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Ring complex granites and anorogenic magmatism
Chemical Geology, 75 ( 1989 ) 145-149 Elsevier Science P u b l i s h e r s B.V., A m s t e r d a m - - P r i n t e d in T h e N e t h e r l a n d s
145
BOOK REVIEWS Ring Complex Granites and Anorogenic Magmatism. Bernard Bonin. North Oxford Academic Publishers Ltd., London, xiii+ 189 pp., UK £24.50 (hardback).
1986,
Bernard Bonin's book on granites was first published in French in 1982 by the Bureau de Recherches G~ologiques et Mini~res (BRGM): Les granites des complexes annulaires. This book has been revised, updated and translated into English by John Renouf. The preface of the English edition is by Russell Black. Bonin's book brings his conception of significant aspects of the geology, mineralogy and petrology of granites based on his own extensive studies of the anorogenic granite complexes of Corsica, on personal observations made in a number of granite provinces in Europe, Africa and North America, and of course on the literature on granites. The chapters have the following titles: (1) Structures and mode of emplacement; (2) Mineral and textural composition, (3) Geochemical data bearing on magmatic evolution and post-magmatic processes; (4) Origin and evolution of anorogenic alkaline magmatism; and (5) General conclusions. Bonin distinguishes three levels in an anorogenic granite complex: a caldera level at the surface, a ring complex at shallow depth, and a magmatic chamber at greater depth. The source of the mainly granitic magmas is to be found in an updoming of the asthenosphere. This scheme is with regard to the caldera and ring complex levels illustrated with examples from Corsica. The Pikes Peak granite, Colorado, is mentioned as an example in the section on the magmatic chamber. The rocks encountered in these complexes are mainly granites, while syenitic-monzonitic
rocks and gabbros are less prominent at the ring complex level which displays a distinct "Daly gab". Hypersolvus granites varying from fayalitehastingsite granites to arfvedsonite-albite granites are predominant; subsolvus biotite granites are more rare, but are characteristic for the Corsican complexes. The book brings valuable information about the mineralogy of the rocks and especially on amphiboles, feldspars and zircons. The mesoperthites of the hypersolvus rocks are considered to be the result of syncrystallization of ordered phases rather than products of unmixing of an unordered high-temperature phase. The magmatic evolution is, based on a study of major elements, the trace elements Rb, Sr, Ba, U, Th and Li, and some data on the Rb-Sr system and on initial strontium isotope ratios, considered to have been governed mainly by feldspar fractionation and by late fluids. The fluids are, of course, especially important with regard to the formation of the mineralizations that accompany a number of the complexes in Nigeria and elsewhere, but apparently not in Corsica. The magmas are considered to be of mantle origin but modified by material from the crust, especially through the interaction of fluids. There are no data on stable isotopes. This brief summary of contents and ideas cannot, of course, give full justice to the rich information found in the book which brings Bonin's personal, coherent picture and analysis of the anorogenic granites. The book marks the continuation of the rich French tradition in granite studies but with links to work carried out especially in North America and the U.K. There is practically no reference to the enor-
146
mous amount of work carried out in this field in the Soviet Union. W h e n this is said it should be added that the book here and there is difficult to read. The Corsican complexes are mentioned one by one, but there is very little information on the regional context and the relations of for instance gabbros and granites. Further there is no map with indication of the location of the complexes, only a small~scale geological map without geographical names. The figure captions are in many cases practically without explanation and there is not always accordance between figures and text. Furthermore, in some cases it is hard to follow the interpretation of the figures, this is especially the case with some of the geochemical diagrams. The use of the term "alkaline" is not quite clear and is not in agreement with the recommendations of the IUGS Subcommission on the Nomenclature and Classification of the Igneous Rocks, that alkaline igneous rocks are characterized by the modal or normative presence of feldspathoids a n d / o r alkalipyroxenes and -amphiboles. I have not had the French original available when reading the book and have thus not been able to check the translation and learn if unclear points here and there are due to the translation. The English text reads, however, well and I find that the translator has done an excellent job. Reminiscence of the French original is found in words such as hyperalkaline (instead of peralkaline), ATD (DTA) and precocious (early). The book is nicely produced and is an appetizing and also provoking presentation of the views and ideas of a leading granite specialist. Its circle of readers is accordingly the international community of granite geologists. H. SORENSEN (Copenhagen)
