BY SYDNEY B. J. SKERTCHLY. XIX 



The hedii, are much twisted and contorted, and seamed with 

 faults. Speaking broadly, the series is more arenaceous towards 

 the east, and more argillaceous as we travel westward. The 

 massive Ringrose Conglomerate (so named by me after Mr. R. C. 

 Ringrose, of Herberton, who first described them) probably 

 constitutes the base of the series, and marks an old shore-line. 

 The beds, however, are faulted in too complicated a manner to 

 allow of this being demonstra ted until after prolonged study and 

 mapping. They are traceable for a considerable distance round 

 Herberton, and are again seen at the Jumbo Mine, six miles west 

 of Koorboora. In both localities they are associated with silver 

 deposits. 



Still speaking broadly, the argillaceous series is stanniferous 

 in the east and south, the tin extending as far west as 

 Koorboora. 



Coppar occurs throughout the whole region, and entirely 

 replaces the tin west of Koorboora. 



Silver is more or less disseminated througliout, but is more 

 plentiful around Newellton, Montalbion, and the west of 

 Chillagoe. In most of these places the original argentiferous 

 ore is galena, but most of the copper carries silver also, often in 

 paying quantities. 



f f.j ])(ir(/(tJo)iti 7>rt/.s. — Flanking the Herberton series to the 

 south is a mass of schistose and gneisic rocks, so different iu 

 character and in strike, that I feel quite sure they belong to an 

 older and unconformable series. They were first separated by 

 Mr. Jack, who, however, thought they might be only a more 

 highly metamorphosed condition of what he then thought were 

 the Gympie Beds. Three years ago I expressed the opinion that 

 they were probably Silurian, and a closer acquaintance Avith them 

 during the past year has strengthened this belief. 



They consist of mica-schist, hornblende, and gneiss, with 

 beds of pegmatite. Occasionally they fade away into the granite, 

 which has eaten through them. They are highly contorted, 

 twisted and gnarled, and are in marked contrast to the Herberton 

 Beds. 



They contain lodes of copper and silver ore, and, here and 

 there, payable gold. 



