Principles of Igneous and Metamorphic Petrology

926

Book Reviews

portance of meteorites or on the stories that are locked up in their chemical, petrologic, and isotopic structure and composition. Almost nothing is said of the origin and early history of the solar system, for which the study of meteorites is of key importance. On the other hand, the book contains a wealth of information on historical and phenomenological aspects. The author is to be congratulated for assembling impressive and interesting illustrations. In addition, the publisher should be commended for providing a well-produced book with nice binding, layout, and graphics at a reasonable price (considering the format of the book and the number of illustrations). Apart from the uneven treatment of the subject, however, there are some flaws ranging from scientific misconceptions to inconsistencies and typos. I assume that more scientific scrutiny and better proofreading would have helped to catch some of these mistakes. Among the scientific misconceptions are (I) meteorites of 100 t mass do not vaporize completely upon impact (p. 41, p. 97); (2) a body encountering the earth without any velocity difference will be accelerated to the escape velocity not only upon entry into the atmosphere (p. 41); (3) the average age of Allan Hills meteorites is not 0.3 Ma (p. 79); (4) ring structures in complex craters are not caused by slumping of the rim (p. 98,99); (5) quartz along planar shock lamellae is not transformed into stishovite (p. 101); (6) fremdlinge in carbonaceous chondrites do not consist of refractory metals only (p. I3 1). The inconsistencies include (1) the Brunflo fossil meteorite is once said to have been found in the “Rodberget” quarry (p. 53), once in the “Riidbrottet” quarry (p. 55); (2) the singular ofthe German word

for chondrule is not “Chondrum” but “Chondre” (p. 54); (3) the diameter at which the change from a simple to a complex crater structure occurs is once said to be 3-4 km (p. 98), once 10 km (p. 99); (4) Allende is not a CVB type meteorite (p. 138); (5) it is CA1 and not CAT inclusions (p. 157); and (6) it would certainly be interesting to have 9000 meteorites in 5000 fragments in the Vienna museum (p. 175). Despite these inaccuracies, the bulk of the text is correct and readable. By treating meteorites mainly as objects of spectacular falls and as collectors’ items, and not so much as research objects, the danger arises of fuel@ the desire of private mineral collectors to obtain “a piece from the sky”-which is not surprising, considering the background of the author. In this respect, chapter 8 is especially deplorable. There should be just one sentence: whoever finds a possible meteorite should turn it over to a major museum and should not scratch it, etch it, or soak (“conserve”) it; meteorites are not to be chopped up and sold by the gram like salami-if you want to see one, visit a museum. Apart from these cautionary remarks, 1 still recommend this book as a very well-illustmted basic in~~uction to the history and phenomenology of meteorites, but not as a description of the whole science behind it.

Principles oJ‘Igneous and Metamorphic Petrology by Anthony R.

use a computer. If we are to attract quality students to petrology in the future, the black-magic approach to teaching must be discarded in favor of a fully quantitative approach. Most of the essential concepts of phase equilib~um, thermodynamics, and kinetics are introduced in the first 13 chapters which, together with chapter 14, deal mainly with igneous rocks. The first chapter sets tbe tone, and includes a discussion of pressure distribution within the earth, temperature gradients and heat flow in the lithosphere, heat sources within the earth, and the steady-state geotherm. This is followed by five chapters dealing with physical properties of magma, intrusion of magma, forms of igneous bodies, cooling of igneous bodies, and cl~fication of igneous rocks. However, a list of chapter titles does not do justice to the contents. The chapter on intrusion of magma, for example, includes an introduction to fluid dynamics whereas that on the cooling of igneous bodies includes a very good summary ofthe theory of heat conduction (error functions included!). The next four chapters deal with thermodynamics and phase equilibrium. A lot of material is covered in 89 pages (including Mo~y-~hr~n~ake~ rules, non-ideal solutions, the residua system, the ternary feldspar system, the pyroxene quadrilateral, and twopyroxene thermometry), but it is presented logically and coherently and applications to rocks are stressed. Chapters 11 and 12 discuss the effects of volatiles on melt equilibria (including an introduction to two-oxide thermobarometry) and crystal growth, whereas magmatic processes and igneous rock associations arc covered in chapters I3 and 14. Me~mo~hism is the subject of six chapters: an intr~uction to isograds, graphical representation, petrogenetic grids, and the facies concept; mineral reactions involving HZ0 and CO,; reactions involving solid solutions; material transport; deformation and textures: and P-T-t paths. I found the section on metamorphism to be patticularly good. Philpotts covers all of the important topics and concepts in 107 pages, yet coverage of some of these (e.g., P-T-t paths, role of fluids) is far better than in most textbooks on me~mo~hic petrology! Once again, this r&e& the emphasis on principles rather than facts and in itself is justification For this approach. Also, metamorphism is largely governed by exactly the same principles described in earlier chapters in the book. The final two chapters are on isotope geochemistry (dating methods, evolution of isotopic reservoirs and stable isotopes) and on the origin of rocks (advective heat transfer, conditions for melting, melt generation and accumulation, mantle composition and partial melting). I do have some minor criticisms of the book. I think that more

Philpotts. Prentice-Hall, 1361X).

