792 geography of blue mts. and sydney district, 



The Plateaus. 



Standing on some eminence in or around Sydney and looking 

 westward, a range of mountains is seen to present an almost 

 unbroken sky-line to the observer. Here and there a flat-topped 

 mass rises above the general level. The even sky-line represents 

 the stretch of the Blue Mountain plateau, and the still higher 

 table-topped hills count Mount Tomah, Mount King George, 

 Mount Victoria and Blackheath among their number. If a trip 

 be taken across the valley of the Nepean at Penrith to Glenbrook 

 (600 feet above sea-level), it will seen that the surface gradually 

 rises until a point is reached almost 3,000 feet above sea-level, 

 when it will be found that numerous large flat-topped masses rise 

 above this level. Crossing one of these mesas, ''^ on which Black- 

 heath and Mount Clarence are situated, a precipitous escarpment 

 is observed to separate the upper and lower plain-like expanses. 

 Thence the 3,000 feet level winds westward, being overshadowed 

 by the mountains possessing subhorizontal summits. Various 

 towns occur on this upland (3,000 feet), among which may be 

 cited Orange, Blayney, Oberon, Hill End, Wattle Flat, Wallera- 

 wang and Lithgow. The plain-like expanses are not all at present 

 co-extensive, but were the intervening gullies filled they would form 

 a huge peneplain continuous in all directions and broken only in 

 the central portions by large mountain masses. Around Lawson, 

 Wentworth Falls, and the several towns just enumerated, these 

 higher table-topped hills are common. Blackheath, Mount Vic- 

 toria, Bell, Mount King George, Mount Tomah and the hills 

 north and north-east of Wallerawang mark points on a higher 

 level which rises some 400 or 500 feet above the lower plateau. 

 Their total area is trifling compared with that of the 3,000 to 

 3,100 feet level, but were the wide intervening basins filled, they 

 would in turn form another plain some 3,500 feet above sea-level 

 in the central portions. Above these again numerous points 

 occur, flat-topped or cone-shaped, which rise to a height of 4,100 



* A flat-topped hill rising above the surrounding plain. 



