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The evolution of the crystalline rocks
88 One would have expected something more of a b o o k published in 1977. However, if one has this very clear definition in mind "the b o o k only discusses literally true hydrothermal deposits", it is of high quality. Following the general discussion case studies are reported from: (1) Canada. (2) United States. (3) Australia (Darwin Region and Mary Kathleen). (4) Central Europe. (5) Western Europe. (6) Gabon. (7) South West Africa (R0ssing Deposit). (8) Zaire. Bearing in mind the restriction on the scope of the b o o k which is very clearly defined by the authors themselves, it is very strongly r e c o m m e n d e d reading. It is a necessary reference source for everybody working or interested in uranium geochemistry. The b o o k is number six in Elsevier's series on Developments in Economic Geology. It very clearly defends its place and it is to be h o p e d that this series continues along the lines so far marked out. KNUT S. HEIER (Trondheim)
The Evolution o f the Crystalline Rocks. D.K. Bailey and R. Macdonald (Editors). Academic Press Ltd., London, 1976, 484 pp., UK £ 1 6 . 0 0 / U S $35.00. This b o o k is described by the editors as a sequel to Bowen's classic The Evolution o f the Igneous Rocks (1928), and it represents "a team effort to bridge that gap" between Bowen's b o o k and modern developments in experimental petrology. This task was a vast one and decisions had to be made regarding which rock groups and systems would be discussed. Readers looking for a comprehensive treatment will be disappointed to find little relating to the broad area of basic magmatism, a topic the editors feel "is more than adequately represented in recent literature". Also omitted is any systematic discussion of mantle petrology. What is covered includes the major groups of metamorphic rocks and the experimental petrology of granites and alkaline rocks. Part I of the b o o k (97 pp.), by Bailey, includes a brief introduction to the methods of experimental petrology followed by a lengthy discussion of the uses of phase diagrams. The latter includes a particularly good treatment of solid--solid equilibria and of the influences of vapour phases on solid and soli d - l i q u i d phase relations. A central theme for the b o o k is established in the warnings accompanying the discussion of the difficulties inherent in diagrammatic portrayal of p o l y c o m p o n e n t systems and of the ambiguities of various
89
reduction methods (e.g. pseudo-system diagrams and projections). Throughout the b o o k the reader is repeatedly cautioned against the pitfalls of a tooready acceptance of the results of experiments and of the direct application (too often careless) of these to complex natural systems. Bailey's discussion establishes an excellent framework for the following chapters. Part IIA comprises three chapters on metamorphic rocks, the first of which (86 pp.), is by R.C. N e w t o n and W.S. Fyfe and deals with high-pressure metamorphism. This chapter presents a systematic review of the experimental p e trology of blueschists with less attention (regrettably) to eclogites and highpressure granulites. Nicely brought into focus -- with an appropriate mix of detail and general summary -- are the many problems that prevail in the interpretation of the physical conditions of high-pressure metamorphism on the basis of mineral assemblages and experimentally studied reactions. Experimental problems are made abundantly clear as the authors exhibit (and encourage) a healthy skepticism (without being cynical). They point o u t adequately where knowledge is lacking and indicate some potentially profitable avenues for future research. The second chapter (73 pp.), by H.J. Greenwood on metamorphism at moderate temperatures and pressures, contains an excellent statement regarding proper use of the facies concept and includes a useful discussion of the influences of the fluid phase (too often ignored) on metamorphic mineral stabilities. The discussion of oxide and sulfide equilibria is most interesting as these topics are frequently neglected in other treatments. One could wish Greenwood had included more examples of applications to natural rocks to go along with his lengthy catalogue of numerous experimentally studied reactions. The third chapter (71 pp.), by W. Schreyer, concerns the experimental petrology of high-temperature and low-pressure metamorphism. Schreyer's approach of presenting the complex phase relations in graphic form and in the text itemizing "the main features and their petrologic implications" is particularly useful to the reader in providing a readily obtainable overview along with the opportunity to examine specific details according to the reader's interests. More attention could have been paid to natural occurrences. Part IIB includes t w o chapters on igneous rocks. The first (84 pp.), by W.C. Luth, deals with granitic rocks and centers on the haplogranite system. A strong point of this chapter is the careful attention devoted to conditions wherein systems are unsaturated with respect to aqueous vapour and how these differ from H20-saturated phase relations. It is unfortunate that more space could n o t have been allocated to developments in granodioritic and related systems. The final chapter (51 pp.), by Bailey on alkaline rocks, aims "to highlight the major unsolved problems, and to ask what new experiments are needed". That such problems are manifold becomes abundantly clear. Peralkaline oversaturated, feldspathoidal, and peralkaline feldspathoidal felsic rock systems
90
are discussed, along with feldspar-free mafic alkaline rocks. An interesting discussion of peralkalinity and its d e v e l o p m e n t in magma systems is provided in which answers are n o t presented but interesting questions are raised. In summary, the b o o k successfully serves as intended as "a poi nt of entry into the m o d e r n l i t e r a t u r e " while also being to a limited e x t e n t a "basic t ext in applied experimental p e t r o l o g y " . Although somewhat uneven as all edited volumes tend to be, the b o o k is less so than many and holds fairly well to its central themes. It is u n f o r t u n a t e in a sense that the editors have invited comparison to Bowen's classic work because it is unfair to expect the degree of perceptiveness and lucidity of presentation of Bowen from any ot her source. Those who approach the b o o k n o t expecting this will n o t be disappointed and will find a useful reference volume for the systems discussed. BENJAMIN N. POWELL (Houston, Texas)
Erratum Mossman, D.J. and Hefferman, K.J., 1978. On the possible primary precipitation of atacamite and other metal chlorides in certain stratabound deposits. Chem. Geol., 21: 151--159.
