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, e.g., on the Macclesfield moors, and on the moors some miles to the north, e.g., 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, et 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 I] 11 3" 1 *a C O o ! 65 per cent.; and, at 500m., out of the 25 days on which readings were taken, the humidity fell below 60 per cent, on 12 days. The number of days on which the atmospheric humidity fell below 60 per cent., and the monthly distribution of these Hays, are indicated below :