788 GEOGRAPHY OF BLUE MTS. AND SYDNEY DISTRICT, 



of the claims of elevation for North Queensland. Yet even 

 workers like these appear to have overlooked what are, in the 

 writer's opinion, the main lessons taught by the shore-line and 

 coastal topography, as also the main criteria of subsidence and 

 late elevation. 



In their discussions the idea does not appear to have been 

 entertained of a dominant movement expressing "the algebraic 

 sum " of various slighter movements, viz., that a region might, in 

 a broad sense, represent the overshadowing influence of elevation 

 or subsidence concomitantly with criteria of subsiding coast and 

 shore-line movements in like or contrary directions. To a student 

 of shore-line topography only, the eastern coast of Australia 

 evidences the influence of late elevation at every turn, but to one 

 who gets above these details of beach and coastal plain on to 

 some high sea-cliff", the shore-line and associated areas are seen 

 to be passing through a youthful stage of drowning on which a 

 vibration of recent elevation has been imposed; while to the 

 topographer viewing the coastal sweep from some commanding 

 elevation like the Guy Fawkes " Look Out " in New England, 

 the whole country is seen to be in a state of pronounced uplift 

 interrupted recently (over restricted areas) by slight subsidence 

 and elevation. Thus the high and widely trenched plateau 

 which advances boldly into the sea in North Queensland 

 points to a pronounced cycle of Tertiary elevation, since the initia- 

 tion of which plateau dissection has advanced to the stage of 

 maturity as regards the coastal area; the long saltwater valleys 

 and boldly seaward advancing headlands, as also the numerous 

 mountainous islands dotting the broad continental shelf, point 

 to a very youthful minor cycle of coastal subsidence (following 

 on well advanced marine erosion)^ which flooded the old base- 

 levelled valleys of the present "canon cycle,"! and allowed of the 

 establishment of the Great Barrier Reef on beds of late Tertiary 



* See also Prof. A. Agassiz, "The Great Barrier Reef of Australia." 

 Bull. Mus. Comp. Zool. Harv. Coll. viii. 



t Term adopted after Prof. W. M. Davis. 



