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The Craters and Lakes of Mount Gambier 

 South Australia. 



By Charles Fenner, D.Sc. 

 [Read August 11, 1921.] 



Plate X. 



1. Introduction. 



2. Discovery and Settlement of Mount Gambier. 



3. Previous Literature (with list of chief references). 



4. General Description: — 



fa) The surrounding country. 

 (b) Mount Gambier. 



5. The Volcanic Materials: — 



fa) The lava and its extent. 



(b) The fragmentary material and its distribution. 



6. Age of the Eruption: — 



fa) Relation to Victorian Newer Basalt period. 

 (b) Physiographic evidence. 

 fc) Fossil evidence. 



7. Duration of the Eruptive and Effusive Phases. 



8. The Number of Craters and the Order of Eruption : — 



fa) Previous opinions. 

 (b) Contour Map. 



fc) Reconstruction of the Cinder Cones, 

 (i.) Dip of tuff beds, 

 (ii.) Slopes of external faces. 

 (d) Section through the reconstructed cones, show- 

 ing collapses, etc. 



9. The Subsidences: — 



(a) Extent, cause, and time of collapse. 



(b) The Blue Lake. 



fc) The Leg of Mutton Lake. 



(d) The Valley Lake. 



(e) Crater Lake. 



(f) The Moorak Depression. 



(g) The Punch-bowl. 



(h) The Water of the Lakes. 



10. Scenic and Economic Aspects. 



11. Summary. 



