Implications of continental drift to the earth sciences. 1

189

al uniformity. which is illustrated by some 70 rock analyses quoted in various papers in the symposium. Several sequences of analyses from single flows are reported. Roman0 and Sturiale claim some limited chemical evolution guy. Two papers deal with the composition and a variation in sulphur content eruptions. An interesting

of the magma but this is contested

.by Tan-

of gases. The presence of hydrogen is affirmed

is indicated

as between continuous

and paroxysmal

general paper by Walker points to rate of effusion as the principal factor

influencing the lengths of lava flows. In another short paper he deals with rate of ash production from a temporary crater. There are two rheological studies of the lava and one on palaeomagnetism of historic flows. A conspicuous omission is the lack of any data on seismology or changes in the gravity field, local magnetic field or surface level during the eruptive cycle. These lacunae point up the obvious need for a well-equipped and adequately staffed permanent observatory on the mountain with a programme of continuous recording of physical phenomena. This could be a fine area for European scientific collaboration over the coming years. that might seek, in friendly rivalry, to emulate the results achieved by the United States in Hawaii. Meanwhile, this symposium is essential reading for all volcanologists, and many geologists who maintain a broad interest in the subject will wish to peruse it. M.H. BATTEY

(Newcastle-upan-Tyne)

Implications of Continental Drift to the Earth Sciences. 1. D.H. Tarling and S.K. Runcorn (Editors). Academic Press, 1973, 620 pp., L13.80. This book is the first of two volumes containing the whole proceedings of the NATO Advanced Study Institute meeting held at Newcastle in April 1972. It contains 45 separate papers, grouped under five headings: Palaeomagnetic Review, Sea-Floor Spreading Review, Palaeontological Implications, Palaeoclimatic Implications and Economic Significance. Of these, the section on Palaeontological Implications is much the most substantial, constituting well over one third of the book’s 620 pages. It is clearly impossible to comment meaningfully in a short review on the individual parts of a book of such length and diversity, but a few general comments may be useful to prospective readers. This reviewer has for some time wondered why publishers go to the trouble and expense of printing in full the proceedings of symposia and conferences - one gets the impression these days that no symposium is sufficiently insignificant for its proceedings to go unpublished. Unfortunately, the editors in their introduction have not offered any enlightment on what they

190

conceive to be the purpose of their book, save for some general remarks about the importance of the changes in geological thinking over the last decade, and the general acceptance of continental drift by the scientific community. Certainly, there was a need for a conference to examine the geological record in the light of plate tectonics, and certainly, it would be desirable to see some of the more pertinent proceedings published. The present expensive and unwieldy two volume work is, however unlikely to be the most useful possible format. It is a fact of scientific life that many of the papers that one hears at large conferences are likely to be re-hashes of papers that one has heard at other times in other places, and that the quality of the papers is likely to range from outstandingly good to appalling. Newcastle was no exception in either of these respects. There were some original papers, but there were also many review papers, and many m-hashes. There were also, inevitably, a good deal of overlap between papers, and therefore much tedious repetition. Those papers which were explicitly reviews are likely to prove most useful, and if usefulness is the best criterion by which to judge a book, the editors would have been well advised to make their publication a review pure and simple, leaving out much of the old material, and suggesting to the authors of significant new papers that they might be better served by publishing them elsewhere. This would certainly have produced a much more functional book, and one which could have been widely sought after. The present book, in the present climate of very rapidly evolving ideas on all aspects of plate tectonics is likely to be of rather ephemeral value, and the best that can be hoped for is that it will prove to be a sort of milestone in the evolution of continental drift, summarising the thinking on this subject over the last few years. Notwithstanding these reservations about the purpose of the book, there is much that is valuable in it, and it will undoubtedly provide an excellent source for those interested in continental drift. Any earth scientist planning to write his magnum opus on plate tectonics in the near future should certainly have a copy available. PETER FRANCIS {Walton, Bletchley)

Theory of the Earth’s Gravity Field. Miles Pick, Jan Picha and Vincence Elsevier, Amsterdam, 1973, 538 pp., 157 fig., Dfl. 96.00,

Vyskoc

In the preface, the authors declare, that their book is intended to be a textbook for university students, studying-geophysics and geodesy, but that it also can serve as a suitable aid to specialists and students of related branches of Science (geology, astronomy, physics etc). After reading a short and rather subjective introduction, dealing with the history and purpose of gravhetry (Chapter I by Picha), the student will find - in three chapters (by Pick), comprising a total of 90 pages - some funda-