49 



This interesting locality can be most conveniently reached 

 by diverging from the mam road at Sellick's Hill township, 

 which is situated one and a half miles from the beach. On 

 two former occasions, one of which was as far back as 1897, 

 I had visited the spot and noted the great throw in the 

 Eocene limestones, but on both occasions circumstances pre- 

 vented my making a detailed examination of the beds. "With 

 the latter object in view I revisited the locality during the 

 late vacation, and took photographs' of some of the more 

 interesting features. 



At Port Willunga, about 7 miles north of the disturbed 

 area, there are excellent sections of the Cainozoic beds in the 

 sea cliffs, showing a dip of about 5° to the south, by which 

 they are lost to sight at about two miles south of the Port 

 Willunga Jetty. Low banks of alluvium and sand-dunes 

 take their place, and, at about four miles south from the 

 jetty, the old mouth of the Onkaparinga River is indicated 

 by a wide valley with a low shore only feebly protected from 

 the sea. 



Immediately south of this point, the sea cliffs, consisting 

 of alluvium, once more make their appearance and increase 

 in height till, at the distance of a mile, they attain a height 

 of 200 ft., with the Cainozoic limestones outcropping at their 

 base. Whether this absence of the limestones from the inter- 

 vening space of three miles arises from a synclinal fold in the 

 rocks or from erosion effected by the old river drainage, is not 

 quite clear. 



Description of the Cainozoic Beds in the Disturbed Area. 

 (See Map, plate x.) 



These beds come to the surface about midway between 

 the outlet of the Sellick's Hill Creek, which has cut a deep 

 ■canyon in the alluvial beds, and the so-called Mount Terrible 

 Creek,' 2 ) about a mile further south. The beds consist of 

 white and yellowish limestones, of varying hardness, made 

 up mainly of triturated fragments of polyzoa, echinodermata, 

 and shelly material. The outcrop is in two sections, divided 



(2) This creek, for the distance of about a mile, forms the 

 boundary between the Hundreds of "Willunga and Myponga. It 

 is locally known as the Mount Terrible Creek (or Gorge) under 

 a misunderstanding as to the correct position of Mount Terrible. 

 The latter, as marked on the official maps, is situated one and a 

 half miles to the east of Sellick's Hill township and about three 

 miles from the Creek to which the name of the Mount has become 

 locally attached. A more appropriate name would be Boundary 

 Creek, as it makes the dividing line between the two hundreds, 

 mentioned. 



