480 On the Agricultural Geology of England and Wales. 



it at various heights up to more than 350 feet on the outcrop of 

 the chalk at Speeton Cliff. According* to Strickland and Mar- 

 shall,* the surface of the lower Wolds consists of a light, calca- 

 reous, friable loam, 3 to 10 inches deep. Mr. Spence, however, 

 in the ' Transactions of the Yorkshire Agricultural Society/ 

 cited by Mr. Legard, has proved that the soil does not partake so 

 much of the nature of the rock beneath it as was formerly 

 thought, and that it contains at the utmost 5 per cent, of calca- 

 reous matter — very often not more than 2 per cent. On the thin 

 soils this may have been brought up by the plough. Extensive 

 gravel beds are described as occurring in the valleys of the 

 Wolds, by Mr. Legard — such gravel being thinly spread, a mile 

 broad, in Dalestown Valley, where it forms a very useful con- 

 vertible soil ; Vv'hile in the narrower valley of Thixendale, where 

 it is three feet deep, and barely covered by a thin coat of soil, it 

 requires frequent dunging and dressing. 



Of the Wolds of Lincolnshire, Young says, that it would be a 

 waste of time to attempt to describe any distinctions in their soils. 

 All he saw or heard of were a " sandy loam on a chalk bottom, 

 the quality very various, from poor sand, producing heath {^Erica 

 vulgaris), to rich deep fertile loams, that yield capital crops of 

 wheat, and some even beans. On the sides of the hills near 

 Louth great spaces were covered with rushes and springs." 



In Norfolk, the area coloured as chalk on most of our geolo- 

 gical maps is covered by the good and poor sandy districts, and 

 part of the district of various loams, of Young's agricultural map. 

 In its range through Suffolk it forms his western sand district, 

 which consists chiefly of blowing sands, with some tracts of 

 loamy sand and sandy loam. Chalk is also the substratum under 

 a great part of his district of strong loams — a tract bounded on 

 the east and south by Halesworth, Woodbridge, Sudbury, Clare^, 

 and Haveril], where the soils rest on boulder clay, marked on 

 some geological maps as alluvial and diluvial deposits ; on others^ 

 but erroneously, as plastic clay. The chalk of Cambridgeshire 

 is described by Mr. Jonas t as forming the substratum of the 

 eastern part of the county, cropping out in its centre, and extend- 

 ing by Ickleton, Meldreth, Royston, Newton, Gogmagog Hill, 

 and Newmarket, to the boundary of Suffolk — the lower chalk in 

 its outcrop at Cherry Hinton, Burwell, and Swaffham Buibeck 

 affording splendid land (white), of a soapy nature, and excellent 

 for wheat. He describes the whole of the chalk as covered with 

 diluvial deposits of sand, gravel, loam, tenacious clays, and various 

 other strata, either in beds uninterrupted for considerable spaces, 

 or in every variety of intermixture. Gooch's description, in the 



* Marshall's Agriculture of Yorkshire. f Journ. Roy. Agri. Soc, vol. vii. p. 85. 