Table I, page 155, line 4 f r om b o t t o m . The figure
"[S- ] "
should be "[H2 S] "
The Evolution o f the Crystalline Rocks. D.K. Bailey and R. Macdonald (Editors). Academic Press Ltd., London, 1976, 484 pp., UK £ 1 6 . 0 0 / U S $35.00. This b o o k is described by the editors as a sequel to Bowen's classic The Evolution o f the Igneous Rocks (1928), and it represents "a team effort to bridge that gap" between Bowen's b o o k and modern developments in experimental petrology. This task was a vast one and decisions had to be made regarding which rock groups and systems would be discussed. Readers looking for a comprehensive treatment will be disappointed to find little relating to the broad area of basic magmatism, a topic the editors feel "is more than adequately represented in recent literature". Also omitted is any systematic discussion of mantle petrology. What is covered includes the major groups of metamorphic rocks and the experimental petrology of granites and alkaline rocks. Part I of the b o o k (97 pp.), by Bailey, includes a brief introduction to the methods of experimental petrology followed by a lengthy discussion of the uses of phase diagrams. The latter includes a particularly good treatment of solid--solid equilibria and of the influences of vapour phases on solid and soli d - l i q u i d phase relations. A central theme for the b o o k is established in the warnings accompanying the discussion of the difficulties inherent in diagrammatic portrayal of p o l y c o m p o n e n t systems and of the ambiguities of various
89
reduction methods (e.g. pseudo-system diagrams and projections). Throughout the b o o k the reader is repeatedly cautioned against the pitfalls of a tooready acceptance of the results of experiments and of the direct application (too often careless) of these to complex natural systems. Bailey's discussion establishes an excellent framework for the following chapters. Part IIA comprises three chapters on metamorphic rocks, the first of which (86 pp.), is by R.C. N e w t o n and W.S. Fyfe and deals with high-pressure metamorphism. This chapter presents a systematic review of the experimental p e trology of blueschists with less attention (regrettably) to eclogites and highpressure granulites. Nicely brought into focus -- with an appropriate mix of detail and general summary -- are the many problems that prevail in the interpretation of the physical conditions of high-pressure metamorphism on the basis of mineral assemblages and experimentally studied reactions. Experimental problems are made abundantly clear as the authors exhibit (and encourage) a healthy skepticism (without being cynical). They point o u t adequately where knowledge is lacking and indicate some potentially profitable avenues for future research. The second chapter (73 pp.), by H.J. Greenwood on metamorphism at moderate temperatures and pressures, contains an excellent statement regarding proper use of the facies concept and includes a useful discussion of the influences of the fluid phase (too often ignored) on metamorphic mineral stabilities. The discussion of oxide and sulfide equilibria is most interesting as these topics are frequently neglected in other treatments. One could wish Greenwood had included more examples of applications to natural rocks to go along with his lengthy catalogue of numerous experimentally studied reactions. The third chapter (71 pp.), by W. Schreyer, concerns the experimental petrology of high-temperature and low-pressure metamorphism. Schreyer's approach of presenting the complex phase relations in graphic form and in the text itemizing "the main features and their petrologic implications" is particularly useful to the reader in providing a readily obtainable overview along with the opportunity to examine specific details according to the reader's interests. More attention could have been paid to natural occurrences. Part IIB includes t w o chapters on igneous rocks. The first (84 pp.), by W.C. Luth, deals with granitic rocks and centers on the haplogranite system. A strong point of this chapter is the careful attention devoted to conditions wherein systems are unsaturated with respect to aqueous vapour and how these differ from H20-saturated phase relations. It is unfortunate that more space could n o t have been allocated to developments in granodioritic and related systems. The final chapter (51 pp.), by Bailey on alkaline rocks, aims "to highlight the major unsolved problems, and to ask what new experiments are needed". That such problems are manifold becomes abundantly clear. Peralkaline oversaturated, feldspathoidal, and peralkaline feldspathoidal felsic rock systems
90
are discussed, along with feldspar-free mafic alkaline rocks. An interesting discussion of peralkalinity and its d e v e l o p m e n t in magma systems is provided in which answers are n o t presented but interesting questions are raised. In summary, the b o o k successfully serves as intended as "a poi nt of entry into the m o d e r n l i t e r a t u r e " while also being to a limited e x t e n t a "basic t ext in applied experimental p e t r o l o g y " . Although somewhat uneven as all edited volumes tend to be, the b o o k is less so than many and holds fairly well to its central themes. It is u n f o r t u n a t e in a sense that the editors have invited comparison to Bowen's classic work because it is unfair to expect the degree of perceptiveness and lucidity of presentation of Bowen from any ot her source. Those who approach the b o o k n o t expecting this will n o t be disappointed and will find a useful reference volume for the systems discussed. BENJAMIN N. POWELL (Houston, Texas)
Erratum Mossman, D.J. and Hefferman, K.J., 1978. On the possible primary precipitation of atacamite and other metal chlorides in certain stratabound deposits. Chem. Geol., 21: 151--159.
Table I, page 155, line 4 f r om b o t t o m . The figure
"[S- ] "
should be "[H2 S] "