301 



form the most important feature in the sea-cHffs till Blanche Point is reached, 

 a distance of a mile and a half. As these beds rise from beneath the older 

 marine series at Blanche Point it will be more convenient to study them in con- 

 nection with that part of the section and then trace their outcrops to the north- 

 ward, which will be done in the next division of our subject. 



Pleistocene and Recent Beds in Section D. 



The main cliffs that occur between the estuary of the Onkaparinga and 

 Pedler's Creek are formed of reddish clays and gravel, much incised by 

 rain sculpture. They reach their maximum height in the headland of Seaford 

 (Sec. 340, Hundred of Willunga), at 100 feet, and have a bed of coarse and 

 hard nodular travertine, 6 feet in thickness, near their upper limits ; large 

 blocks of this travertine encumber the beach. 



Pedler's Creek is the most important outlet for surface drainage between 

 the River Onkaparinga and the Myponga Creek, and at its mouth there is the 

 greatest development of sand-dunes that occurs within the limits of Gulf St. 

 Vincent. They have a frontage to the sea of about a mile in extent, and, on the 

 southern side of the stream, they are a travelling mass, up to 100 feet in height, 

 encroaching towards the north-east. This drift has evidently been long estab- 

 lished, as the creek has been gradually driven, by their encroachment, further and 

 still further to the northward. Its former outlet (into which the sea still flows 

 in high tides) has been, quite recently, cut off from the main creek by the 

 encroaching sand, and the flood waters have had to take a more circuitous 

 course, while much cultivated land has become buried by the sand drifts. 



An interesting feature of this part of the coast is the existence of a raised 

 beach, evidences of which occur on both sides of the entrance to the creek. 

 On the southern side a ridge of large rounded stones occurs enclosed within the 

 present sandhills, distant from the beach by about 20 yards, and at a height 

 of 12 feet above the present highest tides (see pi. xxiii., fig. 1). These stones have 

 been piled up by powerful wave action and in positions where no waves can 

 reach them now. At the back of this raised bank of stones is a much larger 

 area, more or less covered with rounded stones, and the usual littoral of a sea 

 beach. This area has been recently bared by the wind and contains evidences 

 of aborigines' occupation in numerous hearths, chipped stones, and broken 

 Turbo, Purpura, and other shells, but the beach stones are far too numerous to 

 be referred, in their entirety, to human agency, while many of the marine 

 exuviae are of a kind that did not come within the range of the aborigines' 

 attentions. A very large number of the shell, Chama ruderalis. Lam., occurs, 

 many having both valves attached ; also numerous small corals, polyzoa, brachio- 

 pods, and small mollusca, together with other beach sundries. In one place, on 

 the northern side of the creek and near the landward limits of the raised beach 

 area, a bed of Coxiella badgerensis, Johns, has formed a whitish calcareous 

 deposit, which suggests the existence of a brackish pool or lagoon in which the 

 waters of the sea and creek mingled, and in which this brackish-water gasteropod 

 abounded. 



SUB-SECTION E. 



RED OCHRE COVE TO SNAPPER POINT (4i MILES). 



Miocene Series in Section E. 



Blanche Point, 140 feet in height, is the most striking headland within the 

 limits of the coastline now under description. It consists of several subsidiary 

 points, separated by small bays, together with a sea-stack ("gull-rock") that is 

 usually surrounded by water. There is a close similarity between Witton Bluff 

 (Port Noarlunga) and Blanche Point, both geologically and physiographically. 



