16 
evidently due to some old coast of line of chalk, from the flints of 
which they were derived, and on the shore of which they were 
rounded; evidence of some long period, and during which, 
or after, the area was depressed, for these beds overlap, 
and are spread out over the lower strata, while in some parts 
of the old sea, shelly deposits were accumulating as pointed 
out by Mr. Whitaker; and in their nature and age are different 
from the gravel of Croydon in which they are mixed, and also 
_ from that of the present Wandle.* 
‘* Towards the eastern part of Surrey these lowermost Tertiary 
beds begin to have a well-marked escarpment, rising from above 
the chalk, as on the east of Ewell. At Beddington and Croydon, 
where the Thanet sand has thickened, this is also the case. 
‘* Along the outcrop of these beds in Surrey, especially towards 
the east, there are many villages, the line of which indeed is in 
itself enough to mark (roughly) the junction with the chalk. 
Their position is doubtless owing to the springs that occur along 
this line. 
‘* Beyond Croydon, eastwards to the valley of the Cray and 
northwards to that of the Thames, is the broadest tract of the 
Lower London Tertiaries, and there occur their most marked 
features, owing chiefly perhaps to the development of the pebble- 
beds of the Oldhaven Series, the Woolwich and Reading Beds 
being often thin, but the Thanet sand greatly helping to form the 
gentle hills. 
**On the south of this tract the escarpment forms the well- 
known range of the Addington Hills, Hayes Common and Holwood, 
the high grounds of which consist of the pebbly and sandy Old- 
haven Beds, with a more or less even top, furrowed by little 
valleys, covered with wide spreads of heath, of gorse and broom, 
or of firs, and giving rise to some of the most beautiful scenery 
near London.’*} 
After the deposition of these sands, pebbles, and estuarine 
beds (see Map), known as the Lower London Tertiaries, a con- 
siderable change must have taken place in the area of which 
Croydon now forms a part ; however the chalk may have contributed 
* With regard to the organic remains contained in these pebble beds, one of the 
problems which the late Mr. J. W. Flower set himself to work out, on his settling at 
Croydon some 25 years ago, was to ascertain whether the immense pebble beds of 
Addington, belonging to the Lower Tertiary series, were not formed of fiints derived from 
the destruction of higher beds of chalk than any which now remain in the neighbourhood 
of London. Stratigraphical Geology has shown that the chalk formation, as it trends 
towards the weald, had been largely planed down before the deposition of the Tertiary 
Strata, and Mr. Flower’s paleontological researches seemed quite in accordance with 
this view, and to point to the former existence of beds older even than any now re- 
maining in the London Basin. In pursuance of this object, he carried on for years an 
examination of the flint pebbles forming the Addington Hills, and broke up many 
thousands of them in search of the small fossils they occasionally contain. Unfortunately 
the results of this long investigation have never been published. It was, however, 
evident that they were of a nature to confirm the views he had been originally led to 
form,—Geol. Mag., vol. x., p. 430. 
t Whitaker, ibid., p. 368. 
