58 president's address — section c. 



Hector to be Carboniferous in age, together with an undetermined 

 form differing in somi© respects from Inoccramus, and held that 

 these beds were thrust over the fossiliferous Triassic rocks. He 

 also indicated that the Maitai beds might be united with a higher 

 series cf argillites, which were unfossiliferous sa-vei for the presence 

 of an annelid Torh^ssia Mach(vyi. He believed an unconfo'rmity 

 existed between the Maitai and Triassic rocks but that their rela- 

 tions were somewhat obscure. Hutton (1873) at first believed the 

 Maitai and Triassic were continuous, indeed included the latter 

 in the Maitai system, but later urged that a very important 

 orogenic movement separated them. Park (1904) for a brief 

 period considered the Maitai recks as Jurassic, accepting as correct 

 the detennination of the shell mentioned as Inoccramus. Later 

 (1910) he withdrew this, and suggested the form was inorganic, 

 though as thei result of an eixamination of the Maitai braohiopods, 

 he confirmed McKay's view concerning these. The Geological 

 Survey (Marshall and Bell 1911) extended the temn Maitai series 

 toi cover all the older sediments of the Nelson district, and threw 

 doubt on thei occurrence of supposodly Carboniferous fossils, and 

 the determination of the form mentioned as true Inoceramus. 

 Marshall (1912) went further, and used the term Maitai series to 

 cover the whole cf the Triassic and Jur^assic rooks in New Zealand, 

 and correlated with this series some of the greywackes and argillites 

 cif the West Coast, together with the more or less m-etamoirphic 

 mica-schists of Central Otago. He thus made it by far thei most 

 extensive formation in New Zealand. He excluded from it, how- 

 ever, the Haupiri series of conglomerates and basic breccias Tying 

 unconformably on the Aorere rocks in north-western Nelson. They 

 had usually been classed (as here) with the Te Anau rocks, but 

 Marshall suggested that it would be preferable tentatively to 

 class them with the Silurian rocks. Thus at the close of the 

 last decade, two attitudes were adopted m the general statements 

 issued. The one attempted to rearrange the late Palaeozoic and 

 Early and Middle Mesozoic rocks into various subdivisions, on the 

 old lines, accepting as suflticient the tentativei determinations O'f 

 thei fossils therein. The other view noted the confusion that 

 existeid in the stratigraphical and palaeontological data, as they 

 then stood, assumed that v^s a result of isolation, premature and 

 belated forms could be expected here, and concluded that it was 

 not possible to divide the sediments of this period into sub-series, 

 comparable with those in the contemporaneous formations of the 

 northern hemispherei, but rather stressed the unity and apparent 

 conformity of the whole sedimenta,ry system to which the name 

 Maitai was extended. 



With this introduction the importance of the work of the last 

 decade may be more clearly realized, and the results of this are 

 shown on Tables II. and III. Thomson (1913) drew attention to 

 the policy of the Indian Geological Survey in sending carefully 



