10 VEGETATION OF THE PEAK DISTRICT [CH. 
moutonnées. It is not likely that traces of glaciation once 
existed here and have been obliterated, as the moorland plateau 
consists of uninhabited and unenclosed land where there is no 
necessity to remove boulders. Moreover, on hills immediately 
to the west, eg., on the Macclesfield moors, and on the moors 
some miles to the north, eg., on the Ilkley moors, glacial drift, 
boulders, and striae are found; and it is inconceivable that all 
traces of glacial action should have been entirely obliterated 
from the moors of the central and eastern Peak District, and 
not from the similar and neighbouring moors of Macclesfield and 
Ilkley. It is highly probable, then, that the Peak of Derbyshire 
and the high lands to the north, east, and south of the Peak, 
stood up, even during the time of maximum glaciation, as a 
nunatak, and that the ice-sheet fringed the hills of the west of 
the district. The fluvio-glacial sands are probably attributable 
to material washed out at the edge of the waning ice-sheet. 
Barrow (1903: 42) maintains that the glaciation of the 
neighbouring district of Cheadle, Staffordshire, ceased much 
earlier than in Northumberland and Scotland. 
River alluvium, consisting generally of gravels, occurs at 
the bottom of most of the larger valleys. The gravels are 
non-calcareous in the valleys of the sandstones and shales, as, 
for example, between Hope and Grindleford, and calcareous in 
the limestone area, as, for example, in lower Monsal Dale. 
They bring about no important changes in the vegetation. In 
lower Monsal Dale, a calcareous alluvial flat is uncultivated, and 
the plants there are such as occur on the other calcareous soils ; 
and near Grindleford, where a non-calcareous alluvial plain is 
also uncultivated, the plants are such as occur on the other 
non-calcareous soils, At the present time, the river gravels are 
mostly under cultivation, chiefly as permanent pasture; but a 
moderate quantity of wheat is grown on the gravelly alluvium 
near the confluence of the two streams, the Noe Water and the 
Derwent. In early times, it is not improbable that these 
alluvial tracts were characterized by woods of the “alder and 
willow series” (cf. Moss, Rankin, and Tansley, 1910: 122, e¢ seq.). 
Peat occurs on the summits of the higher non-calcareous 
hills, including the plateaux of chert in the limestone area, and 
is fully dealt with in Chapter VII. It is remarkable that 
very extensive deposits of peat in this country, both lowland 
