78 GEOLOGY OF MT. FLINDERS AND FASSIFERX DISTRICTS, Q., 



as far as I could judge, its coQiponent rocks were breccia and 

 dark segirine trachyte-flows. 



]Mt, Elliott and similar smaller cones present close resemblance 

 to Green Knob. 



All these plugs may best be considered as parasitic vents of the 

 great volcano of Flinders. Thin flows from this group must have 

 extended six or seven miles to the west, for isolated remnants 

 overlying sandstone with petrified wood, occur near Peak Cross- 

 ing. Dykes also occur, as on Selections 44 and 47. Basalts 

 appear to cap trachyte in places near Peak Crossing, but they 

 have been emitted from a difl'erent focus of eruption. No true 

 basalt occurs on the tops or slopes of the Flinders mountains. 

 The trachytes mentioned by Pvands as occurring betweon Logan 

 Village and Beaudesert, near Walton Station, are probably 

 genetically connected with those of Mt. Flinders, which cannot 

 be 20 miles distant. 



Between Mt, Flinders and Mt. Blaine, near Perry's house 

 (Selections 103 and 107) numerous faults were noticed in the 

 creek banks (Sandy Creek). Sudden change's of dip occur, but 

 the dominant direction of dip is west. The abundance of faults 

 in this locality is noteworthy (fig. 2). 



Suirpleinentary Notes. — In figs. 2-3 T have tried toofler an expla- 

 nation of the geological structure of South-east Queensland, which 

 has metamorphic rocks fringing the coast and the late Mesozoic 

 rocks forming a tableland 2,000 feet high inland. On the Darling 

 Downs we have the Upper and Lower Cretaceous, and the whole 

 Jurassic and Triassic underlying the Tertiary (Pliocene?) basalt- 

 flows. East of the Darling Downs over the Ipswich Formation 

 no Cretaceous beds occur, except a few lenticular patches of 

 small area, containing a few fossil fishes and fossil plants of fresh- 

 water origin. These small isolated outliers are always of such 

 shape that it is evident that they are deposits formed, in lagoons 

 and riverbeds. It is quite possible that they are of Post- 

 Cretaceous age. 



It appears, therefore, that in Cretaceous time there was land 

 east of the position of the Little Liverpool Range, and sea to the 



