191 



enough, if not pleasant ; it is the getting back to the miniature 

 tree tops that is the difficulty, to say nothing of the possibility 

 of having to spend the night perched on such a roost. 



These are no fancy pictures, but are drawn from some per- 

 sonal experiences of my own when taking bee-lines across 

 parts of the Western Country during brief holidays, and it is 

 to emphasise the necessity for cutting tracks which may 

 serve the purposes of the pioneers of civilization, and espe- 

 cially of the bond fide prospector, the real discoverer of new 

 country, that this paper is chiefly written. 



The geological history of the Western Country can be 

 given, in the present state of our knowledge, only in 

 very general terms. In the eastern division, south of a 

 line about midway between the 41st and 42nd parallels 

 of latitude ; or, in other words, in about three fourths 

 of the eastern half of Tasmania, the oldest sedimentary 

 rocks are those belonging to the Pernio - Carboniferous 

 series. The central plateau is not, as is generallv sup- 

 posed, a vast boss of ancient volcanic rocks, but rather a ring 

 of massive dykes and caps of diabasic greenstone, or dolerite, 

 with intricate reticulations. These traverse all the rocks of 

 pre-Tertiary age, and are interspersed with sheets of more 

 recent basaltic lavas. Some members of the system extend 

 well into the western country, the Cradle Mountain with its 

 outliers, and the Eldon Range, being familiar instances. 

 The older sedimentary rocks, the source of all the precious 

 metals, do not show themselves in force in any part 

 of this eastern division, though I have noted quartzites 

 and foliated micaceous schists in the Russell Falls Valley, 

 and between Lake Echo and the River Nive ; but, once 

 across the boundary, the geological conditions are all changed, 

 the rocks which form such conspicuous features in the settled 

 districts being either entirely absent, or playing a very in- 

 significant part in comparison with the enormous development 

 of the older rocks. Towards the determination of the exact 

 stratigraphical relations of these rocks there has been no 

 great advance made since the discontinuance of the Geological 

 Survey some 30 years ago ; nor can we even definitely 

 identify the several formations with their supposed equivalents 

 in other countries, though much excellent work has been 

 done in this direction, both by amateur and professional 

 geologists. The oldest rocks comprise massive bands of 

 quartzite, of which the most familiar instances are those of 

 the S.W. Coast, Mount Arrowsmith, and Rocky Cape on the 

 North Coast, and in the same series occur chloritic and 

 micaceous schists, with less altered shaly bands in which 

 evidence may one day be found which will help to determine 

 the true nomenclature of the system. The country rocks of 



