BY AV. X. HENSON. 239 



ill the centre is an anticline, beyond wliich follows a series of 

 greatly disturbed beds dipping steeply to the east. Near Manilla, 

 the cherty niudstones are interbedded with bands of coarse, 

 tuffaceoiis breccia. 



The eastern margin of the area of Middle Devonian is pro- 

 bably a fault. Beyond, follow the tuffs and claystones of the 

 Barraba Series, greatly disturbed and highly tilted. Further 

 east, the claystones take on the olive-green colour and lithological 

 character of the Carboniferous niudstones of Burindi, and include 

 a long lenticle of limestone made up almost entirely of crinoid- 

 ossicles. There is, however, no unconformity between these 

 Carboniferous mudstones and those of the Devonian system with 

 which they are associated. 



The Carboniferous belt is continuous for a long distance to the 

 north. On Yellow Rock Creek, six miles south of Crow Mountain, 

 and five miles north of the limestone last described, a similar 

 lenticle of crinoidal limestone occurs, 40 feet thick and 200 feet 

 long, dipping E. 22' N. at 55°. It occurs in soft phyllitic rock, 

 immediately west of the serpentine, and is associated with a band 

 of coarse conglomerate, almost of the Rocky Crcsk type, contain- 

 ing boulders of porphyry and dolerite, with a greenish jasperoid 

 rock, set in a sandy matrix (said to be slightly auriferous). 



Small lenses of crinoidal limestone, frequently very impure, 

 occur here and there two or three miles south of Crow Mountain; 

 and in the creek at the foot of the mountain itself, is a small 

 mass of limestone, beside which the shales contain a typical 

 series of Carboniferous fossils discovered by Stonier in 1896. A 

 list of these, with additions found by the writer, has been given 

 previously (1, Pt. i., pp. 505-507). This limestone is also associated 

 with a bar of heavy conglomerate, which is very sharply separated 

 from the adjacent mudstones. To the south and west of Crow 

 Mountain, the Burindi rocks pass conformably into the mud- 

 stones and tufis (the ''felsites"' of Stonlei') which have characters 

 similar to those of Barraba (Upper Devonian) rocks. A well 

 marked horizon, that may be useful in the mapping of the Car- 

 boniferous rocks near Crow Mountciin, is a peculiar conglomerate, 



