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Glacigenic Sediments
44
BOOK REVIEWS
Heavy minerals M.A. Mange and H.F.W. Maurer, 1991. Heavy Minerals in Colour. Chapman and Hall, London, Hardcover, 147 pp. Price £50.-. ISBN 0-412-43910-7. Much has been written in the last decades on heavy minerals. Yet, there is hardly any literature available that can be considered as a handbook on this subject, especially since publications with sufficient full-colour illustrations are fairly expensive, which apparently made publishers reluctant. Chapman and Hall now accepted this challenge and made it possible for Maria Mange and Heinz Maurer to create this overview that is meant as a manual for both students and research workers. The book shows the disadvantages of such a broad target group: fundamental data are presented together with interesting details that are derived partly from specialised literature. These disadvantages are, however, of minor importance if compared to the advantages of the book. One of the advantages is formed by the restrictions that the authors imposed to themselves: the data are almost entirely limited to microscopic analysis, only transparent species are dealt with, and no attempt has been made to cover all different species (but the 61 most important species are described and depicted in detail). The text starts w~th a general overview of heavy-mineral analysis. It mentions the credits given to this sedimentological topic in the first half of the century, the disappointment felt later when heavy minerals were no longer considered of much practical use, and the renewed interest in the last few years. Topics dealt with include the influence on analytical results of grain size, hydraulic sedimentary conditions, chemical stability and source rocks. There ~s also much attention paid to the sampling methods, preparation procedures (including separation from the light minerals), and counting methods. Apart from the various microscopical techniques that are
described, some auxiliary methods are also shortly mentioned. The text continues with discussions on the presentation of the numerical results of the analyses, and on the significance of these analyses for current research. The second part of the book is entirely devoted to the descriptions of 61 principal species, grouped into the categories silicates (with subgroups epidotes, pyroxenes, amphiboles and micas), oxides, sulphides, sulphates, carbonates, phospates and a group "miscellaneous". Each of the species is described and depicted (in colour) on at least one full page (some have 2 or 3 pages). All descriptions follow the same systematic approach with: grain form in sediments, colour, pleochroism, birefringence, extinction, interference figure, elongation, distinguishing features (with remarks on species that have more or less comparable characteristics), occurrence and further remarks. The same grains of each species are shown both in plain light and with crossed mchols. The colour photographs are outstanding. This also holds for the printing and layout of the book. There are few "printing" errors (e.g., the heading "elongation" instead of "extinction" on p. 39). Both the authors and the publisher did a good job. The price of the book is relatively high (as a result of the abundant colour photographs), but the book is worth the price. At least for those who have not yet a profound knowledge of heavy minerals. This category will not find much new information, but even they may consider the book as a good opportunity to fresh up their knowledge of species that they do not encounter on a daily basis. A.J. van Loon, Oosterbeek
Sedimentology K. Brodzikowski and A.J. van Loon, 1991. Glacigenic Sediments. Developments in Sedimentology 49, Elsevier, Amsterdam, 688 pp. Price: US$135.50/Dfl.230 ISBN 0-44488307-X.
BOOK REVIEWS
There has long been a need for a glacial sedimentological text suitable for the needs of Quaternary and pre-Quaternary glacial geologists, so the arrival of this book was met with anticipation. The authors are well qualified to write this book, having worked extensively on the glacial deposits of Poland and the Netherlands, as well as in other parts of the world. The authors' aims have been to provide an overview of glacial sediments for those involved in fundamental and applied research an the field of glacial sedimentology. Their approach has been to establish a generally applicable, sedimentologically based, genetic nomenclature in the hope that it will be widely adopted. The book is intended to help in the description, interpretation, and examination of the interrelationships and palaeographical development of glacial sediments. The first quarter of the book provides introductory material, including a short historical review and brief discussions concerning the nomenclature of glacial sediments and landforms, the nature of sediments in the glacial environment, glacigenic facies and facies models. About two-thirds of the book describes glacial sediments according to an elaborate classification. Four levels of subdivision are used, and these are coded. The first level distinguishes glacial from periglacial environments (although the use of the term "periglacial" in this book differs from most accepted usage); the second level distinguishes subenvironments in relation to the ice cap; the third level refers to facies based on the principal processes of deposition; and the fourth level indicates specific mechanisms within a particular facies. The end result is complicated; for example, a supraglacial ablation till has the code I-A-I-b% Fortunately, there are good tables and figures, especially flow charts, which show the relationships between the different categories of sediment. Certain important aspects of glacial sedimentology receive only light treatment. Glaciomarine sediments receive little atten-
45
