liv ruoi'fossoK sm t. \v. k. david, k.15.e.. Kxr. j^Y 



There are many hundreds of feet in thickness of soft 

 sandstones and flays below the lowest bed of shingle, but 

 they appear to be pre-fjlacial. 



Mr. Arndell Lewis would ascribe such outwash gravels 

 to the maximum Pleistocene ice-sheet of approximately Riss 

 or Mindel age. Mr. Arndell Lewis appears tentatively to 

 hold the view that the lowest evidence of glaciation in the 

 Broad River Valley at National Park is of about the same 

 age as the outwash gravels of Strahan. Such glaciation at 

 National Park would be approximately at its lower limit 

 about 2,000 feet above sea level, possibly as high as 2,400 

 feet. 



Recently Dr. Loftus Hilis has observed evidences of 

 glaciation at Mount Victoria, between St. Helen? and 

 Seottsdale, at an altitude of about from 3,964 feet (which 

 is given as the altitude of the summit) for several hundreds 

 of feet downwards. 



The question of Pleistocene glaciation and its a.'^e in 

 this north-east pai't of Tasmania ]<? of .special importance 

 in regard to a very important piece of evidence about to be 

 detailed presently, by far the oldest as yet recorded on the 

 iiubject of the antiquity of aboriginal man in Tasmania. 



In this part of the island there are widespread sheets 

 of shingle and gravel, with peaty beds intercalated, which 

 have been worked extensively for stream tin between Herrick 

 and Boobyalla. At the Pioneer Mine, to the north of 

 Herrick, these strata attain a thickness of at least 80 feet; 

 they are up to 68 feet in thickness at the Scotia Mine, oiie 

 mile to the north-west of Gladstone. At the old Doone 

 Mine, about a mile west of the Scotia, the drift was about 

 15 to 25 feet thick. The drift apparently dips below sea 

 level towards thf; coast below Boobyalla. It appears to 

 the writer that this old peaty granite sand drift, which the 

 late W. H. Twolvetrees suggested tentatively (35) was 

 raised beach material, is in reality, in view of later evidence 

 now available, outwash apron material, analogous to that 

 of Strahan. In this case it would have b^en formed by 

 the thaw waters of the last great ice sheet, at newest the 

 Wiirm ice sheet, dating back to about 17,000 years ago. If 

 this supposition is correct, the deposit would have been laid 

 down by extensive floods coming from the head of the 

 Ringarooma Valley and its numerous tributaries, at a time 

 when Mount Victoria was under ice and the lower spurs 

 of the adjacent ranges supported extensive nevee fields. 



