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Reviews - October 2007

Compositional Data Analysis in the Geosciences - From theory to practice: Geological Society Special Publication 264

A Buccianti, G Mateu-Figueras & V Pawlowsky-Glahn (eds)
Published by: The Geological Society of London
Publication date: 2006
ISBN: 978-1-86239-205-2 (hbk)
List price: £75.00; GSL member price £37.50
224 pp

This volume consists of papers by both statisticians and Earth scientists, collectively dedicated to promoting the wider usage of statistically correct methods to interpret "compositional" ("constant-sum") data. This is most commonly encountered in major-element chemical analyses or percentaged counts of taxonomic or mineral abundances. Difficulties with the interpretation of trends exhibited by such data have long been discussed (e.g. Chayes, 1960; Skala, 1979). These result from the fact that the relative abundances of all the components are tied together by their constant sum; thus if one major component greatly increases in its relative abundance those of the others will, overall, decrease. Most published average compositions in the Earth-science literature are certainly wrong – perhaps not by much, but the very fact that they have traditionally been computed by simply averaging each component as though it were quite independent of the others means that the individual averages must all be biased to some degree, and are consequently erroneous.

The British statistician John Aitchison (1982) introduced improved methods (based on the so-called additive- and centred-logratio transformations) for the interpretation of percentaged data. Despite ambassadors in the Earth sciences (e.g. Reyment, 1989), it has taken until now for his techniques and more recent developments to be described in a sufficiently accessible way (and using suitably realistic geological case-histories), to be convincing to a generally less-numerate Earth-science audience. An additional barrier to uptake, the lack of easily usable software embodying these methods, is redressed here through guides to the stand-alone Excel-based freeware CoDaPack and to application of the freeware statistical programming language R. The resultant graphical displays are both clear and helpful. While some of the book's content is quite mathematical, the introductory chapter, which establishes the terminology and basics of the method, and five case-histories should make the majority of the book's 14 papers accessible to the general reader.

This book should be mandatory reading for all postgraduate Earth scientists, and the statistical methods described therein could well be taught to final-year undergraduates. Although there is still a lack of studies (e.g. in petrology and hydrogeochemistry) comparing traditional methods with these logratio-based ones, the case-studies and software presented in this book should greatly encourage reappraisal of the ad hoc approaches hitherto used by the majority of Earth scientists.

Richard J Howarth
University College London


  • Aitchison, J. 1982. The Statistical Analysis of Compositional Data. Journal of the Royal Statistical Society, series B, 44, 139-177.
  • Chayes, F. 1960. On correlation between variables of constant sum. Journal of Geophysical Research, 65, 4185-4193.
  • Reyment, R.A. 1989. Compositional data analysis. Terra Nova, 1, 29-34.
  • Skala, W. 1979. Some effects of the constant-sum problem in geochemistry. Chemical Geology, 27, 1-9.

Land of Mountain and Flood – The geology and landforms of Scotland

Alan McKirdy, John Gordon & Roger Crofts. Introduction by Vanessa Collingridge
Published by: Birlinn Ltd, in association with Scottish Natural Heritage
Publication date: April 2007
ISBN: 978-1-84158-357-0 (hbk)
List price: £30.00
400 pp

Land of the mountain and the flood,
Land of my sires! what mortal hand
Can e'er untie the filial band,
That knits me to thy rugged strand!

The title of this handsome volume echoes Sir Walter Scott's Lay of the Last Minstrel, and it is odd that a book so obviously produced by Scots for Scots (celebrity Introduction by broadcaster unknown outside Scotland; subsidy from state bodies; frequent references to the culture of Caledonia stern and wild, etc.) does not quote the stirring original (above) on the title page, alongside Hutton and Geikie's more prosaic epigraphs.

Still, let us not be churlish - it is hard to praise this book enough for its satisfying melding of the geological history and structure of Scotland with human prehistory, the history of geological science, and pressing societal concerns such as energy (fossil and renewable) and the whisky, brewing and extractive industries.

The first chapter, entitled Geology Enriches All of Our Lives, attempts a comprehensive PR job on the whole of Earth science, its applications and ramifications - even introducing concepts of geodiversity to what one must only assume is intended to be an unsuspecting audience. With its second chapter the book then launches into foundation course mode, and from then on we are into "textbook lite" territory. How the Earth Works places heavy emphasis on the role of Scottish pioneers in elucidating much of the Earth story, before leading into Scotland's Journey Across the Globe, which begins a stratigraphic and structural trek from the Lewisian through the Torridonian, Dalradian, Cambrian, and – well, you know the rest. But all this information is well conveyed, with colour diagrams and photographs (some of whose reproduction is muddy and would disappoint me had I been the photographer). There are also many tinted boxes for side issues to help the reader along.

Chapter 4 describes how the present landscape was sculpted and is mostly about glacial geomorphology. Chapter 5 discusses Future Landscapes and asks what might happen to Scotland in ages to come. There is a useful appendix suggesting places to visit.

If I have a problem with the book, it is that it's far too cheap! Thanks to SNH and the Scottish Arts Council, both of whom have subsidised the volume directly and in kind, this book is quite amazing value for money - you can buy it for a mere £16 on Amazon. I find this triggers a whole range of reactions. You can see it as making geology accessible and attractive to all. It's a fair point that, as a fairly blatant piece of pro-geo propaganda, it might be unwise to make it too expensive. Or one could see it as a self-indulgent excursion into vanity publishing on the public purse. As I believe in the first as strongly as I disapprove of the last, I find myself in two minds. But there can be no doubt that McKirdy and co-authors have produced a worthy addition to the popular literature on the geological heritage of the land of their sires, and I congratulate them on it. I just hope that people read it and do not let it languish on their coffee tables under TV Quick.

Ted Nield

Introducing Geology - A guide to the world of rocks

Graham Park
Published by: Dunedin Academic Press
Publication date: 2006
ISBN: 1-903765-64-1
List price: £9.99
160 pp

This is a great little book in which Graham Park has managed to summarise a broad range of geological issues at a basic level. Ideal for the interested novice, the book covers many key issues but does not presume any prior scientific knowledge. Technical terms are kept to a minimum and a full glossary is provided.

The book comprises 11 chapters and the glossary. The chapters cover all the key topics that you would expect to find in an ‘Introduction’, and some that you might not. For example, there are useful accounts on earthquakes and their prediction, and on relative and radiometric age determination techniques. The evolution of life is discussed as a broad issue, from fossil succession through to mass extinction events, and includes beautiful colour photographs of fossil examples. The use of minerals and geological knowledge within the modern industrial world is explored in Chapter 10 – this is largely focused upon fossil fuels and mineral extraction. The book concludes in Chapter 11 with an overview of Earth history that describes the Hadean, Archaean, Proterozoic and Phanerozoic eons.

The subject matter of each chapter is presented in a clear and logical order, with each of the chapters colour coded to enable ease of identification. The whole book is written in such a style as to allow the reader to dip into and out of any chapter independently of the others, helpful for those readers browsing through chapters or wanting a brief revision. Excellent use is made of examples to illustrate particular points of discussion, and of diagrams and photographic images - these are generously scattered throughout the book, and entice the reader on.

In this book Graham Park has captured the spirit of geology, and at a level accessible to almost anyone. The book is packed with essential information to explain the geology of the world around us, in a way that will inspire the reader to want to learn more. For the price, basic level geology books do not come any better.

Diane Johnson, Milton Keynes