Reviews— Geology of Hungerford and Newbury. 571 
decay of the top of the Chalk after the Eocene bed had been deposited, 
but whatever may be the case in other districts the evidence given 
above clearly shows that a different explanation of the presence of 
green-coated flints in the bottom bed is required here. The tubular 
borings in the surface of the Chalk and the chalky material in the 
bottom bed seem to show that no appreciable amount of dissolution of 
the Chalk surface has taken place since the deposition of the Eocene 
beds upon it. 
Banks of closely packed oyster-shells form a striking feature of the 
bottom bed in not a few sections, and the author records teeth of 
Lamna and a few marine shells. He infers that the bottom bed was 
deposited under shallow-water marine conditions. As elsewhere, the 
Reading Beds above the marine bottom bed consist of sands and 
mottled clays without shells, but leaf impressions have been observed 
at two places. They occur in seams of clay closely overlying the 
bottom bed, i.e. in a similar position to the Reading Leaf-bed. 
Mr. Starkie Gardner believed the mottled clays of the Reading Series to 
be a fresh-water deposit (Quart. Journ. Geol. Soc., vol. xxxix, p. 210), 
and we may probably regard all the beds in this district between the 
bottom bed of the Reading Series and the basement bed of the London 
Clay as of fresh-water origin. 
The London Clay, as has long been known, thins westwards, and at 
the outlier west of Bedwyns in the south-western corner of the district 
it is stated to be only about 15 feet thick, whilst at Chisbury Camp at 
the northern end of the outlier there seems to be nothing between the 
Bagshot Beds and the Reading Series. Mr. Bennett thought that 
some greenish sand near Inkpen might belong to the Bracklesham 
Beds, but Mr. White gives reasons for doubting this, and.consequently 
the highest Eocene formation in the district belongs to the sandy 
series, which in the London Basin intervenes between the London Clay 
and the Bracklesham. This formation is marked i* on the map, and 
is there termed ‘‘ Bagshot Beds,” whilst in the memoir it is described 
as ‘‘ Lower Bagshot Beds.” The similar beds at Bournemouth are on 
sheet 329 marked i‘, and termed ‘‘ Bagshot Beds,” whilst in 
Mr. Clement Reid’s memoir on that sheet (1898) the formation is 
called ‘‘ Bagshot Sands.” We thus find the same formation with three 
different names, which seems needlessly to complicate matters. 
After dealing with the Eocene formations, the author gives us a most 
interesting and original chapter upon the post-Bagshot disturbances 
and drainage features. At one time there was a fairly general idea 
that the sheets of gravel which cap the plateaux in the neighbourhood 
of the River Thames were a marine deposit, but in recent years the 
tendency amongst the workers in the geology of the South of England 
has been to look upon them as old river gravels, and the present 
author, Mr. Osborne White, considers that the drifts are local 
subaérial and fluviatile accumulations, which betray in their dis- 
tribution a more or less obyious relation to, or dependence on, the 
larger (if not the smaller) elements of the existing physiography. 
As to the age of the drift deposits, he says that though some of them 
may be of Pliocene age, the bulk of them seem to belong to the 
Pleistocene and Recent periods, and many of them undoubtedly do so. 
