GEOLOGICAL RECONNAISSANCE OF THE STIRLING RANGES. 83 



level surface, and deep "bays" of plain country penetrate 

 far into the heart of the range. Several broad "passes," 

 whose floors rise very little above the level of the "sand 

 plain," traverse the range completely, and afford a very 

 easy passage across the mountain area. 



Towards the east the range is fairly narrow from north 

 to south. The southern escarpment is a most striking 

 feature, running in almost a straight line bearing about 

 west-south-west, that is, obliquely to the general axis of 

 the range, and cutting it off to a point at its eastern 

 extremity. There are practically no foot hills along this 

 portion of the southern face, which, from Ellen Peak to 

 Bluff Knoll and the unnamed peak which I have called 

 "Wedge" on the map, rises precipitously from the plains. 

 The highest points lie in this eastern section of the range, 

 and, for Western Australia, their altitudes are very con- 

 siderable. Bluff Knoll reaches 3690 feet and Ellen Peak 

 3420 feet, 1 while Pyungoorup and Ooyanarup are very little, 

 if at all lower. 



The northern face of the eastern group conforms to the 

 general trend of the range, that is about west-north-west. 

 It is mostly precipitous, though not perhaps quite as bold 

 as is the southern scarp. Only one of the main peaks, 

 namely Pyungoorup possesses any very considerable foot- 

 hills, though there is a zone of extremely rugged country 

 right along the face. Pyungoorup, however, has a long 

 buttress in the form of a major spur running for several 

 miles into the plains in a north-westerly direction. 



The depression west of Ooyanarup, while low as compared 

 with the ridge to the eastwards, is, nevertheless, a com- 

 plete barrier between the plains on the northern and 

 southern sides, respectively, of the range. The first of the 

 "passes" lies to the west of Yungermere, between that 



1 Lands Department Lithograph, No. 445/80. 



