Geological Notes, Tasmania. 125 



may have been originally moraiiiic ; but, in the absence of 

 further evidence, it seems to us most probable that it has been 

 distributed to its present position by the King River when 

 flowing at a higher level. On the overland track a cutting 

 occurs, about one-third of a mile from the ci'ossing, which shows 

 a " wash " of water-worn pebbles and V)0ulders that is evidently 

 of fluviatile origin, and which is about tifty or sixty feet above 

 the present level of the stream. 



If we are to believe that these boulders have been transported 

 to their present position by the direct action of ice, we will have 

 to admit a much wider glaciation in Tasmania than is generally 

 believed to have taken place, the height of the King River 

 Valley at this place being only 600 or 700 feet above the sea. 

 "We may add that other evidence of glaciation in the foi'm of 

 roches moutonnees and ground moraines seemed to be quite 

 absent. We noted a large mass of greenstone lying close to the 

 track about a mile from the crossing, and resting on Silurian, 

 which is much decomjDOsed and broken up on the surface. But 

 it would be unwise to infer much from this one instance. There 

 may be a dyke in the vicinity. 



From the King River to the Victoria Pass the rocks are of an 

 ordinary Silurian type — slates, shales, and sandstones. Fossils 

 are abundant in places. At a cutting on the track near the 

 King River crinoids were abundant, and trilobites and other 

 forms were common, but we saw no graptolites. Our specimens 

 have unfortunately gone astray. 



From Victoria Pass the character of the rocks changes to 

 white quartzites and quartz and talcosQ schists, while the hills 

 are much barer of vegetation than those further west, a fact 

 pi'obably due to the nature of the rocks, which are, of course, 

 nearly pure silica. At the Collingwood River micaceous sand- 

 stones occur, and then from the Franklin River, the white 

 quartzites and schists extend to Mount Arrowsmith. Mount 

 Arrowsmith is just at the edge of the great central plateau of 

 Tasmania, which varies from 2000 to 4000 feet above the sea. 

 Leaving Mount Arrowsmith, the Silurian rocks are also left 

 behind, and one sees instead the massive greenstone crests of 

 Mounts Gell, King William, Rufus, Hugel, and other more or 

 less prominent heights. 



