PALEOLITHIC RACES 383 



The chalky boulder clay is said to be the most recent 

 glacial deposit in Norfolk. If, as we have suggested, it may 

 be referred to the third (III.) glacial episode of the Continent, 

 then the Acheulean in England may be placed in the third 

 (3) genial episode, and the Chellean may belong to the same 

 episode, but to an earlier portion of it, perhaps represented by 

 the temperate Alder bed of lignite. If this correlation is correct 

 then we ought to find evidence somewhere of the fourth (IV) 

 glacial episode. 



Of late years observations have been made in the neigh- 

 bourhood of Oxford which have an important bearing on this 

 question. At Wolvercote, a little north of the city, a river 

 terrace, lying about 40 ft. above the Thames, is admirably 

 exposed in an extensive brick pit. The section 1 shows that 

 a river channel excavated in the Oxford clay, which here 

 forms the country rock, was subsequently converted by some 

 unknown means into a lake. Lying on the bottom of this, 

 i.e. on the Oxford clay, Mr. Bell found a number of very 

 beautiful lower palaeolithic implements. They are in a perfect 

 state of preservation, with sharp edges, and unworn by erosion. 

 Overlying them is a bed of coarse gravel, followed by a series 

 of lacustrine deposits, clay, laminated sandy silt, and occasional 

 layers of fine gravel, altogether about 15 ft. in thickness. A 

 lenticle of peat is intercalated near the base, above the coarse 

 gravel ; it has afforded numerous remains of plants belonging 

 to species which indicate a temperate climate. Over the whole 

 sweeps a bed of coarse gravel which here forms the surface 

 of the river terrace, 40 ft. above the present level of the 

 Thames. This gravel presents very peculiar characters, re- 

 calling the contorted drift of glaciated regions. It is, as it 

 were, folded in with the immediately underlying deposit, 

 whether this be the clay of the lacustrine series or the Oxford 

 clay. The tongues of clay which are intruded into the gravel 

 show signs of violent movement ; they are overthrust, slicken- 

 sided, and rudely foliated. These phenomena have been 

 referred by Mr. Bell to some form of ice-action. Similar 

 characters are to be seen in several other gravel pits of the 

 district, notably at Coombe, about seven miles N.N.E. of Oxford 

 (137 ft. above the Evenlode), and Picket's Heath Farm, on 



1 A. M. Bell, " Implementiferous Sections at Wolvercote," Quart. Journ. Geo/. 

 Soc. 1904, 60, pp. 120-30. 



