GEOLOGICAL NOTES IN THE NEIGHISOURHOOD OF ONGAR. 9 1 



2. Gravel roughly stratified, composed of flint pebbles and 

 subangular flints with some large unworn flints, many 

 small quartz pebbles and a few pieces of large cjuartz, 

 one three inches in longest diameter, also a little 

 chert and ironstone. 



Gravel pit dose to Greensted Chi/rc/i. 219 feet O.D.'- 



1. At one place there is a patch of red clay i\ feet thick, 



and at another 2 feet of grey clay. Boulder Clay. 



2. Well stratified gravel, 6 feet seen. Glacial Gravel. 



I'he gravel is composed of flint pebbles, subangular flints, a little 

 quartz, some fragments of ironstone and chert. I could not find 

 quartzites or quartz blocks, or other glacial erratics. 



Fit in field j furlongs north-west of Greensted Church, 

 near Old Barn, 240 feet O.D. 



Gravel, 4 feet, very like the Westleton Shingle of Cooper- 

 sale Common at first sight, being of a greyish- 

 white colour, very clayey. 

 Composed as follows : 



Flint pebbles, very large proportion, many three, some four 

 inches in length. 



Subangular flints, several in situ, low down in the section, 

 and on the heaps. 



Quartz, very little, largest pebble one inch long. 



I could find no glacial erratics. 



The gravel at Greensted differs from that described at Laver, 

 Moreton and Shelly Bridge in the greater abundance of flint 

 pebbles, and in the scarcity, or perhaps absence, of erratics. The 

 reason, no doubt, is that it is mainly derived from the Pre-Glacial 

 pebble gravels of the neighbourhood ; indeed, if, as I suspect, the 

 Roding Valley had been partially excavated before the Boulder Clay 

 period, it is quite possible that some of the Greensted gravel may 

 be pre-glacial. 



Gravel Pit ivest of the Lake in Navestock Park, about 

 140 ft. O.D, Whitaker, op. cit., p. 314 ; Mr. Wood- 

 ward's notes. Gravel, seven feet of a yellow colour 

 with som.e colourless patches, coarse sand in places, 

 roughly stratified and in one place contorted. The 

 gravel is composed of flint pebbles and subangular 

 flints in about equal proportion, quartz pebbles up 

 to half an inch in length occur. 

 I did not find erratics here, but further search is required. I 



12 See Whitaker, op. cit., p. 314. — Professor Dawkins' notes. 



