president’s address. 
355 
The evidence obtained in the Thames Valley tends to show that 
the fossiliferous valley-deposits with remains of Mammoth and 
Khinoceros, Cor/dcu/a Jluminalix, Ac., are somewhat older than the 
main mass of rough Hint-gravels and associated stony briekearths. 
Dr. Hicks has obtained line examples of Mammoth just above the 
London Clay, near Euston Square, in London : lie believes that 
they belong to a period prior to the Chalky Boulder Clay of 
Finchley."' At present, however, there is no proof that this is 
the case. 
Mr. lieid speaks of these fossiliferous beds as relics of lacustrine 
strata that may be compared with similar beds at Selsey, in Sussex. 
There freshwater beds, with Mammoth, Khinoceros, Ac., overlie 
a glacial deposit that he correlates with the Chalky Boulder Clay 
in time, though not in method, of formation. 
These fossiliferous freshwater beds are covered in both Sussex 
and the Thames Valley bv what he terms “ frozen-soil gravels.” 
They indicate a mild interglacial period, while “Afterwards an 
increase of cold caused a second glaciation of the area north of the 
Wash, whilst in non-glaciated areas rain falling on frozen soil led 
to the formation of extensive sheets of gravel.” t These would 
include the beds of rough flint-gravel, Ac., that overlie the 
Mammoth-bearing deposits in the Thames Valley. 
Wo have evidence that the Chalky Boulder Clay preceded these 
“ frozen-soil gravels” of the Thames Valley, for it has been exposed 
beneath them in a section at Hornchurch, in Essex, lately described 
by Mr. T. V. Holmes.J When this discovery was announced it 
seemed as if at last the positive evidence of the relations between 
the Thames Valley deposits and the Boulder Clay, that has been 
looked for in vain for the last forty years, hail been found. If, 
however, the beds yielding Mammoth belong to a period antecedent 
to the main mass of valley gravel, then the above evidence is 
inconclusive as to the relative age of the Boulder Clay and the 
Mammoth-bearing deposits in the Thames Valley. 
* Quart. Journ. Geol. Soc. vol. xlviii. p. 453. 
t Quart. Journ. Geol. Soc. vol. xlviii. pp. 359—361. 
X Quart. Journ. Geol. Soc. vol. xlviii. p. 365. 
