Daly— The C oral-Reef Zone. 139 



and by Pilgrim at 1,320,000 years. 4 Pilgrim's assign- 

 ment of time for the European events of the period is as 

 follows : 



Giinz (earliest) glaciation 300,000 years 



Interglacial interval 80,000 



Mindel glaciation 170,000 



Interglacial interval 190,000 



Riss glaciation 230,000 



Interglacial interval 130,000 



"Wurm glaciation 190,000 



Post-Wiirm 30,000 



Total 1,320,000 " 



Without unduly stressing any of these figures, the 

 experts are generally agreed as to the considerable length 

 of each named subdivision of the Glacial period. 



Shores and Shoals at the Beginning of the Glacial Period. 



From what is known of tropical geology one may 

 fairly consider the early-Pleistocene topography of the 

 coral-reef zone to have been, in the large, of the same 

 quality as the existing topography. The continental 

 shore-lines were not far from their present positions. 

 The larger islands, such as Madagascar, Borneo, Suma- 

 tra, Viti Levu, etc. as well as numerous smaller islands, 

 volcanic and other, already existed in their approximate 

 forms. Many shores had been established, through sub- 

 sidence, elevation, or volcanism, not long before the 

 Pleistocene, and had been comparatively little affected 

 by marine erosion. Others had been established, subject 

 to minor changes, at earlier times, so that broad detrital 

 shelves passing into wave-cut benches, probably nar- 

 rower than the purely detrital shelves, were already 

 fronting the coasts of Australia, Malaysia, New Guinea, 

 Fiji, etc. Local subsidence of islands and continental 

 borders had caused many embayments by the drowning 

 of valleys. 



The sinking of the non-volcanic islands was connected 

 with warpings and faulting of the earth's crust. As indi- 

 cated in the 1915 paper (page 233), sinking of volcanic 



4 A. Penck, Zs. fur Ethnologic, Berlin, 1908, p. 402 ; L. Pilgrim, Jahres- 

 hefte cles Vereins fur vaterlandische Naturkunde in Wiirttemberg, pp. 26- 

 117, 1904. 



