277 
series, so as to outcrop on both sides of the limestone, to- 
gether with collateral evidence, proves the existence of the 
important strike fault (A), already described. 
At the head of the gully road (going down to the ford of 
the river), the beds displaced by the fault (B) are cut 
diagonally by the strike fault (C). At this point the impure 
limestones, underlying the main limestone, form a small 
triangular patch on the east side of the fault, but are cut 
out, about one-third distance down the hill towards the 
river. They occupy most of the ground bounded by the 
faults (C), (D), and (F), and can be well studied in the 
gorge of the river and its tributaries within the space 
named. Where they are cut by the fault (F), in Long 
Gully, the beds are strongly banded, and dip south-east, at 
10°. Towards the mouth of Long Gully the dip changes to 
north-west, at 30°, and then increases to 65°-70°, with 
wavy and vermiculate structure strongly shown at the 
junction of the creek with the Onkaparinga. 
Higher up Long Gully, near the east-and-west district 
road, these beds have a great spread on both sides of the 
creek. On the west side the beds are intersected by several 
faults, and make a sudden curve to the east; whilst on the 
edst they occupy the entire space stretching to the 
Onkaparinga. 
From the first appearance of these siliceous and earthy 
limestones in the bed of the Onkaparinga, near the Ford, 
they continue to form the cliffs of the river for more than a 
mile, measured in a straight line up the stream. Immedi- 
ately underlying the main limestone. are very siliceous and 
earthy beds, which dip west, at 73°, and are thrown into 
acute anticlinal and synclinal folds, reaching high angles, 
from 55° to 70°, as far as the outlet of Long Gully, in Sec- 
tion 57, where the beds are more calcareous. On the eastern 
side of this tributary the dip is 45° east, passing into a 
Syncline at low angle. The turn of the river to the north- 
wards, in Section 49, makes its course almost co-incident 
with the strike of the beds, until the river bends in a north- 
east direction, and at the curve the beds are seen to be 
vertical. The dip then passes to the south-west and then to 
the south-east, in rolling curves of about 20?, in Section 50. 
in Sections 43 and 51 the beds partake more of the char. 
acter of banded calcareous slates, with a dip west, at 40°, 
and mark the passage from the siliceous limestones to the 
Tepley's Hill slates, although the transition is gradual, and 
by no means strongly marked. The cleavage planes are, 
almost at right angles to the bedding, with a strike of 10° 
west of south. The dip of the beds increases, from the posi- 
