824 GEOGRAPHY OF BLUE MTS. AND SYDNEY DISTRICT, 



of other bars and ])eache.s further ofF-shore, and then the steady 

 march inland of the sea with destruction of the present bars, 

 beaches and lagoon-meadows, concomitant!}' with the gradual 

 reduction of the neighbouring and distant hills b}- the forces of 

 subaerial erosion. 



All these points can be clearly made out by the observer from 

 the Sydney cliffs or coastal plains, and thus are accessible to any 

 metropolitan resident. The additional recommendation in their 

 favour is that they may be appreciated b}' the " man who runs," 

 and depend not for their understanding on laborious observation 

 and skilled laboratory research. A wonderful charm is thus 

 found to invest our characteristic scenery, since ability to trace 

 the antecedent stages of the more prominent "facts of form" in 

 a landscape cannot but conduce to the pleasure of contemplating 

 sights at once noble and beautiful from the purely emotional 

 point of view. The consideration of the control of population by 

 the great uplift, the slight movements of later drowning, the pro- 

 found canons of the Upper Haw^kesbury, the thievish propensities 

 of that stream, the barren sandstone and mural sea-fronts of 

 Sydney, also afford delightful cogitational exercises and illus- 

 trate the utter insignificance of man, the reflective, when opposed 

 to natural activities. 



DESCRIPTION OF PLATES XXXIX. -XLIV. 



Plate xxxix. — Ideal Sections across the Blue Mountains during various Cycles. 

 Fig. a. — Jenolan Plain at close of Cycle. 

 Fig. b. — Jenolan Plain after elevation. 

 Fig. c— Blue Mountain Plain at close of Cycle. 

 Fig. d. — Blue Mountain Plain after elevation. 

 Fig. e. — Lithgow Plain at close of Cycle. 

 Fig. f. — Lithgow Plain after elevation. 



Fig. !i. — Present contour illustrating insignificance of denudation during 

 canon cycle compared with that of Plateau periods. 



Plate xl. — Govett's Leap, illustrating canon-formation in alternating hard 

 and soft layers of rock. Photo by A. E. Dyer. 



Plate xli. — Valley of Grose, illustrating denudation during Canon Cycle. 



