Vol. 60.] GLACIAL GEOLOGY OF TASMANIA. 39 



accepted the former occurrence of local ice-sheets in the Mackintosh 

 Valley. 



The earliest-published suggestion of the recent glaciation of 

 Tasmania known to me is in a report by Mr. T. B. Moore, issued 

 in 1883. ] In this report the author refers to a boulder-deposit on 

 ' Painter's Plain ' in Central Tasmania, at the junction of the 

 Franklin River and its tributary, the Loddon ; these plains are 

 at the height of 1220 feet above the sea. Moore describes the 

 bed as an 



' accumulation composed of every variety of rock, with large boulders of green- 

 stone strewn over the plains. These boulders are also met with cropping out 

 on the tops of the surrounding quartzite-hills. It is quite possible that these 

 masses of greenstone, occurring as they do in solitary blocks or groups, have 

 been brought, in the Glacial Period, from the higher lands of Mount Lyell, or 

 the Eldon Range, and deposited by that agency in their present resting-place.' 



Further evidence was advanced two years later in a paper by 

 C. P. Sprent, 2 who claimed a glacial origin for some erratic boulders 

 in the Mackintosh Valley. The Mackintosh or Upper Pieman 

 River flows through a gorge which is said to be 1400 feet deep, and 

 cut through a plateau about 2000 feet above sea-level. Sprent 

 crossed the Mackintosh, between its tributaries the Bingham River 

 and the Cradle River, which flows from Cradle Mountain ; hence 

 his locality can be closely determined, and it is clearly in the high 

 plateau of North-Western Tasmania. 



Sprent's most striking evidence was the discovery in the Mackin- 

 tosh gorge of some granite-boulders, 5 tons in weight. The 

 adjacent rocks were of sandstone ; he could find no granite in 

 situ ; and thought it impossible to account for the occurrence of 

 these granite-masses ' except on the glacial supposition.' This 

 evidence was not convincing, for the erratics might have come 

 either from Upper Paheozoic glacial deposits, or even from local 

 granite, which might have occurred in the district. Sprent asserted 

 {op. cit. p. 58) that 



' traces of glacial action are common all over the West Coast in localities close 

 to the high mountains ' : 



he gave, however, no evidence in support of this view, and stated 

 that 



'it is probable that these glaciers did not extend to the low lands.' 



Mr. Johnston, in his voluminous work, ' The Geology of Tas- 

 mania ' 1888 (p. 104), admitted glacial action as 



' an important agent in the denudation of the immense canons or gorges 

 which trend away from the elevated plateau [of North-Western Tasmania] 

 westward.' 



But he agreed with Sprent that the glaciers were local in their 



1 ' Exploration.— Mr. T. B. Moore's Report upon the Country between Lake 

 St. Clair & Macquarie Harbour' Pari. Pap. Tasm. vol. xlv (1883) no. 56, 

 p. 6. 



2 'Recent Explorations on the West Coast of Tasmania' Trans. & Proc. 

 Roy. Geogr. Soc. Austral. Vict. Branch, vol. iii (1887) p. 58. 



