same place, a spot where storm- waves never reach and where the tidal 

 range is so small that all the higher benches or notches are practically 

 preserved from wave erosion (Fairbridge, 1948, 1949 ; Teichert, 1948). 



Taking the matter from another point of view, if we recognize that 

 there have indeed been Recent higher sea-levels, we would expect to 

 find the appropriate benches of those stands ranging up above the present 

 " Old Hat " or storm-wave platforms. But, curiously enough, we do not. 

 In places of considerable tidal range to-day, however (say, anywhere in 

 excess of 10 ft. spring range), I would not be surprised if all the inter- 

 mediate benches and notches are destroyed, so that all we see to-day is 

 a single, large notch, the maximum incision of which stands at 12-15 ft. 

 above present datum. This is a relic of the 10 ft. sea-level, with limited 

 modification by all subsequent stands. It seems thus very likely that the 

 " Old Hat " bench of protected waters in New Zealand is also the product 

 of the 10 ft. sea-level ; its resistant surface is not due to contemporary 

 saturation by sea-water, but to induration at low-water level in early 

 Recent times. And the " storm- wave " notches, which rise 5-10 ft. 

 higher, are products of the same high sea-level, but in more exposed places. 



For these reasons I am inclined to think that all the varied types of 

 platforms attributed to contemporary marine erosion are nothing but 

 " normal " platforms of various former sea-levels, some of which were 

 broad and some were narrow and easily effaced, and which are subject 

 to-day to varied exposures and types of weathering. 



Some Earlier Points of View 



The initial conclusion is that marine erosion on rocky coasts is very 

 different from the text-book picture. We find a horizontal rock bench, 

 tending towards an ultimate plane at the height of low- water spring tides. 

 This is the base-level of subaerial decay. The mechanism of the erosion 

 is more subaerial than marine, more chemical than physical. Wave 

 action seems relatively unimportant below a few fathoms depth. Some 

 investigation of the literature indicates that' this is not really a new 

 discovery, but merely that early work of the " chemical school " has been 

 forgotten. I find the contrast between the two schools of thought on the 

 subject of marine erosion — i.e., the chemical versus the mechanical — 

 so astonishing and so fundamental that a few appropriate quotations 

 might be illuminating : — 



Ramsay (1846), while being largely responsible for the theory of 

 mechanical marine denudation, which was first outlined by de la Beche, 

 conceived a platform of mechanical marine erosion which reached down 

 only to a moderate depth ; nevertheless, he expressed the opinion that 

 subaerial erosion was a vital aid to marine planation by wave action. 

 The term " abrasion " was coined for the mechanical process by von 

 Richthofen (1886), who developed the idea further. 



Lyell (1865) would consider the mechanical explanation and no other, 

 saying, " No combination of causes has yet been conceived so capable 

 of producing extensive and gradual denudation as the action of the waves 

 and currents of the ocean upon land slowly rising out of the deep." 

 Crossing the Atlantic, the teachings of Lyell appear to be reflected to 

 some extent in the way in which the early American physiographers, 

 such as Gulliver (1899) and Fenneman (1902), Davis (1909, &c.), Barrell 

 (1913, &c.), and others make no mention whatever of subaerial agency 

 in shore-line erosion. Summarizing the conclusions of this school, 



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