6Y W. N. I5KNS0N\ 263 



lower portions of Banaba rocks, and beyond, across a small 

 creek, the scarp of the Baldwin rocks rises up steeply. They are 

 very full of fragments of chert and limestone. 



The geology of the northern end of the Bingara Range was 

 described by Anderson in 1888 (11, 12), and later by Stonier (19). 

 He stated that the formation contains Lepidodendrc'U aicsh-ale, 

 and various marine shells, including Spirijh\i sp. It consists 

 of thin, bedded mudstone, sandstones occasionally conglomer- 

 ates, argillaceous, oolitic and crinoidal limestones, quartzites, 

 hard, thick-bedded, gritty, and tuffaceous mudstones and sand- 

 stones passing into volcanic tuffs. Apparently, therefore, 

 Barraba and Burindi strata are present. In addition to the 

 above formations, the Middle Devonian cherts, claystones, and 

 tuff- breccias appear to be present on the eastern slopes of the 

 mountain on the Rocky Creek Road. A sharp anticline of richly 

 radiolarian chert was noticed, halfway up the mountain. The 

 western slopes of the range along the same road consist entirely 

 of Barraba rocks. Around the northern end of the range, the 

 section exposed along the river-road consists of banded claystones, 

 that may belong either to the Tamworth or the Barraba Series. 

 No Baldwin Agglomerate was seen in the northern extremity of 

 the Bingara Range, unless it be Stonier's "conglomerate"; nor is 

 there any sign of its presence north of the Gwydir River. It is 

 probable, therefore, that it has thinned out here, and that the 

 Tamworth Series passes conformably up into the Barraba Series, 

 as it does elsewhere, e.g.^ south of Tamworth. There is, there- 

 fore, no need to trace the belt beyond the Gwydir River. It is 

 evident that the structure of the northern end of the range is 

 very complex, and requires further elucidation. 



The Palaeozoic rocks are capped by Tertiary gravels and basalts, 

 which have been investigated in greater detail than any other 

 portion of the area dealt with in this paper, having been visited 

 by Liversidge(6, 7), Pittman(9), Wilkinson (10), Anderson (11), 

 and Stonier (18, 19). The last-named, summarising all informa 

 tion, notes the following succession of Tertiary formations : — 



Newer Basalt 350 feet. 



Flu viatile sands and gravels 120 feet. 



