INTRODUCTION

The main direct sources of information about food come from animal bones and plant seeds. The types of meat and varieties of vegetables and fruit consumed will be considered later in the book. Here the various factors that govern the type of information that can be extracted from this material, and the biases that are inherent in its study, will be discussed. The opportunity will also be taken to consider the question of quantification. Knowing how much of a commodity has been found at a site is essential if comparisons of consumption patterns on different sites are to be made. Finally in this chapter, the nature of rubbish disposal will be considered.

ANIMAL BONES

The biases that affect animal bone assemblages can be divided into two broad categories relating to what can actually survive, and how what survives is excavated and subsequently studied.

What survives depends very much on the soil conditions in which the material was deposited. Bone does not survive well in acidic soils, and in extreme cases can disappear in its entirety. The acidity of a soil is measured on the pH scale from 1 (extremely acid) to 14 (extremely alkaline), and below a value of 6 the mineral that makes up bone becomes extremely soluble. Soil acidity can vary greatly over small areas depending on husbandry, drift geology, and whether or not deposits are waterlogged.