804 



SCIENCE. 



[N. S. Vol. VII. No. 180. 



use of his own personal knowledge and when 

 that gave out resorted to the bibliographic 

 method of research. Suess had no small share 

 in the recognition of the wonderful overthrust 

 phenomena of the Alps. He thus came into 

 possession of knowledge of earth movements 

 which were still unperceived, except by a few 

 individuals, in the time when De Beaumont 

 wrote of the 'pentagonal network.' Following 

 up his own investigations in the field about the 

 eastern Mediterranean with a study of the 

 literature, Suess worked out a system of move- 

 ments in the earth's crust, which is, to say the 

 least, possessed of the merit of novelty. 



Suess has arranged his facts and the interpre- 

 tations which he has placed upon them in a 

 classification of crustal movements. He recog- 

 nizes one group of movements which result from 

 tangential pressure. In this category he places 

 the overthrusts, or essentially horizontal move- 

 ments on horizontal surfaces, and ' decroche- 

 ments,' or horizontal displacements along verti- 

 cal planes. These movements he finds taking 

 place in regions of folded rooks, such as the 

 great mountain chains of Europe and Asia. 



Suess makes a second group of dislocations, 

 including- effects due, as he thinks, solely to 

 gravity. He states that everything in this group 

 of dislocations behaves as if the parts of the 

 earth's crust affected by them "fell under the 

 infiuence of their own weight into large open 

 cavities below, or as if the surface of the globe 

 sank into a soft base j'ielding under pressure." 

 It is in respect to this view that the conception 

 of crustal deformation entertained by Suess is 

 in most striking contrast to the generally re- 

 ceived interpretation of faults coming in his 

 second group. Where several fault blocks di- 

 vide, for instance, a table-land, into masses 

 standing at different levels with reference to 

 each other, Suess postulates an invariable down- 

 ward movement for the blocks which stand 

 relatively low. He does not suppose that up- 

 lift has taken place in the case of the blocks 

 which stand relatively high. To account for 

 this falling-in of the crust, Suess postulates a 

 radial force as one of the components of the 

 force of contraction. 



The present volume consists of a number of 

 essays in which, in one way or another, the effects 



of these several dislocations of the crust are 

 shown and traced with great detail. The open- 

 ing chapter is a most entertaining discussion of 

 the Deluge, a subject which geologists have, per- 

 haps wisely, neglected since the time of that 

 masterful romancer, Burnet, and his school. 

 The story of the Deluge is told in the light of 

 the Chaldean account of Genesis. An abstract 

 of this chapter has alreadj' been presented to 

 the readers of Science by Professor Emerson 

 (see Vol. IV., 1896. pp. 335-344). Suffice it to 

 state here that Suess finds an explanation of the 

 disaster in the valley of the Euphrates in the 

 conjunction of an earthquake and a cyclone. 

 Many circumstances, as, for instance, the boat 

 of Xithrusos being carried inland instead of out 

 to sea, go to show, he thinks, the effects of a 

 great marine invasion. He concludes that the 

 "traditions of other people do not authorize us in 

 any manner to suppose that the Deluge passed 

 the limits of the lower basin of the Euphrates 

 and of the Tigris, and still less to state that it 

 extended over the whole earth." The legend 

 appears to have been introduced by our author 

 to show that some of the dislocations and falling- 

 in of fault blocks in that part of Eurasia took 

 place within the memory of man. 



The chapter on earthquakes is an attempt to 

 establish the existence of lines of fracture and 

 earth movement, and incidentally to show that 

 these movements are not of an elevatory kind. 

 Admitting that there are earthquakes which 

 have a local point of origin, there are other 

 earthquakes, he states, which cannot be traced 

 to one small place, but are due to the simul- 

 taneous movement of an extended portion of 

 the earth's surface. He selects for discussion 

 four areas in which shocks are held to be of a 

 different character. These may be briefly sum- 

 marized : 1st. The Alps of the Northeast, 

 without volcanoes. In this region, near 

 Vienna, shocks have been propagated at right 

 angles to the chains of mountains, indicating 

 horizontal movements on cross-fractures (' de- 

 crochements' or 'Blatten.') 2d. Southern 

 Italy, with volcanoes, but these without align- 

 ment. Here there is a circular line of areas of 

 earthquake shock passing from Calabria into 

 Sicily and having the Lipari Isles at center. It 

 is thought that within the area limited by the 



