66 AUSTRALIAN QUATERNARY CLIMATES AND MIGRATION 



route, and the Timor-Tinamba route (Fig. 10). The least amount 

 of sea-travel mileage necessary to cross the channels together with 

 their depths is 



Route 



Least number of travel-miles 



Depth in 









feet. 





Glacial 



Rain-forest Mid-Postglacial 







Period 



reached C. York 





Celebes-New Guinea 



176 



176 176 



3,000 



Timor 



. 60 



180 188 



2,000 



Timor-Tinamba . . . 



. 288 



300 300 



1,500 



Soundings on the Admiralty Chart on the whole are too far 

 apart for detailed bathymetrical contouring, but they plainly 

 indicate three coastal plains in the profile (Fig. 12) of the con- 

 tinental shelf. The lowest shows up at 276 feet below existing sea- 

 level, and, allowing for the recent 15-20 feet lowering of sea-level, 

 is undoubtedly the surface of the coastal plain of the last glacial 

 period. The high pinnacles in Fig. 11 are presumably due to 



SEA LEVEL 

 feet 

 + 18 Postgjacia^ _PptiniuTii__ 



Present sea-level 



DATUM 



36 Torres Strait sea-level 



294- 



I50_ Rai n-forest at Cape York 



168 Mi?-Postnlacial coastal plai n 



Sea-level Glacial Per/iod 



FIG. 11. 



Section of sea-floor from outlet of Flinders River in Glacial Period through 



Torres Strait. 



coral growths. That it was a land-surface formed by eustatic 

 adjustment is suggested by the following indirect evidence. It 

 will be noted (Fig. 10) that, during the last glacial period, the 

 outlets of the Victoria and Ord Rivers of the western river system 

 emptied into a landlocked bay across the opening of which lay an 

 island. The floor of this bay was 174 feet below the mean level 

 of the coastal plain during the glacial period, now about 264 feet 

 below existing sea-level. Ascertained by soundings, this floor 



