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Analytical methods in geochemical prospecting
180 tion to the subject for many workers and students in the fields of pure and applied chemistry, earth sciences and engineering. F.G. THOMAS (Townsville, Qld.)
Analytical Methods in Geochemical Prospecting. W.K. Fletcher. Handbook of Exploration Geochemistry, 1. Elsevier Scientific Publishing Company, Amsterdam-Oxford--New York, N.Y., 1981, xii + 256 pp., Dfl. 140.00/
us$59.50. This is the first of seven volumes of the Handbook of Exploration Geochemistry, being published within the next few years. The volume has been written by W.K. Fletcher of the University of British Columbia, Vancouver, Canada, who is well known for his critical view of analytical methods. The book begins with the choice of the analytical methods, appropriate for the respective problem. Cost, precision, interferences, output (samples per man day) are discussed, as well analytical and organizational considerations, the necessary reliability and reproducibility and safety aspects as well as whether to install a field laboratory or put up with longer transport distances. An important chapter follows on the quality control in the laboratory, a sometimes not sufficiently considered task. The main part of the book deals with the methods of analyses, starting with the sample preparation and its different aspects in prospecting, at first with the possibility of contamination by the material of crushers, mills, etc. The main part of the sample preparation, drying, sieving, magnetic separation; etc., is given in a flow chart. Another paragraph deals with the preparation of water samples: kind of bottles, filtering, etc. The sample decomposition--solution techniques are the basis for any analytical result. Often more time is needed to dissolve a sample than for the determination of the elements. The techniques are shown in detail to enable the analyst to find the best compromise in each case, regarding time consumption, possible contaminations, extractions to separate special elements as well as many applications. The fundamentals of the analytical methods and their use are well described: colorimetry and related techniques (especially suited for field laboratories), atomic absorption spectrometry {including hydride and flameless techniques, e.g. for As, Hg), at present the most important method, emission spectroscopy including plasma methods, XRF, and electrochemical methods, especially ion sensitive electrodes. In an appendix colour photographs show colorimetric (dithizone) determinations and a plasma spectrum. In another appendix the preparation of standard solutions is given. The reference list contains about 500 citations,
181 all mentioned in the b o o k Only English written literature is cited, but from all over the world. Thus, for example, Russian literature is n o t mentioned, no disadvantage in analytical methods. The detailed subject is useful with its more than 750 terms. The reviewer f o u n d just one omission: There is no list of standard samples with their sources of supply. Over all, the volume is a good start of the Handbook of Exploration Geochemistry series. It is h a n d y from its size, and, with its clear style easily readible, also for those whose mother-tongue is not English. Fletcher's book can be r e c o m m e n d e d to everyone concerned with analytic tasks in exploration activities, as well as a chemist or as project leader. It will also find a good place in teaching geochemical exploration. Congratulations to author, editor and publisher. H. GUNDLACH (Hannover)
Precambrian Plate Tectonics. Alfred KrOner (Editor). Developments in Precambrian Geology, 4. Elsevier Scientific Publishing Company, Amsterdam--Oxford--New York, N.Y., 1981, xxi + 781 pp., Dfl. 380.00! US$185.25. This is an exciting book, because it focuses simultaneously on two of the most rapidly advancing fields in modern geology, namely global tectonics and the study of the Precambrian. Both fields owe their rapid growth to the extensive use of relatively new techniques, among which isotope geology (in particular the juxtaposition of different isotope systems like Nd--Sm, 87Sr--86Sr and Pb--Pb), trace element geochemistry and paleomagnetism must be mentioned. No less than 40 authors have contributed 28 chapters which have been grouped under General Reviews of Precambrian crustal evolution (4 chapters), Archean tectonics (6 chapters), Proterozoic tectonics (7 chapters, subdivided in lower and upper Proterozoic examples), Geochemistry and Isotope Geology (5 chapters), Precambrian paleomagnetism (4 chapters) and Precambrian metallogeny (2 chapters). Although the editor has done a good job in bringing together these authors and in ably editing their writings, not all chapters are of equal significance and quality. A less satisfactory style was noted particularly in the chapter by Taylor and McLennan on the rare earth evidence, as well as in the opening chapter by Windley. One example (p. 3), where Windley says: "... the long-term thermal and tectonic evolution of the earth must be related to the abundance and life span of these heat-producing isotopes". If one reads back, the last isotopes referred to are Rb--Sr and Sm-Nd which certainly did n o t greatly contribute to the thermal and tectonic evolution of the earth. A more general objection to Windley's statements is that he too easily assumes that comparable rock chemistries imply identical tectonic processes, and that he happily proceeds on this false basis to prove
