Yol. 52.] 



GLACIAL ACTION IN AUSTEALIA. 



297 



they had been rasped away by the ice ; their diameter varies 

 from a few inches to 5| feet, but most of them measure less 

 than a foot in diameter. They are very firmly embedded 

 in the matrix, so that they can be dislodged only by repeated 

 blows from a heavy hammer. (Several fine specimens of 

 these glaciated blocks were exhibited, including one brought 

 by the author as a donation from Mr. C. (J. Brittlebank to 

 the British Museum. See the accompanying figure.) The 



Glaciated Boulder from the Permo- Carboniferous of Dunbar, 

 near Bacchus Marsh, Victoria. {About -J natural size.) 



[Eeproduced from a photograph.] 



maximum thickness of any individual bed measured proved 

 to be 193 feet. 



(ii) Conglomerates. — Greenish brown, lithologically very 

 like those of the Permo-Carboniferous Newcastle Beds in 

 New South Wales. They are composed of well-rolled pebbles 

 from 1 to about 6 inches in diameter, with occasionally 

 large glaciated erratics. The thickness of individual beds 

 of conglomerate varies from a few feet up to about 20. 

 In places they make a very uneven junction -line with the 

 strata below them, as though they had been squeezed down 

 into these so as to occupy irregularly-shaped pockets. 

 In places the upper surface of the conglomerate is much 

 indented, as at the elbow of Myrniong Creek, about | mile 

 below Dunbar (the residence of Mr. Brittlebank). 



