126 



active evaporation, and on reaching the up-turned edges of the 

 older beds trickles in at every pore and crevice surcharging the 

 same to great depths. We have thus formed at considerable 

 altitude an internal cistern, as it were, which has only to be 

 tapped, naturally or artificially, at a lower level to obtain an 

 overflow. In this case, to reach the contents of the subter- 

 ranean reservoir, nature has excwated the deep valleys of 

 Gould's, Little Garden, and Tenafeat Creeks nearly in paral- 

 lelism with the strike, and on the dip side of the fundamental 

 rocks. These geological features would naturally lead the 

 geologist to conclude that all, or nearly so, of the outflow 

 would be by these channels. It is not so, however ; the deep, 

 transverse chasms of Smith's Creek and Spring Gully have 

 effected an outlet direct to the west, by which by far the 

 greatest outflow takes place. Indeed I might almost venture 

 to say that the permanent supply to these creeks is not to be 

 surpassed for the given area by any other in South Australia. 

 On the map I have indicated the sites of the springs, all of 

 which flank the heights overlaid by the Upland Miocene beds. 



Soils. 



The soils in Munno Para partake much of the character of 

 the beds on which they rest. Therefore, throughout the 

 uplands, the character of the soil might be taken as a pretty 

 sure index to the kind of rock below. Where a stiff clay soil 

 prevails the bed-rock will consist chiefly of clay-slate. When 

 the soil is more friable and loamy, the underlying slate is pro- 

 bably interbedded with a band of fundamental limestone giving 

 a more pulverous character to the soil, and this is in my 

 opinion one of the chief sources of our crust limestone or 

 travertine. This description of soil, though probably not so 

 inexhaustible, is in the virgin state more fertile than those 

 overlying the Drift. The soils formed from the debris of the 

 quartzites and Upland Miocenes are generally of a coarse 

 sandy character, and are less enduring than either of the 

 above. 



Finally, I beg to direct attention to patches of subsoil 

 occurring in protected spots at high altitudes, which at first 

 sight might readily be mistaken for outliers of the true Drift 

 series. A little investigation of the imbedded material and 

 comparison with that from the natural surroundings, from 

 whence it might reasonably be expected to have been derived, 

 has invariably led me to the conclusion that it is merely the 

 product of a comparatively recent subaerial wash from the 

 adjoining slopes. 



Vegetation. 



Thirty years ago the prevailing indigenous grasses of Munno 



