Vol. 52.] GLACIAL ACTION IN AUSTRALIA. 295 



organism has yet been met with in these beds. The matrix 

 has evidently been derived from the wearing away of the 

 local pre-Cambrian rocks, whereas many of the erratics are 

 foreign to the neighbourhood. 



3. Miocene limestone and Miocene (?) clays. The former is 



separated by a slight unconformity from the underlying 

 glacial beds. It varies in composition from that of an 

 arenaceous limestone to that of a calcareous sandstone, 

 having a thickness of from 2 to 3 feet. The following are 

 some of the marine fossils contained in it, as determined by 

 Prof. Ralph Tate: — Plesiastrcea St.-Vincenti, Ten. Woods, 

 Pecten spondyloides, Tate, Mytilus submenkeanus, Tate, Pec- 

 tunculus convexus, Tate, Conotrochus typus (Seguenza ?). 

 The limestone passes upward into clays, perhaps also of 

 Miocene age, and about 60 feet in thickness. 



4. Recent (?) nodular travertine, about 3 to 4 feet thick. 



5. Blown sand and beach sand, resting successively on all the 



preceding formations. 



It maybe concluded that, as proved by the transport of the erratics 

 and the grooving of the rock-pavements, the ice which produced the 

 glaciation moved from south to north, and that it was of an age inter- 

 mediate between Miocene and Pre-Cambrian. The comparatively 

 slight induration of the glacial beds and remarkable freshness of 

 the striae suggest that the glaciation did not antedate the close of 

 the Palaeozoic era, as all rocks older than this in Australia are 

 -considerably indurated. 



(b) Wild Duck Creek, Derrinal, near Heathcote. 



The formations here represented are : — 



1. Lower Silurian (Ordovician), which in places exhibit strongly 



grooved polished surfaces, the trend of the grooves being 

 from S. 5° E. towards N". 5° W. 



2. Permo-Carboniferous Glacial Beds, consisting chiefly of mud- 



stones, with erratics up to 30 tons in weight, and sandstones. 

 Nearly all the erratics and small boulders are beautifully 

 glaciated, being grooved, polished, and faceted. The beds have 

 been traced by Mr. Dunn for 15| miles in a north and south 

 direction, and they have a width of 5 miles. They attain an 

 elevation of about 750 feet above the sea, and have a thick- 

 ness of probably at least 300 or 400 feet. Both Mr. Dunn 

 and Mr. A. W. Howchin are of opinion that the erratics re- 

 semble the rocks of North Gippsland in Victoria, the age of 

 which ranges from Silurian to Carboniferous. Here, as at 

 Hallett's Cove, the glaciation of the rock-pavements shows 

 that the ice probably came from the south. (Photographs 

 of the glaciated Lower Silurian rock and of the large erratic 

 known as * The Stranger ' were exhibited at the meeting.) 



