inter-tidal zone, but are not considered to be of the same significance 

 as chemical erosion. Research into these various operations is still 

 proceeding. 



The scientific consequences and implications of these discoveries 

 may be of considerable interest to geomorphologists and archaeologists. 

 If the levels themselves are truly eustatic — i.e., world-wide — and if 

 the four changes in level have actually taken place along the coasts near 

 settlements of classical antiquity, such as Egypt and Mesopotamia, 

 then important correlations may be worked out. An interesting essay 

 in this direction was made by H. W. Pearson already in 1901, but this 

 and other early attempts are full of weaknesses due to uncritical reading 

 of evidence, to a failure to recognize the full complexity of the problem, 

 and so on. 



Finall}-, looking to the widespread coral islands of the Pacific, it would 

 be surprising indeed if further intensive study here also did not reveal 

 traces of these most recent strand displacements. 



Bibliography 



Ehrenberg, C. G. (1834) : " Ueber die Natur und Bildung der Corallenbanke 



des rothen Meeres. Phys. Abhandl. k. preuss. Akad. Wiss. (Berlin), for 1832, 



pp. 381-438. 

 Fairbridge, R. W. (1948) : Notes on the Geomorphology of the Pelsart Group 



of the Houtman's Abrolhos Islands. Jouyn. Rov. Soc. West. Aust., Vol. 33 



(for 1946-47), pp. 1-43. 

 ■ (1949) : The Geology and Geomorphology of Point Peron, Western 



Austraha, Journ. Roy. Soc. West. Aust., Vol. 34 (for 1947-48), No. 3. (In the 



press.) 

 Johnson, D. W. (1933) : Supposed Two-meter Eustatic Bench of the Pacific 



Shores. C.R. Congr. Int. Geogr. (Paris), Vol. 2, pp. 158-163. 

 KuENEN, P. H. (1933) : Geology of Coral Reefs. The Snellius Expedition, Vol. V, 



Geological Results, Pt. 2, 125 pp. 

 Pearson, H. W. (1901) : Oscillations in the Sea-level. Geol. Mas;., Dec. IV, 



Vol. 8, pp. 167-174, pp. 223-231, and pp. 253-265. 

 Stearns, H. T. (1941) : Shore Benches on North Pacific Islands. Bull. Geol. 



Soc. Amer., Vol. 52, pp. 773-780. 

 Tei CHERT, C. (1948) : Late Quarternary Sea-level Changes at Rottnest Island, 



Western Australia. Proc. Roy. Soc. Vic, Vol. 59 (2), pp. 63-79. 



MARINE EROSION 



By Rhodes W. Fairbridge, University of Western Austraha 



Observations on the nature of marine erosion, resulting in the formation 

 of contemporary marine benches, platforms, terraces, or reefs around 

 the shores of the Pacific, Indian, and Atlantic Oceans have puzzled the 

 writer for some time. Investigations into the relative effects of chemical, 

 biological, and mechanical erosion here have led to conclusions which 

 concern the whole nature of marine erosion, ranging from the emergent 

 " wave-cut " terraces, which fringe so many Pacific islands, to the broad 

 floor of the continental shelf. 



The " Normal " Shore Profile 



Reading that the normal shore terrace was theoretically part of a 

 profile of equihbrium achieved by mechanical erosion operating to wave- 

 base (according to the Gulliver, Fenneman, Davis, Johnson school), it 

 is somewhat astonishing to find in reality that the most usual profile 

 of the continental margin in the more stable parts of the earth is in fact 

 a series of steps, either sloping gently outwards or often even more or less 



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