28 Transactions. 



Art. III.^ — On Stage Names applicable to the Divisions of the Tertiary in 



New Zealand. 



By J. Allan Thomson, M.A., D.Sc, F.G.S., Director of the Dominion 



Museum, Wellington. 



[Read bejore the Wellington Philosophical Society, 20th October, 1915.] 



Contents. Page 



28 

 31 

 35 

 37 

 39 

 40 



I. Introduction 

 II. Stage names derived from the Oamaru district . . 



III. Stage names derived from the Wanganui district 



IV. Stage names derived from the West Coast of the South Island 

 V. Summary and conclusions 



VI. List of papers referred to 



[Note. — References are indicated by the date after the author's name, and will 

 be found in the list of papers at the end of this article.] 



I. Introduction. 



There are two objects to be aimed at in framing a classification of the 

 younger rocks of New Zealand., and it is important to distinguish, them. 

 The first is to set up a standard of reference by which rocks from different 

 parts of the country may be correlated with one another ; the second is 

 to correlate the various divisions of the classification thus established with 

 their equivalents in the classifications of other pai'ts of the world, and par- 

 ticularly in the accepted time-scale based on the rocks of Europe. The 

 need for attacking the problem of classification in this order is imposed 

 by the differentiation of the world's fauna into geographical provinces, a 

 differentiation that has been, on the whole, accentuated as the present day 

 is approached. It may be possible to correlate our Cretaceous rocks in 

 individual districts directly with the European equivalents, but for the 

 divisions of the Tertiary such a procedure is impossible in the present state 

 of our knowledge. 



It is undesirable, therefore, to speak of Eocene or Miocene rocks of New 

 Zealand if what is meant is really rocks of the age of the Ototara limestone, 

 the age of which has not yet been firmly established. For this reason the 

 classification of the Upper Cretaceous and Tertiary rocks by Hector and 

 McKay as Cretaceo-tertiary, Upper Eocene, Lower Miocene, Upper Miocene, 

 and Pliocene must be abandoned, at least temporarily, so far as the names 

 are concerned, whether or not one agrees with the distinctness of the 

 groups of rocks on which it is based. Instead we must adopt a classifi- 

 cation on the lines followed by Hutton, Haast, Park, and Marshall, in 

 which names for the various series recognized are derived from New 



