121 
The section at Hallett’s Cove is as follows :— 
Feet 
Red and grey argillaceous sands tie ae rah oe) 
Sand-rock Sete ve oi ee SS etl 
Sands (yellow)... = a: ae clay eo 
White chalky limestone, with much sharp quartz-sand 
interspersed ; fossiliferous ee aps ee 4 
135 
The common fossils are Potamides sp., Pecten antiaustralis, 
P. consobrinus, Spondylus Aldingensis,* Placunanomia Tone, 
Ostrea arenicola, Anapa variabilis, Laganum platymodes, and 
Orbitolites complanata. 
III. THe EocEnE oF ALDINGA Bay. 
Though a reference to this most important and instructive 
section was published as early as 1878, yet as previously stated, 
no detailed description has been given. The characteristic 
features of it are:—_The varied nature of its sediments, the 
largely unique fauna, and diverse life-groups co-ordinate with the 
change in sedimentation. 
The Eocene beds occupy a continuous section of nearly three 
miles in length, commencing about 40 chains due north of 
Blanche Point, and terminating southwards on the approach to 
Schnapper Point, where they descend below sea-level], but they 
reappear on the extreme south of Aldinga Bay. (See map.) 
The Eocene and the overlying Miocene occupy a small basin of 
low-level country bounded all round, except the sea-frontage, by 
more elevated country occupied by Archean rocks. The most 
inland occurrence of Eocene strata is at Tintaro (Section 681, 
Hundred of Willunga) about five miles due East from the coast. 
The maximum inclination of the Eocene strata is 5° in a direc- 
tion W. 10° S., from which is deduced an increasing altitude in 
an easterly direction; this is partly corroborated by a few well- 
sinkings and quarries situated at various distances, up to a mile 
or so from the coast. The occurrence of bedded deposits with 
Turritella Aldinge at elevations up to 250 feet in Maclaren Vale 
{sections 126, 127, 137), and of blocks of a siliceous rock charged 
with Eocene fossils at an elevation of 600 feet at Tintaro (section 
681), cannot be accounted for on the basis of the observed dip of 
the coastal sections ; but they point to a basal deposit having a 
slope corresponding with that of the surface on which they rest. 
* Pecten spondyloides, mihi, proves to be a Spondylus, and as the original 
species-name is incompatible with the revised generic location, it is altered 
as above.—R. T. 
