560 



The presence of arenaceous limestones — or calcareous 

 grits — can generally be noted among the lower members of 

 the purple-slates series. They occur at Marino, near 

 Brighton, at Hallett's Cove, and at Noarlunga; at the last- 

 named place they are quarried for road metal. They occur 

 over a somewhat wide outcrop on the White Mine Creek, just 

 west of the position where the two faulted segments of lime- 

 stone are opposed at a sharp angle and can be traced down 

 to the creek, adjacent to and parallel with the north and 

 south fence. They are also seen to the northward, across the 

 Waterfall Greek, and on the top of the ridge, on the north 

 side of this creek, and after passing through the east and 

 west fence follow the slope of the bank into the next valley. 



The faulted segment seen in the Spring Creek a little 

 west of the Wilmington Road, gives a new direction to the 

 beds. The throw which has brought the limestones into a 

 position almost parallel with the creek has controlled the 

 overlying beds in a like manner, so that the purple-slates have 

 there a strike to the north-east. The latter continue to the 

 northward, as the main surface features, for many miles, by 

 Wilmington, Horrock Pass, etc. The road that passes from 

 Wilmington through Horrock Pass to the coastal plains is in 

 purple-slates throughout, exhibiting very fine rock scenery, 

 and near the bottom of the pass precipitous hills of these 

 slates rise 1,000 feet or more in height. 



(c) THE PURPLE-SLATES AT THE SOUTHERN END OF THE MOUNT. 



The southern end of Mount Remarkable is cut trans- 

 versely by a powerful fault, which truncates all the beds 

 coming in from the north, and is bounded on its southern 

 side by the purple-slates series. The line of division made by 

 the fault is very marked, and for some distance is coincident 

 with the bed of the creek. 



The approach to the southern end of the mount is by 

 Bartagunya sheep-station house. Behind the house there 

 is a rough surface of quartzite (dip, W. at 72°) with under- 

 lying purple-slates. Similar beds are exposed in the small 

 creek close by the house (dip, W. 20° S. at 80°) and at a 

 few hundred yards further down the creek is a strong ridge of 

 whitish quartzite (dip, W. 10° S. at 55°). On the left-hand 

 side of the path, rising to the saddle in going over into the 

 Mount Creek, are some large blocks of a reddish slaty-lime- 

 stone very characteristic of the 'purple-slate beds. Going 

 down, on the other side of the saddle, the slates show a dip 

 to the S.W., but at the bottom of the hill, near the gate, 

 the dip is to the N.E., the beds being much broken and 

 sheared as they near the fault-plane. 



