material would have a tendency to accumulate. These two 

 features are well illustrated in the case of the Bluff, viz., a 

 broken or "plucked" face in the direction of the flow, and a 

 great accumulation of erratics and glacial-till on the landward 

 side — that is, on the lee-side of the hill. 



By reference to the map (plate i.) it will be seen that a 

 ridge of older rocks (Cambrian) divides the morainic deposits 

 of Encounter Bay from similar deposits on the Waitpinga or 

 western side of the ridge. This dividing ridge forms an 

 inlier of the glacial beds, and was, until exposed by denuda- 

 tion, entirely covered by glacial deposits. Outliers of the 

 latter can still be found in patches along the sides and on the 

 crest of the ridge. One such occurs in Section 180, Hundred 

 of Encounter Bay, where a group of erratics can be seen in a 

 paddock on the east side of Hall's Creek Road. 



Confining our attention at present to the eastern side 

 of this dividing ridge, the morainic material forms a nearly 

 continuous sheet, sculptured into foothills and terraces, ex- 

 tending from the Bluff to Glastonbury Hill, at the entrance 

 to the Inman Valley. The moraine is seen on the beach, in 

 places, at Encounter Bay, where it helps to form a remarkable 

 reef which extends nearly a mile seawards and is largely 

 bared at low tide (plate iii.). At the higher elevations the 

 glacial deposits consist mainly of sand or sand-rock, but in 

 the main trail from the Bluff the beds are a stifnsh clay, form- 

 ing good wheat-land, which is sometimes stony and contains 

 large erratics. Good sections of this boulder clay can be seen 

 in the creeks, and especially in washouts, which are easily 

 developed in the cultivated ground. A washout in Section 

 177, Hundred of Encounter Bay, is several hundreds of feet 

 long and, in places, 30 ft. deep. 



In plate ii., fig. 2, a longitudinal sketch-section of the 

 Rosetta Head moraine is given. The main portion of the Bluff 

 consists of granite, but on the landward-side there is an outcrop 

 of schists which occupy the mid-distance of the ascent, and 

 at lower levels these are obscured by the prevalence of glacial 

 drift. The glacial beds make a curve on the lower slopes of 

 the Bluff and pass into an irregular ridge, resting on an 

 uneven floor of the older rocks. 



The ice-plough in passing over the Bluff cut deeply into 

 the schists, producing a hollow in the rocks by "over- 

 deepening" its floor. The excavation was brought about 

 partly from the high gradient of the glacier's path and partly 

 from the more yielding nature of the schistose rocks as com- 

 pared with the granite. This ice-cut hollow is now occupied 

 by glacial drift (plate ii.), extending from the Bluff for about 

 a quarter of a mile. Some very large erratics are exposed 

 a2 



