186 Proceedings of the Royo.l Socleiij of Victoria. 



Rock material and erratics. The rock material found in tho 

 glacial beds is very abundant and of all kinds. Professor David 

 in liis Presidential address before A.A.A.S. remarks in his 

 observations on the Korkuperrimul beds, that the bulk of the 

 ground mass is of local origin, together with many of the boulders. 

 Our observations, however, have led us to the conclusion that 

 very few of the boulders are of local origin ; some fragments of 

 black slate quartz and quartzite may have been derived from local 

 Silurian rocks, but the fact appears patent to us that the great 

 bulk of the boulders is foreign. How far this is the case with the 

 ground mass we hardly care to say, but we are inclined to think 

 that a considerable portion of it is also foreign. 



Another remark of Pi'ofessor David's we are thoroughly in 

 accord with, viz., the universal rounded and worn aspect of the 

 boulders and pebliles, it being (i[uite the exception to find an 

 angular fragment. 



A point to which we would also direct attention is that at 

 certain horizons the boulders have a much greater average size 

 than at others, besides being more numerous and more frequently 

 and strongly glaciated. This can especially be observed in the 

 sections of the blue mudstones on Goodman's Creek near Elam's 

 farm. A section a little beyond Elam's shows a regular floor of 

 boulders embedded in the mudstones. Just about liere too occur 

 the largest eri'atics we have found in the district. The following 

 are particulars of a few of the best : — 



(1) Hard sandstone, G' G" x G' x 3' 6". 



(2) Quartzite, 4' - 6" x 4' x 3' - G". 



(3) Granite, with large crystals of reddish felspar several 



inches in length, and well scored and grooved. 

 Three years ago when we first discovered this 

 erractic it measured 8' - 3 " x 4' - 5 " x I'-IO". 

 Mr. Elam informed us it was originally about 17 

 feet long. 



(4) Granite similar to the last, and a little further down 



stream, about 10 feet in diameter. 



(5) Hard blue quartzite, 8' x 3', partially exposed. 

 (G) Quai'tzite, 5' x 4' x 3' - G ". 



