CONCLUDING STATEMENT 27 



the selection of one unconformity rather than another of those in the 

 Algonkian as the basis of the division. If the use of these terms results 

 in the practice becoming at all general, it will be believed by the students 

 beginning geology and soon by the geologists themselves that Eo- and 

 Neo- Algonkian or Proterozoic in one region correspond with those of the 

 other, and this would be certain to lead to error. I know of no region 

 in whicTa emphasis on one break in the Algonkian more than others is 

 justified, and if this be not the case, the division is purely theoretical 

 rather than factitious. In short, T foresee confusion and no advantage 

 in the arbitrary introduction of the two proposed terms which have no 

 philosophical basis or definite facts in the field which justif)^ them; for 

 their i;se amounts to the introduction of zoic terms for the divisions of 

 the Proterozoic, and thus the objection made (pages 16-17) to Protero- 

 zoic and Archeozoic for the major divisions of the pre-Cambrian applies 

 with much greater force to Eo and Neo divisions of the Proterozoic. 



Concluding Statement 



In view of the foregoing considerations I present the following classifi- 

 cation of the pre-Cambrian as representative of the best current views : 



Alsronkian I ^^^ °^ more series in various geological provinces separated by 



° I unconformities. To this series local names are applicable. 



Unconformity. 



f Keewatin. 



Archean -I Eruptive unconformity. 



(. Laurentian. 



Whether the physical contrasts which separate the Archean and Algon- 

 kian are such as to justif)^ the belief that corresponding to them are two 

 life groups which may be called the Proterozoic and Archeozoic, I leave 

 the future to determine, and adhere to the terms which have arisen as a 

 result of inductive studies of pre-Cambrian geology. 



Those who decline to accept a dual zoic division of the pre-Cambrian 

 may still favor a single zoic term to comprise the two groups. Thus 

 Emile Hang, professor of geology in the University of Paris, in his text- 

 book on geology, which has just appeared, so uses the term' Agnotozoic. 

 But if the consensus of opinion turns in this direction, it would be better, 

 I think, to use Proterozoic rather than Agnotozoic as the life term. If 

 the term Proterozoic be decided on for all pre-Cambrian rocks, for the two 

 major divisions of the Proterozoic, the terms Algonkian and Archean 

 clearly have precedence and right of way from every point of view, and 

 tliis Haug recognized by making them the major divisions of his Agnoto- 

 zoic. This clearly emphasized the standing these terms have gained and 

 to Avhich their clear definitions and general applicability entitle them. 



