112 THE PROGRESS OF GEOLOGICAI RESEARCH IN TASMANIA, 



its work are such as to r.eeessitate detailed investigations of 

 limited areas, rather than cursory examinations of larger 

 areas. It must be remembered that the raison d'etre of the 

 Geological Survey is the demand of the Mining Industry for 

 reports on mineral and coal deposits, and the portions of the 

 State subjected to such detailed geological examination are 

 almost wholly confined to our mineral and coal areas. With 

 the ever-growing demand for examination of mining fields it 

 has, not been possible to pay much attention to the general 

 geology of the remainder of the Island. 



It is not intended to imply that this intensive examina- 

 tion of limited areas is undesirable. In fact, these detailed 

 investigations are essential to the ultimate elucidation of the 

 factors controlling ore-deposition in Tasmania, and they have 

 already enabled important deductions to be made regarding 

 certain important phases of general geology. The only dis- 

 appointing feature in regard to them is that indicated above 

 in relation to the arcal geology of the Island. 



Before proceeding to deal with the actual progress in 

 the various branches of geology recognition must be given 

 to those whose work has made this progress possible. 



It is with mixed feelings of admiration and regret that 

 the writer mentions the name of the. late W. H. Twelvetrees 

 — admiration for the great work he accomplished, and regret 

 that he was not spared to be present at this meeting and to 

 be still amongst us. He had looked forward to this meeting 

 since before its first postponement, and it would have been 

 very fitting if this summary could have been presented by 

 him, as it deals very largely with the achievements in geo- 

 logical research by himself and those working under his 

 genial and able direction. For twenty years the late W. H. 

 Twelvetrees occupied the position of Government Geologist 

 of Tasmania, and for seventeen years of the eighteen covered 

 by this review he directed the acquisition of our knowledge 

 of the geology of Tasmania. It was he who was responsible 

 for the initiation of systematic geological surveys of definite 

 areas in place of the restricted examinations of mining pro- 

 spects — a change beneficial both to geological science and to 

 the mining industry. The contributions by this indefatigable 

 worker to our knov/ledge embrace all of the branches of geo- 

 logy, but, perhaps, his greatest achievements were in the 

 domain of petrology. The geological literature of Tasmania 

 has been greatly enriched as the result of his labours, and 

 Tasmania undoubtedly must ever remain indebted to him, his; 

 example, and his memory. 



