Meteorite Craters

BOOK

REVIEWS

hleteorite Craters, edited by G. J. H. MCCALL, Dowden. Hutchinson & Ross. 1977. 364~. 835.00. THIS IS Volume 36 in the series of Benchmark Papers in Geology. Twenty-eight papers are reprinted and complemented with thirty-odd pages of commenrar> in an attempt to provide a “comprehensive. coherent and obJective coverage” of the world literature on meteorite craters. Unfortunately. the book fails to achteve its stated objective. Craters are divided into those with: 1. meteorite fragments; 11. shock effects but no meteorites: 111. slmplc crater-form but no shock or meteorites: IV. buried. eroded or complex structures with shock: V. structures requiring further study: and VI. structures not of impact origin. An outdated and inaccurate list of craters in these classes is provided. Pretoria Salt Pan. Roter Kamm and Telemzane are discussed as class II craters. although no shock effects have been described from them: whereas Tenoumer. with its excellent crater-form and shock eflects. is relegated to class IV. Many of the structures m class IV have no shock effects. while others. including virtually all the shock-metamorphosed structures in the U.S.S.R. as well as some in Canada and the U.S.A.. have been omitted. Onl) the first three classes are dealt with here. The others will be the subject of another volume b) the same editor. The treatment of impact structures in two volumes and the lack of any real introductory discussion on this so-called controversial subject and the alhed topic of shock metamorphism (“a sub.ject better suited to a separate book”l elTectively pre-empts the presentation of arguments which call for a logical continuum from class 1 to class IV structures. Fifteen papers are presented on class 1 craters. The first. E. L. Krinov’s “Meteorite Craters on the Earth’s Surface”. provides an excellent summarq of this class. Several of the following papers are unnecessar). There are two papers on Dalgaranga by the editor. both published m 1965. and two on Henbury by D. J. Milton. Others deal more with the recovered meteoritic material than the craters themselves and would have been better dtscussed m the editor’s comments. Paper 7 is a summar) of Krinov’s discussion of the Wabar craters from his book “Giant Meteorites”. However. It is simpl) a rewrite of what appears in the first paper by Krinov. Meteor Crater is described through G. Seddon’s philosoplucal treatise “Meteor Crater. A geoE. M. Shoemaker’s “Penetration logical debate”. Mechanics as illustrated by Meteor Crater” and “The Canyon Diablo Meteorite”. by G. P. Vdovykin. it is unfortunate that the editor did not include an earlier. less accessible work such as one of G. K. Gilbert’s papers from the 1890s or J. D. Boon and C. C. Albrltton’s serves of papers published in the late-thirties. Class II craters are covered in twelve papers. The first

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I< on El Aouelloul and is presented as a summarv of “Les accidents cratiriformes ou circulaires du Sahara” by Th Monod. It is. however. a two-page discussion complete with references all of which post-date Monod’s 1953 paper It has a few inaccuracies. with the Ni content of Aouelloui glass given as 0.22”,, instead of 0.022”,, and the rim height as 6.5 m in place of 30 to 6.5 m. This crater would habe been better exemplified bq the well-illustrated. origmal paper “Lr cratire d’Aouellou1 fAdrar. Sahara occIdentalI*‘ by Th. Monod and A. Pourquie in Bull. 6[/atl 13. 1951 The papers on Monturaqui. Bosumtwl, Lonar Lake and New Quebec are good selections The last three papers are on Pretoria Salt Pan. Rater Kamm and Telemzane. which are really class III craters. The final sectlon is on class 111 craters and includes a paper b! V. B. Meen on Merewether. which the editor calls Hebron. and a one page summarq of information on eight other structures. The reprmting of some papers is ver) poor. with the photographs and diagrams almost impossible to make out The editorial comments are not particularly helpful. No attempt has been made to integrate the informatlon from the various craters mto a coherent picture of impact craters with a bowl-shaped form. From the editor’s own papers and his comments. it IS evident that he still has doubts about the meteoritic origin of some of the craters dtscussed. There are a number of typographical errors and some very awkward English usage. The use of visitant instead of vlsltor. classifactory status instead of classlficatlon. material meteorite assoaatlon (3 times on p. 352) Instead of associated meteoritic material. and the numerous times meteoric is used instead of meteoritic all make for annoging reading. The specialist will find the book dated. for although published in 1977 only eleven references are given beyond 1970. The general reader will be confused b) the lack of explanation of such unreferenced comments as: the Mauretanian linear group (of craters), scaled depth of burst greater than 0.5 diameter. the questioning of the nuclear explosion model used in Shoemaker’s paper. and that craters “show a remarkable frequent spatial association with alkaline-carbonatiteekimberlite magmatlsm”. In conclusion there is httle to recommend about this book. This volume does not provide a good background to the sclentific elTort that has gone into the study of terrestrial impact structures. RICHAHD

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