Dr. P. Marshall — Younger Rock Series of Neiv Zealand. 317 



he has accepted our explanation of the section, for he writes in your 

 article : " The unconformity which I thought I recognized at Waipara 

 between the Mo^^nt Bi'own and Motanaa Beds may not exist, or if 

 it does it may be purely local." ^ He offers no criticism of our 

 explanation of the structure that he had described as an unconformity 

 between the Weka Pass Stone and the Mount Brown Beds, and 

 therefore admits the conformable nature of the stratigraphy as insisted 

 upon by us. He does, however, still advocate a palseontological 

 unconformity. " The Ototara Stone is everywhere fossiliferous 

 generall}', and its characteristic fossils from one end of New Zealand 

 to the other are Pseudamusimn htdtoni, which is never known to be 

 absent, Cirsotrema hrowni^ and Meoma craivfordi. The Weka Pass 

 Stone, on the other hand, has never yielded any recognizable fossils." 

 Again, on p. 548, " Moreover, Cirsotrema hrowni, Pseudamusium huttoni, 

 and Meoma craivfordi are characteristic of tlie Ototara horizon from one 

 end of jSTew Zealand to the other." On p. 541 the Weka Pass Stone 

 is shown in his tabulated series as the highest member of his 

 Cretaceous (Waipara) Series and the Ototara Stone as the highest 

 member of his Lower Tertiary (Oamaru) Series. 



These statements have been quoted here because quite recently 

 Dr. J. A. Thomson and Mr. C. A. Cotton have found Pseudamusium 

 huttoni, Cirsotrema Irotvni, and Echinoderm remains not sufficiently 

 well preserved for identification within the Weka Pass Stone not 

 two feet from its base. 



We thus have a very satisfactory palseontological proof that the 

 AVeka Pass Stone and the Ototara Stone are of similar age. Since, 

 in the article referred to, the Waipara Series is represented as perfectly 

 conformable below the Weka Pass Stone, and the Mount Brown and 

 Motanau Beds perfectly conformable above the Weka Pass Stone, 

 we find that this fortunate discovery of palasontological evidence 

 brings Professor Park's position exactly to ours. We feel that it is 

 most satisfactory to have this complete agreement on such a contro- 

 versial and, to New Zealand geologists, most important matter. 

 This discovery further allows of complete correlation between the 

 Waipara Series and the Oamaru Series, called respectively Cretaceous 

 and Lower Tertiary Series by Professor Park. The Weka Pass Stone 

 is the highest member of the former, and the Ototara Stone is the 

 highest member of the latter, and there is a remarkably similar 

 lithological succession in the two series. 



The Weka Pass Stone has been admitted by everyone but Hutton 

 to be conformable to the Amuri Limestone below it. Park, for 

 instance, says : "I carefully examined the line of contact of the 

 two rocks, but was unable to find any evidence of unconformity." ^ 

 McKay has been even more emphatic on this point. ^ The Amuri 

 Limestone is a hardened chalk, formed mostly of broken tests of 

 Globigerina; the Weka Pass Stone is an arenaceous limestone with 

 much giauconite. There is much the same relation between the 

 two rocks as between the Ototara Stone, which typically contains 



' Geol. Mag., Dee. V, Vol. VIII, p. 548. 



- Trans. N.Z. Inst., vol. xxxvii, p. 546, 1904. 



■' McKay, Eep. Geol. Explor. of N.Z., 1886-7, pp. 83-7. 



