158 Wisconsin Academy of Sciences, Arts^ and Letters. 



DISCUSSIOK 



BY PROFESSOR C. R. VAN HISE. 



Dr. Buckley's paper upon the behavior of expanding and con- 

 tracting ice and the resulting deformation of ice and shore is 

 of very considerable geological interest, because of the many 

 analogies that the phenomena present to the crustal deformation 

 of the earth. Many experiments have been made in the labora- 

 tory with various materials, the aim being to reproduce on a 

 small scale the phenomena of crustal deformation, in order that 

 inferences might be made as to the nature of the forces which 

 produced the phenomena. Laboratory experiments simulating 

 the phenomena of crustal deformation date back as far as Hall,^ 

 the contemporary of Hutton. The much later experimental 

 work of Daubree^ is well known. In the last few years a num- 

 ber of men have been working upon the problem in the labora- 

 tory. Rotable among these are Willis^ and Prinz.* 



The shore and ice deformation caused by ice expansion de- 

 scribed by Dr. Buckley stimulates more nearly many of the phe- 

 nomena of crustal deformation than have laboratory experi- 

 ments. Moreover the phenomena are on a much larger scale 

 and are of correspondingly greater value in judging of the man- 

 ner in which the phenomena of crustal deformation are pro- 

 duced. Dr. Buckley's work is of especial interest to me since 

 the phenomena described by him almost exactly illustrate a num- 

 ber of the phenomena which I have elsewhere discussed. These 

 will be separately mentioned. 



First is the manner in which normal folds pass into over- 

 turned folds. It has been supposed in such cases that the 

 thrusts have come ^^more largely from one direction than from 

 the other, and the axial planes of the folds have usually been 



1 Sir James Hall : Trans. Roy. Soc. Edinburgh, Vol. VI, 1805. 



2 G6oloRie Experimentale, by A. Daubr6e: "Vols. I and II, 1879. 



• Thfi Mechanics of Appalachian structure, by Bailey Willis: Thirteenth Ann. Rept., 

 U. S. Geol. Surv., Pt. II, 1893, pp. 211-281. 



*L'Echelle Reduite des Experiences Gfiologiques, by W. Prinz: Revi>e de I'Univ. de 

 Bruxelles, Tome II, 1896-97, p. 47. Bull. Soc. Beige d' Astronomie, 1899, p. 70. 



