Marshall, Spkioht, (Jot'iox. — Yotnn/cr linrh-iterieK of N.Z. 895 



One of us has spent much time in this district, and lias made a careful 

 inspection of these and other sections (see fig. 8), and is positive that the 

 different members of the series are perfectly con- 

 formable in all the sections that he has visited. 

 I Even if, as is reasonable, the series be recognized as 



completely conformable, the correlation of the strata 

 , allows room for a difference of opinion when they 

 I J are referred to the typical" occurrences in North 

 e'.i Canterbury, How great these differences of opinion 

 \ J are may be seen from the accompanying table (fig. 7). 

 In our opinion, it is perfectly reasonable and satisfac- 

 tory to correlate the groups that are lithologically 

 similar throughout. Thus the Oamaru stone and the 

 Amuri limestone are similar, and should be corre- 

 lated. So with the concretionary greensands and 

 the Moeraki boulder-beds, the quartz grits and the 

 basal conglomerate, the Weka Pass stone and the 

 Hutchinson Quarry beds. The full reasons for this 

 suggested correlation will be explained later. 



It is of importance to note that Boehm is unable 

 to accept the separation of the Oamaru stone as 

 Cretaceo - tertiary from the Hutchinson Quarry as 

 Eocene. He says that the only distinction he can 

 '^ discover is that one formation is richer in fossils 

 ^ than the other, and that at Oamaru he can find no 

 evidence in favour of placing the Oamaru stone in 

 a Cretaceo-tertiary class.* 



Park has made much of a suggested distinction 

 between two limestone series at Oamaru. f The only 

 place where these two limestones are said to occur 

 in the same section is at Kakanui North Head, and 

 there they are separated by a volcanic rock only. 

 Since the breccia at Oamaru and numerous sections 

 in its neighbourhood show clearly that volcanic 

 action was prevalent during the deposition of the 

 limestone, this section is not convincing. McKay 

 in his last report on the district omits all mention 

 of two limestones, and one of us who has closely 

 examined the district has quite failed to find any 

 evidence of the presence of more than one limestone. 

 This limestone is commonly known as the 

 Oamaru stone, but in geological reports it is called 

 in almost every case the Ototara series. While too 

 much space would be taken in stating the strati- 

 graphy in detail, the writers are of opinion that 

 there is but one limestone formation in the district, 

 and that its character becomes in general less pure and gradually more 

 arenaceous as the old shore, usually tfo the west, is approached. 



This point of view is strongly supported by Boehm, who specifically 

 states that the rock at the Devil's Bridge, the upper limestone at Kakanui, 



* Boehm : Zeit. d. Deutsch. Geolg. Gcsellschaft Jahrg., 1900, p. 175, 

 t Park : Trans. N.Z. Inst., 1904, vol. 37, p. 504 et seq. 



