140 the progress of geological research in tasmania, 



(8). The Ore Deposits of Mount Balfour. 



These were examined by L. K. Ward, and described in 

 Geological Survey Bulletin No. 10. 



Two groups of deposits are shown to exist — the Copper 

 Group and the Tin-Tungsten Group. Both are described, 

 and a zonal distribution in relation to a hypothetical granite 

 core to the Balfour Range is suggested, although not definite- 

 ly established. However, it is assumed that they are both 

 genetically connected with the Epi-Silurian granite of the 

 district, although the evidence for the copper deposits is by 

 no means conclusive. 



(9). The Ore Deposits of Jukes-Darwin. 



Following upon the work carried out by the late W. H. 

 Twelvetrees twelve years before, the writer in 1913 made a 

 thorough investigation of the ore deposits of this region. The 

 results of this investigation are contained in Geological Sur- 

 vey Bulletin No. 16. 



The ore deposits are classified into the following 

 groups: — 



(1) Copper- Silver-Gold Ore-bodies; 



(2) Hsematite and Magnetite Deposits; 



(3) Blue Hgematite-Bornite Veins; 



(4) Barytes Lodes; 



(5) Quartz Lodes; 



(6) Epidote Veins. 



The composition, structural features, and paragenesis 

 of these deposits are described. It is shown that the hasma- 

 tite and magnetite ore-bodies are genetically connected with 

 the granite of the porphyroid igneous complex. The prob- 

 lem of metallogenesis is discussed at some length, but the 

 evidence was at that time not found sufficient to justify de- 

 finite conclusions as to which metallogenic epoch or epochs 

 the remaining groups were to be assigned. 



(10). The Ore Deposits of the Middlesex-Pelion 



Area. 

 These have been described in successively greater detail 

 by G. A. Waller, the late W. H. Twelvetrees, and A. Mcintosh 

 Reid. 



The late W. H. Twelvetrees was the first to recognise 

 the true nature and origin of the garnet rock which forms 

 the country rock of the tin-wolfram-bismuth lodes of the S. 



