580 



also flank the outer foot hills of Mount Remarkable opposite 

 Melrose, and attain a height of 200 feet above the plain. 

 This extensive alluviation exists on a present-day watershed. 

 Such an anomaly is explained by cognate evidences which 

 prove the former existence of great waterways coming down 

 from the north, and which found their outlet by the valley 

 now occupied by Gulf St. Vincent. The Willochra Creek 

 •occupies the bed of this dead river, but instead of flowing 

 south, as of old, it flows in the opposite direction and empties 

 its waters into Lake Torrens. 



In one of my visits to Mount Remarkable I had the 

 pleasure of being accompanied by my colleague, Dr. E. O. 

 Thiele, who has kindly undertaken to describe the igneous 

 rocks that occur on the foot hills of the south-eastern portions 

 of the mount, and these descriptions will form an appendix 

 to the present paper. 



The difficulties of mapping the geological features have 

 been considerable on account of the very imperfect and 

 erroneous outlines of the "Hundred" maps covering the region 

 examined. This difficulty was in part met by the courteous 

 assistance of the Surveyor-General (Mr. E. M. Smith, I.S.O.), 

 who kindly placed at my disposal the latest results of the new 

 survey of such portions of the ground that were being sub- 

 divided by the Government for repatriation purposes. I have 

 also to acknowledge the kind assistance of the Geological 

 Survey Department for valuable aid in preparing the map 

 for publication. 



DESCRIPTION OF PLATES. 



Plate LIII. 



Geological Sketch-map of Mount Remarkable and the Foot 

 Hills of the mount. 



Plate LIV. 



Fig. 1. Photographic view of Mount Remarkable taken from 

 the eastern plains at a distance of four miles from the mount. 



Fig. 2. Photographic view of the "Cat Rocks," opposite 

 Melrose, at a height of about 600 feet from the base of the mount. 

 These rocks form an irregular outcrop of mashed slates. 



VI. — Appendix. 



Petrographical Notes on the Igneous Rocks of 

 mount Remarkable. 



By E. O. Thiele, D.Sc. 



The following observations are the result of the peno- 

 logical examination of a series of igneous rocks occurring in 

 the foothills of Mount Remarkable, near the township of 



