BY L. KEITH WARD, B.A., B.E. 155 



Supposing for the moment that the Tasmanian un- 

 conformity should correspond exactly to one of those 

 recognised in the North American region, we do not 

 know which of these it might be, nor whether it is a 

 major or minor one. 



Nevertheless, in the future attempts to unravel the 

 Pre-Cambrian history of Tasmania, the observations of 

 North American geologists must be kept constantly in 

 view. 



It may be possible to effect some compromise be- 

 tween the schemes of nomenclature proposed by Van 

 Hise and Adams, which are shown side by side in the 

 accompanying table. The use of terms with a "zoic" 

 termination appears to the writer to involve the assump- 

 tion of a greater knowledge of Pre-Cambrian life than 

 that which we really possess. And, on the other hand, 

 the term Algonkian is rapidly gaining acceptance in 

 countries outside of America. Perhaps the modifications, 

 Analgonkian and Katalgonkian may serve to distinguish 

 the two major groupings of those Pre-Cambrian rocks 

 which post-date the Archaean. 



It has been found impossible to correlate the Pre- 

 Cambrian rocks of Tasmania with those of Australia 

 from a lack of familiarity with the extra-Tasmanian de- 

 velopments. 



In the latest volume of the Official Year Book of 

 the Commonwealth of Australia (i), condensed sum- 

 maries are given of the geology of the various States. 

 From a perusal of these it will be seen that rocks of 

 Algonkian type are developed in Victoria, South Aus- 

 tralia, Western Australia, and in the Broken Hill area 

 of New South Wales. 



(i) Op. cit., No. 2, 1909, pp. 78-111. 



