120 ME. A. MONTOOMERIE BELL ON [May I904, 



10. Implementiferols Sections at Wolvercote (Oxfordshire). 

 By Alexander Montgomerie Bell, Esq., M.A., F.G.S. (Read 

 January 6th, 1904.) 



A section at Wolvercote, a village 1^ miles north of Oxford, has 

 been open for the past ten years, and will reward study by geolo- 

 gists interested in the phenomena of Pleistocene time, whether their 

 object is to study the changes of land and climate, or whether, as 

 was the case with the writer, they seek for some detail in the 

 fragmentary story of Palaeolithic Man. 



The section contains four parts, which may thus be named in the 

 order of their age : (1) the Oxford Clay beneath, which is largely 

 quarried for bricks ; (2) an old surface, in which pits or troughs 

 chiefly filled with gravel are seen enveloped in weathered clay ; 

 (3) a river-bed, containing gravel at the base, and layers of variously- 

 coloured clay above ; and (4) a surface-layer of humus over all, 

 about 2 feet thick, containing Neolithic remains. The relation 

 which the various parts bear one to the other is also plain. The old 

 Pleistocene surface lies upon eroded Oxford Clay ; the river-bed 

 has worn a channel in the old Pleistocene surface ; between the 

 river-bed and the Neolithic surface is the trail usually named 

 ' warp,' which, however, is not discussed in this paper. 



The river-bed first attracted my attention ; it lies on the summit 

 of land between thelsis and Cherwell, at an equal height above either 

 river. There seems to be no reason to doubt that it represents the 

 deposits of a stream which contained the united waters of both 

 rivers, at a time before they became separated to their present levels 

 by the erosion of the soft clay. The channel is 17 feet in depth 

 from the present surface to the clay beneath ; it is seen descending 

 on the western side from about 3 feet from the surface to 17 ; it 

 has a considerable breadth, as about 40 yards of the old bottom 

 are visible, and the bank of the stream on the eastern side is not 

 laid bare. 



The riverine section itself has two parts : at the base, to a 

 depth of about 2\ feet, is a bed of gravel and sand, largely current- 

 bedded, and containing many quartzite-pebbles of medium size. 

 There are also exceptional stones, about 2 feet square, both of 

 quartzite and of sandstone. 1 A quartzite-stone of this size, but 

 little weather-worn, is an anomaly in the Thames Valley, though 

 its appearance in the river-bed requires no further explanation than 

 deposition from river-ice, or from the roots of a floating tree in 

 which it had been embedded. The lighter stones point north and 

 south, showing that the current flowed in the same direction as the 

 present Isis and Cherwell. 



At the top of this gravel-bed was a thin lenticular layer of 



1 It has been suggested to me that these may be greywethers, but the sand- 

 stone is probably Lower Green sand. 



