44 



AUSTRALIAN QUATERNARY CLIMATES AND MIGRATION 



The volcanics of western Victoria may be considered under two 

 headings — the earlier lava-plains phase and the recent scoria-cone 

 phase, the latter comprising scoria, scoria-cone lava-flows and 

 tuff. 



The lava-plains or lava-field phase extends westwards from the 

 meridian of Melbourne to near the western Victorian border ; it is 

 bounded on the south by the Otway Ranges and further west by 

 the Southern Ocean, the coastline of which is fringed with dunes. 

 It extends northwards almost to the Dividing Range in its former 

 position. No artefacts have been found under it, but an under- 

 standing of its place in regard to the scoria-cone phase is desirable. 



The scoria-cone phase is, from the standpoint of archaeology, 

 highly important, for under some form of it have been found 

 the Pejark Marsh Millstone, Buninyong Bone, Maryborough Axe, 

 Bushficld Axe, and the Myrniong implements. The most compre- 

 hensive survey of both of these volcanic phases is that by Grayson 

 and Mahony (1910) who mapped in Quarter Sheets 8 N.E. and 

 8 N".W. (New Series) over 580 square miles and described the area. 

 The legend of these Quarter Sheets does not give geological ages 

 for any of the features mapped other than the basal marine 

 sediments on which the lava-plains rest. The legend given in 

 Fig. 4 is compiled from their statements and our own observations. 





Quater- 













Age 



nary 

 Periods 



Soils, Clays, Tuffs 



and Gravels 





Volcanic 

 Phases 



Climate and 



Rainfall 







Black alluvial soil 





Surface 











Dunes of quartz sand and 



Surface 



lacustrine 











redeposited tuff 



flood-plain 



' 



k 











Hampden tuffs 



t 









RECENT 



Postglacial 



Black clay containing 







scoria cones, 



f increasing 







wind-blown sand and 











scoria cone 



\ rainfall 

 f arid period 

 \ postglacial 







tuff 

 Diprotodnn Bed 











flows & tuffs 







Yellow clay of wind-blown 



Sub-surfate 









1 optimum 







sand and tuff 



flood- 



ilain 









f decreasing 







Buckshot gravel 













/ rainfall 



f cool, rainfall 



( 



Margaret 



t 







Sub-surface 





\ period 





glacial 







lacustrine 





| increasing 







Vertical 













{ rainfall 



PLEISTO- J 

 CENE 



Yolande- 

 Margaret 

 Intcrglacial 



eros 

 Buckshot gravel 



ion 













j arid 



} period 



| decreasing 



















1 rainfall 



















f cool, rainfall 





Yolande 















\ period 













flava plain] 





FIG. 4. 

 Legend compiled from Quarter Sheets of Camperdown and Mt. Elephant Districts. 



Grayson and Mahony state that the scoria-cones and scoria-cone 

 flows are of very recent origin, and though they are ' ' approximate- 

 ly of the same age, some of the flows ar^ no doubt considerably 

 older than others, and no sharp line can be drawn between them 

 and the earlier [lava-plain] basalts." Nevertheless, that there is 



