DESICCATION AS A PHASE OF THE GLACIAL EPOCH. 187 



Professor R, D. Irving, of the Wisconsin Geological Survey of 1873-77, 

 thus succinctly states his views in regard to the Glacial period and a subse- 

 quent period of inundations : '• The stratified drift of the valleys owes its 

 structure and distribution to the water of the swollen streams and lakes that 

 marked the time of melting of the glaciers."* Professor T. C. Chamberlin, 

 chief of the same survey, holds a similar opinion, as is clearly to be gathered 

 from the following quotation from his report: "The melting of the ice- 

 mass save rise to swollen lakes and flooded rivers, which eroded at some 

 points and filled up at others, and so still farther modified the face of the 

 country."! 



Professor N. S. Shaler, former Director of the Kentucky Geological Survey, 

 in speaking of certain deposits of blue clay occurring in the terraces of the 

 Ohio Valley, says : " I am inclined to think that it was formed at the time 

 the valley was swept by the floods, which came during and at the close of 

 the glacial period, when, for a great length of time, this valley was the seat 

 of a far more powerful stream than at present.''^ 



Professor C. H. Hitchcock, Director of the New Hampshire (Second) Geo- 

 logical Survey, says, in describing the terraces occurring along the Merri- 

 mac and Connecticut Elvers : " We conclude that at the close of the 

 glacial period, when the ice was melting rapidly, the rivers filled their 

 valleys even with the tops of the highest terraces." § 



Quotations enough have been given to show that American geologists 

 concur very generall}' in looking upon the close of tlie Glacial period as a 

 time of great floods, and an abundance of water running and standing upon 

 the surface, all coming from the melting of the " great glacier." It will be 

 proper, however, to add the very clear and emphatic testimony to this effect 

 offered by Professor Dana, in his text-book, which is, and very properly, in 

 the hands of all professional geologists and of most advanced students of the 

 science throughout this country, and which reflects very closely the general 

 opinion held here in regard to geological " questions of the day." He says, 

 after describing " the glacier of the Northern Hemisphere," || under the head 

 of '' The Final Flood from the melting of the Glacier " : " That the melting 

 of the glacier should have ended in a great flood may be inferred from the 



* Geology of Wisconsin. Survey of 1S7.3 - 77, Vol. 11. p. 635. 



t 1. c, \>. 98. 



J Geological Survey of Kentucky. New Series, Vol. III. Part III. p. 75. 



§ The Geology of New H:inipslure. Concord, 1874, Vol. I. p. 542. 



II Manual of Geology. Third Edition. New York, 1880, p. 555. 



