1] INTRODUCTION 7 
been yet commenced by the Geological Survey, though several 
papers on the subject have been published by various geologists. 
Considering first those soils which are directly a result of 
the underlying strata, it is, so far as this district is concerned, 
necessary and sufficient to distinguish two main classes, 
calcareous and non-calcareous. The latter overlie the rocks of 
the Pendleside series, the Millstone Grits, and the Coal-measures. 
The calcareous soils overlie most of the rocks of the Carboni- 
ferous Limestone. 
The non-calcareous soils of the Pendleside beds, the Millstone 
Grits, and the Coal-measures are here taken together, for the 
soils to which they directly give rise are essentially alike in their 
chemical and physical characters, and produce identical plant 
associations. ‘The rocks consist largely of coarse grains of sand, 
of pebbles, of quartz, of pieces of decomposed felspar, and of 
flakes of mica. 
Local floristic differences may perhaps be related to the 
different strata; but, in any case these differences are very 
slight. Linton (1903: 15) correctly states that the Coal- 
measures “can scarcely be said to possess a distinctive flora” ; 
but the plants given by Linton (op. cit.) as characteristic of the 
grit are, in nearly all cases, plants confined to peat; and he 
gives no list of species characteristic of the Pendleside (or 
Yoredale) rocks, erroneously including these with the Carboni- 
ferous Limestone. The beds of all three series of rocks consist 
of alternating beds of sandstones and shales. In no other 
part of the British Isles are these strata so characteristically 
developed or so widespread as in the region of the Pennines. 
Over the shales, the surface soils weather ultimately into a 
kind of false clay, dark yellow in colour, and very slippery 
when wet. The soils produced by the weathering of the sand- 
stones consist, when newly formed, of yellow sand; but this 
quickly becomes mixed with humus, when its colour is much 
darker. Pure sand is of very limited occurrence in the Peak 
District, and is almost limited to the vicinity of quarries, 
where a few arenicolous, as opposed to silicolous, species 
sometimes occur, such as Spergularia rubra. 
Generally, the soils over the sandstones and shales are poor 
in soluble mineral salts, especially calcium carbonate. Woodhead 
(1906: 376) states that soils of this type in the Huddersfield 
