KY E. C. ANDREWS. 151 



Here great mangrove swamps, miles in width, pass into flats 

 as much as 20 miles across in places, and from which the great 

 coast range rises. From these extensive flats monadnock-like"^ 

 forms arise, for example. Glass House Mountains. North of 

 Card well the great extent of coastal plain around Rockingham 

 Bay, traversed by the Tully, Murray and Hull Rivers, forms a 

 conspicuous object in the topography. 



At Cairns other great coastal flats exist. One interesting 

 plain between Cape Grafton and False Cape may be noted here. 

 It is about a mile across and two miles long ; and but a few feet 

 above high tides. 



We have thus found these large flats or " coastal plains " raised 

 but a few feet above high tides to exist right along the eastern 

 coast of Queensland. 



They appear almost undoubtedly to be matter derived from the 

 large coastal rivers and from the forces of marine erosion redistri- 

 buted by the various agents of along shore action. 



"They are due to fluviatile action being invariably absent from 

 coasts possessing no considerable rivers."! 



A slight elevation would account for their present position. 



Similar flats will be described under the head of islands. 



Associated with these plains are numerous lagoons, lagoon 

 marsh meadows, and shallow creeks. Especially well are these 

 seen along the coast between Rockhampton and the Tweed Heads. 



3. The Continental Shelf. — This, in Queensland, maintains 

 generally a great width. To the south of the Great Barrier Reef 

 it is represented by reefs of old stratified rocks, enormous shoals, 

 and soft deposits uniformly distributed over the surface, and 

 having a gradual dip to the east, and which rise 40 or 50 miles 

 away to the east from enormous depths. 



"" An isolated hummock or hill rising from a surface developed by subaerial 

 Agencies to extreme old age. 



t Prof. Pencke, Morphologie der Erdoberfliiche. 



