452 



NATURE 



[June i6, 1910 



less important than the petrographic ; he retains the 

 terms for Harker, Bccke, and Prior's two petrographic 

 regions, of which the Atlantic is characterised by 

 igneous ribcks rich in alkalies, and the Pacific by 

 those rich in lime and magnesia. Both the char- 

 acters of recent mountain formation and the chemical 

 composition of the lavas can only be applied with 

 numerous exceptions ; and we cannot but think it 

 would be regrettable if the great geographical truth 

 in Suess's original view were abandoned, and his two 

 terms retained with a meaning so changed and in- 

 appropriate as to be misleading. 



Though no general theory is advanced in this 

 volume, Prof. Suess gives in an appendix (pp. 783-5) 

 his final classification of the lands of the earth. He 

 arranges them in the following ten divisions : — 



(i) Eurasia, including part of North America; (2) 

 Laurentia ; (3) Gondwanaland; (4) Australia, Oceania, 

 and parts of Antarctica ; (5) South America and the 

 western mountains of North America ; (6) the British 

 Isles, excluding the southern counties, but including 

 part of Norway and the mountains of the western 

 Sahara; (7) the volcanic islands of the Atlantic type, 

 with which are grouped some of the islands of the 

 eastern Pacific, Indian and Southern Oceans ; (8-10) 

 the Cape Mountains, the north-w-estern peninsula of 

 New Guinea, and the Fiji Archipelago are each 

 independent elements. 



This classification, embodying the conclusions that 

 have been reached by Prof. Suess after thirty years 

 of most careful research, must command respectful 

 consideration from all geographers, though objection 

 may be taken to some parts of it. 



The first seven chapters (Nos. x. to xvi.) describe 

 the mountains of western Eurasia, of which the 

 most important are referred to two groups, the 

 Altaids, including the Hercynian Mountains of Ber- 

 trand, and the Alpids, formed by Cainozoic foldings 

 in areas that had foundered in the frame of the older 

 Altaids. The Caucasus are now transferred from the 

 Alpine to the Altaid system. There are unquestion- 

 ably important differences between the Alps and the 

 Caucasus, but these two chains and the Pyrenees 

 were all due to earth movements that probably had 

 a connected origin, though they affected western 

 earlier than eastern Europe. Thus the Pyrenees were 

 folded at the end of the Eocene ; the Alps in the Upper 

 Miocene, and the Caucasus in post-Sarmatian times. 

 No doubt the Caucasus has a foundation of older 

 mountains; but so also have the Pyreness, which have 

 indeed a more tvpical Altaid basis than the Caucasus. 



No one can differ from Prof. Suess on mountain 

 classification without great hesitation. But a classi- 

 fication which correlates the Caucasus with the hills 

 of Devonshire instead of with the Pyrenees is obvi- 

 ously not intended for general geographical use. The 

 geological evidence still seems consistent with the 

 conclusion of Fournier, who, in his monograph on 

 the Central Caucasus, reports "que la Caucase, 

 par sa direction, par I'age et le sens de son dernier 

 plissement, par le parallelisme meme des stades de 

 sa formation, est le prolongement direct de la grande 

 chaine Alpine." 



The African representatives of the Altaids include 

 NO. 2120, VOL. 83] 



the Atlas Mountains, to the south of which is a 

 mountain band composed of .\rchean rocks with a 

 north to south strike. From this fact Prof. Suess 

 identifies them as a section of the Caledonian moun- 

 tains. In Scotland the general trend of the foliation 

 in the gneiss and crystalline schists is not from north 

 to south, which is the direction characteristic of the 

 Archean rocks of equatorial and northern Africa ; 

 there seems no very convincing reason for correla:ting 

 these mountains of the western Sahara with the 

 British rather than with the African Archeans. 



The discussion of the Eurasian Mountains closes 

 with an especially valuable chapter, in which Prof. 

 Suess traces the Altaid system through the Appa- 

 lachians and across the United States as far west as 

 Texas and the frontiers of Mexico. Then follow two 

 chapters, one on the African fractures and the other 

 on the Oceanids, the island festoons of Australasia. 

 In dealing with Australia, Prof. Suess's most im- 

 portant proposal is its separation from Gondwanaland, 

 on the ground that not enough is known of the 

 intervening area to show their relations. The 

 evidence, however, of the fossil flora and fauna of 

 Australia seems conclusive of the former land con^j 

 nection of Australia and Gondwanaland. I 



Prof. Suess next discusses the western moun- 

 tains of America, and traces the Asiatic structure 

 into America through Alaska. He re-classifies the 

 mountains of North America, and again, as with tht 

 correlation of the Caucasus, appears to attach unduf 

 weight to the early history and materials of th< 

 mountains in comparison with the movements tc 

 which they owe their existing forms and geographi< 

 importance. He divides the w;estern mountains o 

 North America into three groups. The eastern grouj 

 is that of the Rocky Mountains, which Suess shows 

 by a masterly study of Alaska, belong to the Asiatit 

 Structure. The westernmost group is the Mount St 

 Elias chain, which passes out into the Pacific througl| 

 the Alexander Archipelago. All the mountains bei 

 tween the Rockies on the east and the chain op 

 Mount St. Elias, and the Coast Range of Californi. 

 on the west he calls the Intermediate Mountains^ 

 they reach the Pacific coast in British Columbia anj 

 the northern part of the United States. On th 

 strength, mainly, of these " Intermediate Mountains, 

 Prof. Suess now maintains the essential unity 

 structure between North and South America, thoug 

 of the four chief mountain elements in the form 

 only the Intermediate Mountains occur in both. Tl 

 view of the unity of the two Americas is based par 

 on these Intermediate Mountains and partly on I 

 Andes, of which the low Archean Coast Range 

 California is regarded as the northernmost repi 

 sentative. Prof. Suess represents the Andes as form 

 by pressure from west to east, so that where t 

 movement was not obstructed by the great mass 

 the Eastern Highlands of South America the Andea 

 line projected eastward in two great loops, tl 

 northern Antilles in the West Indian area, and tJ 

 " Southern Antilles," including Tierra del Fueeo, tl 

 South Shetlands, and Graham Land. In both the: 

 "Antilles" the Pacific is represented as having a< 

 vanced into the Atlantic region. The writer om 



