Glacial till

196 King could possibly have kept up with the deluge of new data in hundreds of geologic maps as well as the fresh ideas tucked away in obscure guidebooks, and whether he has integrated these into his revision. The best aspects of the earlier book are retained. The general organization flows easily from an introductory chapter on 'the natural history of continents'. A pair of short chapters on the shield and the central part of the United States close with some personal experiences, told with King's informal and easy style. Then come chapters on the mountain ranges that the author obviously loves to wrestle with - the Appalachians, the Caribbean and Gulf of Mexico as a modern analogue, the eastern Rockies, and the main Cordillera. The book closes with a brief overview of the Cenozoic history of the west. It is a remarkable sweep. And superficially this is much the same book, with the same page size and format and essentially the same useful comments on early workers and on the flavour of the countryside. One minor though surprising change is that the general tectonic map of the continent is glued into the back so that it faces away from the text. But much more ~s changed that strikes one immediately, for while the same charming landscape drawings by the author adorn the book, many of the cross sections and stratigraphic layouts are brought up to current thinking based on new references, some from only two years before this edition appeared. Even on the tectonic map the added details and those subtracted, e.g. the Sykesville 'granite' in Maryland is now missing because it is no longer considered a pluton, show that the author has maintained his grasp of the material. The coverage is impressive. Many of the questions about regional geology that King has pondered for a long time show up in this new edition. The connection between the Appalachians and his thrusts in west Texas is now clearer, though not yet completely clear, because of plate tectonics. His comments on the Cenozoic structures of the Great Basin and on where felsic plutons in the Sierra Nevada originated are more provocative in the new context, as is his observation that the southern extension of the Sevier belt beyond the

Mohave is unknown. So, too, is the connection of the Paleozoic miogeosynclinal rocks involved therein with the eugeosynclinal rocks of the same age west of the Sierras; here King wisely refrains from mentioning the Wrangel Mountains a few thousand kilometers up the coast. In each of these questions and in many others, King's enjoyment of the ideas and his relish for the new challenges in regional geology come across clearly. After reading this book, you will reach for a hammer and start out with new enthusiasm for solving the problems of regional geology in North America. Lucian B. Platt, Bryn Mawr, Pa.

GLACIAL

TILL

R.F. Leggett (Editor), 1976. Glacial Till. The Royal Society of Canada Special Publications, No. 12, 412 pp., £ 20. In recent years interest in glacial deposits has grown rapidly, accompanied by a realisation that tills are exceedingly complex, difficult to interpret in terms of glacial advances and retreats, and even difficult to classify. Major advances in our understanding of tills have been brought about following detailed investigation at existing glaciers, notably in Arctic regions, within the last decade. Glacial Till emphasises the interdisciplinary nature of the study of glacial deposits, and as such will be of interest to geologists, geomorphologists, soil scientists, mineral prospectors and engineers in particular. The volume consists of a collection of four review and eighteen research papers, each with a French abstract, originally presented at a symposium in Ottawa in February 1975 and, as the editor writes, it complements the 1969 Ohio conference volume Till: A Symposium, which has since become a standard work for glacial geologists. Each paper is followed by a discussion, either in French or English. Naturally there is a strong, one might say overwhelming, bias towards North America, but many of the papers contain practical information which will be of benefit to scientists in other continents. The book is divided into four sections,

197

each headed by an invited review paper by a leading authority. The first section, Geology of Tills, begins with an excellent review of the origin and properties of tills by A. Dreimanis, which includes discussions on terminology and the genetic classification of tills. J.S. Scott then discusses the distribution and characteristics of Canadian tills; M.M. Fenton and A. Dreimanis methods of stratigraphic correlation of tills in Canada; P.F. Karrow the texture, mineralogy and petrography of North American tills; R.W. May and A. Dreimanis the compositional variability of till; and E.A. Christensen and S.H. Whitaker glacial thrusting of drift and bed roc k. The second section concerns the pedology of tills, and is headed by a useful review by R.J. St. Arnaud, which includes information on the importance of till pedology to agriculture, forestry, recreation and wildlife. Then follow papers of regional interest: C.R. De Kimpe and others with respect to Quebec, D.F. Acton and J.B. Fehrenbecher to Saskatchewan and N. Keser to British Columbia. The third section considers how tills can be used for mineral exploration, beginning with a review of the relatively newly developed methods of mineral prospecting in tillcovered areas by W.W. Shilts. This is followed by one of the few papers concerned with an area outside North America, R. Kujansuu on prospecting in Finland. Papers by P. La Satle and others, and D.W. Alley and R.M. Slatt conclude this section, dealing respectively with parts of Quebec and Newfoundland. The final section is on geotechnical aspects of till and starts with a review by V. Milligan. This overlaps to some extent with Dreimanis' paper on the characteristics of t,ills but goes on to discuss the effect of till on foundations, the stability of tilt slopes, tunnels in till and the use of this material in construction. Next, a paper by G.S. Boulton considers the geotechnical properties of tills at present-day glaciers, examples being particularly drawn from Svalbard. G.E. Gvisak and others consider the hydrogeological and hydrochemical properties of till in the interior plains of Canada; R.M. Quigley and T.A. Ogunbadejo the engineering and physico-chemical properties of

till in Ontario, and A.A. Loiselle and J.E. Hurtubise the use of till as a construction material. J. Peters and J. McKeown then recount the experiences of a hydro company with till during the construction of a dam in Manitoba; S.W.E. Pepler and I.D. MacKenzie show how till has been used to make dams watertight in Labrador and finally W.J. Eden describes the construction difficulties encountered with tills during the development of a hydro scheme also in Labrador. The main criticism that can be made of this volume is that it seems to lack an overall theme. It is also a pity that a book which stresses the interdisciplinary nature of the study of tills has no contributions from glaciologists, and there is very little, apart from Boulton's paper, on present-day glacial processes. Nor are there any contributions on glacio-rnarine sedimentation which is such an important aspect of the geological record. The volume is well printed and laid-out, but is let down by the poor quality of some of the diagrams, both in terms of draughtsmanship and reproduction - in some diagrams the detail is completely lost. There is also an irritating mixture of imperial and metric measures, sometimes even within the same paper. Referencing to most of the papers is good, though the presentation within the text is inconsistent: sometimes the author's name appears followed by a reference number, sometimes a reference number alone is given. There is nevertheless a useful index, divided according to author, area and subject matter. In spite of these adverse points Glacial Till is a very worthwhile contribution to glacial literature and, although the book is of most interest to Canadians, scientists in other countries will find much of interest to them while at the same time they are provided with a useful guide to North American literature at a reasonable price. M.J. Hambrey, Cambridge

SCIENTIFIC RESEARCH IN ANTARCTICA E. Fuchs and R.M. Laws (Organizers), 1977. Scientific Research in Antarctica. A Royal