Principles of isotope geology

Principles of isotope geology

190 aging a half page figure for every one and half pages o f text. These have all been taken from other publications and little or no reference is m...

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aging a half page figure for every one and half pages o f text. These have all been taken from other publications and little or no reference is made t o them in the text. The captions are more emotive than educational. Some schematic drawings are t o o complex to read whilst others are too simplistic to serve other than school children. In a professional tome serving as a manual, in which factual information is being sought, the reviewer believes that pictures of estuaries should not be included unless they are making a technical point. There are six photos of fresh-salt marshes with essentially the same caption that these vital areas should be preserved. References, like the text, vary greatly in their relevance. In a manual where many topics are being presented in limited space it would seem advisable for the author and contributors to concentrate on books as references rather than technical papers. Even of the latter, many references are difficult for foreigners, or even U.S. citizens to obtain. For example, reports of subcommittees of the U.S. Senate and acts of parliament are not readily available in libraries. Some publications are listed as draft copy whilst in others the actual source is omitted. One contribution had no references at all. Because of his background the reviewer is more aware of the shortcomings or otherwise in the area of coastal sediment processes. The understanding and reading of the author and his contributors in this and hydraulic engineering generally appears very rudimentary. Many statements are likely to lead the reader astray when making judgements on engineering proposals. In a draft copy of this review a discussion of coastal phenomena was prepared equal in volume to this final submission, but was not included due to lack of space. Suffice it to say, that in this crucial aspect of coastal ecosystem management the reader will gain little useful information. However, the reviewer found the contribution on 'thermal discharges' very refreshing, and wished that the rest of the manual could have taken the same approach. The writer's thesis was that assimilative capacity should be considered for the community as a whole and not just f o r one specific natural asset. Referring to warm water dis-

charge from power plants he states: 'Many ecologists, regulatory personnel, and legislators are reluctant to use assimilative capacity because of the difficulties in using it properly. They substitute zero discharge as a viable alternative despite the fact that zero discharge does not necessarily mean zero environmental impact. In fact, full treatment permitting complete recycling of water requires substantial additional energy, treatment facilities, and chemicals. There have to be produced somewhere, and presumably their production will ultimately have environmental impact somewhere . . . In short, although reduction of impact is quite possible, absolute containment is impossible.' This realistic approach needs to be taken by all persons concerned in environmental matters, besides the view that man can enhance nature if the funds are available to do so. The concept of this book is to be commended, the manner in which it was implemented cannot. If it were to be rewritten, with input from the more practical personnel of the c o m m u n i t y , it could serve the purpose it was meant to, as stated in the opening of the book and of this review. By its size this tome should cost in the region of U.S. $ 70, unless heavily subsidised by the Conservation Foundation of the United States, of which the author is Senior Associate. Richard Silvester, Nedlands, W.A.

PRINCIPLES OF

ISOTOPE

GEOLOGY G. Faure, 1977. Principles o f Isotope Geology. Wiley, Chichester, 464 pp., £ 13.60, U.S. $ 24.25. The author is to be congratulated upon presenting a lucid account of the principles of isotope geology and has steered clear of any temptation to dwell upon one method to the exclusion of others. This volume consists of twenty-one chapters and deals with all the major methods in a balanced manner; each chapter concludes with a series of problems together with answers. The publishers have achieved an excellent

191 presentation of the text which is very readable. With few shortcomings the author has achieved his objective in producing a text suitable for the geological cirrlculum of universities. The text will undoubtedly stimulate interest in the subject although the author is careful to point out the contents do not provide a concise account of isotope behaviour applicable to all situations, but rather forms a basis to promote understanding of current advances in the subject. The scope of the volume ranges from a consideration of local case histories to an understanding of large-scale global features which can be studied through measurement of isotopes. The text is divided into three areas of interest, the first concerns general matters, the second those methods based upon radioactive decay processes while the final section is devoted mainly to various methods based upon the fractionation of isotopes; the text concludes with an appendix concerning the isochron method for R b - S r dating and the Geological Time Scale. The text lacks any serious discussion of the very demanding requirements for chemical and physical measurements; the type and quality of data which can be achieved by isotopic methods is ample illustrated in the case of ~'/Sr/86Sr ratios for example 0.69897 +-0.00003, which is a quality of assay rarely found in many analytical techniques applied to natural systems. The introductory matter deals with the fundamentals of radioactive decay which may prove to be a little daunting to some geologists, for example, after a little preamble the appearance of the Bateman equations which, although simple, could appear very complex to the uninitiated. Without detracting from the excellence of this volume my main criticism lies in the discrete manner in which each method is described, there is a lack of continuity and some readers may find it difficult to judge what is the most suitable method for a particular problem. Some attention could have been directed towards identifying where one method compliments another, for example K - A r and 14C. Another example is contained in the discussion of radioactivation analysis which is restricted to a consideration of sodium with no mention, at this

juncture, of the application of the technique in Ar and O s - R e dating, or the examination of fractionation between isotopes of calcium. The book could have been improved by the inclusion of at least one chapter dealing with the application of isotopes in studying large geological processes, for example in plate tectonics. Although the application of isotopes to technical contamination and pollution of the environment is mentioned in various parts of the text, their importance in modern environmental chemistry is not stressed, for example the use of the isotopic composition lead in relation to the global dispersion of technical lead. This volume is recommended to a large audience and should provide a sound basis upon which the current literature on isotopic measurements may be interpretated. E.I. Hamilton, Plymouth HYDROTHERMAL

URANIUM

DEPOSITS R.A. Rich, H.D. Holland and U. Petersen, 1977. Hydrothermal Uranium Deposits. Elsevier, Amsterdam, 264 pp., Dfl. 85.00, U.S. $ 34.75. This publication is the sixth in Elsevier's series Developments in Economic Geology and hopefully will serve as an example for reviews of other specific topics in ore petrology. Single-subject summaries are increasingly in demand. Hydrothermal Uranium Deposits (i.e., those occurring as discordant veins, stockwerks, breccia zones and irregular deposits in metasomatized rocks) offers two parts; the first dealing with important properties, the uranium geochemical cycle, mineralogy and genetic concepts, whereas the second part provides geological overviews of many of the major hydrothermal uranium deposits in the world. The authors stated in the Preface that their literature survey led to the conclusion that 'hydrothermal ° uranium deposits and 'sandstone-hosted' uranium mineralization are geochemically very similar -- the resulting exploration implications of this are discussed in their section on genesis.