30 
LAMPLUGII : GLACIAL SECTIONS. 
tlie underlying sand and gravel ; shells are absent from this part 
of the bed, but there are many plant remains. 
Dr. Nathorst found leaves of the arctic birch ( Betula nana ) 
in these marls ; he records his discovery as under.* 
'*Die Suszwasserablagerung en nehmen kleine Becken in Geschiebelehm. 
* * * Ich in einer solchen Bildung uumittelbar am slidlichen Ende der 
Stadt mehrere Blatter von Betula nana L. fand."t 
He also doubts not that rich additions might be made from 
the deeper layers of these beds, and regrets he had not time to 
search further.:j: 
The Chalky Gravel. (2). A chalky gravel is seen directly 
under the fresh- water marls in Fig. 1, but is absent from 
the remainder of that section. What I believe to be the same 
gravel, however, reappears a little further south, where the cliff 
sinks slightly, and is much better developed. I have therefore 
extended my section in Fig. 2, so as to embrace its recommence- 
ment ; but it is still better seen yet further south, and can be 
traced for above a mile, till the cliff has sunk so low as to be 
hidden by blown sand. 
It consists of fine gravel, chiefly of chalk, with seams of 
sand, often showing cross-bedding-. The chalk pebbles are mostly 
flat and sub -angular. I have examined it carefully and up to the 
present have found no organic remains, but think my di-aiuage 
sections will show that it is of fresh- water origin. It generally 
rests on a highly denuded surface of the underlying sand and warp 
series, which is cut into deep hollows (best seen beyond the 
limits of my section), and it seems to be altogether unconformable 
to those beds. The gravel has, however, been said to dovetail § 
* Ueber neue Funde von fossilen Glacialplanzen. Englers botanischer 
Jahrbucli, 1881. 
t " The fresh-water deposits occupy small hollows in boulder clay, * * * I found in 
one such bed immediately at the south end of the town, several leaves of Betula nana, L." 
X I hope sometime to be able to follow Dr. Nathorst's suggestion and 
my own inclination, and to make a close examination of these marls. 
§ J. R. Dakyns, Proc. York. Geol. and Pol, See, 1879, p. 126. 
