116 THE PKO(Tl.E!^S OF GEOLOGICAL RESEARCH IN TASMANIA, 



Geology. Under such conditions it is not to be wondered at 

 that there is such a paucity of observers with sufficient know- 

 ledge to make observations of value. 



The conditions existing in Tasmania at present are, 

 therefore, such that the work of investigating the complex 

 geology of the Island devolves entirely on the Geological Sur- 

 vey. With practically no help from outside, and because of 

 the complexity of our problems, the inclement climatic con- 

 ditions, the rugged topography, and the heavy forest growth, 

 our progress must be somewhat slow. 



II. PHYSIOGRAPHY. 



The advance in this branch of geology has been con- 

 siderable, but we are still far from a complete understanding 

 of the evolution of the topographic features of Tasmania. 



As a matter of fact, there has not yet been produced 

 a topographic map of Tasmania of even approximate ac- 

 curacy. The existing map of Tasmania is admittedly inac- 

 curate to a marked degree. In fact, there has not yet been 

 completed a trigonometrical survey of the State, as although 

 such a survey was started many years ago, it had not been 

 nearly completed before work on it was suspended, and 

 has not been resumed to date. 



The most detailed maps available are the Mineral and 

 Land Charts, which show boundary lines of sections and 

 some of the principal streams and occasional mountain peaks, 

 but even these latter details are to some extent unreliable. 



The necessity, therefore, arises of mapping the topo- 

 graphy concurrently with the geology in carrying out the 

 work of the Geological Survey. In 1909 the late W. H. 

 Twelvetrees endeavoured to arrange for the addition of a 

 topographer to the Geological Survey staff, but was unsuc- 

 cessful. The geologists of the Survey, therefore, are com- 

 pelled to map topographic features as far as opportunity 

 allows or necessity dictates. Under these conditions progress 

 must necessarily be slow. 



To Professor J. W. Gregory is due the credit of first 

 recognising the peneplain on the West Coast, which has 

 been so deeply dissected as to make its recognition difficult. 

 The work carried out by the various officers of the Geological 

 Survey since Professor Gregory first drew attention to it 

 has shown that this peneplain extends from northwards of 

 Port Davey to the Mersey River, over an area roughly cres- 

 centic in shape, varying in height from 200 to 2,000 feet 

 above sea-level, and having a slope of from 40 to 100 feet 