tion, and the models presented do not take account of recent developments in understanding the role of sub-ice shelf freeze-on of saline water, or the importance of the biogenic component (especially diatoms) in offshore glaciomarine sediments. There is little on the role of ice dynamics in sedimentation, the extent of ice, stratigraphy and palaeontology of glacial sediments, sea level changes, the importance of glacial sediments in the geological record (although more than in most books), nor of the modification of sediments by glacio-tectonic processes. The book would have benefited from more rigorous checking, especially by a native English speaker. The style is somewhat cumbersome and stilted, and odd terms like "inventorising", "terminoglacial", "thermosubrosion", "morainization", and "eternal glacial ice" (for an ice shelf) crop up throughout the text. The text is exceedingly well referenced, but this can be annoying because the text in places is totally disrupted. The layout of the text is unimaginative and the lack of numbering of the chapters does not allow for easy reference. There are also numerous spelling errors, notably of the names of people and places (e.g. Lampluch for Lamplugh, Carrey for Carey, Barett for Barrett, Dunidin for Dunedin). Several of the photographs are miscaptioned, e.g. in Figure 68 Chamonix is placed in Switzerland, not France; in Figure 84 the reference is to the Bernina Alps in Italy, but the glacier pictured is on the other side of the range in Switzerland; and Figure 224 is a view of Hornsund in Spitsbergen, not of West Greenland. How well does this book meet the requirements of the glacial sedimentologist? In my view the subject matter is not presented in the most effective manner. The book is centred around a complex genetic classification of the sediments. One is first presented with interpreted sediments and the descriptions of the facies follows their grouping into genetic categories. I would have preferred the description to come first. Otherwise, how does the uninitiated, confronted with, say, a
4(3
BOOK REVIEWS
massive diamictite use this book to find how it was deposited? I think he will find it difficult. Even the experienced researcher will need a lot of patience to wade through all the relevant material. The authors hope that their classification scheme will be widely adopted, so as to facilitate communication. I have some doubts as to whether this will happen, partly because of the complexity of the scheme, and partly because there are marked differences from internationally agreed classifications proposed by the International Quaternary Association. Despite the above reservations, there is no doubt that the book is a mine of information and every glacial sedimentologist will find it useful. As a lead-in to other literature, and in particular to that from Eastern Europe, this book is invaluable, for there must be some 2300 references. Best of all is the high quality and range of photographs from contemporary and Quaternary environments of the wide range of glacigenic facies. Michael J. Hambrey, Liverpool
Economic Geology G. Bfirdossy and G.J.J. Aleva. Lateritic Batocttes. Developments in Economic Geology, 27. Elsevier, Amsterdam and Akad6miai Kiad6, Budapest. 624 pp. US$151.25. ISBN 0-44498811-4 Lateritic bauxite is the aluminous endmember of the family of lateritic rocks (which themselves are autochthonous tropical regoliths and soils developed on aluminous bedrock), transitional to lateritic ferrite and lateritic kaolin. It is the principal variety of the hydrated alumina ores of aluminium (88% of global resources). The two other mineralogically comparable but genetically different varieties: the (1) Tikhvin-type bauxites ( = detrital bauxite deposits overlying the eroded surface of alumosilicate rocks) and the (2) karst bauxites (bauxites overlying karstified surface of carbonate rocks), are
not discussed here. The (1), however, represent only 0.5% of the global bauxite resources; the (2) represents 11.5%. Karst bauxites have already been exhaustively reviewed in the earlier book by the senior author (B~rdossy, 1982). The present book has three parts: the general part (202 pp.) is followed by a systematic description of lateritic regions of the world (292 pp), and concluded by a part discussing industrial exploitation. The general part provides definitions, review of past research, classifications and nomenclature, structures and textures, mineralogy, physical chemistry and thermodynamics, genetic ideas, economic aspects, lithology and geochemistry. The material is a mixture of existing published data; data and observations collected by the authors in the field with much oral communication; and new research contributions. Out of the many bits and pieces of new information one might mention the interesting subdivision of allochthonous exolaterites (1: lateritoids precipitated from solutions, 2: clastic resedimented lateritoids, 3: transitional karst bauxites); the description of alveolar-tabular structures attributed to termite activity; and others. The regional part covers much of the Cainozoic tropical belt, and minor scattered relict deposits as old as Carboniferous outside it. Every area described contains a brief geological introduction, geomorphology, bauxite description, exploration status and ore resources. The reviews contain maps, profiles, composition graphs and histograms. The coverage is exhaustive but not exhausting. Many hard-to-know and exotic districts as in Venezuela, Guinea, Madagascar, Indonesia, Vietnam (3 billion tonnes of possible bauxite reserves!), Poland and Russia (Carboniferous bauxites), are described. The last part deals with processing technology, prospecting methods, analytical methods, grade and tonnage estimates and mining. The book is concluded by 17 pages of references, indexes, and by 16 plates of colour photographs.