Advances in Soil Science, Vols. 4 and 5. B.A. Stewart (Editor). Springer-Verlag, Berlin, 1986, viii+226 and viii+ 242 pp., D M 128.00
and D M 138.00, respectively (hardbacks). One of the main functions of this series of volumes, of which numbers 4 and 5 are reviewed, is to scrutinize and identify principles that have practical applications in both developing and developed agriculture and in overlapping disciplines. It is the aim of the series to pitch the level of the contributions so that any scientist interested in natural resources and man's influence on them can, with modest effort, obtain a sound overall picture of a number of important issues. Land-use and, of course, misuse is shouldering a lot of the blame for much existing contamination of surface and groundwaters and, in a subtler manner, for long-term changes in the composition of the Earth's atmosphere. Many of the contributions to the volumes deal with such matters along with other environmental problems including soil erosion and various aspects of its control. Two of the chapters in Volume 4 are concerned very much with soil chemical problems, namely, the transfer of chemicals to runoff, including a modeling approach, and the longstanding matter of the impact of irrigation on the salinization and alkalization of soil and water, processes which have been instrumental in the fall of quite a number of civilisations down the ages. A contribution towards our understanding of the atmosphere centres on the emission of nitrous oxide from soils, which agriculturists regard as wasteful of nitrogen and atmosphere scientists view as harmful because nitrous oxide contributes towards the photochemically induced destruction of the protective layer of ozone. The most detailed chapter in Volume 4 is a concise history of Soil Physics written, to some extent anecdotally, around the personalities responsible for the development of much of the subject. In the preface to the book, the Editor of the series hopes that the particular article may stimulate others to write similar histories of other sectors of science. Volume 5 contains two contributions on the surface treatment of soils. One deals with the
145
BOOK REVIEWS Ring Complex Granites and Anorogenic Magmatism. Bernard Bonin. North Oxford Academic Publishers Ltd., London, xiii+ 189 pp., UK £24.50 (hardback).
1986,
Bernard Bonin's book on granites was first published in French in 1982 by the Bureau de Recherches G~ologiques et Mini~res (BRGM): Les granites des complexes annulaires. This book has been revised, updated and translated into English by John Renouf. The preface of the English edition is by Russell Black. Bonin's book brings his conception of significant aspects of the geology, mineralogy and petrology of granites based on his own extensive studies of the anorogenic granite complexes of Corsica, on personal observations made in a number of granite provinces in Europe, Africa and North America, and of course on the literature on granites. The chapters have the following titles: (1) Structures and mode of emplacement; (2) Mineral and textural composition, (3) Geochemical data bearing on magmatic evolution and post-magmatic processes; (4) Origin and evolution of anorogenic alkaline magmatism; and (5) General conclusions. Bonin distinguishes three levels in an anorogenic granite complex: a caldera level at the surface, a ring complex at shallow depth, and a magmatic chamber at greater depth. The source of the mainly granitic magmas is to be found in an updoming of the asthenosphere. This scheme is with regard to the caldera and ring complex levels illustrated with examples from Corsica. The Pikes Peak granite, Colorado, is mentioned as an example in the section on the magmatic chamber. The rocks encountered in these complexes are mainly granites, while syenitic-monzonitic
