140 NEW YORK STATE MUSEUM 



" An attempt has been made to explain the arrangement from 

 the rotation of the earth. Douville has adduced the earlier more 

 rapid rate of rotation and obtains a prevalent east and west direction . 

 Prinz, on the other hand, finds a prevalent north and south direction. 

 We may also point to the folding, directed to the south, of the 

 United States chain, situated on the other side of the pole, also 

 of the Aleutian islands and the southern marginal arcs, and in 

 particular to the Cape mountains directed towards the north; the 

 exceptions are the same." 



And again (p. 626, op. cit.) Suess states, pointing to the same 

 evidence, that " we are led to consider whether in respect to this 

 great part of the earth, we must not admit the action of bodily 

 tides or of the rotation, in addition to the contraction of the planet, 

 as a possible factor in determining the plan of the folded ranges. l 



a Retardation of rotation 



Andree, in his excellent treatise (1914, p. 13 ff.) traces the origin 

 and development of the theory of the retardation of the rotation 

 of the earth through the influence of the tidal waves from William 

 Thomson (1867), and G. D. Darwin to those authors who would 

 apply this factor to the explanation of the mountain folds of the 

 earth (Taylor, 1885), notably Bohm von Bohmersheim, and con- 

 siders it as repudiated by later authors (notably G. von dem Borne 

 and Ampferer) on geophysical grounds ; the impossibility of assuming 

 a sufficient flattening of the poles in these late periods of the earth's 

 history to explain the Tertiary folds of the earth, the failure to 

 produce similar effects by experiments, 2 and the equal failure to 

 bring the present mountain ranges into this scheme, as it was 

 attempted by Suess. 



While thus the influence of changes in the velocity of rotation 

 may be considered as nonexistent or negligible in the case of the 

 Postproterozoic mountain folds, there is still a possibility that 

 these changes may have been so much greater and more rapid 

 during the Precambrian era of the earth that they did have a distinct 

 effect upon the worldwide folding of that time. Indeed, it is 

 claimed by Chamberlin (1916, p. 544) that rotation was the greatest 



1 The principal influence of the rotation, Suess (op. cit.) saw, however, in its 

 producing the eustatic movements of the ocean. Later (191 1, p. 107) he expressed 

 himself as being now uncertain about the rotation being a vera causa of eustatic 

 movements, since we do not know where the pole was. 



2 Keyes (1919, p. 87) has, however, lately stated that "recent experiments 

 indicate that the larger relief features of the globe are not the complex dynamical 

 phenomena commonly fancied, but merely somewhat different expressions of 

 the same simple tangential force and direct resultants of the earth rotation " 

 and " that the effects of tangential compressive force which many mountain 

 structures display appear to be not the result of earth contraction, but of stress 

 release due to retardation of the earth's rotation." 



