THE CRETACEOUS REGION must be divided. The eastern section is overlain by the Boulder Clay, and along with it may be considered those parts of the London Basin which are also covered with the deposits of the glacial ice-sheet, and even the Fens, where both Jurassic and Cretaceous rocks lie under a covering of alluvium. The fertile soil, the low rainfall, and the warm summers of the whole of this area render it well suited for the cultivation of wheat, and the East Riding of York, the eastern part of Lincoln, and Norfolk, Suffolk, Essex, Cambridge, and Hertford contain over two-fifths of the total area under wheat in Great Britain. In these counties, also, the area under arable land is more than twice that which is in permanent grass, and barley and roots are extensively grown.
Over the greater part of the Cretaceous area in the south and west of the country, the chalk comes to the surface. As there is little soil on the uplands, and the rainfall is quickly absorbed, these districts are mainly devoted to sheep, which thrive on the good, if somewhat thin, grass with which the chalk is covered. In the valleys, where the soil has accumulated, arable farming is possible.
In the Weald economic conditions are more varied. To the north and the south lie the chalk downs, but, in the country between, the lower members of the Cretaceous system are exposed. Of
these the most fertile are the Hythe beds and the Upper Green sand. The former constitute the typical soil of Kent, on which some of its best hop gardens and fruit orchards are to be found, while the latter, which is one of the best light soils in the country, grows both hops and wheat.
Over the whole Cretaceous area there are few manufactures. The most important industries include straw-plaiting at Luton, originally established there on account of the white wheat straw grown on the chalk, but now carried on with raw material imported from China and Japan ; chair-making at High Wycombe, where the beech woods, also on the chalk, originally provided the necessary timber ; and agricultural machinery at Norwich, in the arable area. Norwich also retains the manufacture of silk and wool, and makes boots and shoes. In the north-east, Goole, Hull, Immingham, and Grimsby, all on the Humber, carry on the trade of Lanca shire and Yorkshire with the Baltic and North Sea ports. Grimsby is also a great fishing centre ; and Dover, Folkestone, and Newhaven, in the south-east, are important packet stations.