296 BOOK REVIEWS In the third part of the book the authors discuss stratigraphic problems peculiar to pyroclastic

deposits, citing examples from Oshima, San Juan, Colorado, and the Archaean greenstone belts of Canada. The final chapter deals with the tectonic environments of pyroclastics and particularly with volcaniclastic sedimentary basins adjacent to magmatic arcs. This is an outstandingly produced book, well organized, lucidly written and very well illustrated with

clear diagrams and sharp black and white photographs. The authors have distilled their com- plementary experience of 'pyroclastics' into a first class book which will undoubtedly form a standard text for many years to come. It is mainly a book for postgraduates and specialist research workers but will also have some application in undergraduate courses. Unfortunately the price will be a deterrent to all but the most dedicated specialists.

P. E. BAKER

ACRITARCHS IN BRITISH STRATIGRAPHY by C. Downie, Geological Society London, Special Report, No. 17, Blackwell Scientific Publications, 1984. No. of pages: 26. Price: f3.50 (paperback).

This pamphlet is designed as a stratigraphical introduction to the acritarchs for earth scientists. The acritarchs are cysts of small marine planktonic algae that form the vast majority of the Palaeozoic marine microflora. They are polyphyletic, belonging to various unknown algal groups. In total there is regularly a much greater acritarch numerical abundance and species diversity than for other fossil groups in sedimentary rocks. They are of considerable value in Palaeozoic biostratigraphy and palaeoecology in both simple and complex structural provinces. Additionally. they are of economic importance in age dating, well correlation and organic thermal maturation in the hydrocarbon exploration industry. From the early Jurassic they become less important in biostratigraphy, for cysts of known dinoflagellate affinity become dominant in most marine palynomorph assemblages in the Jurassic, Cretaceous and Tertiary.

The main part of the text concerns a comprehensive historical review of the stratigraphical study of acritarchs in sedimentary rocks from the British Isles, arranged in sections for the Precambrian, Cambrian, Ordovician, Silurian, Devonian, Carboniferous, Permo-Triassic, and Post-Triassic. Line drawings illustrate selected species from the Precambrian, Carboniferous, Permian, and Mesozoic. Thirteen pages are devoted to stratigraphical range charts of selected species from the Cambrian to Devonian, illustrated with little line drawings. W e the line drawings illustrate representative specimens, those using the tables would be well advised to heed the warning that anyone using the charts to identify species would be very misguided. Two consecutive tables are presented for each series, with some tables continuing on to a second page. The continuation pages are difficult to follow; Fig. 7 on page 18 has a stratigraphid caption on page 17 overleaf, while readers of Fig. 6 on page 16 and Fig. 8 on page 20 may prefer to refer to the stratigraphical column on the subsequent table, which is on the facing page. The data for the range charts is mainly based on British type or reference section samples examined during research work at Sheffield. The stratigraphical data from the type sections is of variable utility, due to differences in lithology, preservation and organic geothermal alteration. The preservation of acritarchs in the Tremadoc Shineton Shales and type Caradoc, Wenlock and Ludow sections is generally excellent and is of low geothermal alteration. In contrast, the poor preservation and high themal alteration of most Ash# and marine Devonian assemblages from the British Isles has discouraged detailed studies. At these intervals, selected species ranges from other areas have been used to supplement the limited data available for the British Isles.

?his introductory work on the application of acritarchs in stratigraphy, illustrated with data from the British Isles, will be of considerable value to geologists worldwide, particularly those working in the Pdaeozoic. The range charts provide a useful summary of the ranges of some of the more important species, of practical value to stratigraphers and palaeontologists Palynologists will be able to locate detailed descriptions, range charts and zonations from the literature cited in the comprehensive bibliography.

K. J. D0R"G

THE INTERNATIONAL KARAKORAM PROJECT by K. J. Miller (Ed.), Cambridge University Press, 1984. No. of pages: Volume I, 412 pp; Volume U, 635 pp. Price: Volume I, €40, Volume II, 247.50.

