THE ICE-FLOOD HYPOTHESIS OF THE NEW ZEALAND 



SOUND BASINS 



E. C. ANDREWS 

 Sydney, New South Wales 



INTRODUCTION 

 The author feels confident that the glacial explanation of the 

 striking geographic forms in the southwestern Alps of New Zealand 

 finds readier acceptance among those students who, until such time 

 as they themselves have conducted careful and detailed physiographic 

 examinations, have not so much as seen a region of former or present 

 intense glaciation, than with those who have spent their lives amid 

 such ice-modified surroundings. Only to such workers does the 

 whole series of novel perceptions presented during a first glimpse 

 at a formerly strongly glaciated region come with the startling force 

 of a revelation. The foregoing is applicable to the case of the author, 

 and because of it he feels warranted in presenting this glacial expla- 

 nation for certain New Zealand forms. For several years prior to 

 visiting Alpine New Zealand in the summers of 1901 and 1902, he 

 had made numerous topographical observations in Australian New 

 England, Monaro, The Darling Downs, northern Queensland, and 

 Fiji. Between the latitudes embracing these localities, viz., 15° and 

 37° S., thousands of tributary water-courses had been inspected. 

 All were observed to join the main river channels with non-conflicting, 

 or but triflingly conflicting, grades. The magnificent plateaus of 

 eastern Australia still, in great measure — when composed of felsites 

 and acid granites — retain their individuality as to their central por- 

 tions, and here, naturally, as they are traced headward, the rivers 

 are observed to leave the wide and well-matured valleys of the uplands 

 in gigantic waterfalls for rapidly trenching canyons. But even at 

 this initial stage of canyon growth, with one or two exceptions, easily 

 explicable by local rock variations, etc., the legions of side gulches, 

 although insignificant in length, come in " at grade." Thence, follow- 



