Basic Geological Mapping


Richard J. Lisle

School of Earth and Ocean Sciences, Cardiff University

Peter J. Brabham

School of Earth and Ocean Sciences, Cardiff University


John W. Barnes

Title Page

The Geological Field Guide Series

The Field Description of Metamorphic Rocks, Norman Fry

The Mapping of Geological Structures, Ken McClay

Field Geophysics, Fourth edition John Milsom

The Field Description of Igneous Rocks, Second edition Dougal Jerram and Nick Petford

Sedimentary Rocks in the Field, Fourth edition Maurice Tucker

Preface to The Fourth Edition

This book is a basic guide to field techniques used in geological mapping. It is meant to be kept in camp with you and even carried in your rucksack in the field. In addition, because no piece of geological mapping can be considered complete until the geology has been interpreted and explained, chapters are provided on drawing cross-sections, on preparing and presenting ‘fair copy’ maps, and on presenting geological diagrams from your fieldwork suitable for inclusion in your report. A report explaining the geology is an essential part of any field project, and a brief chapter on the essentials for writing and illustrating it concludes this book. Some emphasis, too, is given to field sketch-mapping because many reports lack those large-scale detailed maps of small areas that can often explain complex aspects of the geology that cannot be shown on the scale of the field map being used, and that are difficult to describe in words. Attention is also given to field notebooks, which are, in many cases, deplorable.

It is assumed that readers of this book have already had at least one year of university or equivalent geology, and have already been told what to look for in the field. Geological mapping cannot, however, be taught in lectures and the laboratory: it must be learnt in the field. Unfortunately, only too often, trainee geologists are left largely to their own devices, to sink or swim, and to learn to map for themselves with a minimum of supervision on ‘independent’ mapping projects. It is hoped that this book will help in that task.

John W. Barnes and Richard J. Lisle


Preface to The Fifth Edition

This fifth edition of Basic Geological Mapping was revised without the help of John Wakeham Barnes who sadly passed away in 2007. On the suggestion of referees we have updated the text by including mention of modern technological aids and data that are used in modern geological mapping, such as applied geophysics, digital terrain models, and optical and GPS-based surveying. There has also been more emphasis given to structural geology and cross-section construction. Whilst making these additions we have been conscious of the need to maintain John's successful formula; to offer a practical guide for the student undertaking a mapping project with a minimum of resources and academic supervision.

We are grateful for the advice of Jim Hendry and Rob Strachan (University of Portsmouth), Chris Berry and Alun Rodgers (Cardiff University) and the book's reviewers.

Richard J. Lisle and Peter J. Brabham

January 2011