BY A. B. WALKOM. 



135 



CRINOIOAL 

 STAGE 



ISOO -30OO 



Ml/REE 

 STAGE 



The lowest (Branxton) stage is from 3,000 to 3,200 feet thick, 

 and follows immediately on the Greta Coal-Measures. This stage 

 might be divided into two parts, (1) lower, with a thickness of 

 about 1,400 feet; and (2) upper, 1,600 to 1,800 feet thick. The 

 lower part consists of 

 hard, massive, white 

 to brown sandstone, 

 often passing into 

 conglomerate. In the 

 lower 900 ft, the sand- 

 stone is often con- 

 siderably iron-stained , 

 and contains occa- 

 sional bands of iron- 

 stone. At 900 feet 

 from the base, there 

 is a bed about 100 feet 

 thick, of bluish-grey 

 to brown mudstone, 

 in which Mytilus and 

 Aphanaia&re common. Branxton 

 Above this, there is a 3ooo. izoo 

 very hard, white sand- 

 stone, which forms a 

 prominent outcrop 

 near Black Creek, 

 south of the railway 

 line just west of 

 Branxton. This par- 

 ticular bed is about 

 200 feet thick, and its 

 outcrop is shown on the map. It contains a few marine fossils 

 (e.g., Spirifer, Martiniopsis, and Aviculopecten), and numerous 

 remains of plant-stems. 



The remainder of this substage consists of more brownish 

 sandstones. Marine fossils occur abundantly in this lower part 

 of the Branxton Stage, and, where conditions were favourable, 



Chtrti Shjlt, 



Mostly sh*ly mvdslont* 



b&ndstontt tni Conqfomt/dTi' 



Fo.-aminiferal Morixo" 



Sandstone j Jn( j 



<Jlca rtom ►nud»ron«j 



Brownish Sandstones 



Hard mMt Sandstone 

 6ro*nish Mudsfbne 



Massive Sandstone 

 and Conglomerate 



GiCTA COU 



Fig 10. — Vertical Section of the Upper Marine 

 Series. 



