42 AUSTRALIAN QUATERNARY CLIMATES AND MIGRATION 



If sea-level started to recede 4,000 years ago and it has fallen 

 from 15 to 20 feet at the saint; rate since, the inner ridges at Altona 

 emerged from 2,400 to 3,200 years ago. 



Point Cook, where there is evidence of inner ridges and swales, 

 is topographically and apparently structurally like Altona. The 

 basal bed consists of fluviatile deposits at the mouth of the 

 Skeleton Water Holes. 



Both Altona and Point Cook have been prolific collecting 

 grounds for all kinds of stone artefacts. Altona is a growing 

 suburb of Melbourne and the opportunities are fast disappearing; 

 it is deplorable that so few records of the positions of artefacts 

 when they were found have been kept. Enquiries suggest the 

 probability that they were on the surfaces of the inner ridges or 

 the floors of the swales. It will be realized that if any were 

 m situ in the surface sand of the inner ridges, such would be 

 evidence of the presence of the aborigines during the last glacial 

 period or the opening stages of the Postglacial. It is obvious 

 from the parallel bedding of the ridges that the whole area was 

 formerly covered by these bedded deposits and the swales respon- 

 sible for the ridges were formed later. Whether or not the imple- 

 ments found on the floors of the swales were incorporated in the 

 material that has been removed must remain an open question. 

 An intelligent searcb of the upper sands of the inner ridges 

 would be informative. 



At Point (look, the artefacts are found on the dunes or on the 

 basal bed where it has been exposed by the shifting of the dune- 

 sands. Whether those on the basal bed have been let down on to 

 it by the removal of the dune-sands, or were there before the dune 

 was formed, cannot be determined. The extant native fire-places 

 in the dunes consist of a subcircular collection of fire-stones so 

 placed by the aborigines; they occur at all levels. Where the 

 dune-sand on which a fireplace rested has been shifted by wind 

 action from under it, the stones are scattered, but many fireplaces 

 retain their original shape. At one place the author observed one 

 that had been placed on the basal bed. The fact that they occur 

 at different levels might be taken as evidence that the aborigines 

 were there throughout the whole dune period and even before, 

 but there is the possibility that they selected a depression, or 

 made one, in which to place their hearths ; if so, they could be 

 readily covered by drifting sand. 



Summarizing these notes, up to the present, the evidence at 

 Altona and Point Cook points to the earliest occupation of those 

 areas by the aborigines about 3,000 years ago, when the inner 

 ridges at Altona were first uncovered. The beds in the areas 



