Igneous rocks and processes: a practical guide, by Robin Gill. Wiley-Blackwell, Chichester, 2010. No. of pages: ix + 428. Price: UK£ 34.95. ISBN 978-0-6320-6377-2 (paperback).


Trevor Jackson, Seismic Research Centre, University of the West Indies, St Augustine, Trinidad and Tobago.

Email: trevor.jackson@uwimona.edu.jm

The inclusion of the word ‘practical’ in the title of this book has relevance in that it attempts to combine the theoretical and applied aspects of igneous petrology into one text. It is divided into nine chapters with three important appendices, plus a series of colour plates located at the centre of the book. These appendices and colour plates provide an aid to the more practical application of the book and provide a useful guide when undertaking the petrographic examination of igneous rocks. The sequencing of the chapters is to be commended as there is a smooth flow of subject matter throughout the book. The opening chapter provides the platform for further discussion on the genesis of igneous rocks that follows subsequently. These chapters tend to follow a logical approach, beginning with parent basaltic magma and followed by magmatic differentiation; mafic, ultramafic and ultrabasic plutonic rocks; derivative magmas in the form of andesites, dacites and rhyolites; pyroclastic processes and deposits; granites; and, finally, the vast array of alkaline rocks.

Each chapter is informative and written in a style that can be easily understood and appreciated. Within each chapter, there are text boxes that provide useful practical information. Towards the end of each chapter, there is a review section that summarises and highlights the salient points discussed therein. Exercises are also provided at the end of each chapter, which are designed to test the knowledge acquired and which again highlight the practical aspect of the book. The correct answers to these questions can be checked in a section located at the back of the book. The well-illustrated and annotated diagrams in each chapter add value to the topics. I was particularly impressed with the inclusion of the large number of colour photomicrographs displaying the mineralogy and texture of a wide variety of igneous rock types. The author is to be commended for the way in which the phase diagrams were incorporated into the text. The discussion on phase equilibrium and the application of phase diagrams is appropriately introduced in Chapter 3 on magmatic differentiation but is not entirely confined to it. Throughout the subsequent chapters, phase diagrams are also applied wherever it has relevance to a particular topic in that chapter. The importance of correct terminology and nomenclature is stressed throughout the book with emphasis on the use of the IUGS classifications of volcanic, plutonic and volcaniclastic rocks. A glossary at the back of the book also provides useful information on terminologies used in the text.

For those of us who have had to work with volcanic rocks that have undergone postmagmatic alteration, I was disappointed that there was no mention of the use of discriminant-element chemistry in the determination of basalt types. I thought that a couple pages on the subject matter could have been included in Chapter 2 on basalts and related rocks.

The book is an excellent up-to-date text for university undergraduate students who are majoring in geology. It is ideally suited for a specialised igneous petrology course that would be offered at the more intermediate level of the undergraduate degree programme, as well as a useful reference book for postgraduate students majoring in volcanology and igneous petrology. The bibliography is comprehensive with a reference list that goes up to 2008. The price of the book might seem to be a bit expensive, but when one considers that it is not the typical igneous petrology book and that there is added value with the additional sections on optical mineralogy and petrography, the price is amply justified.