499 



THE NEW ZEALAND SOUND (AND LAKE) BASINS 

 AND THE CANYONS OF EASTERN AUSTRALIA 

 IN THEIR BEARING ON THE THEORY OF THE 

 PENEPLAIN. 



By E. C. Andrews, B.A. 



(Plates xxxix.-xli.) 



INTRODUCTION. 



The following brief note was suggested by a perusal of three 

 recent geographical articles* by Professors W. M. Davis, W. S. 

 Tangier Smith and R. S. Tarr, and is mainly an extract from 

 a larger note just going to press. In the latter — copiously 

 illustrated with maps, photographs, sketches, and sections — an 

 attempt is made to prove that the various high plateaus of New 

 South Wales are the result of incomplete reductions to base-level 

 (sea-level) by stream agency during periods of comparatively 

 stable equilibrium. It may here be stated that several of the 

 physiographic processes discussed in this note are not unknown to 

 science, as the works of Playfair, W. M. Davis, G. K. Gilbert, 

 Penck, Tarr, and others so ably prove. The claim to originality 

 consists in taking certain, heretofore, isolated facts and pointing 

 out the logical consequences of accepting them. Their co- 

 dependence becomes at once strikingly manifest, and successive 

 steps in a whole routine of perceptions admit of clear and ready 

 statement. Thus a corollary from the proposition that stream 

 channel grades in bed-rock are the result of mighty floods only is 

 tli at we must wait until the next immense ice-flood before expecting 

 to see the old glaciated contours altered ; similarly, the grand 



* W. M. Davis, (c) pp.207-239; W. S. Tangier Smith, pp.155-178; R. S. 

 Tarr, pp.351 -370. 