rocks and gabbros are less prominent at the ring complex level which displays a distinct "Daly gab". Hypersolvus granites varying from fayalitehastingsite granites to arfvedsonite-albite granites are predominant; subsolvus biotite granites are more rare, but are characteristic for the Corsican complexes. The book brings valuable information about the mineralogy of the rocks and especially on amphiboles, feldspars and zircons. The mesoperthites of the hypersolvus rocks are considered to be the result of syncrystallization of ordered phases rather than products of unmixing of an unordered high-temperature phase. The magmatic evolution is, based on a study of major elements, the trace elements Rb, Sr, Ba, U, Th and Li, and some data on the Rb-Sr system and on initial strontium isotope ratios, considered to have been governed mainly by feldspar fractionation and by late fluids. The fluids are, of course, especially important with regard to the formation of the mineralizations that accompany a number of the complexes in Nigeria and elsewhere, but apparently not in Corsica. The magmas are considered to be of mantle origin but modified by material from the crust, especially through the interaction of fluids. There are no data on stable isotopes. This brief summary of contents and ideas cannot, of course, give full justice to the rich information found in the book which brings Bonin's personal, coherent picture and analysis of the anorogenic granites. The book marks the continuation of the rich French tradition in granite studies but with links to work carried out especially in North America and the U.K. There is practically no reference to the enor-
146
mous amount of work carried out in this field in the Soviet Union. W h e n this is said it should be added that the book here and there is difficult to read. The Corsican complexes are mentioned one by one, but there is very little information on the regional context and the relations of for instance gabbros and granites. Further there is no map with indication of the location of the complexes, only a small~scale geological map without geographical names. The figure captions are in many cases practically without explanation and there is not always accordance between figures and text. Furthermore, in some cases it is hard to follow the interpretation of the figures, this is especially the case with some of the geochemical diagrams. The use of the term "alkaline" is not quite clear and is not in agreement with the recommendations of the IUGS Subcommission on the Nomenclature and Classification of the Igneous Rocks, that alkaline igneous rocks are characterized by the modal or normative presence of feldspathoids a n d / o r alkalipyroxenes and -amphiboles. I have not had the French original available when reading the book and have thus not been able to check the translation and learn if unclear points here and there are due to the translation. The English text reads, however, well and I find that the translator has done an excellent job. Reminiscence of the French original is found in words such as hyperalkaline (instead of peralkaline), ATD (DTA) and precocious (early). The book is nicely produced and is an appetizing and also provoking presentation of the views and ideas of a leading granite specialist. Its circle of readers is accordingly the international community of granite geologists. H. SORENSEN (Copenhagen)
Advances in Soil Science, Vols. 4 and 5. B.A. Stewart (Editor). Springer-Verlag, Berlin, 1986, viii+226 and viii+ 242 pp., D M 128.00
and D M 138.00, respectively (hardbacks). One of the main functions of this series of volumes, of which numbers 4 and 5 are reviewed, is to scrutinize and identify principles that have practical applications in both developing and developed agriculture and in overlapping disciplines. It is the aim of the series to pitch the level of the contributions so that any scientist interested in natural resources and man's influence on them can, with modest effort, obtain a sound overall picture of a number of important issues. Land-use and, of course, misuse is shouldering a lot of the blame for much existing contamination of surface and groundwaters and, in a subtler manner, for long-term changes in the composition of the Earth's atmosphere. Many of the contributions to the volumes deal with such matters along with other environmental problems including soil erosion and various aspects of its control. Two of the chapters in Volume 4 are concerned very much with soil chemical problems, namely, the transfer of chemicals to runoff, including a modeling approach, and the longstanding matter of the impact of irrigation on the salinization and alkalization of soil and water, processes which have been instrumental in the fall of quite a number of civilisations down the ages. A contribution towards our understanding of the atmosphere centres on the emission of nitrous oxide from soils, which agriculturists regard as wasteful of nitrogen and atmosphere scientists view as harmful because nitrous oxide contributes towards the photochemically induced destruction of the protective layer of ozone. The most detailed chapter in Volume 4 is a concise history of Soil Physics written, to some extent anecdotally, around the personalities responsible for the development of much of the subject. In the preface to the book, the Editor of the series hopes that the particular article may stimulate others to write similar histories of other sectors of science. Volume 5 contains two contributions on the surface treatment of soils. One deals with the