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Atlas of electron microscopy of clay minerals and their admixtures
314
BOOK REVIEWS
discussion of the reservoir aspects of carbonates with respect to oil and gas, is also of interest to anyone concerned with diagenesis in carbonates. For initial and secondary porosity and permeability within carbonates strongly influences, anti is influenced by, post-depositional phenomena of solution, re-precipitation, cementation, and so on. The last chapter, Carbonate rocks and palaeoclimatology in the biogeochemical history of the planet, by R. W. Fairbridge, is a provocative and stimulating discussion of the relationships of carbonate formation and the general history of the earth. Fairbridge makes clear the tentative nature of such a treatment, and after suitable caveats to the reader, attempts, in an interesting way, to summarize what we know about carbonates through geologic time. The author sees five revolutions in earth history relating to carbonate formation: the first appearance of life, the invention of photosynthesis, the initial secretion of calcareous skeletons, changes in p e o and p o during the Carboniferous, and finally the evolution of pelagic carbonate-secreting organisms in the Cretaceous. However much one might cavil over some of Fairbridge's assumptions or lines of reasoning, the discussion is thoughtful, and certainly deserves attention. The author is concerned, and correctly enough, that geologists consider the larger implications and significance of carbonate formation, for as he states, " . . . carbonates.., constitute a vital biogeochemical group that is intimately bound up with the nature and course of early physiologic evolution, of which scientists know little..." In summary, then, despite the shortcomings of several chapters in this book, it is clear that this volume provides an extremely useful summary of information, concepts, and unsolved problems within the field of sedimentary carbonates and the editors are to be congratulated for making this prodigious effort. L. F. LAPORTE(Providence, R. I.)
Atlas of Electron Microscopy of Clay Minerals and their Admixtures. H. BEUTELSPACHERand H. W. VAN DER MAREL. Elsevier, Amsterdam, 1967, 333 pp., 262 fig., 1 plate, Dfl. ll0.00. This book is the first of a series planned to give results of subjecting a selection of representative clay minerals to examination by a number of techniques: the present volume deals with electron microscopy, and future volumes will deal with infra red spectroscopy, X-ray diffraction, and differential thermal analysis, each of the four techniques being applied to the same set of samples. The danger of relying on only one technique for clay mineral work is well known, so that the full value of the series will only emerge when all of the volumes have been published. The volume on electron microscopy is certainly lavishly produced. It con-
Palaeogeography, Palaeoclimatol., Palaeoecol., 4 (1968) 305-317
BOOK REVIEWS
315
tains a great number of full page and half page prints of transmission and replica electron micrographs. The accompanying text is well set out and all of it is produced twice, once in English and again in German. The electron micrographs illustrate three classes of material: clay minerals and closely related layered silicates, non-clay minerals which occur as accessories in clays, and other miscellaneous but relevant substances. The first category includes the kaolinite group, serpentines, montmorillonite group, mica (illite) group, pyrophyllite, talc, chlorites, interstratified and expanded minerals, attapulgite, sepiolite, iron and aluminium oxides and hydroxides. The accessory minerals illustrated are: iron sulphides and polysulphides, forms of silica, carbonates and sulphates, and among the miscellaneous specimens are: glacial clays, volcanic ashes and diatoms. The book opens with sections which outline briefly the working principles of an electron microscope, and the principal methods of specimen preparation. The micrographs are presented in several series relating to the different mineral groups, and each series is preceded by brief notes on the main features of these groups under the headings "formula", "occurrence", "electron micrograph", and "general remarks". References to handbooks and papers in journals are given at the end of the book and are well-grouped according to subject matter, and these are followed by subject and author indices. The micrographs themselves are not taken from the literature, but have been produced specifically for the present work. Their quality is variable but on the whole good, if particle morphology alone is regarded as the object of the study. Clearly the authors have gone to considerable trouble over the organisation and production of this book, but, in the reviewer's opinion, it has serious shortcomings. These stem from excessive reliance on particle morphology, and the absence of even a single electron diffraction pattern. As pointed out by the authors, but only in a minor way, most modern electron microscopes can produce, by a simple adjustment, a selected area diffraction pattern as well as a micrograph from a given specimen, and this pattern can make a wealth of difference to the problem of identification. For example, the fibrous minerals sepiolite and chrysolite both have fibrous morphology but are readily distinguishable by their electron diffraction patterns. Among the platy minerals, antigorite, for example, gives a very distinctive electron diffraction pattern, and some accessory non-clay minerals with platy morphology give patterns which are very different from those of the clay minerals. It is true that crystals of several different kinds of platy clay mineral, when lying on their cleavage planes, will give rather similar electron diffraction patterns, but even here distinction may be possible if the patterns are subjected to careful measurement or if a specimen tilting device is employed. Using only the micrographs in this book, one would have great difficulty in distinguishing certain specimens of montmorillonite, illite, chlorite, hydrargillite, boehmite and haematite from each other. Palaeogeography, Palaeoclimatol., Palaeoecol., 4 (1968) 305-317
