Thomson. — Stage Na7nes a2Jplicable to Divisio?is of Tertiary. 35 



No exception can be taken to " Hutchinsoniau " on the grounds of 

 priority, for no other earlier name has been used for this horizon in the 

 Oamaru district. Park speaks of the Hutchinson Quarry beds as the 

 Mount Brown beds ; but the latter, in the Weka Pass district, include cer- 

 tainly the Awamoan as well as the Hutchinsoniau stage, and possibly also 

 the Ototaran. In the Hutchinsonian I would place all beds between 

 the Ototara limestone and the shell-bed of Target Gully, described 

 by Marshall and Uttley (1913), the latter bed forming the base of the 

 Awamoan. 



"Ototaran" is alike indicated by priority and subsequent usage as 

 the most suitable name for the limestone member of the Oamaruian, and 

 should be accorded general acceptance. 



The Waiarekan stage has be^n studied in most detail as the Waihao 

 greensands, but as the Waihao formation of Haast refers to much older 

 rocks no stage name can be based on these greensands without ambiguity. 

 The Waiareka tuffs are frequently included in older classifications, and a 

 name based on them should find ready acceptance. Should this stage 

 be too large in comparison with the others, the Waiarekan may be I'e- 

 stricted to the tuffs themselves, and the underlying Windsor and Enfield 

 beds may be made the type of a new stage. 



The Ngaparan is the only one of the proposed stages that is not based 

 on a well-established name for a geological series. Park, in 1905, called the 

 coal-beds at the base of his Oamaru system the Awamoko beds. In 1910, 

 however, he called them the Ngapara beds when speaking of the Oamaru 

 district only, but for New Zealand generally he designated this horizon 

 the Kaikorai coal-measures. For a subdivision of an Oamaru series 

 a name derived from the Oamaru district is obviously most suitable. 

 I select Ngapara as the type locality because it is nearer to the outcrop 

 of the Ototara limestone than Awamoko, and the coal-beds there are 

 demonstrably the basal member of the Tertiary series represented at 

 Oamaru. The limits between the Ngaparan and Waiarekan cannot be 

 exactly drawn without a more detailed investigation of the Ngapara 

 district. 



The Ngaparan in the North Otago and South Canterbury district does 

 not contain a marine fauna, and cannot be correlated directly with marine 

 beds of the same stage, such as probably occur in North Canterbury, 

 and possibly on the West Coast. I suggest that " Ngaparan " should be 

 restricted to coal-beds, and that a different stage name should be used for 

 the normal marine beds of the same horizon. Applying the same principle 

 throughout, wr shall get a double set of stage names for the normal marine 

 and for the littoral or terrestrial beds. 



III. Stage Names derived prom the Wanganui District. 



As in the Oamaru district, there has not been complete agreement 

 amongst geologists regarding the order of succession of the rocks in the 

 Wanganui district. The principal point in dispute relates to the beds 

 of Kaimatera Cliff, considered by Hutton (1886) as an upper series of 

 Pleistocene beds unconformable with the Pliocene beds of the district, 

 and by Park (1887) as an integral part of the " Newer Pliocene." As 

 Hutton's view was founded on a biief inspection of the cliff without a 

 full knowledge of the geological structure of the district, while Park's was 

 based on an extensive reconnaissance survey, the latter may be accepted. 

 2* 