BOOK REVIEWS
Heavy minerals M.A. Mange and H.F.W. Maurer, 1991. Heavy Minerals in Colour. Chapman and Hall, London, Hardcover, 147 pp. Price £50.-. ISBN 0-412-43910-7. Much has been written in the last decades on heavy minerals. Yet, there is hardly any literature available that can be considered as a handbook on this subject, especially since publications with sufficient full-colour illustrations are fairly expensive, which apparently made publishers reluctant. Chapman and Hall now accepted this challenge and made it possible for Maria Mange and Heinz Maurer to create this overview that is meant as a manual for both students and research workers. The book shows the disadvantages of such a broad target group: fundamental data are presented together with interesting details that are derived partly from specialised literature. These disadvantages are, however, of minor importance if compared to the advantages of the book. One of the advantages is formed by the restrictions that the authors imposed to themselves: the data are almost entirely limited to microscopic analysis, only transparent species are dealt with, and no attempt has been made to cover all different species (but the 61 most important species are described and depicted in detail). The text starts w~th a general overview of heavy-mineral analysis. It mentions the credits given to this sedimentological topic in the first half of the century, the disappointment felt later when heavy minerals were no longer considered of much practical use, and the renewed interest in the last few years. Topics dealt with include the influence on analytical results of grain size, hydraulic sedimentary conditions, chemical stability and source rocks. There ~s also much attention paid to the sampling methods, preparation procedures (including separation from the light minerals), and counting methods. Apart from the various microscopical techniques that are
described, some auxiliary methods are also shortly mentioned. The text continues with discussions on the presentation of the numerical results of the analyses, and on the significance of these analyses for current research. The second part of the book is entirely devoted to the descriptions of 61 principal species, grouped into the categories silicates (with subgroups epidotes, pyroxenes, amphiboles and micas), oxides, sulphides, sulphates, carbonates, phospates and a group "miscellaneous". Each of the species is described and depicted (in colour) on at least one full page (some have 2 or 3 pages). All descriptions follow the same systematic approach with: grain form in sediments, colour, pleochroism, birefringence, extinction, interference figure, elongation, distinguishing features (with remarks on species that have more or less comparable characteristics), occurrence and further remarks. The same grains of each species are shown both in plain light and with crossed mchols. The colour photographs are outstanding. This also holds for the printing and layout of the book. There are few "printing" errors (e.g., the heading "elongation" instead of "extinction" on p. 39). Both the authors and the publisher did a good job. The price of the book is relatively high (as a result of the abundant colour photographs), but the book is worth the price. At least for those who have not yet a profound knowledge of heavy minerals. This category will not find much new information, but even they may consider the book as a good opportunity to fresh up their knowledge of species that they do not encounter on a daily basis. A.J. van Loon, Oosterbeek
Sedimentology K. Brodzikowski and A.J. van Loon, 1991. Glacigenic Sediments. Developments in Sedimentology 49, Elsevier, Amsterdam, 688 pp. Price: US$135.50/Dfl.230 ISBN 0-44488307-X.
BOOK REVIEWS
There has long been a need for a glacial sedimentological text suitable for the needs of Quaternary and pre-Quaternary glacial geologists, so the arrival of this book was met with anticipation. The authors are well qualified to write this book, having worked extensively on the glacial deposits of Poland and the Netherlands, as well as in other parts of the world. The authors' aims have been to provide an overview of glacial sediments for those involved in fundamental and applied research an the field of glacial sedimentology. Their approach has been to establish a generally applicable, sedimentologically based, genetic nomenclature in the hope that it will be widely adopted. The book is intended to help in the description, interpretation, and examination of the interrelationships and palaeographical development of glacial sediments. The first quarter of the book provides introductory material, including a short historical review and brief discussions concerning the nomenclature of glacial sediments and landforms, the nature of sediments in the glacial environment, glacigenic facies and facies models. About two-thirds of the book describes glacial sediments according to an elaborate classification. Four levels of subdivision are used, and these are coded. The first level distinguishes glacial from periglacial environments (although the use of the term "periglacial" in this book differs from most accepted usage); the second level distinguishes subenvironments in relation to the ice cap; the third level refers to facies based on the principal processes of deposition; and the fourth level indicates specific mechanisms within a particular facies. The end result is complicated; for example, a supraglacial ablation till has the code I-A-I-b% Fortunately, there are good tables and figures, especially flow charts, which show the relationships between the different categories of sediment. Certain important aspects of glacial sedimentology receive only light treatment. Glaciomarine sediments receive little atten-
45
