550 



erratics are relatively small, the largest observed being about 

 18 inches in length. 



The most southerly outcrop of the beds is at the Mount 

 Remarkable Creek, just below the junction of the roads on 

 the southern boundary of Sec. 206. The tillite does not 

 cross the creek to the southern side. The strike of the beds 

 at this point is due north, and for about a mile, going up 

 stream, the creek makes the dividing line between the tillite 

 on its left bank and the Tapley Hill shales on its right. 

 "Within this distance the tillite makes some bold features in 

 the outcrop, including two heavy ledges of rock that cause 

 waterfalls and a conspicuous pinnacle of rock on the sky line. 



On the southern boundary of Sec. 205 the Mount Creek 

 makes a sharp turn to the west (going up stream), from which 

 point the creek, instead of flowing along the boundary-line 

 between the two sets of beds, has the Tapley Hill shales on 

 both sides, while the tillite, with its northerly strike, follows 

 a more easterly line along the higher slopes and passes over 

 the watershed that separates the Mount Creek from the 

 Spring Creek. 



In passing over into Spring Creek the latter forms the 

 dividing line between the tillite and the Tapley Hill shales 

 for a distance of four and a half miles, when the tillite is cut 

 out by a strike-fault at about a mile up stream from the 

 Spring Creek copper mine. Looking up the valley from the 

 northern extremity of the tillite there is seen to be a clear 

 line of demarcation between the tillite and the underlying 

 quartzite, marked by the vegetation of the respective areas; 

 the former being well grassed, while the latter is almost bare 

 of grass and carries low scrub. Notwithstanding the rise in 

 the valley of the Spring Creek towards its head, the tillite 

 rises along the flanks of the hill still more rapidly until, near 

 its highest point, the middle slopes of the western side of the 

 mount consist of this rock. 



4. Ribbon Shale (Tapley Hill Series). 



In the type district, near Adelaide, as well as in some 

 other localities, the beds of this series have developed some 

 measure of cleavage by which they split readily at a high 

 angle to the bedding-plane and are commonly worked on the 

 cleavage. At Mount Remarkable, and in most localities in 

 the northern portions of the State, the corresponding beds 

 have been subjected to less tangential pressure, and conse- 

 quently have not developed slaty-cleavage, but split readily 

 on the bedding-planes ; they are, therefore, more appro- 

 priately classified as shales rather than slates. 



