president's address. — SECTION c. 169 



after receiving the Siccus River as a tributary, flows into the south end 

 of Lake Frome. Bores put down near the lake have penetrated 

 hundreds of feet of alluvial and carbonaceous sediments ; and, at 

 Orroroo, a Government bore penetrated 591 feet of river sands and 

 gravel without reaching bed-rock.* The last-named fact is the more 

 remarkable because Orroroo is situated near the present water-parting 

 of the country. 



The rivers of South Australia that occur on the southern side af 

 the east-and-west water-parting are insignificant. The proximity of 

 the watershed to the coast precludes the possibility of large rivers. 

 The old meridional rivers of the southern seaboard were wiped out as 

 the consequence of a double reverse — 1st, through the cutting off of 

 their main supplies, which came from the inland regions ; and, 2nd, 

 by the successive throw-downs to the west, which removed their 

 western barriers and compelled them, sectionally, to find an outlet 

 towards the sinking area (or drowned valley) on the west. Thus, 

 the Bundaleer Creek, Freshwater Creek, the Hut and Hill Rivers, 

 and Farrell's Creek, are an interesting group of streams as they occupy 

 in portions of their courses old meridional valleys, and are residuals 

 of the older drainage ; but, in relation to the present, they are a group 

 of subsequents which unite, near Spalding, to form the River Broughton, 

 and then, by a deep and narrow gorge, they penetrate the ranges, at 

 right angles to their previous courses, and find their outlet in Gulf 

 St. Vincent. 



The Rivers Light and Gilbert pursue a similar course, first north 

 and south and then west to the Gulf. These rivers are so recent as to 

 occupy only shallow ditches, cut out of the softer rocks, and the rotten 

 condition of the Cambrian beds over which they flow proves that the 

 existing surface has been long exposed to atmospheric corrosion ; 

 that is, the present drainage is super-imposed on an older and dead 

 system of drainage. This is made evident by sheets of consolidated 

 gravels quite distinct from the present streams, as at Yacka, on the 

 Broughton River, where the old consolidated gravels are three miles 

 wide. 



The River Torrens takes its rise on the eastern side of the Mount 

 Lofty Ranges and penetrates these ranges at a right angle, and, as in 

 the case of the other rivers mentioned, also finds its way to Gulf St. 

 Vincent. The Torrens is one of the oldest of the existing rivers of 

 South Australia. It is a consequent stream, brought into existence by 

 the elevation of the South Australian plateau. It has had to cut its 

 way down through some of the hardest Cambrian and pre-Cambrian 

 rocks, but has been able to keep time with the elevation and maintain 

 its westerly course to the sea. The gorge of the river is sometimes 



* Howchin — " Description of an Old Lalie Area in Pekina Civek and its Rtlation to Recent 

 ecological Changes." Trans. Roy. Soc. S. Aus., Vol. XXXIII, pp. 253-261. 



