BOOK REVIEWS 385

University Press, Montreal and Kingston, 1993. No. of pages: xxii + 339. Price f42.75. ISBN 0-7735-0925-9.

This is an undergraduate-level text on regional physical geography in which the causes, nature and effects of cold climatic conditions provide a unifying theme. The book includes contributions by 11 Canadian geo- graphers of international repute, and offers an excellent synthesis of Canada’s cold northern environments with emphasis on possible impacts of future climatic change. Thirteen chapters are arranged into four parts: ‘Cold Land, Cold Seas’, ‘Northern and Polar Lands’, ‘Mountain Environments’ and ‘The Changing Cold Environments’.

The first chapter, written by the editors, summarizes the physical geography of northern Canada and discusses concepts of coldness and nordicity. Roger Barry then provides a detailed factual account of the cold seas off the northern Canadian coastline including sea-ice conditions, salinity and circulation patterns. Part Two of the book opens with Wayne Rouse’s chapter on northern climate which discusses latitudinal gradients in radiation and heat fluxes, atmospheric circulation, seasonal weather patterns, and energy and water balances in different terrain and ecosystem types. The contribution by James Ritchie is concerned with northern vegetation and outlines the importance of Quaternary environmental change, climatic controls on vegetation, the structure of plant communities and the role of fire. It is a pity that this chapter is not followed by one on fauna and ecosystems, to provide a fuller account of Canadian northern ecology. Northern hydrology is next described, by Ming-Ko Woo, and this chapter stands with several in the book that are of particular value in that they include much that is of general interest, beyond the purely Canadian context. The same can be said for Hugh French’s chapter on cold-climate processes and landforms, although the lack of space available in a text such as this limits the amount of detail that can be included here.

Part Three, concerned with mountain environments, includes a series of excellent reviews, commencing with Olav Slaymaker’s discussion of mountain environments which ranges from geomorphology and glaciation to hydrology and vegetation. This is followed by an equally valuable contribution by Derek Ford in which cold climate karst processes and landforms are reviewed, with examples drawn from Canadian mountains. The final two chapters in this section are concerned with mountain palaeoenvironments (John Clague) and mountain hazards (James Gardner), and both are specifically related to the Canadian experience. It is surprising in the latter chapter that no account of landslide and rockfall hazards is given.

The opening chapter of Part Four will probably be one of the most widely read, being concerned with climate variability, change and sensitivity. Ellsworth Ledrew expertly guides the reader through the complexities of process links in climate modelling, including factors specific to high latitudes, such as sea-ice variation, ocean circulation, changes in the extent of permafrost and

tundra, and the release of methane. This chapter provides an appropriate lead into Michael Smith’s excellent review of possible impacts of climatic change on permafrost terrain. Finally, Slaymaker and French attempt to draw the various threads of the book together in the final chapter entitled ‘Cold Environ- ments and Global Change’. This includes a considera- tion of Holocene climatic variability and projected impacts on northern terrain and northern ecosystems of future global warming.

This text is to be welcomed, both as a lively and highly readable account of the physical geography of Canada, and as a synthesis of the significance of climatic factors in general and climatic change in particular on high latitude geomorphological and ecological systems. It is well illustrated with clear line drawings, though the qual- ity of photographic reproduction is often poor for a book of this price. Although unrepentantly Canadian in its context, this book contains sufficient that is of general geomorphological interest to warrant a place in univer- sity libraries outside Canada, and on the bookshelves of all who have a specific scientific interest in that country.

CHARLES HARRIS Dept. Earth Sciences, University College of Wales,

Card@ CFl , 3 YN

AEOLIAN SEDIMENTS: ANCIENT AND MODERN edited by K. Pye and N. Lancaster, International Asso- ciation of Sedimentologists, Special Publication 16, Blackwell, Oxford, 1993. No of pages: viii + 167. ISBN 0-632-03544-7.

This volume represents a selection of the papers presented at a symposium of the same title held at the International Sedimentological Congress in Nottingham in 1990. There are 10 papers, including one from each of the editors, divided almost equally between sections on ancient and modem aeolian sediments.