1990, 498p., US $5 1.00 (ISBN Ol-369-

FOR MANY YEARS I have been unable to find a satisfactory, up-todate textbook for use in my classes on igneous and metamorphic petrology. The problem with most texts, in my view, is that they emphasize petrogenesis. This approach usually involves presentation of a bewildering number of facts and descriptions of numerous localities followed by an attempt at synthesis to reach qualitative conclusions. All too often, the reader is left with the impression that nearly all of the major questions in petrology have been satisfactorily answered. Nothing could be further from the truth. Petrology is a rapidly evolving subject, and petrogenetic models are discarded or modified as data accumulate and are interpreted. Consequently, books which emphasize petrogenesis are soon out of date and their main use is that they give an overview of the ideas prevailing just prior to the time of publication. As recognized long ago by Bowen, it is the basic principles that should be emphasized because these provide the coherent framework within which petrogenetic models must be constructed. This is exactly the philosophy followed by Anthony R. Philpotts in Principles @Igneous and Metamorphic Petrology. This book is a most welcome, long-awaited, and important addition to the geological literature. Philpotts treats petrology largely in terms of simple models that can be tested by quantitative analysis. These models are based upon well~~blish~ physical and chemical principles. Accordingly, description of field aspects and of rock associations is kept to a minimum, and there is no lengthy discussion of petrogenesis on the basis of magma-type, metamorphic rock-type, or tectonic environment. Roth physical and chemical aspects of petrology are clearly and lucidly explained, and the text is punctuated by numerous, helpful illustrations. Thankfully, Philpotts does not sidestep the need to quantify petrologic, geophysical, and geochemical phenomena. Indeed, one of the strong points about the book is that the mathematics necessary to understand the basic concepts is not only included, but derivations of important relationships are given in full. Problem sets given at the end of each chapter reinforce and extend the concepts described in the text (and provide many ready-made examination questions for the instructor), and are an integral part of the material covered. Use of this text should convince all geology students of the need to formulate models in mathematical terms, and of the need to learn to

Institute ofGeochemistry University of Vienna A-1010 Vienna, Austria

Christian Koebert

Book Reviews

927

discussion of trace element systematics would have been useful. After all, interpretation of trace element data is critical for constraining the role of processes such as assimilation and magma mixing, as well as for inferring the characteristics of the source regions of magmas. Similarly, I would like to have seen the chapter on isotope geochemistry placed earlier and greater use of isotopic data made in the section on assimilation. However, these are minor points and reflect my own prejudices. This book is designed as an introductory text for students who have completed undergraduate coursework in physics, chemistry and calculus. It could be used both for undergraduate and beginning-level graduate courses, and would serve as a useful supplementary text for

introductory courses in other subjects (e.g., geophysics). I shah certainly adopt it for my own classes, and it deserves serious consideration by other petrology instructors. In my opinion Principles of Igneous ana’ Metamorphic Petrology is destined not only to become a standard petrology text, but to become the standard against which other books will be judged. It belongs on the shelves of all petrologists, geochemists, and geophysicists, indeed all of those interested in the solid earth.

Planetary Mapping edited by R. Greeley and R. M. Batson. Cam-

the problem of what projection to use in mapping. For experienced planetologists, one of the most interesting chapters will probably be that on Planetary Nomenclature by M. E. Strobe11 and the late H. Masursky (former President of the I.A.U. Working Group for Planetary System Nomenclature). Names for topographic features have proliferated almost exponentially since 1964, when Ranger 7 returned the first high-resolution pictures of the Moon, and many researchers have only a vague idea of the etymology of features such as “Gob,” “Bianca,” and “Setibos” (left as an exercise for the reader). And two years of high school Latin four decades ago are little help with physiographic terms such as “scopulus,” “vastitas,” and “labes.” For readers of this journal, the most useful chapter will certainly be “Geologic Mapping” by D. E. Wilhelms. Far more than a “howto-do-it,” this chapter covers the logical foundations of geologic map ping in general, the origin of various lunar and planetary structures and lithologic units, and the role of sun angle in mapping. This chapter should in fact be read by all advanced geology students to increase their understanding of how any sort of geologic mapping is (or should be) done. An interesting implication of this chapter is that fundamentally sound geologic maps of the Moon-at least the near sidecould have been done in the 19th century by applying stratigraphic principles to telescopic observations. For completeness, this review should make it clear what Planetary Mapping is not. It is not an atlas and makes no pretence of presenting encyclopedic coverage of the solar system or even the Moon. (Yenne’s The Atlas of the Solar System, Bison Books, 1987, makes a good complement for this book.) There is little on geophysical or geochemical mapping, a significant omission for the Moon. There are no color plates or fold-out maps, and readers must supply their own stereoscopes for the few stereopairs presented. But Planetary Mapping is a collective tour de force of scientific publishing useful, educational, entertaining, and occasionally humorous-the astonishing “topography” revealed by Lunar Orbiter (p. 188) nicely balances the spherical harmonic expansions. Layout and typography are excellent, as we might expect from a publisher in business since 1584.

