TiioMsox. — Stage Names applicable to Diris/oiis of Terfiar//. 37 



Awatere district rontains a sequence of beds, and includes Oamaruian as 

 well as Wanganuian stages. What is probably the uppermost stage, repre- 

 sented in the Starborough Creek beds described by Park in 1905, contains 

 far fewer Oamaruian species than the Waitotaran list given by Park in 

 1887 ; so that, even allowing for some incorrect identifications in the latter, 

 the former can hardly be earlier than Waitotaran. The same applies to 

 the " Motunau beds " of the Waipara section, which rest directly, and 

 apparently withoiit imconformity, on the Awamoan. It does not appear 

 probable, therefore, that any stage between the Waitotaran and the 

 Awamoan will be necessary ; but, as said before, further research, including 

 a detailed investigation of the Waitotara beds, is necessary before the 

 matter can be settled. 



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



It has been generally held that the rocks of the West Coast coalfields 

 ■contain in their lower members horizons lower than those represented 

 at Oamaru. At one time these horizons were considered Cretaceous, but 

 as no definitely Cretaceous marine fossils have been described it is now 

 generally agreed that the whole marine sequence is Tertiary. It is, 

 therefore, necessary to examine the evidence available with a view to 

 discovering whether infra-Oamaruian stages may be safely named. 



The fullest sequence, showing not only all the upper horizons repre- 

 sented on the West Coast, but also lower horizons than e.xist in any other 

 district, is contained in the Greymouth district, recently surveyed in detail 

 by the Geological Survey (Morgan, 1911). So far as the development and 

 the relationships of the rocks are concerned, this area is one of the best 

 known in the Dominion, and Morgan's account, based on a detailed survey, 

 must be accepted in preference to all earlier accounts. The Tertiary rocks 

 are grouped by him as follows : — ■ 



Pliocene beds .. .. .. Soft sandstones, lignite, and somewhat 



consolidated gravels. 

 /^Blue Bottom formation. 

 Cobden limestone. 

 Greymouth series, Miocene . . -, Port Elizabeth beds. 



I Lower Kotuku conglomerate. 

 lOmotumotu beds. 

 Kaiata mudstone. 



Coal-measures (Mawheranui series). 

 Eocene 



Island sandstone. 

 Brunner beds. 

 ,Pa4)aroa beds. 



The so-called Pliocene beds are fluviatile, and contain no marine fossils. 

 The whole of the Greymouth series and the Kaiata mudstone and Island 

 sandstone of the Mawheranui series are marine, but the lower beds are 

 sparingly fossiliferous. The Brunner and Paparoa beds consist of con- 

 glomerates, sandstones, grits, and shales, with coal-seams, and contain no 

 marine fossils, but well-preserved leaf-impressions at several horizons. 



Morgan correlated the middle and lower beds of the Greymouth series 

 with the Oamaru formation of Hutton, suggesting the following individual 

 correlations : — 



Cobden limestone = Ototara stone. 

 Port Elizabeth beds = Middle Oamaru. 



Omotumotu beds = Possibly the coal horizon of the Oamaru 



formation. 