The International Karakoram Project was organized to celebrate the 150th anniversary of the Royal Geographical Society. The expedition in 1980, involved 73 scientists from China, Pakistan and Britain.

BOOK REVIEWS 297 These two volumes arise from two conferences; the first, before the expedition, at Quaid-i-Azam University in Islamabad, was concerned with work in the Karakoram before the expedition while the second at the Royal Geographial Society in London was based on the work done on the expedition itself. The volumes not only contain a comprehensive survey of the Karakoram, one of the worlds most formidable mountain ranges, but may also be regarded as a review of the ‘state of the art’ of

The members of the expedition were grouped into six subject areas: geology. glaciology, geomor- phology, seismology, topography and human geography (social, economic and health aspects of villages, housing and natural hazards).

Because it contains most of the new work, the second volume is the more interesting. Preliminaries occupy too much space: fanfares, lists of achievements, personnel, firms who supported the expedition and so forth. The section on geology contains little new; that on glaciology is overladen with dcscription of sweying methods (radar) but the results-three dimensional survery of two great glaciers-are important. Interesting work was done on glacial sediments and on the glacial history of the area. The account of the survey work is interesting and this part of the work was very successful. The southern half of the great 1913 triangulation network from India across the Karakoram into Russia was resurveyed. Unfortunately the errors on the 1913 survey were of the same order of magnitude as the estimated shortening due to the colliding Indian and Asian plates, so no significant check was possible. The basis is now laid for the future.

The substantial space devoted to the geomorphology leads to no very striking results. NearIy half of the second volume, and perhaps the most significant contribution made by the

expedition, may be described as the human geography of the H u m Valley. In particular, the astounding natural hazards which to with life at the foot of the greatest precipices on earth are very thoroughly examined and many carefully thought out proposals for minimizing the dangers are set out. Medical studies also led to some constructive proposals, including, not surprisingly, guidance for improving sanitation and water. The Hunza people were at one time supposed to be amongst the healthiest in the world, eating apricots and out of range of infection. It now appears that not only are they subject to many common ailments but a surprising number suffer from neuroses attributed to the strains on their life as a result of the construction of the Indus Highway. Mysterious swellings reported by the women are not so easily explained.

Overall these two volumes are a little disappointing. They do not provide a very well integrated account of the Karakoram nor do they give a very convincing demonstration of the vitality of the science and art of geography. The’ illustrations are not as breath-taking as the reality. In short, volumes for the library but many readers will return them half read.

R. M. SHACKLETON

BeograPhY.

STATISTICAL. METHODS IN GEOLOGY FOR FIELD AND LAB DECISIONS. by R. F. Cheeney. M e n and Unwin, London 1983. NO. of pages: 169. Price: €5.95 (paperback), €12.00 (hardback).

There have been three ‘statistics for geologists’ books before this one. Two are American multivolume works largely concerned with large scale data-massage exercises and the third is Roger Till‘s SI4tirtical Metho& for Earth Scifnces, 1974, Macmillan. The latter is in the tradition of elementary statistical texts published for most sciences, in which frequent worked examples based on data appropriate to the science concerned appear throughout and in which the sequence in which tests and theory are introduced follow the example of texts written for statistics students.

Cheeney’s book differs from these traditional texts in a number of ways. The order in which he introduces statistical concepts and tests is unusual. In the absence of any justifioltion for this departure from normal I can only say the order appears to me to be random and valueless. Another departure from normal practice is a paucity of worked examples of tests and exercises which do not even appear until after thirty or more pages. Thus the book is of no use as a course text and not much use for background reading. The students to whom I teach this subject constantly demand more and more geological examples however many I give them; they would not be satisfied with Cheeney’s miserly

The book also teaches invalid procedures and methods. In Chapter 6, four different tests are applied in turn to the same sample. It should be obvious that such a procedure is invalid. The more times a set of data is tested the more likely it is that a sigui6cant result wiU be obtained, thus altering the Critical values to be used in subsequent tests. You can’t go on testing the same data until you get the result you want.

offering.