235 



the drainage. Previously to this crust-movement, the streams 

 of the present maritime districts drained to the north, but 

 when a southerly tilt was given to the land, as a consequence of 

 the great submergence, the drainage was directed to the south, 

 as at present. The Permo-Carboniferous ice-sheet travelled up 

 the present valley of the Inman, from south to north, which 

 is proved by the travel of erratics in that direction ; and there 

 is little doubt that the ice which filled the basin of the 

 Finniss also came from some points of the south, and, after 

 blending with the great Inman Valley glacier, travelled 

 north-westerly, till it formed a junction with the still greater 

 body of ice which filled the valley now occupied by the sea 

 in Gulf St. Vincent, (i) 



III. GLACIAL. 



(a) Stratigraphical Divisions. 



Lithologically, the glacial beds maintain a striking uni- 

 formity throughout the district. They can be roughly 

 divided into two divisions : — 



(1.) An upper section, chiefly arenaceous, consisting of 

 soft sandstones, hard sandstones, coarse gritty sandstones, 

 often containing rounded stones, some of which measure a 

 foot or 18 in. in diameter ; these beds weather readily when 

 exposed, producing free sand and pebbles passing up into a 

 light, thin, sandy soil. A thick, black, peaty soil com- 

 monly occurs in swamps along the lines of drainage. 



(2.) A lower section, chiefly clay, including more or less 

 of sand in irregular bands or patches scattered through the 

 clay. The clay, in exposed positions, has a yellow colour, 

 but at a slight depth is blue. Pebbles occur sporadically 

 through the clay or in pockets. 



The dividing line is not sharply defined between the two 

 sets of beds, but it may be taken as a general characteristic 

 that sands prevail in the upper and clay in the lower 

 section. Many of the sandy ridges are capped by ferru- 

 ginously-cemented sands and conglomerates. The ferric 

 oxide has probably been a later introduction. 



The glacial district now under consideration is naturally 

 divisible into two areas : (1) the Mount Compass and Nang- 

 kita Basin, and (2) the Finniss Basin. 



(b) Mount Compass and Nangkita Glacial Basin. 

 The peculiar physiographical features of this basin have 

 already been described. So far as the clays of the lower set 



(l) A review of the physical features of this district in their 

 broader aspects, and the remarkable survival of so ancient a 

 physiographical cycle, will be dealt with in a subsequent paper. 



