ON SOUTH AFRICAN STRATA. 137 



the Laurentians ; but no one can say that the Huronians are all younger 

 than all the rocks that would be readily ascribed to the Laurentian. Nor 

 in India would it be right to say that the Dharwars are, as a whole, 

 younger than many large spreads of granitoid gneisses, which our earlier 

 workers readily assumed, in conformity with the prevalent views of the 

 time, to be older. Evidently, also, among the Swaziland and Namaqua- 

 land Series there are many altered clastic rocks that retain enough of 

 their original chemical (if not physical) characters to be distinguishable 

 from the gneisses and granitoid rocks of the fundamental complex. 

 These might be distinguished lithologically under local names ; but the 

 whole mass of closely folded and foliated rocks ought to be placed to- 

 gether in one group : for this group the name Archaean might be con- 

 veniently used, in spite of the fact that in its original sense it would cover 

 the Witwatersrand beds, and in spite of the fact that its meaning has 

 since been restricted by many American authors to the gneissose rocks 

 of the basal complex. Clearly, if our terminology is to express strati- 

 graphical history, the epi-Swaziland unconformity should be recognised 

 as a great dividing line; all below should be in one group, and for this 

 group I would use the name Archaean ; all pre-Palseozoic rocks above 

 should be given another group-name, either a local name or Purana. 



' I have already lodged objections against terms like Azoic, Eozoic, 

 Archseozoic, and Proterozoic; you might at the same time have led to 

 the slaughter such terms as Hypozoic, Prozoic, and Pyro-crystalline ; 

 Chamberlin and Salisbury have spoilt the chances of perpetuating their 

 group-names by inverting the meaning of the term Archaeozoic as pro- 

 posed by Dana. They have also unfortunately drawn a group-boundary 

 line between the Huronian and the Schist Series, at the same time 

 including within their Proterozoic group an interval probably long 

 enough to be regarded as an aeon. We cannot now use the term 

 Archaeozoic for pre-Cambrian sediments and Azoic for the complex 

 below. The use of the term Archaean that I have suggested corre- 

 sponds with the classification adopted by Hatch and Corstorphine. I 

 have offered to lend the term Purana for the pre-Palaeozoic sediments 

 above the Swaziland Series, as the term has been kept from the changes 

 of meaning to which Algonkian has been subjected by the Americans. 



' Before you close your report, may I suggest that you should read 

 again G. M. Dawson's Address to Section C at Toronto in 1897? He 

 there shows how the use of the term Huronian for the sedimentary 

 rocks now known to the Canadian Survey as Animikie arose through a 

 clerical error in describing the geographical distribution of Logan's 

 typical Huronian. Unfortunatelv the rocks, thus indicated by mistake 

 in the typical Huronian, are well exposed in a very accessible part of 

 the lake shore, and thus a large number of geologists have gathered 

 their ideas of the Huronian in a way that would not have been possible if 

 these wrongly included exposures were in a very inaccessible region. 

 You will remember that the break between the Huronian proper and the 

 Animikie Series, on which Dawson laid so much stress, was also 

 noticed by Van Hise in his paper on " An Attempt to Harmonise 

 some apparently Conflicting Views of Lake Superior Stratigraphy 

 (Amer. Journ. Sci., Series in., vol. si. 1891, pp. 117-137). Van Hise 

 observed the importance of this great break too late apparently to enable 



