Elements of physical geography

105 own) that have been omitted, however, I t h i n k that Whitaker has done an outstanding job of choosing representative papers. This volume includes a very early paper on canyons (1887), t w o classic papers f r o m the 1930's that relate the early arguments about canyon origin, and " m o d e r n " papers, f r o m 1955 to 1974, that illustrate the "explosion" of marine geology publications generated by advanced technology and increased funding. The ancient canyons and fans discussed in this collection range in age f r o m lower Paleozoic to Tertiary and in geography from Canada to Australia and the modern features range in geography from Africa to Alaska. Continents represented include Africa (3 papers), Asia (3), Australia (1), Europe (6) and North America (11). The geographic imbalance seems due in part to the editor's experiences, but mostly to the course of h i s t o r y - many of the canyons and fans on the South American continental margin, for example, are just now being described in the literature. However, three chapters are included that provide excellent summary tables, comparisons, and reference lists of: Submarine Canyons (Ch. 8, Shepard and Dill), Ancient Submarine Canyons (Ch. 21, Whitaker), and Modern and Ancient Deep-Sea Fans (Ch. 26, Nelson and Nilsen). The most valuable contribution of this Benchmark volume, in my opinion, is the lO-page Introduction in which the editor explains his choices o f papers and then provides a very complete selection of recent references, each introduced with a phrase or name that succinctly indicate the topic of the paper. In addition to the I n t r o d u c t i o n , the editor has included well-chosen comments prefacing groups of papers. In these comments the editor expands on the reasons for his selection o f papers, provides a sense of continuity throughout the volume, and introduces the authors to the reader. A few minor criticisms include poor reproduction of a few figures, especially sea f l o o r photographs, and of some of the printed pages. Several of the papers are represented only by excerpts, and by and large the surgery was accomplished cleanly; although, in a few cases figures referred to in the included t e x t were omitted. Some o f

these figures are not missed but omission of a few of them hampers the points being made. I was disappointed by the minimal texts included for t w o ancient canyons reported from Japan. One of these papers (Ch. 15) is included in the section on ancient submarine canyons, but the limited t e x t describes submarine channels and deep basinal facies, suggesting to me a deep sea fan system. This volume will be useful as a compendium of references and very likely will be incorporated in the library of most serious students of canyons and fans. Paul R. Carlson, Menlo Park, Calif.

GLOBAL

PHYSICAL

ENVIRON-

MENTS Arthus N. Strahler and Alan H. Strahler, 1976. Elements of Physical Geography. John Wiley, Chichester, 469 pp., £7.75. This book has been designed for onesemester courses for students following "general education programs in non-science fields who need only an overview of global physical environments". Throughout the w o r k the relevance of the physical environment to human activity is stressed, including examples of anthropogenic effects such as the significance of aerosols and supersonic transport on the ozone layer and the carbon dioxide theory. Relevance to man often provides the subject for the concluding section of each chapter. The book begins with world climate (30% o f the book) with chapters which outline radiation balance, global circulation and air mass climatology. Many topics are introduced in outline but as in the case of the Jet Stream, cannot be fully explained. World climatic types are introduced from a genetic basis although the Thornthwaite approach is explained in the succeeding t w o chapters on the soil water balance and soils which together comprise 8% of the book. The section on soils is intentionally brief and latosolic soils persist in the outline review of world soil types. The succeeding section on the biosphere (9%) successfully introduces productivity comparisons for world biomes

106 and this is followed by three useful chapters each of which presents a summary o f the major features o f low latitude, middle latitude, and high latitude and highland environmentS. These three chapters provide a convincing synthesis of climate and vegetation types as a background f o r agriculture, but it is unfortunate that erosion systems and landforms are not included here but are isolated in the final section (38%) o f the book. This final section of chapters begins with earth materials and major structural considerations including an outline of place tectonics, and it proceeds to concentrate on the landforms produced by weathering and mass wasting, ground water and surface water, glaciers, waves and wind. In the section on mass wasting the emphasis is upon the movements and forms rather than on the processes involved and there is little mention of rotational slumps or subsidence. The sections on ground water and surface water are more comprehensive and although there is no elaboration of modern ideas of r u n o f f production, water pollution and the effects of urban/sat/on are included and the succeeding chapter gives a clear account of fluvial landforms especially on floodplains. The section on landforms and rock structure is concerned with broad regional relationships and the short chapters on glaciers, coasts and wind are primarily directed to the resulting Iandforms and do not explain processes in detail. Despite the objective of the volume there is no consolidating chapter outlining the effects of man as pertinent to physical geography although an epilogue chapter reviews the relation between man and environment including reference to energy and resources. The standard of presentation throughout the volume is very commendable, there are numerous well chosen photographs, many of North American examples, some excellent colour plates, and a large number of instructive line diagrams. A large volume of up-to-date information is provided by the volume in a way guaranteed to interest new students of the subject and to awaken a real/sat/on of the significance of the physical environment. Although it would have been desirable to include landforms and geomorphological processes in the overview of world physical

environments, that this was not done is to some e x t e n t a reflection o f the independent way in which landform studies have been pursued isolated f r o m the remainder of the physical environment. This book should make students aware of the need for an integrated approach. K.J. Gregory, Southampton

ICE CORE DRILLING J.F. Splettstoesser (Editor), 1976. Ice Core Dr//ling. Universit£ of Nebraska Press, LinColn, Nebr., 189 pp., U.S. $ 7.95. Ice core drilling offers engineering challenges and scientific rewards that equal any other drilling venture. It requires drilling through a moving medium at temperatures ranging from the coldest on our planet to the melting point of the medium itself. The medium, o f course, is glacial ice and drillers can expect increasing shear deformation, hydrostatic pressure, temperature, and rock content with depth; that is, with distance from the drilling team. These changes conf r o n t most drilling programs with problems related to premature corehole closure due to ice deformation, corehole flooding and subsequent refreezing by surface or basal water, penetrating debris-choked ice layers or subglacial material, retrieving unaltered core from their high temperature-pressure environments at depth, and preventing corehole contamination. Scientific rewards justify ice core.drilling. Entrapped air bubbles contain C]4-datable samples of paled atmospheres. Ice cores contain datable records of paled air transport, temperature, and precipitation in their cation chemistry, stable isotope ratios, and microparticle content. The dynamic history of glaciation is studied by the pressure, size, and shape of air bubbles, the fabric, texture, purity, and debris content of ice cores, and the temperature, deformation, and subglacial hydrology down coreholes. All this information is needed to address the fundamental questions o f the relationship between glaciation and climatic change. In recognition of the problems and promise o f ice core drilling, the Ross Ice Shelp Project Management Office of the