Conference proceedings from aeolian geomorphology and sedimentology are now beginning to have a familiar format. They start with papers on grain entrainment and transport. In this collection there is one in this category: a re-working of existing data by Willetts and McEwan. The proceedings then move to papers on description and monitoring of contemporary aeolian systems. Here the papers are by Burkinshaw and Rust on the Alexandria coastal dunefield in South Africa, and by Pye on parabolic megadunes in north-eastern Australia. There is a contribution by Corbett on sand- flow through the southern Namib deflation basin which highlights the lack of attention paid, within a burgeon- ing literature on the Namib, to the southern Namib as a source for sediments in the sand sea. This is followed by two papers on sedimentary structures in contempor- ary aeolian systems. The first, by Schenk et al., assesses the use of ground-penetrating radar to determine the internal structure of a dune, a technique which will

386 BOOK REVIEWS

surely be widely applied in situations where it is difficult to create clean, vertical sections. The second, by Lancaster, considers supersurfaces in the Gran Desierto.

The four papers on ancient aeolian sediments cover: supersurfaces which represent breaks in aeolian accumu- lation in the Jurassic Page Sandstone of the Colorado Plateau (Havholm et ul.); downwind changes in the Permian Cedar Mesa Sandstone in Utah, also consider- ing the significance of supersurfaces (Langford and Chan); the relationship of aeolian to other facies in the Hermosa Formation of Utah (Atchley and Loope); and the linear draa in the Permian Yellow Sands of north- east England (Chrintz and Clemmensen).

The volume has been well edited and is well presented. Text and diagrams are clear, and it appears free of proof- reading errors. As a collection, rather than being porten- tous of sea-change, it confirms major current themes in aeolian geomorphology: the search for better links between modelling and empirical results for grain trans- port; measurement of flow and sand transport regimes over different dune types; and the cross-fertilization between geomorphology and sedimentology in under- standing aeolian sedimentary structures.

Ultimately the collection suffers from the fact that a number of other volumes, often with the same contri- butors covering similar material, have beaten it to publi- cation, most notably and recently the collection edited by Pye himself (Pye, 1993). Compared to Pye's other volume, this IAS collection seems rather sparse, even allowing that the other is less restricted in scope. The spate of recent publication is indicative of the rightful place which aeolian geomorphology and sedimentology now holds in the literature, and there are good papers in this collection, but there must be some concern that the material is being spread too thinly.

IAN LIVINGSTONE School of Environmental Science,

Nene College, Northampton, "2 7AL

REFERENCES

Pyk, K. (Ed.) 1993. The Dynamics and Environmental Context of Aeolian Sedimentary Systems, Geological Society Special Publication No. 72, 332 pp.

GSA Special Papers range from essay collections to monographs; this is one of the latter, and owes its origin to a doctoral thesis by the author. Pleistocene Lake Bonnville breached and rapidly eroded its sedimentary dam in Red Rock Pass, Idaho, about 14500 years ago, to release a flood peaking at about lo6 m3 s-' , but attenu- ating to about half this value over the study reach. This paper summarizes the historical research on the conse- quences of this catastrophic event (twice the volume but with a lower peak than the largest Missoula flood, which affected the Snake River further downstream), reports field mapping of the erosional and depositional consequences over a 1100 km reach, and step-backwater modelling of water levels constrained by the geological evidence, describes sedimentary structures and gives estimates of flood competence. The methods are by now familiar, but the consolidated evidence of an event with velocities of up to 40ms-', depths up to 150m, shear stresses up to 3000Nm-' and stream powers up to 120 000 W m-2, transporting boulders 5 m in diameter and depositing gravel bars up to 6 km long, cannot fail to be of interest, especially when the 'tractive deposits are remarkably similar to those measured for pebbles and cobbles in flumes and small streams' (p. 51). Novel elements of this study are a preliminary attempt to apply dynamic flood routing as well as the steady-state step- backwater method (which is applied to 10 sub-reaches of 30-100 km in length), an emphasis on critical condi- tions for transport rather than entrainment, and an attempt to evaluate quantitative criteria for cavitation erosion. This is a good companion paper for Baker (1973), and illustrates that these catastrophic events, so controversial when Bretz (1923) first described their effects, are now part of the mainstream.

KEITH RICHARDS University of Cambridge

REFERENCES

Baker, V.R. 1913. Palaeohydrology and Sedimentology of Lake Missoula Flooding in Eastern Washington. Geological Society of America, Special Paper, 144.

Bretz, J.H. 1923. 'The Channeled Scabland of the Columbia Pla- teau', Journal of Geology, 31,617-649.

HYDROLOGY, HYDRAULICS, AND GEOMOR- PHOLOGY OF THE BONNEVILLE FLOOD by J.E. OConnor, Geological Society of America, Boulder, Col- orado, Special Paper No. 274, 1993. No. of pages: vi+ 83. ISBN 0-8137-2274-8.