GEOLOGICAL NOTES IN THE NEIGHBOURHOOD OF ONGAR. 89 



Gravel Pit by the high road, nearly three furlojigs south of 

 " Bryces." 333 feet O.D. Gravel (not mapped). 

 The section is five feet deep and shows beds of sand 

 with scattered pebbles — masses of pebbles, many on 

 end. Masses of mottled reddish sand and clayey 

 sand. The whole without a sign of stratification. 

 The stones are mainly flint pebbles, but there are a 

 good many subangular flints and few small quartz 

 pebbles and some flints very little water-worn. 



The pebbles in these gravel patches are most probably derived 

 from pebble beds of Bagshot age. The subangular flints probably came 

 from the south, brought by streams or rivers, or they may be relics of 

 a very old submergence. Even if we do not believe in a submerg- 

 ence at the time of the deposition of the Boulder-Clay, there is every 

 probability that the sea covered the south of England during some 

 part of the long time which elapsed between the Bagshot Period and 

 the Glacial Period, and during that submergence many a foreign 

 rock or pebble may have been scattered over the sea bottom. In 

 this way I account for the presence of the quartz boulders which I 

 found in the Berkshire plateau gravels and for the foreign rocks 

 described from the same gravels by Mr. Shrubsole.*^ 



The presence of unworn flints and the absence of stratification 

 lead me to believe that the gravels at Dudbrook and Bryces were 

 much disturbed and the materials rearranged in Glacial times. Per- 

 haps it is most correct to call them rearranged pre-glacial gravels. 



There is, I believe, a patch of this rearranged pre-glacial gravel 

 on Norton Heath." I did not see a very good section, but there 

 seemed to be a good deal of quartz and many unrolled flints in the 

 gravel. Level about 320 feet O.D. 



Near Chiver's Paun Manor House, on the south of Norton 

 Heath, there is a large gravel pit. The gravel is over 6 feet thick and 

 glacial erratics are very abundant.*^ The place is mapped " Hill 

 gravel of doubtful age," but I fail to see why it should not be called 

 Glacial gravel, for I have no doubt it is of Glacial origin. 



At Nine Ashes I saw a small pit in gravel of flint pebbles, 

 subangular flints, and quartz ; there was, however, no good section. 

 (Mapped loam.") 



6 Quart. Journ. Geol. Soc. (1892), vol. xlviii., p. 34, and (1893). vol. xli.v., August number. 



7 Whitaker, op. cit., p. 276. — Mr. Penning's notes. 



8 Moncklon and Herries, Proc. Geol. Assoc. (1891), vol. xii., p. no. 



9 Whitaker, op. cit., p. 297. — Mr. Bennett's notes. 