Analytical Methods in Geochemical Prospecting. W.K. Fletcher. Handbook of Exploration Geochemistry, 1. Elsevier Scientific Publishing Company, Amsterdam-Oxford--New York, N.Y., 1981, xii + 256 pp., Dfl. 140.00/
us$59.50. This is the first of seven volumes of the Handbook of Exploration Geochemistry, being published within the next few years. The volume has been written by W.K. Fletcher of the University of British Columbia, Vancouver, Canada, who is well known for his critical view of analytical methods. The book begins with the choice of the analytical methods, appropriate for the respective problem. Cost, precision, interferences, output (samples per man day) are discussed, as well analytical and organizational considerations, the necessary reliability and reproducibility and safety aspects as well as whether to install a field laboratory or put up with longer transport distances. An important chapter follows on the quality control in the laboratory, a sometimes not sufficiently considered task. The main part of the book deals with the methods of analyses, starting with the sample preparation and its different aspects in prospecting, at first with the possibility of contamination by the material of crushers, mills, etc. The main part of the sample preparation, drying, sieving, magnetic separation; etc., is given in a flow chart. Another paragraph deals with the preparation of water samples: kind of bottles, filtering, etc. The sample decomposition--solution techniques are the basis for any analytical result. Often more time is needed to dissolve a sample than for the determination of the elements. The techniques are shown in detail to enable the analyst to find the best compromise in each case, regarding time consumption, possible contaminations, extractions to separate special elements as well as many applications. The fundamentals of the analytical methods and their use are well described: colorimetry and related techniques (especially suited for field laboratories), atomic absorption spectrometry {including hydride and flameless techniques, e.g. for As, Hg), at present the most important method, emission spectroscopy including plasma methods, XRF, and electrochemical methods, especially ion sensitive electrodes. In an appendix colour photographs show colorimetric (dithizone) determinations and a plasma spectrum. In another appendix the preparation of standard solutions is given. The reference list contains about 500 citations,
181 all mentioned in the b o o k Only English written literature is cited, but from all over the world. Thus, for example, Russian literature is n o t mentioned, no disadvantage in analytical methods. The detailed subject is useful with its more than 750 terms. The reviewer f o u n d just one omission: There is no list of standard samples with their sources of supply. Over all, the volume is a good start of the Handbook of Exploration Geochemistry series. It is h a n d y from its size, and, with its clear style easily readible, also for those whose mother-tongue is not English. Fletcher's book can be r e c o m m e n d e d to everyone concerned with analytic tasks in exploration activities, as well as a chemist or as project leader. It will also find a good place in teaching geochemical exploration. Congratulations to author, editor and publisher. H. GUNDLACH (Hannover)
Precambrian Plate Tectonics. Alfred KrOner (Editor). Developments in Precambrian Geology, 4. Elsevier Scientific Publishing Company, Amsterdam--Oxford--New York, N.Y., 1981, xxi + 781 pp., Dfl. 380.00! US$185.25. This is an exciting book, because it focuses simultaneously on two of the most rapidly advancing fields in modern geology, namely global tectonics and the study of the Precambrian. Both fields owe their rapid growth to the extensive use of relatively new techniques, among which isotope geology (in particular the juxtaposition of different isotope systems like Nd--Sm, 87Sr--86Sr and Pb--Pb), trace element geochemistry and paleomagnetism must be mentioned. No less than 40 authors have contributed 28 chapters which have been grouped under General Reviews of Precambrian crustal evolution (4 chapters), Archean tectonics (6 chapters), Proterozoic tectonics (7 chapters, subdivided in lower and upper Proterozoic examples), Geochemistry and Isotope Geology (5 chapters), Precambrian paleomagnetism (4 chapters) and Precambrian metallogeny (2 chapters). Although the editor has done a good job in bringing together these authors and in ably editing their writings, not all chapters are of equal significance and quality. A less satisfactory style was noted particularly in the chapter by Taylor and McLennan on the rare earth evidence, as well as in the opening chapter by Windley. One example (p. 3), where Windley says: "... the long-term thermal and tectonic evolution of the earth must be related to the abundance and life span of these heat-producing isotopes". If one reads back, the last isotopes referred to are Rb--Sr and Sm-Nd which certainly did n o t greatly contribute to the thermal and tectonic evolution of the earth. A more general objection to Windley's statements is that he too easily assumes that comparable rock chemistries imply identical tectonic processes, and that he happily proceeds on this false basis to prove