been responsible for 

 the removal of the fine material. Near 

 the surface, however, the bedding is 

 much broken and twisted, and in places 

 all signs of stratification have been 

 obliterated (fig. 4) . A thickness of 10 or 

 11 feet of gravel is exposed, the lower 

 portion only being comparatively free 

 from contortions. The pebbles are chiefly 

 quartzites, chert, cherty limestone, and 

 gritstone. Limestone is not found in the 

 clean gravel, having been dissolved by 

 percolating water. Even in the beds of 

 sandy clay the limestone has been almost 

 wholly dissolved, nothing remaining in 

 some places but a white chalky powder 

 and hard core. A boring through the 

 gravel passed into Keuper Marl and 

 proved the thickness of the deposit to 

 be 13 feet 8 inches. 



Many excavations in the town of 

 Derby and its suburbs have exposed 

 gravel. In all cases the upper portion 

 was seen to consist of contorted or un- 

 stratified yellow or red sandy clay with 

 pebbles, or disturbed red gravel. An 

 excavation for a cellar on the London 

 road showed great rolls of red stony 

 clay cutting down into the gravel to 

 depths of 6 feet or more. 



Although limestone is not plentiful 

 in the gravel and sand near the edge of 

 the terrace, it is abundant in the gravel 



: 125 feet 



Trent Riuer 



190 f»et 



130 feet 



< 128 feet 



130 feet => 



m 



170 feef 



Allenton 



\<129 feat 



Derwent Riuer 



o3' 



$0 



i 







