The Field Description of Igneous Rocks

Book excerpt: This is a companion volume to the handbooks on sedimentary and metamorphic rocks published by the Geological Society of London in association with the Open University Press. Despite the title, this is more than just a guide to the study of igneous rocks in the field--it provides a concise, compact survey of many facets of igneous petrology. The chapter on volcanic rocks provides a particularly clear exposition of the various features encountered in modern volcanic environments, although serious students should know that palaeovolcanic rocks cannot always be satisfactorily interpreted in these terms. There is also a welcome coverage of the mineral deposits often associated with the later stages of granitic activity. The diagrams are clear and relevant, although some of the photographs suffered during reproduction. It would serve as a general introductory text, although it would need to a companion volume on thin-section petrology, at least for more serious students of the subject. Recommended as a well-balanced attempt to foster a sensible, rational approach to the mysteries of igneous rocks in the field. It also fits the pocket--literally and figuratively.