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Carbonatite-nephelinite volcanism. An African case history
Geochimica et Cosmochimica
Acta.1978. Vol. 42. p. 449. Pergamon Press. Printed in Great Britain
BOOK
REVIEW
Carhonatite-Nephelinite Volcanism. An African Case History, M. J. LE BAS, Wiley, 347 pp., 20 plates, 98 figs. $44.00. 1977. THE VOLUME is a culmination of a six-year field programme in Kenya (1963-1969). It collates the results of at least six Ph.D. theses with the accumulated knowledge of Dr. Le Bas and Professor B. C. King. It is the finest collection of field data and petrographic description available for the carbonatites of the Homa Bay district, Western Kenya. Although a limited geographical area, this group of carbonatites offers a wide range of erosion levels and compositional ranges. Consequently the book is the first detailed account of carbonatite variations within one tectonic region and is of fundamental rather than local importance. A general discussion of carbonatite-nephelinite provinces is followed by a summary of the Kenya Precambrian, and a discussion of alkalic rock nomenclature. The next eighteen chapters describe individual carbonatite complexes or eruptive centres laying great stress on field relations and petrography. There is a short summary of the geological history of the carbonatite province and then two chapters that discuss the theoretical aspects of carbonatite petrology and attempt to produce a petrogenetic scheme. Two appendices offer 41 K--Ar age determinations and about 250 chemical analyses of rocks. A well-chosen
449
collection of approximately 100 photographs illustrates the more important textures to be observed in the rocks of carbonatite complexes both in outcrop and in thin section. A bibliography of about 350 references (citations as recent as 1976) gives extensive coverage of the study region and includes many more general references. A particular value of this book is that it combines the work of a team of geologists who, broadly speaking, belong to the same school of thought. It has a unity often lacking in this type of book, and has the added advantage that virtually the whole book has been written by Dr. Le Bas in a consistently clear style. The specialist will find here that wealth of observational data on which all theoretical deduction and experimental study must be based. The average geologist knows little of these rocks, and it is doubly important that their precise detail be available. The geologist who desires a good solid description of what to expect in the field will find it here. It is a splendid effort and is produced to the high standards that one has learned to expect of Wiley. ~epu~t~ent of Geology University of Toronto Townto Canada
J.
GITTINS
Acta.1978. Vol. 42. p. 449. Pergamon Press. Printed in Great Britain
BOOK
REVIEW
Carhonatite-Nephelinite Volcanism. An African Case History, M. J. LE BAS, Wiley, 347 pp., 20 plates, 98 figs. $44.00. 1977. THE VOLUME is a culmination of a six-year field programme in Kenya (1963-1969). It collates the results of at least six Ph.D. theses with the accumulated knowledge of Dr. Le Bas and Professor B. C. King. It is the finest collection of field data and petrographic description available for the carbonatites of the Homa Bay district, Western Kenya. Although a limited geographical area, this group of carbonatites offers a wide range of erosion levels and compositional ranges. Consequently the book is the first detailed account of carbonatite variations within one tectonic region and is of fundamental rather than local importance. A general discussion of carbonatite-nephelinite provinces is followed by a summary of the Kenya Precambrian, and a discussion of alkalic rock nomenclature. The next eighteen chapters describe individual carbonatite complexes or eruptive centres laying great stress on field relations and petrography. There is a short summary of the geological history of the carbonatite province and then two chapters that discuss the theoretical aspects of carbonatite petrology and attempt to produce a petrogenetic scheme. Two appendices offer 41 K--Ar age determinations and about 250 chemical analyses of rocks. A well-chosen
449
collection of approximately 100 photographs illustrates the more important textures to be observed in the rocks of carbonatite complexes both in outcrop and in thin section. A bibliography of about 350 references (citations as recent as 1976) gives extensive coverage of the study region and includes many more general references. A particular value of this book is that it combines the work of a team of geologists who, broadly speaking, belong to the same school of thought. It has a unity often lacking in this type of book, and has the added advantage that virtually the whole book has been written by Dr. Le Bas in a consistently clear style. The specialist will find here that wealth of observational data on which all theoretical deduction and experimental study must be based. The average geologist knows little of these rocks, and it is doubly important that their precise detail be available. The geologist who desires a good solid description of what to expect in the field will find it here. It is a splendid effort and is produced to the high standards that one has learned to expect of Wiley. ~epu~t~ent of Geology University of Toronto Townto Canada
J.
GITTINS