Published by the American Geophysical Union as part of the AGU Reference Shelf Series, Volume 4.

Quaternary geochronology is the field devoted to dating Earth's history of the past 1.8 million years, the Quaternary Period. The field has come a long way since its early formulations at the beginning of the 20th century and the advent of radiocarbon dating 50 years ago. Since that time the field has witnessed a manifold increase in the number of available dating methods, no one of which can do all that the sum can provide.

It seems appropriate that this volume, which is devoted to the subject of natural time, be published at the end of the second millennium, a moment also significant in a cultural sense. It is one of the very reasons that we compiled this volume; so that we might better tell the history of the Earth during the Quaternary Period—the time in which the human species evolved and during which all that we know as history occurred.