Recent Sewer Section at Park Hill Rise, Croydon. 211 
fossils were seen in it. The age of this clay seems doubtful ; 
from its position above the pebble bed it cannot belong to the 
Woolwich series: it might be an outlier of the London Clay, 
though it does not resemble that bed as met with in the lower 
part of Park Hill Rise; and it may perhaps be a later superficial 
bed derived from the denudation of the mottled clay of the 
Woolwich beds, which is exposed on higher ground to the south. 
E. Fault.—The beds which have been described are abruptly 
terminated near the top of Park Hill Rise by a fault, on the 
other side of which a different set of beds is met with. This 
fault runs transversely to the road, about 33 yards from 
Chichester Road, and exactly opposite the south-east end of the 
house called Chichester Lodge ; its position was clearly seen in 
the bottom of the trench, and was also conspicuous by the 
difference of material in the heaps of stuff thrown out; but its 
exact direction and slope were not ascertained. The upthrow is 
on the south-east side, and its amount is evidently considerable, 
but could not be measured, as no one bed could be recognized 
as occurring on both sides of the fault. On the north-west side 
of the fault the beds have a moderate slope (about 23°) to the 
north-west ; but on the south-east side the beds dip at a high 
angle (20°) to the south-east, contrary to their general slope. 
From this I infer that this fault corresponds with the northern- 
most of the two faults shown in Mr. Klaassen’s section of the 
railway-cutting; the position of which fault, as there shown, 
would be some 3800 yards to the east-north-east of the point 
where the fault crosses Park Hill Rise. 
F. Mottled Clay.—The bed next met with on the further side 
of the fault, and which is thrown up by it into juxtaposition 
with the pebble bed, is the oldest bed which was exposed in the 
excavations. It consisted of a mottled clay, with veins of sand, 
and was very brightly coloured; the clay being yellow, pink, 
and greenish blue, while the sand veins were deep yellow or 
ferruginous brown, rendering the stratification very distinct. 
As before stated, it had a high dip to the south-east. In the 
lowermost part of this bed dark blue stiff clay predominated, 
containing Cyrena and ill-preserved leaves; while the upper 
part consisted chiefly of mottled clay intermixed with yellow 
sand, but it contained lenticular masses of blue clay crowded 
with Cyrena. 
This bed doubtless belongs to the Woolwich series, and 
probably corresponds to the beds e and f in Mr. Klaassen’s 
section; but whereas in the railway cutting blue fossiliferous 
clay rested on mottled clay devoid of fossils, in Park Hill 
Rise the blue clay was found below the mottled clay. No 
distinct line of demarcation following the dip of the strata was 
to be observed between the blue and the mottled clay, and it 
