50 DISCOVERY OF AN ABORiaiNAL CIIlPrED FLAKE. 



any way of making even a roughly approximate estimate 

 of this? Two and a half miles to the north-west, near the 

 MacGregor and Aberfoyle claims, two hills of made ground, 

 Brown's Hill (sometimes called the Aberfoyle Hill) and 

 the Little Hill, rise from the plain to a height of about 

 60 feet. These arc residual hills of cemented marine 

 drift which once covered the area of this great plain. 

 A mile and a quarter to the north-west of the Doone the 

 Government line of bores shows bedrock at upwards of 

 100 feet below the surface of the drift, but in that direc- 

 tion there does not appear to be any available indication 

 to serve as guide in an estimate of denudation. To keep 

 strictly wdthin the limits of the evidence, we must confine 

 our estimate of minimum denudation to about 70 feet, 

 which is the difference of level between the Doone wash 

 and the summit of the Aberfoyle Hill. 



The Doone is about 7 miles from the coast line at 

 Boobyalla ; its height above sea level has not been deter- 

 mined, but probably does not exceed 60 or 70 feet, and 

 i.^ perhaps less than that, as I am informed that the tide 

 backs up the fresh w^ater in the Ringarooma west of the 

 Aberfoyle Hill. 



Further confirniat ion of the antiquity of the wash 

 is derived from the fact that the general body of drift 

 extends southwards across the Ringarooma River, which 

 has subsequent!}' intersected it. Thus the wash and the 

 overlying drift existed before the Rinoarooma flowed in 

 its present channel. But can tlie age be thrust as far 

 hsick as the tirjie when the ancient Ringarooma flowed 

 cut to sea at the west end of Mt. Cameron? Such a 

 conclusion would involve an age too great to accord with 

 accepted views of the antiquity of man in Tasmania, but 

 the deposition of these sediments was plainly prior to llio 

 f^nal establishment of the existing channel in this part 

 '•[ the rc.ursp of the river. 