tion, and the models presented do not take account of recent developments in understanding the role of sub-ice shelf freeze-on of saline water, or the importance of the biogenic component (especially diatoms) in offshore glaciomarine sediments. There is little on the role of ice dynamics in sedimentation, the extent of ice, stratigraphy and palaeontology of glacial sediments, sea level changes, the importance of glacial sediments in the geological record (although more than in most books), nor of the modification of sediments by glacio-tectonic processes. The book would have benefited from more rigorous checking, especially by a native English speaker. The style is somewhat cumbersome and stilted, and odd terms like "inventorising", "terminoglacial", "thermosubrosion", "morainization", and "eternal glacial ice" (for an ice shelf) crop up throughout the text. The text is exceedingly well referenced, but this can be annoying because the text in places is totally disrupted. The layout of the text is unimaginative and the lack of numbering of the chapters does not allow for easy reference. There are also numerous spelling errors, notably of the names of people and places (e.g. Lampluch for Lamplugh, Carrey for Carey, Barett for Barrett, Dunidin for Dunedin). Several of the photographs are miscaptioned, e.g. in Figure 68 Chamonix is placed in Switzerland, not France; in Figure 84 the reference is to the Bernina Alps in Italy, but the glacier pictured is on the other side of the range in Switzerland; and Figure 224 is a view of Hornsund in Spitsbergen, not of West Greenland. How well does this book meet the requirements of the glacial sedimentologist? In my view the subject matter is not presented in the most effective manner. The book is centred around a complex genetic classification of the sediments. One is first presented with interpreted sediments and the descriptions of the facies follows their grouping into genetic categories. I would have preferred the description to come first. Otherwise, how does the uninitiated, confronted with, say, a
4(3
BOOK REVIEWS
massive diamictite use this book to find how it was deposited? I think he will find it difficult. Even the experienced researcher will need a lot of patience to wade through all the relevant material. The authors hope that their classification scheme will be widely adopted, so as to facilitate communication. I have some doubts as to whether this will happen, partly because of the complexity of the scheme, and partly because there are marked differences from internationally agreed classifications proposed by the International Quaternary Association. Despite the above reservations, there is no doubt that the book is a mine of information and every glacial sedimentologist will find it useful. As a lead-in to other literature, and in particular to that from Eastern Europe, this book is invaluable, for there must be some 2300 references. Best of all is the high quality and range of photographs from contemporary and Quaternary environments of the wide range of glacigenic facies. Michael J. Hambrey, Liverpool
Economic Geology G. Bfirdossy and G.J.J. Aleva. Lateritic Batocttes. Developments in Economic Geology, 27. Elsevier, Amsterdam and Akad6miai Kiad6, Budapest. 624 pp. US$151.25. ISBN 0-44498811-4 Lateritic bauxite is the aluminous endmember of the family of lateritic rocks (which themselves are autochthonous tropical regoliths and soils developed on aluminous bedrock), transitional to lateritic ferrite and lateritic kaolin. It is the principal variety of the hydrated alumina ores of aluminium (88% of global resources). The two other mineralogically comparable but genetically different varieties: the (1) Tikhvin-type bauxites ( = detrital bauxite deposits overlying the eroded surface of alumosilicate rocks) and the (2) karst bauxites (bauxites overlying karstified surface of carbonate rocks), are
not discussed here. The (1), however, represent only 0.5% of the global bauxite resources; the (2) represents 11.5%. Karst bauxites have already been exhaustively reviewed in the earlier book by the senior author (B~rdossy, 1982). The present book has three parts: the general part (202 pp.) is followed by a systematic description of lateritic regions of the world (292 pp), and concluded by a part discussing industrial exploitation. The general part provides definitions, review of past research, classifications and nomenclature, structures and textures, mineralogy, physical chemistry and thermodynamics, genetic ideas, economic aspects, lithology and geochemistry. The material is a mixture of existing published data; data and observations collected by the authors in the field with much oral communication; and new research contributions. Out of the many bits and pieces of new information one might mention the interesting subdivision of allochthonous exolaterites (1: lateritoids precipitated from solutions, 2: clastic resedimented lateritoids, 3: transitional karst bauxites); the description of alveolar-tabular structures attributed to termite activity; and others. The regional part covers much of the Cainozoic tropical belt, and minor scattered relict deposits as old as Carboniferous outside it. Every area described contains a brief geological introduction, geomorphology, bauxite description, exploration status and ore resources. The reviews contain maps, profiles, composition graphs and histograms. The coverage is exhaustive but not exhausting. Many hard-to-know and exotic districts as in Venezuela, Guinea, Madagascar, Indonesia, Vietnam (3 billion tonnes of possible bauxite reserves!), Poland and Russia (Carboniferous bauxites), are described. The last part deals with processing technology, prospecting methods, analytical methods, grade and tonnage estimates and mining. The book is concluded by 17 pages of references, indexes, and by 16 plates of colour photographs.