Geoscientist Online

Regional Geophysics of Southern Scotland and Northern England (CD)
G S Kimbell, R M Carruthers, A S D Walker & J P Williamson

Regional Geophysics of South-east England (CD)
J P Busby, A S D Walker & K E Rollin

Both published by: British Geological Survey
Publication date: 2006
List price: £25.00 each, including VAT
ISBN: 6000001010 & 6000001029
CD Guide (Version 1.0)

www.bgs.ac.uk

These geophysical compact discs are the first of four that will cover the whole of Britain and its surrounding waters. Through a series of gravity and magnetic maps and models they provide a compelling guide to the hidden structures and tectonic fabric beneath our landscape. They are designed to be viewed like a web site with the aid of a browser, so it is possible to toggle between different points at the same time. Alternatively, as the contents are logically structured into a series of nested subheadings, they can be read like a book and can be crudely printed as a series of landscape pages.

The overall format of each CD is the same. After an Introduction, a geology section clearly outlines key aspects of each region’s tectonic history and underlying features such as granite intrusions and sedimentary basins. Following this, the nature of the data sources (gravity, magnetic and seismic records) is detailed. However, this section ought to have been much more forthcoming about how the gravity terrain corrections were calculated, as in other sections the methods used are set out in detail. It is also worth noting that using uncorrected Free Air anomalies in marine areas results in spurious anomalies that can in rare cases, at the modelling density used in these studies (2400 kg m-3), exceed 3 mGal; e.g. off the Bill of Portland. This section also includes very useful data on the densities and magnetic susceptibilities of different rock types, including the extent of variation within given formations.

The core of the content comprises an extensive series of shaded images showing the region's gravity and magnetic anomalies, residuals and gradients illuminated from various angles, so that is even possible to view one set with a rotating sun as a continuously moving loop. While this last feature would be impossible to print, it might be possible to produce images as synthetic holograms. As most of the other content of the CDs would arguably be easier to absorb in book form, these images could have been confined to a disc in the back of a more conventional hardcopy publication, like the recently published BGS Seismic Atlas of Southern Britain. This would also benefit the user in not having to pay the VAT levied on CDs.

The gravity-stripping section CD provides useful information about the depths, densities and thicknesses of different formations, even if the resulting maps would have been much clearer as simple contour plots rather than indistinct colour shades. After this, the section on two-and-a-half dimensional modelling provides a series of well analysed profiles, often through significant structures that usually tightly fit the magnetic and gravity anomalies - where there are exceptions to this the text could have discussed possible reasons for such departures in greater detail. The last major section, on 3D modelling, investigates to depth to magnetic basement and explores some key questions, such as the extent of hidden granites around The Wash, and the likely causes of the gravity anomalies in the Southern Uplands. Each disc also incorporates a brief conclusion and an extensive reference list and navigable index linked to main contents.

As a package these discs provide a wealth of useful background information that can be explored in many different ways to yield key details about the nature of the basement rocks beneath Britain.

David Nowell

 

Fine Wine and Terroir: The geoscience perspective
Geoscience Canada Reprint Series 9

R W Macqueen & L D Meinert (eds)
Published by: The Geological Association of Canada
Publication date: 2006
ISBN: 1-897095-21-X
List price: CDN $49.95 (GAC Member price: CDN $37.46)
266 pp

www.gac.ca

The validity of the concept of ‘Terroir’ has been disputed for a number of years among geoviticulturalists and wine makers. For many European vignerons the concept of ‘Terroir’ has been used in the same way as a drunk uses a lamppost, more for support than illumination. A leading ‘anti-terroiriste’, the late great geoviticulturalist Jake Hancock opined that ‘Terroir’ was nothing more than a combination of second-rate science and medieval mysticism (Hancock, 1999). Many winemakers from the New World share Professor Hancock’s cynicism. Indeed when this reviewer once asked an Australian wine maker what impact geology had on wine his reply was unprintable. Moran (1988) went so far as to argue that the concept of ‘Terroir’ is just another way of hiking up the price of land. Fine Wine and Terroir showcases the present thinking of North American geoviticulturalists on the ‘Terroir’ concept.

The book is dedicated to the memory of the late Simon J Haynes, one of Canada’s leading geoviticulturalists. Over a period of seven years Haynes commissioned a series of articles on geology and wine for Geoscience Canada. These are reprinted in this volume, together with three articles by Haynes, six new papers, a Dedication by Macqueen and an Introduction by Meinert. Haynes’ papers set the scene, expounding his views on ‘Terroir’. Haynes defines ‘Terroir’ as ‘that specific quality of a wine produced from a particular grape variety at the micro-level of a vineyard.’ He goes on to write that ‘Terroir is a fundament (sic) of the complex interrelationship of all the factors above and below ground that affect the grape during growth, excluding pests, diseases, herbicides, mutations, etc..’. Haynes lists these factors as meteorology, physiography, pedology, geology and viticulture. Several authors, notably Wilson, offer their own definitions of ‘Terroir’ in their papers. They all follow, with minor differences, Haynes’ definition quoted above.

Most of the papers in this volume discuss the interplay of geology, climate and viticulture in various winelands. Geographically they cover California, Idaho, Oregon and Washington in the USA, and Ontario and British Columbia in Canada. There are also single papers on Italy and the Cape Province of South Africa. These two contributions usefully provide a wider perspective. Greg Jones contributes a valuable paper on the impact of climate change on viticulture. Two papers discuss the application of GIS to understanding ‘Terroir’. Most interestingly, Bowen et al attempt a level of objectivity by analysing the correlation between medal winning wines and soil types. The validity of the concept of ‘Terroir’ is implicit in most contributions to the volume, but words such as ‘mystery’, ‘religious belief’ and ‘matter of faith’ abound throughout the book, and will set sceptical scientists’ antennae aquiver. A contribution by a New World ‘anti-terroiriste’ would have given this book better balance. Nonetheless Fine Wine and Terroir is essential reading for any geologist interested in the relationship between rocks and wine.

The text is interspersed with tables and plenty of good quality illustrations, many in colour. There is no index, but the Introduction by Meinert provides a useful route map for readers opening the book for the first time. Francophone readers will be grateful for the French abstracts.

Dick Selley