LAMPLUGH: GLACIAL SECTIONS. 
389 
section No. 1 ), or against tilted masses of gravel (enlarged sections 
1 and 3 ). The bedding however, which is well brought out by 
seams of sand and layers of sandy clay, is not often completely 
lost. The gravel consists in great part of chalk pebbles, not very 
completely rounded. These pebbles being stained by water from 
the marls above, give a decided, and in places very deep, iron- 
red look to the mass. Drift pebbles occur throughout in varying 
proportion, and I have noticed a few large boulders in the lower 
part. 
I have found fresh-water remains in the gravels at one or 
two points of the section, notably at D and E. These consisted 
of shreds of sandy clay with shells of one species — Limncea pere- 
gra — at D ; and at E, and one or two other points, of black silty mud, 
with vegetable — chiefly mossy — remains. These at E seemed to be 
connected with patches of an older gravel ; but in a section so 
disturbed as this, it was somewhat difficult to tell whether these 
remains were shreds torn from a lower bed, or were in place, and 
evidence of fresh-water conditions. To this point I shall revert in 
the concluding notes. The mode of occurrence of these remains 
is shown in the enlarged sections Xos. 1 and 2. 
The junction of the gravel with the boulder-clay is most 
irregular and peculiar, the clay protruding in long tapering masses 
far into the gravel in every direction and at every angle, and as- 
suming many curious shapes : throwing- off also detached bosses 
(though these may in many cases be really sections across pro- 
trusions) ; presenting often steep-sided hollows filled with gravel, 
with interlocking arms of clay (between C and D, section 1 ); and 
thus giving rise to the fantastic outline shown in the section. 
The gravel (2a) which divides the Purple Boulder-clay in 
section No. 2, very closely resembles the upper gravel ; it 
contains, perhaps, a little larger proportion of sand, and has been 
shielded by the overlying clay from the irony tinge derived from 
the marls ; but otherwise there is no difference between them in 
appearance. This second gravel is evenly bedded, and shows 
