236 



of beds (the boulder clay of other districts) are concerned,, 

 they scarcely come into view. They are seen in the chan- 

 nels which have been cut to drain the swamps, in the road 

 cuttings near the Mount Compass township, and in some of 

 the creeks which drain the swamps, especially those of Cle- 

 land's Gully and the Black Swamp. Along these lines of 

 drainage settlers have confined the running water to definite* 

 channels which has promoted erosion and led to the deepen- 

 ing of the beds of the creeks, thereby exposing the clay-beds, 

 but the exposure is trifling, and but little definite informa- 

 tion can be gathered with reference to the beds. The stones 

 thrown out from the drains were carefully examined and, in 

 some instances, were found to be ice-marked. 



The swamps throughout the district may be considered 

 to represent, stratigraphically, the upper portions of the 

 glacial clay-beds. Their principal occurrences are as follow: 

 — (a) To the west of Mount Compass township ; (b ) sur- 

 rounding Mount Moon and extending easterly into the Black 

 Swamp; (c) Cleland's Gully, with its lateral branches, also 

 draining into the Black Swamp ; (d) swamps on either side of 

 the main road, including the Square Waterhole ; and (e) on 

 the north-east side of the Hundred of Nangkita, parallel with 

 the Bull's Creek Road. The Black Swamp is the natural 

 outlet for the drainage of this country, and gives sections of 

 the clay-beds at various points in its course. They can be 

 studied just above the railway bridge at Black Swamp railway 

 siding. Similar swamp country passes over into the Hun- 

 dreds of Myponga and Encounter Bay. The Edinburgh 

 Swamp, in the last-named Hundred, is of considerable ex- 

 tent, but the drainage from these Hundreds finds an outlet 

 to the south or west. 



The upper members of the glacial series form the domin- 

 ant geological features of the country. From whatever stand- 

 point the basin is viewed, the characteristic white, sandy soil 

 can be recognized, and as the upland soils are poor it is, for 

 the most part, still in a virgin condition covered by a thick 

 and dwarf scrub. 



From the northern slopes of Mount Compass a command- 

 ing view is obtained of the sandy flats which form the in- 

 appreciable water-parting between east and west, already re- 

 ferred to (plate xxxii.). From Mount Moon, near the centre 

 of the basin, a panoramic view of great extent and striking 

 features is obtained. To the west, the land rises in a sandy 

 slope about 300 ft. in height, forming the dividing ridge 

 between the Hundreds of Nangkita and Myponga (plate 

 xxxvi.). On the south-east, between Mount Moon and Cle- 

 land's Gully, is a ridge of about the same elevation as the last- 



