Park. — 0)i the Jurassic Aye of the Maitai Series. 445 



Cecil Peak series) formation, thus clearly disproving the De- 

 vonian age hitherto ascribed to those rocks. 



By correlatnig the Eeefton quartzite series with the Mount 

 Arthur system, which seems the only reasonable and con- 

 sistent course to follow, we are left without a representative 

 of Devonian age in New Zealand ; and the Maitai formation 

 having been shown to be Jurassic, and not Carboniferous, it 

 seems probable that New Zealand is also without a formation 

 truly representative of the Carboniferous period of Europe. 



With respect to the age of the Eeefton gold-bearing for- 

 mation, there now remain two courses open to us. We can 

 either consider it an entirely distinct formation and refer it 

 to the Devonian or Carboniferous, or we can refer it to the 

 Mount Mary series in North Otago, to which I have ascribed 

 a Permo-carboniferous age. 



The Eeefton rocks were first correlated with the Maitai 

 formation of supposed Carboniferous by Mr. Cox as far back 

 as 1875.''= They were described by him as resting uncon- 

 formably on fossiliferous rocks which were referred to the 

 Lower Devonian or Upper Silurian. It seemed, therefore, but 

 natural to refer them to the Carboniferous, and in doing so 

 Mr. Cox had doubtless in his mind the marked unconformity 

 which existed between them and the underlying formation — 

 an unconformity noticed by Sir James Hector in 1873. f 



Mr. McKay, in his report on Inangahua County m 1882, 

 followed Mr. Cox in correlating the Eeefton gold-bearing 

 rocks with the Maitai formation ; but when we examine the 

 grounds upon which this conclusion was based we find the 

 evidence not altogether satisfactory or conclusive. Discuss- 

 ing the age of these rocks, he says, "There is but little re- 

 semblance between the Eeefton auriferous series and the 

 Permian or Trias rocks of New Zealand, and, as shown, not 

 much with the Te Anau formation as developed nearest to 

 Eeefton ; so that, in a word, the auriferous series of Eeefton 

 can be the equivalent of no other than the Maitai forma- 

 tion. ";[ 



Although I have shown the Maitai formation to be 

 Jurassic, it does not necessarily follow that the Eeefton gold- 

 bearing rocks are not Carboniferous, as originally indicated by 

 Mr. Cox. On the other hand, there is nothing to justify the 

 conclusion that they are a separate formation ; and until 

 something more definite is known about them I will refer 

 them to the Mount Mary formation of Permo-carboniferous 

 age. 



* Eeps. Geol. ExpL, 1874-76, p. 77. 

 t Reps. Geol. ExpL, 1872-74, p. 87. 

 I Reps. Geol. Expl., 1882, p. 132. 