bridge University Press, 1990, xi + 296p., US $70.00 (ISBN 0-52130774-0). A RATHER matter-of-fact title has been given to this extraordinarily interesting scientific text, simultaneously (to varying degrees) a history of solar system exploration, a history of solar system astronomy, and an account of the techniques by which the Moon, the solid planets, and dozens of satellites have been mapped since space flight began. Edited by two experienced planetary mappers, the seven chapters are authored by those who have actually pioneered planetary cartography. This book was written just in time, so to speak. Some 30 years have elapsed since modem lunar and planetary mapping began, and many of the pioneers, such as Arnold Mason, Bob Hackman, and one author of this book, Hal Masursky, have died or at best retired. Delayed five more years, Planetary Mapping could have been written, but not by the first generation of space age mappers. The subject matter and organization are summarized by chapter headings: History of Planetary Cartography, Cartography, Planetary Nomenclature, Geodetic Control, Topographic Mapping, and Geologic Mapping. Three appendices cover map projections, printing processes, and digital planetary cartography. Each chapter concludes with an extensive bibliography, chiefly to the primary literature. The treatment level varies. The chapters on Geodetic Control (M. E. Davies) and Topographic Mapping (S. S. C. Wu and F. J. Doyle) give the mathematical foundations of the respective subjects and require a solid grounding in, at the very least, trigonometry. However, most of the book is non-mathematical and should be easy reading for anyone interested in science. The historical aspects of the subject are perhaps of broadest interest. Despite 30 years of experience in lunar research, for example, this reviewer had never seen W. Gilbert’s 1600 naked eye map of the Moon-a strange-looking diagram, yet one in which Mare Imbrium, Oceanus Procellarum, and even Mare Crisium (Gilbert’s “Britannia”) can be recognized. The invention of the telescope shortly thereafter revolutionized lunar mapping, and “the first true map” of the Moon, by van Langren, is recognizably familiar. Van Langren’s nomenclature, however, is not; Armstrong and Aldrin did not land on “Mare Be&urn.” The chapter on Cartography by R. M. Batson illustrates some of the peculiarities of “planetary” mapping. Many of the small satellites and asteroids are potato-shaped-lumpy potatoes at that-presenting

Trace Elements in Coal by Dalway J. Swaine. Butterworth & Co. Publ., 1990, 278p., US $185.00 (ISBN O-408-03309-6).

THE CHEMICAL composition

of coal is related to the behavior of numerous elements which directly or indirectly participate in the life process of plants or in the decay of their remains. Decay reduces the original mass of the plants to only a few percent of the former material and changes the properties of the surrounding environment. In 1930 V. M. Goldschmidt initiated systematic investigations of trace elements in coal and coal ashes after he detected unusual accumulations of Ge in hard coal. He already suggested a commercial exploitation of this element from coal ashes. After the introduction of Ge as semi-

Departmenf of Geological Sciences The Ohio State University Columbus, Ohio 43210, USA

Goddard Space Flight Center Code 922 Greenbelt, MD 20771, USA

Michael Barton

Paul D. Lowman Jr.

conductor material, etc., some research on trace elements in coal was actually stimulated by commercial interest. D. J. Swaine joined the Australian research institution of coal technology thirty years ago as a soil chemist. His experience is mainly based on trace element investigations predominantly of Australian coals which he compared with results from worldwide sampling. Swaine’s book summarizes the author’s 50 special publications combined with short reviews on information selected from a large set of more than 1500 references. Many readers will be interested in the mode of occurrence of trace elements in coal beds and their origin. The conformable results of several authors indicate that more than 70% of the total Ge, B, Be, Ga, Ti, and V concentrations in coal are associated with their organic fraction. The book could have benefitted