ABSTRACT

This chapter discusses the particle size distribution and mineralogical composition as characteristics of soils in England and Wales resulting from geological processes of deposition and pedological processes of reorganisation and alteration. Particle size distribution and, to a lesser extent, mineralogy are also imporant criteria in the system of soil classification developed for England and Wales by the Soil Survey. The cheapest methods of size analysis in the subsieve range are the pipette sampling technique and the hydrometer method of Bouyoucos. The mineralogical composition of most soils and clastic sediments varies with particle size, so it is usually necessary to separate size fractions before attempting mineralogical analysis. This has the additional advantage that most mineralogical techniques are best applied to particles of certain size ranges.