316
BOOK REVIEWS
The neglect of diffraction is regrettable also from another standpoint, that is, the extent to which diffraction phenomena are responsible for the appearance of the electron image. This means that diffraction contrast can easily be mistaken for density or thickness contrast and therefore misinterpreted. Becat~se of the above criticisms, and the very qualitative nature of the book implied all ~oo accurately by its sub-title "A Picture Atlas", it is felt that this will be the least useful of the planned series of four volumes. Its severe limitations on its own will be only partially relieved when it is joined by the others. J. ZUSSMAN (Manchester)
The Stratigraphy of the British Isles. D. H. RAYNER. Cambridge Univ. Press, London, 433 pp., 80 fig., 60 tables, 70 s. There has long been a niche for a comprehensive textbook on British stratigraphy suitable for the needs of the advanced undergraduate and as a general reference work for the professional geologist. Dr. Rayner's book is an attempt to fill this niche. Following an introductory chapter in which stratigraphical principles are dealt with rather cursorily, the various geological systems are considered successively in the usual way, but with a certain individuality of treatment. Thus the Dalradian is included with the Cambrian in Chapter 3, the Ordovician and Silurian (as also the Permian and Trias) are grouped together in a single chapter while the Carboniferous is held to warrant two chapters. In each case I feel the author to be amply justified. The book concludes with an epilogue dealing with a few detailed palaeogeographic interpretations and more general topics, an appendix giving stratigraphical divisions and zonal tables and an ample list of references, many of which are to recent work. The style of writing is lucid and economical, though perhaps rather dry for some tastes, and there is a refreshing absence of that sloppiness of thought and presentation which characterises so many books on historical geology. There are numerous neat and carefully drawn diagrams, though palaeogeographic maps are largely eschewed. The text is also illustrated by eight photographic plates of rather variable quality. While I welcome the inclusion of a detailed account of Irish stratigraphy, well integrated into the British picture, I regret that continental Europe is dealt with so perfunctorily, since without much extra writing the British Isles could have been fitted far more satisfactorily into the general European context and a more positive step taken to free British stratigraphy from its customary parochialism. To balance this, however, the subject of continental drift has not been balked and the author has made a most welcome effort to sink without trace
Palaeogeography, Palaeoclimatol., PalaeoecoL, 4 (1968) 305-317
BOOK REVIEWS
discussion of the reservoir aspects of carbonates with respect to oil and gas, is also of interest to anyone concerned with diagenesis in carbonates. For initial and secondary porosity and permeability within carbonates strongly influences, anti is influenced by, post-depositional phenomena of solution, re-precipitation, cementation, and so on. The last chapter, Carbonate rocks and palaeoclimatology in the biogeochemical history of the planet, by R. W. Fairbridge, is a provocative and stimulating discussion of the relationships of carbonate formation and the general history of the earth. Fairbridge makes clear the tentative nature of such a treatment, and after suitable caveats to the reader, attempts, in an interesting way, to summarize what we know about carbonates through geologic time. The author sees five revolutions in earth history relating to carbonate formation: the first appearance of life, the invention of photosynthesis, the initial secretion of calcareous skeletons, changes in p e o and p o during the Carboniferous, and finally the evolution of pelagic carbonate-secreting organisms in the Cretaceous. However much one might cavil over some of Fairbridge's assumptions or lines of reasoning, the discussion is thoughtful, and certainly deserves attention. The author is concerned, and correctly enough, that geologists consider the larger implications and significance of carbonate formation, for as he states, " . . . carbonates.., constitute a vital biogeochemical group that is intimately bound up with the nature and course of early physiologic evolution, of which scientists know little..." In summary, then, despite the shortcomings of several chapters in this book, it is clear that this volume provides an extremely useful summary of information, concepts, and unsolved problems within the field of sedimentary carbonates and the editors are to be congratulated for making this prodigious effort. L. F. LAPORTE(Providence, R. I.)
