World coal resources methods of assessment and results

projection would not be out of place here. Chapter 7, Internal Structure of the Earth, gives a thorough description of the structure and of the preeminent role of seismology in its elucidation. Chapter 8, Methods to Improve Seismological Observations, summarizes the establishment of seismograph stations and the international exchange of data, as well as suggesting lines of future development. It has been updated somewhat, although some recent moves towards fulfilling future needs, e.g. the SRO network, are not included. Chapter 9, Model Seismology, is unchanged from the first edition, introducing the reader to laboratory, rather than mathematical (e.g. synthetic seismogram) modelling. Chapter 10, Prediction and Artificial Release of Earthquakes, has been augmented by eight pages, including a new section on mining operations and rockbursts. Regarding point 3 (p. 301) under existing research, mapping, etc., of active faults, using all projects: “intensified available geological and tectonophysical methods”; some elaboration of the various methods alluded to here might be in order, in the context of this section. Mathematically sophisticated methods, e.g. pattern recognition, are understandably not discussed here, though presentation of some results might be of interest. The author justifiably separates the overlapping areas of seismic risk (“statistical prediction”) and earthquake prediction proper (“deterministic prediction”). However, the book lacks a unified discussion of the former, with elements of it found in chapters 4, 5 and 10. Chapters 11, Nuclear Tests and Other Explosions, 12, Planetary Seismology and 13, Seismological Education and Practice, present authoritative and updated introductions. However, in Chapter 11 (or perhaps 7) some greater treatment of crust and upper-mantle explosion profiling might be considered. The literature review has been expanded by almost 50% and latest references are now from 1977. The book is here and there flavoured by descriptions of research carried out at Uppsala, which, however, lend authenticity to the treatment. Birkhluser has changed from the glossy paper of the first edition to glarefree paper which is easier on the eyes; however, the quality of some figure reproductions has suffered. The publisher has apparently not edited the additions for spelling convention (all British in the first edition) or for usage or typesetting (e.g., “lighten”, p. 302, line 16; “a”, p. 325, line 21). Remaining from the first edition are “have” (p. 71, line 20) and a type error (p. 369, line 29). This book is without doubt a wise purchase for anyone who feels him- or herself included in the intended readership. R.J. BROWN (Lulei)

World Coal Resources

Methods

Elsevier Scientific Publishing 415 pp., Dfl. 165,..

of Assessment

Company,

and Results. Gunther Amsterdam-Oxford-New

B. Fettweiss. York,

The book is the translation of the German Publication Weltkohlenvorriite of the same author and has grown out of a paper Contributions to the Assessment of World Coal Resources, or Coal is not so Abundant, submitted to the first IISI Conference of Energy Resources Laxenburg near Vienna 1975. In this important informativ book four principle questions are discussed. (1) What are the viewpoints for the techno-economic assessment and for classification of mineral occurrences in general, and with special references to coal? (2) What can we learn from these viewpoints for the assessment of World coal reserves and resources? (3) What is therefore the total of economically significant resources of coal in the world? (4) How can we improve the terminology of mineral occurrences in order to achieve better data for decision making? After a short introductionary chapter in which definition and delimitations are discussed, Chapter II is concerned with the position of coal among the mineral raw materials and some feature related to origin, occurrence and geology of coal. Chapter III comprises mining such as economic mineability types of mining, technological limits, production losses as well as recovery. The Chapter IV deals alternative technology - especially underground gasification - and their technical possibilities. Chapter V is one of the most important, because the correct and comparable classifications of coal resources is the prior condition (the premises) for every useful1 information on coal resources. The coal resources itself are discussed in Chapter VI. Following the report of 1974 the coal resources can be classified in 3 categories. Categorie I. Resources in the broadest sense. Total quantities available in the earth that may be successfully exploited and used by man within foreseeable future. Category II. All other resources with a lower degree of certainty. Category III. Reserves: measured and assessed as being exploitable under present economic conditions. Category IIa; Fraction of reserves in place that can be recovered. In paragraph VI.2 the results of international surveys are presented. Some additional informations are given in Appendix H. The resources of Category I coal are subdivided in hard- and brown-coals. Paragraph VI.3 deals with the resources of individual countries. For Great Britain it is very interesting to learn, that the data of the international surveys are based on geologically orientated investigations. “The recoverable economically significant coal resources therefore make up only a few percent of the total coal resources in the international survey.”

79

The resources of the Federal Republic of Germany are discussed in more details. They show, just as in the case of Great Britain, the obsolescence and inadequacy of much of the data still in circulation. This indicated how dangerous it is to change repeatedly the guidelines for the international surveys and confirm the need for an international classification (see Chapter V). Looking at the resources presented for the U.S.A., South Africa, Australia, Soviet-Union and China the same uncertainty especially for the amount of category II and IIa can be recognized. Therefore the figures given on the economically significant coal resources of the earth can only be taken as an approximation of the true situation or as an attempt at one. In Chapter VII (conclusion) the author points out, that there is in the moment no system available for the classification of the resources. The purpose of this important book - explained by the author is: “to provide a basis for further considerations” because “there can be no doubt as to the necessity for better values than those we have at present”. The bibliography which is presented at the end of each chapter together with the appendex A-H are a very good help for everybody to understand the problem which is discussed by the author from an interdisciplinary viewpoint. M.Th.

MACKOWSKY (Essen)

Geophysics of Mars. Developments in Solar System and Space Science, 4. R.A. Wells. Elsevier, Amsterdam, 1979, 680 pp., 245 illustr., 5 colour plates, US $ 87,75, Dfl. 180.00. Any book on mars appearing in 1980 must be influenced strongly by the flood of scientific data from the various space missions to that planet. There have been: (a) three flyby satellites: Mariners 4 (1965), 6 and 7 (1969); (b) three orbiters: Mariner 9 (1971), Vikings 1 and 11 (1976); and (c) two landers from the Vikings. The main substance of the present book is based on a combination of earth observations and space data up to and including Mariner 9, but Viking results have been added in a final chapter which is cross-referenced back to earlier chapters. This process is simplified by a subject index which is a very useful feature. It is a well researched and thorough book for the specialist. It is not a text-book, except that in two areas there are explanatory mathematical expositions which provide background theory for the reader, viz. Mie aerosol scattering in relation to the appearance of the Martian atmosphere, and the theories of Coode and Runcorn applied to Martian tectonic features and mantle convection. The author develops both these themes in some depth and injects his own ideas. At the end of each chapter there is a very useful and comprehensive summary, as well as a long list of references. Chapter 1 deals with the Martian atmosphere, its composition, clouds and