305 



On the landward side of Blanche Point the older marine beds form a strip 

 of country, bordering the coast, for at least a mile and a half in width. A little 

 east of Port Willunga, a north and south district road crosses the Aldinga Creek 

 (Sec. 392, Hundred of Willunga), and in a cutting on the northern side of the 

 stream these beds are exposed. The main road to Adelaide crosses the Aldinga 

 Creek on the eastern side of the township, and after crossing the first ridge on 

 the road and rising to the second, going northwards, the road passes through a 

 deep cutting, at the southern end of which are marlstones containing remains of 

 Pecten, Turritella aldingae, etc. (Sees. 377, 179, Hundred of Willunga). These 

 fossiliferous beds are overlain by ancient fluviatile deposits. Still further to the 

 north (but situated on the parallel road to the westward of the main road) are 

 other outcrops of these beds. This district road, on the northern side of Ben- 

 nett's Creek, goes through a deep cutting of the marine beds in which the char- 

 acteristic Turritella occurs in great numbers. The fossiliferous rock is seen, 

 not only on the road, but in outcrops in the adjoining grounds facing into 

 Bennett's Creek (Sec. 374, Hundred of Willunga). The beds have an easterly 

 trend and are no doubt connected with the outcrops on the main road described 

 above. Similar outcrops can be traced at intervals as far as McLaren Vale, 

 four and a half miles from the coast. A ridge of these rocks occurs on the 

 northern side of McLaren Vale railway station — the district road that passes 

 the station, going north, exposes a section of the beds in a cutting on the rise. 

 The beds have also been proved in various sinkings in the neighbourhood, and 

 are indicated, in places, by fossiliferous surface stones scattered over the culti- 

 vated land. 



Between the township of Port Willunga and the jetty the older marine beds 

 form the lower portion of the cliff in vertical walls of calcareo-siliceous rocks, 

 but include layers of an argillaceous character. The gradual dip of the beds to 

 the south-west, at a low angle, reduces the height of the cliffs to the southward, 

 until each superior bed, in turn, reaches sea level. 



From Port Willunga jetty, southwards, there is a wide floor of the Tertiary 

 rocks, extending from the base of the cliffs, seawards, representing a plain of 

 marine denudation that is bared at low water. At Snapper Point this marine 

 pavement has a width of, at least, a quarter of a mile which is bared at low water 

 and evidently causes shallow water much further out to sea. Snapper Point 

 presents the unusual feature of a headland that has a greater extent of foreshore 

 than the cliffs on either side. This no doubt arises from the great breadth of 

 the rock pavement which breaks the force of the sea and has led to an accumula- 

 tion of sand in front of the Point. The sea has receded at this point, within 

 recent times, the cliffs being situated inland and are bordered by a festoon of 

 sandhills, between the cliffs and high-water mark, with a well-grassed valley 

 between the sandhills and the cliffs. 



Lower Pliocene Beds in Section E. 



The fossiliferous Pliocene beds are practically continuous from Blanche 

 Point to Snapper Point. At Blanche Point the beds form the upper limits of 

 the vertical face of the lower cliff. Southward from the Point they make a 

 distinct scarp and platform in the cliffs, as far as Aldinga Creek, the white, 

 craggy limestone of the beds rendering them conspicuous. 



These newer marine beds are, in a general way, divisible into two parts 

 which are very much in contrast from each other. The lower portions consist 

 of white and reddish sands, either friable or irregularly cemented, and contain 

 most of the fossils. The upper portions consist of a white marly limestone, 

 often concretionary in structure, and weathers into a rough and craggy face 

 which is, generally, the most prominent feature in the outcrops. Grains of 



