78
approximations for dealing with seepage
forces are unsuitable if the permeability
characteristics of the subsoil are complex,
and that under these circumstances it would
be advisable to construct a flow net. This is
perhaps an unfortunate inference that complexity of subsurface conditions, often only
poorly definable at best, can be reduced by
invoking more complex analytical procedures.
The book is, nonetheless, a valuable and
outstanding contribution, helpful to the
researcher, and extremely useful to anyone
meaning to carry out stability studies and
needing guidance through an extensive and
sometimes inconsistent literature.
R.B. Beck, Albuquerque, New Mexico
BENTONITES
Ralph E. Grim and Necip GQven, 1978.
Bentonites - Geology, Mineralogy, Properties and Uses. Developments in Sedimentology, 24. Elsevier, Amsterdam, 256 pp., Dfl.
131.00, U.S. $ 57.00.
This book is a notable contribution to
the geology and mineralogy of bentonites
and of the smectites, mainly montmorilIonites, which are the principal clay minerals
in bentonites. Ralph Grim has had a long
acquaintance with these materials throughout the world and chapter 3, which occupies
a major part of the book, pp. 13--160 or
58%, summarizes his extensive knowledge of
their geology. Chemical analyses by atomic
absorption spectrometry, cation exchange
capacities, amounts of extractable cations,
and X-ray data limited to (001) and (06),
(33) spacings are tabulated for 85 carefully
chosen samples. These appear to be new
data and the experimental procedures are
fully described. Chemical analyses for 152
other samples also are tabulated. To obtain
structural formulae, the authors prefer the
method of fixed cationic numbers, ideally
four tetrahedral and two octahedral cations
per formula unit. They state (pp. 150,151)
that this method 'does not require an accurate analysis of exchangeable interlayer
cations' yet they also mention the results of
Foster (1951) which show that only when a
correction is made for exchangeable Mg is
the number of octahedral cations reduced to
1.99-2.01. Electron-optical data are given
considerable prominence and reflect Dr.
Gdven's interests in the diffraction study of
smectites. Results obtained by TEM and by
selected area, single crystal diffraction are
reproduced for many samplcs. The chapter
concludes with useful summaries of the
geology of bentonites and the mineralogy,
chemistry and crystal growth of smectites.
Chapter 4 takes up the electron diffraction study of smectites in considerable
detail and it requires a good acquaintance
with diffraction theory to follow the arguments. This is the second longest chapter,
pp. 161--216 or 22% of the book. The question whether electron diffraction by single
crystals of montmorillonite can be considered in terms of a two-dimensional
space group or must be treated as a threedimensional problem even though smectite
crystals have regularity only in two dimensions is treated very fully. The conclusion
that a three-dimensional consideration is
necessary seems well established.
Chapter5 dealing with properties and
uses occupies no more than about 30 pages
or 13% of the book. Much of the material
is very similar to what is given in Grim's earlier books published in 1962 and 1968 and
seems to have been only slightly up-dated.
Most of the references cited are pre-1960 (in
fact, 80%) and only five references are in
the 1970's. As the authors state, properties
are contingent on chemical composition,
atomic structure and morphology. However,
the properties which are important in many
(or most) applications are viscosity, thixotropy,
plasticity,
shrinkage,
bonding
strength, etc., all of which involve clay-water relations. A chapter dealing specifically with clay--water and clay--organic
interactions would have been a useful intermediate step between the fundamental crystal chemistry of smectites and their applications. Smectites as catalysts get no more
than about one page of text; is the information locked up so firmly that only one reference can be cited (Grim. 1962)?
I welcome this book for what it gives us,
an excellent account of bentonite geology,
79
the chemistry and structure of smectites, and
a detailed treatment of electron diffraction
by these highly disordered layer structures,
and regret that properties and uses receive
much less attention.
G.W. Brindley, University Park, Penn.
PETROLOGY
C.J. AIl~gre and S.R. Hart (Editors), 1978.
Trace Element in Igneous Petrology. A
Volume in Memory of Paul W. Gast. Developments in Petrology, 5. Elsevier, Amsterdam, 272 pp., Dfl. 121.00, $49.95.
It is a welcome coincidence that the
two major geo-science journals, Earth and
Planetary Science Letters and Geochimica
et Cosmochimica Acta , have separately
published two special volumes on trace
element geochemistry during 1978. The
volume by E.P.S.L. dedicated to the late
Paul Gast, which is published by Elsevier
in a book form edited by AIl~gre and Hart,
deals with the application of trace element
geochemistry to the problems in petrology.
The volume by G.C.A. is the proceedings of
the international conference on trace element geochemistry held at Sedona, Arizona,
in September 1977.
The topics in the book were wellselected and thus providing a wide perspective view of petrology of earth's lithosphere
based on trace element studies. The topics
include studies on isotopes, both radiogenic and non-radiogenic, in addition to the
trace element distribution studies in the narrower sense, benefiting to widen the scope
of the volume. The papers cover the wide
variety of magma species, rock formations
and their genetic mechanisms as well as the
wide chronological time range. It is also welcome that Hoffman and Hart have introduced the diffusion processes in isotope
petrology, as diffusion coefficients, though
not well determined yet, will be important,
useful parameters like partition coefficients
and radioactive decay constants in trace element petrology. Most papers, either review
or original work, are written in comprehensive styles, yet keeping up with the highest
professional levels.
In the opening chapter, AIl~gre and
Minster gave full presentation of generalized
treatment of the models of trace element
fractionation and also introduced an interesting symbol-presentation method of the
models. However, overdose of generalization
and symbol notations tends to make the
reader dizzy with i's, n's, arrows and waves,
and to my regret, the formulae and symbols
in the chapter are not well utilized in the
rest of the volume. On the other hand,
important and promising methods such as
S m - N d isotope study are little discussed in
the volume (I found the word 'Nd isotopes'
just twice and no data in the whole volume).
Although Nd--Sm data are scarce, so far, the
method will be competent with the other
existing chronological methods with the
advantage that it is readily connected to the
rare earth distribution studies. The method
atso has an advantage that the mother and
daughter isotopes involved are more compatible with the crystal structures of many
rock-forming minerals compared with those
of other methods. Thus it might well be discussed in the introductory chapter.
The mechanism and theoretical background of trace element partition is not
discussed in this volume. In fact, the present
status of the theoretical grounds of partition
coefficients may be said as 'far from
achieved yet' as AIl~gre and Minster noted.
However, recent developments of theoretical and experimental studies shown in the
proceedings of the Sedona Conference, for
example, have made the nature of partition
coefficients much clearer as ever, at least in
setting limitation of their use in petrological
problems. In the sense, I recommend to
keep the two volumes together in a bookshelf. I acknowledge the editors of both
volumes for publication of the two contrasting, complementary works.
Hiroshi Nagasawa, Tokyo
GEOTECHNICAL ENGINEERING
Alois Myslivec and Zdenek Kysela, 1978.
The Bearing Capacity o f Building Foundations. Developments in Geotechnical Engineering, 21. Elsevier, Amsterdam, 237 pp.,
Dfl. 91.00, U.S. $ 39.75.