president's address. 587 



are referable rather to the Gympie horizon, as they contain a form 

 closely allied to Protoretepora ampla, and also a small species of 

 Productus not determinable specifically. The rocks are chiefly 

 unfossiliferous dark grey claystones alternating with harder and 

 more quartzose bands with occasioaaj bands of gritty sandstone 

 and pebble conglomerate, though the latter is absent from the 

 lower part of the series, which is also unfossiliferous. Near 

 Ashford a bed of limestone, perhaps a thousand feet thick, occurs, 

 possibly interstratified in this series.* The thickness of the 

 whole series has not been determined, but it must be many 

 thousands of feet. These rocks have been much folded. Their 

 prevalent strike in the Vegetable Creek district is N.N.W. and 

 S,S.E. They are far more strongly folded than the Lepidodendron 

 ausircde beds which dip off them and may be unconformable to 

 them, and, what is important, the author last January observed 

 that at Eraser's Creek, near Ashford, they were strongly uncon- 

 formable to the rocks of the Permo-Carboniferous System. The 

 Gympie beds in that locality must have been tilted into a nearly 

 vertical position before the Gangamoideris coal measures (Permo- 

 Carboniferous) were deposited upon their eroded surface. The 

 basal conglomerates of the Permo-Carboniferous rocks there are 

 almost wholly composed of rolled fragments of felspathic quartzites 

 and hardened claystones derived from the Gympie Series. 



The Gympie Series has not yet been identified on the eastern 

 side of the great granite plateau of New England, but judging 

 from the lithological character of the rocks between Tenterfield 

 and Tabulam, I think they might provisionally be referred to the 

 Gympie horizon. The calcareous shales and mudstones of Upper 

 Muswellbrook, containing Productus semireticulatus and Phillipsia, 

 are probably homotaxial or perhaps a little higher in the series, 

 and may belong to a horizon homotaxial with that of the Star 

 Series of Queensland. The clay shales in the upper portion of the 



* Mr. G. A. Stonier, F.G.S., of the Geological Survey of New South 

 Wales, however, informs me that he is extremely doubtful as to these thick 

 limestones in the Bingara district and elsewhere in New England being 

 interstratified with the Gympie Series. 



