This book is designed to introduce the main methods used in the examination of quantitative records of ancient environmental changes. Such records are obtained from sources as diverse as the composition of sedimentary rocks, the varying percentages of microfossils and the thicknesses of growth bands in corals. These data sets, or time series, describe environmental changes lasting from half a day to millions of years. The emphasis of the book is on explaining concepts, procedures and problems not the details of the mathematics. I have avoided equations and derivations and have instead tried to employ simple diagrams in the explanations. This is because palaeoceanographers, environmental scientists, palaeoclimatologists, sedimentologists and palaeontologists sometimes find it easier to grasp new ideas graphically, rather than through formal mathematical treatments. There are, of course, many texts devoted to mathematical explanations, but this book attempts to explain time-series analysis to non-mathematicians in an accessible form.

Examination of ancient examples of varves and sedimentary cycles linked to orbital-climatic forcing (Milankovitch cycles, explained in Chapter 6) using time-series analysis began in the early 1960s. My own work spans Silurian to Recent cyclic sediments and includes the study of cores from three oceans with an emphasis on orbital-climatic (Milankovitch) forcing (Ocean Drilling Program Legs 117, 154 and 181). However, over the last few years the fastest growth in the use of time-series analysis has been amongst environmental scientists studying short period cyclicity related to phenomena such as El Niño and the Southern Oscillation and millennial-scale cycles and sedimentologists interested in stratigraphic records of tidal cycles.