BY W. N. BENSON. 339 



there did not appear to be the same close relationship between 

 the tuffaceous matrix and the inclusions (the former derived by 

 the attrition of the latter) that was so marked a feature of 

 Macllveen's complex, or in the Baldwin Agglomerates {see 6, 

 pp.573, 578). This, however, requires thorough investigation. 

 Should the matrix really prove to be clastic, not merely pyro- 

 clastic, the occurrence in it of the radiolarian chert and the 

 keratophyres, etc., might indicate another regression of the sea 

 at this point, and the exposure and erosion of Lower or Middle 

 Devonian rocks some distance east(?) of this region. The pos- 

 sible significance of this is considered later (pp.341, 355). 



The zone is very continuous. It forms the long ridge in 

 Portions 17 and 18, and, southwards from thence, it makes up 

 the little hills which sharply mark the ends of the ridges that 

 separate the western tributaries of Reedy Creek. About four 

 miles south of the boundary of the Parish of Loomberah, it rises 

 as a long spur into Scrub Mountain, and south-east of here it 

 forms Rodney Mountain, beyond the limits of the map here- 

 with, and further to the south-east it rises into Nundle Sugar- 

 loaf, and crosses the Peel River to form the western end of the 

 Yellow Rock Hill south of that township. The last three occur- 

 rences of the conglomerate have been already noted (3, p. 581). 

 Thus the Conglomerate affords another horizon which can be 

 traced through from the Loomberah Parish into the region 

 mapped in the JSundle District. Small fragments of the con- 

 glomerate occur here and there adjacent to Reedy Creek; they 

 are perhaps due to repetition by schuppen-i'a,\x\tm^. Round 

 Mountain, which rises from beside the Main North Road on the 

 northern edge of the Goonoo Goonoo Estate, ten miles due south 

 of Tamworth, is apparently composed of this conglomerate. 



The Pyramid Hill Tuff. 

 West of the Scrub Mountain Conglomerate and stratigraphi- 

 cally above it, the mudstones are interstratified with numerous 

 bands of tuffs of moderate grain-size, and these, being resistant 

 to erosion, form the long ridge which runs south-eastwards from 

 Pyramid Hill. This structure of the range is that of a faulted 



