LETHAIA REVIEWS

Lethaia, Vol. 19. p. 108. Oslo, 1986 04 15

Another Mesozoic instalment PETER BENGTSON

Moullade, M. & Nairn. A. E. M. (eds.) 1983: The Phaneroroic Geology of the World: 11. The Mesozoic, B. x + 450 pp. Else- vier, Amsterdam, Oxford, New York, Tokyo. ISBN 0-444- 41672-2. Price US$ 112.75 (USA and Canada), Dfl. 265.00 (elsewhere).

Asia in part, Africa and Australasia were the scope of the first volume (labelled ‘A’ ) in the Mesozoic part of the Elsevier se- ries The Phanerozoic Geology of the World (reviewed by Mar- tinsson. 1979. in Lethaia 12(4/) . A second volume, carrying the prosaic but consequent subtitle ‘The Mesozoic, B’, is now avail- able, covering the Americas in part, the Indian subcontinent s./.. and Antarctica. The subject of Mesozoic regional geology may not appear very exciting at first glance, but is essential to our understanding of late Phanerozoic earth history. Mesozoic plate movements were intermittently very rapid and reshaped the old Pangaea into something approaching present-day conti- nental configurations. The deposits on the ocean floors are all of Mesozoic age or younger. The floras and faunas evolved to render forms that are not too different from what we have to- day, and at the very end of the Mesozoic there occurred one of the most spectacular biological events known in the history of the earth - the terminal Cretaceous extinctions.

Regional geology of the Phanerozoic by necessity involves a great deal of stratigraphy, and this book is largely a strati- graphical-palaeogeographical synthesis. The chapters are as follows: (1) Arctic North America and northern Greenland (H. R. Balkwill ef al.) . (2) the northwestern Atlantic Ocean margin (J. P. Owens). (3) Mexico (K. Young), (4) the Caribbean re- gion ( J . Butterlin), ( 5 ) the northern Andes (W. v. Maresch), (6) Brazil (S. Petri & J. C. Mendes), (7) the Triassic of Argen- tina and Chile (P. N. Stipanicic, (8) the Jurassic of Argentina and Chile (A. C. Riccardi), (9) the Cretaceous of Argentina, Chile, Paraguay and Uruguay (N. Malumisn, F. E. Nullo & V. A. Ramos), (10) India (S. N. Bhalla), (11) Pakistan (A. A. Ku- reshy), (12) Papua New Guinea (S. K. Skwarko, C. M. Brown & J . C. Pigram), and (13) Antarctica (M. R. A. Thomson).

The editors repeatedly emphasize the difficulties met with in achieving coherency and homogeneity in coverage and style throughout the volume. The heterogeneous coverage is most ap- parent from a comparison of the treatment of Brazil with that of Argentina and Chile, both areas having widespread Mesozoic deposits. The chapter on Brazil occupies 18 pages of the book and barely touches upon the stratigraphy, whereas there are three chapters across 124 pages on Argentina and Chile, with an abundance of stratigraphical detail. The comparatively super- ficial treatment of Brazil could have been compensated for by an extensive use of references to more detailed works, but n o such attempt has been made. Only one page of references is provided, against 20 pages for Argentina and Chile; the latter are, of course. an invaluable source for those who wish to obtain more data. For this very purpose, many chapters begin with a useful enumeration of previous, major regional work of the area. Most of the contributions synthesize the geological, depositional and palaeogeographical history of the area but few actually discuss the biological events. Notable exceptions are the chapters on the Jurassic of Argentina and Chile, India and Pakistan, where a plethora of biostratigraphical detail is provided.

A different problem concerns the rapid advance of scientific knowledge in many of the areas treated, compared to the time involved in production of the book. By the time the book has appeared, part of the material is no longer current knowledge - but previous knowledge. To illustrate this, in seven of the 13 contributions the latest references are three to five years old, and one of the articles - dealing with the Triassic of Argentina and Chile - may even be as much as ten years old, judging from the references.

The book is attractively produced on glossy paper, and the quality of printing is excellent. This has saved many of the heavily reduced figures. which would probably have become il- legible had they been reproduced in regular journals. A tech- nical flop is the map series belonging to the chapter on the Cre- taceous of Argentina etc., where a heavy grid pattern and too ambitious detailingof the map spoil the pleasure for the reader. In addition, many authors have chosen the technique of merely numbering the legends in the maps, transferring the pertinent explanations to the caption below. This saves work for the au- thors but is a nuisance to the reader who must look up every- thing twice.

The book is provided with an author index and a general in- dex (subject index), a must for a book of this kind. Since in- dexing is normally done by professional indexers, who are not specialists in the subjects treated, it is important that the author or editor supervise the work. This may have been done, but some peculiarities have slipped through. One wonders, for ex- ample, what is so special about the mention of ‘boreal creta- ceous ammonites’ from Arctic North America that it merits the exclusive entry on ammonites in the index. Ammonites are not only mentioned, but discussed and/or listed in most of the other chapters of the book.

Finally, a few words on terminology. One of the most la- borious tasks for the editors of this kind of joint work is to uni- form as much as possible the divergent terminology and no- menclature of the contributors. The editors point to the over- whelming nomenclatural problems in their preface to volume A. I assume that they have done what they felt feasible, but much has remained that may bewilder the reader (such as the long non-recommended terms ‘Neocomian’, ‘Vraeonian’ and ‘Senonian’ for parts of the Cretaceous).

Despite the shortcomings outlined here, my overall impres- sion of the book remains positive. The editors have managed well to fill another gap in the regional literature. Part of the ma- terial presented has never been published in English before, and so should be of particular interest. The editors hope to present the remaining regional articles in a third volume (‘C‘), where we are promised data on Europe, Maghreb, the Ocean floor and on broad geological issues. May I suggest that also the U.S. Western Interior, Texas, and the Central Andes be given due consideration? Until the third volume appears, everyone should make sure that his or her library gets both the first and the second volumes. I hesitate to recommend them to individu- als at the prices stated by Elsevier; they are, as usual, beyond the reach of the geologist ‘in the street’.

Peter Bengtson. Paleontologiska museet, Box 558, S-751 22 Uppsala, Sweden; 15th November, 1985.