50 The Soils of England and Wales 



by comparatively shallow or very thin soils, and these are 

 frequently poor in mineral plant-food, but numerous ex- 

 ceptions occur, e.g. in soils produced by the disintegration 

 of rocks rich in certain minerals. At high altitudes, apart 

 from crag and cliff, the soil is covered by various types of 

 " siliceous pasture " or by moorland ; at lower altitudes, 

 where trees and shrubs can successfully establish them- 

 selves, by woods of the oak and birch series, or their 

 corresponding scrub. 



Generally speaking the Palaeozoic, metamorphio and 

 igneous rocks are not fertile (apart from climatic con- 

 ditions), but various important exceptions occur. Thus 

 the Old Red Sandstone of Herefordshire yields a strong 

 loamy soil which is fertile, and largely under good 

 permanent pasture, with many orchards and hopyards. 

 The limestone bands (called "cornstones") which occur 

 in it form however the richest land. The diabases, tuffs 

 (volcanic ash) and slaty volcanic rocks, forming red soils, 

 of the Ashprington series of the Middle Devonian near 

 Totnes in south Devon, support some of the best arable 

 and grassland in the district. Again the Magnesian 

 Limestone of Permian age forms a good light dry arable 

 soiP. This comparatively soft limestone is however some- 

 times included in the secondary (Mesozoic) series. 



The secondary rocks which rest on or abut agaiast 



the primary groups enumerated, form a much 

 rock^. ^^ ™°^® regular series. Speaking generally they 



dip regularly to the south-east, one under the 

 other, so that their outcrops are arranged in a succession 

 of bands crossing England from north-east to south-west, 

 and occupying more than half the area of the country. 

 The north-eastern ends of these bands bend northwards 

 and occupy the eastern part of northern England to the 

 east of the Pennine ridge, running out successively to the 

 north-eastern coasts of Yorkshire and Durham. 

 ' H. B. Woodward, op. cit. 



