Introduction

Abstract

We start this chapter with Fig. 1.1, which shows how the price, the average grade and production of copper ore changed from 1900 to the present. At the start of last century the price was about $7,000 per ton (expressed in today’s currency); by 2002 it had decreased threefold to about $1,800 per ton, then, in the past 3 years to 2010 (when this book was written), it rose sharply to about $9,000 per ton. Over the same period, the total amount of copper mined gradually increased, except in the early 1920s and 1930s when both price and production dropped. Figure 1.2 shows that other metals followed similar trends. How do we explain these changes, and what do they tell us about how the metal is found and mined, and about how it is used by society? Understanding these concepts is the basis of economic geology.