32 The South Australian Naturalist. 



rose to form dry land, and a great river found its way across the 

 new land surface, carving awaj^ portion of the limestone beds 

 to form the valley wall represented by this line. 



The beds marked B are not so clearly ''bedded" as those 

 first dealt with, but there is evidence that they were laid down 

 under water. They consist of fine sands and occasional gravelly 

 beds, all brown Avith iron. Fossils are found in them, but 

 these (mainly fragile shells) are all remains of fresh- water 

 molluscs. Although these sands are 50 to 60 feet above the 

 present river level, the evidence is clear that they were de- 

 posited by this same Kiver Murray. Fed with waters drawn 

 from the great highland belt, that extends from Southern 

 Queensland to the Victorian Grampians, the river carved out 

 the sloping valley face that is partly preserved in the line 

 separating the beds A and B (see sketch). Then the course of 

 the stream was changed, the carving-out energies were directed 

 towards another portion of the valley -wall, and river silt was 

 slowly deposited at the place we are discussing. 



Chapter C. — Let us now read the last chapter of this clift: 

 story. Overlying the beds A and B, there is a small deposit of 

 roughly-bedded, dark-coloured sands, marked C in the sketch. 

 They are somewhat insignificant, and from the point of view 

 of the geologist should doubtless be quite ignored. Still, their 

 story is there for the reading. These sands are (luite loose and 

 uncompacted, with some signs of irregular bedding. They 

 have been carried down by a small intermittent stream, Avith 

 some assistance from the winds. There is fossil evidence here 

 also, if one may be forgiven for slightly straining the generally 

 accepted meaning of the word fossil. Well embeddecl in the 

 sand, just above their base, was found — a piece of horse-dung. 

 Evidence here also of the existence of man, if such were neces- 

 sary, insofar as machine-cut chaff testifies to his handiwork. 

 The sands have been Avashed doAvn from the higher bank, pre- 

 vious to the excavation for the pumj^ing plant, but subsequent 

 to the appearance of men and horses on this portion of the 

 river bank. In a few years all trace of this last deposit may be 

 gone. Still, to a party of naturalists regarding only the clift*- 

 face, and seeking there for signs and tokens to tell the age of 

 each deposit, it was of some interest to find the story carried up 

 to a point where Ave may speak in terms of years. 



SloAAdy acting through tens of thousands of years, the forces 

 of Nature built up those great limestone clifi:'s, AAiiose faces Avill 

 still be braving the elements for uncounted years to come. But 

 the rapid Avork of the small runnel, carrying doAA^n the topmost 

 bed of sand, must be quickly noted ere it is gone again for 

 ever. — (Adapted from an article in "The Australasian.") 



