180 



greatest extent of the ash is in a southern and. south-easterly 

 direction, and the total area affected is about 25 square miles. 

 As pointed out by Dr. T. S. Hall (Ref. No, 5), the 

 stratified tuffs, away from the Mount itself, closely follow 

 the contour of the land surface, and were undoubtedly de- 

 posited subaerially. The manner in which the beds follow the 

 gently undulating surface of the limestones and sand-dunes 



Fig. 3. 



Plan showing the extent of the ash deposits surrounding 

 Mount Gambier, covering an area of about 25 square miles. 



is excellently shown in practically every cutting where such 

 sections are available. 



Since there is no doubt whatever that the whole of the 

 ash was ejected from the two> or more foci at Mount Gambier, 

 the unsymmetrical distribution of the finer material at once 

 suggests the influence of the prevailing winds as the chief 

 agent of its distribution. 



