REVIEW.

Evening Star, Issue 14966, 28 August 1912, Page 8

REVIEW.

‘Geology of New Zealand.’ Bv P. Marshall, D.Sc., M.A., F.G.5.," etc., Professor of Geology and Mineralogy, Otago University. Bvo, pp. 218. By authority. John Mackay, Government Printer, Wellington. Geology, geography, physiography, and paleontology are allied and overlapping sciences, it is impossible to impart or acquire anything but a superficial knowledge of any one of these without resource to tho others. As geography is taught in all our primary and secondary schools, the necessity for a text-book arose which would embrace the allied and inseparable sciences of geology and physiography. Such a work with local illustrations is the one under notice. Presumably this has been recognised by the Education Department, as the work is printed and published by the Government Printer, and the Department of Mines has lent many valuable photographs for reproduction. The claim made by the author in the preface is that the work is “an elementary treatise on the subject.” It is more than that, and will be invaluable to teachers in State and secondary schools, and to students who, with no desire to attain distinction in the science, have to take the subject as part of a syllabus, as, for instance, for the degree of Bachelor of Commerce. To the general reader it will prove both interesting and instructive, the more so as, like the author's more comprehensive work on the same subject recently published in Heidelberg, the tendency throughout is the simplification of the problems inherent to the geology of the Dominion. The tendency of the work is to lead the student or general reader into the subject matter, to place before him the observed facts in a simple and concise manner, to give him the_ benefit of the deductions of other authorities where necessary or where thev differ from the authors, and to thoroughly interest him in the question under discussion. The title ‘Geology of New Zealand,’ taken in its narrower sense, gives little insight into the contents. It is really an elementary text-book of geology, mineralogy, physiography, etc., in which the examples to illustrate the text are drawn from New Zealand. Only three of the 17 chapters are devoted to the geology proper of the Dominion. Of these one deals with the physical structure of the islands, another the geological history of New Zealand, and the third with the_ _stratigraphical classification. The simplicity of the author’s views on the geology of the islands is best shown by a quotation from his own preface: “Briefly stated, these are—(l) that the great series of folded stratified rocks of which the main mountain ranges are constituted were deposited during a long continuous period, lasting almost throughout tha rnesozoic age, when the position of the country was on or near the shore line of a great continent; (2) that another great series of rocks of tertiary or cainozoic age was deposited whilst a general regional depression was in progress.” 'Hie first of these depositions is the author’s Mait-ni system (Trias-Jura), the second bis Gamaru system (Oainozoic); and if these arc removed from the geological map accompanying the volume under review very little of our present land surface remains. An interesting chapter is devoted to the relation of Now Zealand to the other physical features of the Western Pacific. It is accompanied by a plan showing the depths of the surrounding oceans, and also sections of the floor of the Tasman Sea and Pacific from Australia across New Zealand. Rain, rivers, and lakes fonv. the subject matter of one chapter, whilst glaciers, coasts, mountains, and volcanoes have each a chapter of their own. Among the chapters devoted to the processes are one each upon metamorphism, percolating water, and chemical action, the atmosphere and physical action, and tho geological action of organisms. There are also chapters on the minerals and on the rocks of New Zealand, and one on the outlying islands. The general get-up of the work is excellent. The geological map, drawn to a scale of 1 in 1,500,000, is printed in 13 colors, and although Borne are hardly distinguishable in artificial light, they are plain en ugh in daylight. There are 113 illustrations, including diagrams, and the paper and type leave nothing to be desired. The typographical errors must be extremely few for a work curtaining so many technical terms, as none were noticed. An excellent index is provided, and a list of corrections next to tire author’s preface, the first of which is incorrect. The author’s solution of the different f-tructunl and skatigraphical problems of New Zealand geology will five rice to discussion, as they differ considerably from those of the earlier writers, especially regarding tha tertiary succession ; but as further research in the field is lending confirmation to his views, it is probable they must ultimately be accepted as correct. Exception may bo taken to the statement on page 99 that ultra-basic igneous rocks have their volcanic representatives, or to that on page 155 that the magnetite in basic igneous rocks is an impregnation. Apart- from these debatable statements, one vainly looks through the pages for any artistic imaginative theory "to relieve the solemnity of the long procession of physical facts and processes. Where anything of the sort is admitted, it is the theories of the earlier writeis—as for instance, on page 204, the theories of Hector, Von.Haast, and Hutton are given to account ror Ike disappearance of the moa and the position in which the bones are found. The volume is laid down at the finish with feelings of regret that there is not more of it.