160 SURFACE GEOLOGY. 
for a distance of 150 feet. Near its east ‘end, iron-stained gravel and sev- 
eral stones a foot in diameter were found between the clay and the west 
edge of the underlying sand. 
Eastward, these deposits lie in a kame-like ridge, a section of which 
(Fig. 45) shows one side of it to be wholly gray clay, while the other side 
Gray clay, its lower portion Silver street, ‘i 
i Uistingtly stented, bridge over R. R. Sand overlain by gray clay. 
8 eS SSS 
Fig. 45.—EXCAVATION FOR THE PORTSMOUTH & DOVER RAILROAD, 1000 
FEET EAST FROM FIG. 44. 
Length, about 500 feet; depth, 20 feet; top of section is about 100 feet 
above the sea. 
is mainly sand; but their junction is concealed by the abutments of a 
bridge. The outer edge of the sand, however, is overlain by similar clay. 
Pine Hill cemetery, a half mile farther south-east, is a level plain of 
horizontally stratified sand, 150 feet above the sea., It is bounded on the 
north and west by escarpments, which descend steeply 30 feet. The dep- 
osition of this sand appears to have been confined here by walls of ice. 
On the south-east are ledgy hills which are somewhat higher, in whose 
hollows are low mounds or ridges of gravel and sand, one of which was 
observed to contain masses of till, one to three feet thick, full of angular 
boulders up to two feet in diameter (Fig. 46). These materials probably 
fell from the glacier upon the margin of 
ice at its foot, and when this was broken 
up, they were floated away on rafts, which 
; at length melted, dropping their freight 
Big. 46—“Secti0n N 4 FAME to be thus embedded in modified drift 
CEMETERY, DOVER. The pebbles which we have mentioned as 
Scale, 1 inch=1o feet. . occurring here and there in the gray clay, 
were distributed in the same manner. This clay and its pebbles were 
deposited at a later date, following the withdrawal of the ice-sheet by 
which the earlier gravel and sand were confined in these kame-like plains. 
The sea in this period stood at a higher level than now; and the 
clay was probably a marine deposit brought down from the melting ice- 
sheet at the north-west. It is well shown in Dover, Madbury, Durham, 
and Newington, forming the surface of much of these towns, but not 
