59 



possibly, modern South Australia took its main features of 

 relief. It is in this view of the subject that the importance 

 of the Sellick's Hill section must be judged. It forms the 

 geological key for a much wider interpretation, the evidences 

 it supplies is accumulative and consistent, and the conclu- 

 sions to which it brings us is that within comparatively recent 

 geological times the mountain systems of South Australia 

 have been profoundly affected and have passed through recon- 

 structive stages. 



EXPLANATION OF PLATES. 



Plate X. 

 Map of locality described. Shows the areas occupied by the 

 Cainozoic rocks (which have undergone distortion by earth move- 

 ments), and also a geological plan of the Cambrian beds that 

 form the Willunga Ranges. Note the juvenile drainage seen on 

 the northern scarp-face of these ranges. The inset-map shows the 

 position of a small high-level outlier of Cainozoic limestones which 

 occurs on the Hindmarsh Tiers. 



Plate XI. 

 View of Willunga and Sellick's Hill Valley, with the Willunga 

 Ranges and Sellick's Hill in the distance, as seen from Aldinga. 

 The ranges form the north-west fault-scarp of the dislocated 

 block. 



Plate XII. 

 The basal beds of Cainozoic limestones, tilted, and resting 

 unconformably on Cambrian slates in the sea cliffs. 



Plate XIII. 

 Folded lower Cainozoic rocks, in sea cliffs, looking north. 



Plate XIV. 

 General view of Lower Cainozoic rocks, thrown down at high, 

 angle, forming sea cliffs, looking south. 



Plate XV. 

 Nearer view of cliffs shown in plate xiv. 



Plate XVI. 

 Lower Cainozoic rocks, at high angle, forming spur of cliffs, 

 looking north. 



Plate XVII. 

 Contorted Lower Cainozoic rocks, forming an isolated' 

 pedestal on beach. 



Plate XVIII. 



Vertical and reversed folds of Lower Cainozoic rocks on beach. 



Plate XIX. 

 Thrust-plane developed in Lower Cainozoic rocks, caused by a 

 slide, consequent on trough-faulting. Looking south. 