Atlas of Electron Microscopy of Clay Minerals and their Admixtures. H. BEUTELSPACHERand H. W. VAN DER MAREL. Elsevier, Amsterdam, 1967, 333 pp., 262 fig., 1 plate, Dfl. ll0.00. This book is the first of a series planned to give results of subjecting a selection of representative clay minerals to examination by a number of techniques: the present volume deals with electron microscopy, and future volumes will deal with infra red spectroscopy, X-ray diffraction, and differential thermal analysis, each of the four techniques being applied to the same set of samples. The danger of relying on only one technique for clay mineral work is well known, so that the full value of the series will only emerge when all of the volumes have been published. The volume on electron microscopy is certainly lavishly produced. It con-
Palaeogeography, Palaeoclimatol., Palaeoecol., 4 (1968) 305-317
BOOK REVIEWS
315
tains a great number of full page and half page prints of transmission and replica electron micrographs. The accompanying text is well set out and all of it is produced twice, once in English and again in German. The electron micrographs illustrate three classes of material: clay minerals and closely related layered silicates, non-clay minerals which occur as accessories in clays, and other miscellaneous but relevant substances. The first category includes the kaolinite group, serpentines, montmorillonite group, mica (illite) group, pyrophyllite, talc, chlorites, interstratified and expanded minerals, attapulgite, sepiolite, iron and aluminium oxides and hydroxides. The accessory minerals illustrated are: iron sulphides and polysulphides, forms of silica, carbonates and sulphates, and among the miscellaneous specimens are: glacial clays, volcanic ashes and diatoms. The book opens with sections which outline briefly the working principles of an electron microscope, and the principal methods of specimen preparation. The micrographs are presented in several series relating to the different mineral groups, and each series is preceded by brief notes on the main features of these groups under the headings "formula", "occurrence", "electron micrograph", and "general remarks". References to handbooks and papers in journals are given at the end of the book and are well-grouped according to subject matter, and these are followed by subject and author indices. The micrographs themselves are not taken from the literature, but have been produced specifically for the present work. Their quality is variable but on the whole good, if particle morphology alone is regarded as the object of the study. Clearly the authors have gone to considerable trouble over the organisation and production of this book, but, in the reviewer's opinion, it has serious shortcomings. These stem from excessive reliance on particle morphology, and the absence of even a single electron diffraction pattern. As pointed out by the authors, but only in a minor way, most modern electron microscopes can produce, by a simple adjustment, a selected area diffraction pattern as well as a micrograph from a given specimen, and this pattern can make a wealth of difference to the problem of identification. For example, the fibrous minerals sepiolite and chrysolite both have fibrous morphology but are readily distinguishable by their electron diffraction patterns. Among the platy minerals, antigorite, for example, gives a very distinctive electron diffraction pattern, and some accessory non-clay minerals with platy morphology give patterns which are very different from those of the clay minerals. It is true that crystals of several different kinds of platy clay mineral, when lying on their cleavage planes, will give rather similar electron diffraction patterns, but even here distinction may be possible if the patterns are subjected to careful measurement or if a specimen tilting device is employed. Using only the micrographs in this book, one would have great difficulty in distinguishing certain specimens of montmorillonite, illite, chlorite, hydrargillite, boehmite and haematite from each other. Palaeogeography, Palaeoclimatol., Palaeoecol., 4 (1968) 305-317
316
BOOK REVIEWS
The neglect of diffraction is regrettable also from another standpoint, that is, the extent to which diffraction phenomena are responsible for the appearance of the electron image. This means that diffraction contrast can easily be mistaken for density or thickness contrast and therefore misinterpreted. Becat~se of the above criticisms, and the very qualitative nature of the book implied all ~oo accurately by its sub-title "A Picture Atlas", it is felt that this will be the least useful of the planned series of four volumes. Its severe limitations on its own will be only partially relieved when it is joined by the others. J. ZUSSMAN (Manchester)
The Stratigraphy of the British Isles. D. H. RAYNER. Cambridge Univ. Press, London, 433 pp., 80 fig., 60 tables, 70 s. There has long been a niche for a comprehensive textbook on British stratigraphy suitable for the needs of the advanced undergraduate and as a general reference work for the professional geologist. Dr. Rayner's book is an attempt to fill this niche. Following an introductory chapter in which stratigraphical principles are dealt with rather cursorily, the various geological systems are considered successively in the usual way, but with a certain individuality of treatment. Thus the Dalradian is included with the Cambrian in Chapter 3, the Ordovician and Silurian (as also the Permian and Trias) are grouped together in a single chapter while the Carboniferous is held to warrant two chapters. In each case I feel the author to be amply justified. The book concludes with an epilogue dealing with a few detailed palaeogeographic interpretations and more general topics, an appendix giving stratigraphical divisions and zonal tables and an ample list of references, many of which are to recent work. The style of writing is lucid and economical, though perhaps rather dry for some tastes, and there is a refreshing absence of that sloppiness of thought and presentation which characterises so many books on historical geology. There are numerous neat and carefully drawn diagrams, though palaeogeographic maps are largely eschewed. The text is also illustrated by eight photographic plates of rather variable quality. While I welcome the inclusion of a detailed account of Irish stratigraphy, well integrated into the British picture, I regret that continental Europe is dealt with so perfunctorily, since without much extra writing the British Isles could have been fitted far more satisfactorily into the general European context and a more positive step taken to free British stratigraphy from its customary parochialism. To balance this, however, the subject of continental drift has not been balked and the author has made a most welcome effort to sink without trace
Palaeogeography, Palaeoclimatol., PalaeoecoL, 4 (1968) 305-317