Park. — Upper Cretaceous and Lower Cainozoic Formations. 393 



the Upper Cretaceous age of the lowermost beds, and the apparent strati- 

 graphical conformity of the strata from the Miocene to the Cretaceous, but 

 finds himself, after a judicial summary of all the available evidence, unable 

 to support the Cretaceo-Tertiary theory of the old Geological Survey. He 

 describes the uneven corroded surface of the Amuri limestone where over- 

 lain by the Weka Pass stone in North Canterbury, and, while not placing 

 undue stress on the magnitude of the discordance at this contact, he seems 

 to think that the break between the Cainozoic and Cretaceous may occur 

 at this horizon. In this he agrees with the view all along held by Hutton, 

 and in 1912 adopted by myself* after the discovery (or rediscovery) of 

 Cainozoic molluscs in the Weka Pass stone at Waipara by Thomson and 

 Cotton. 



In his paperf on the " Flint-beds associated with the Amuri Lime- 

 stone " Thomson records the occurrence of Tertiary (Oamaruian) molluscan 

 fauna in a bed of tuff intercalated in the Amuri limestone in the Trelissick 

 Basin. This discovery, made by Thomson and Speight in 1915, seems 

 destined to furnish the solution of many of the perplexities that have in the 

 past obscured the unravelling of the relationship of the Lower Cainozoic 

 and Cretaceous of New Zealand. The bed of tuff is overlain by 10 ft. of 

 Amuri Limestone and underlain by 350 ft. of Amuri limestone. Of the mol- 

 luscs enumerated by Thomson, 19 per cent, are Eecent, and the remainder 

 are all well-known Tertiary species, mostly Oamaruian (Miocene). Save 

 foraminifera (mostly Globigerina), some radiolarians, and sponge spicules, the 

 Amuri limestone itself is unfossiliferous, or, at any rate, devoid of molluscan 

 remains ; and, while recognizing the Oamaruian age of the tuffs and over- 

 lying portion of Amuri limestone, Thomson expresses the view that the 

 portion of the Amuri limestone below the tuffs fills the hiatus between the 

 Senonian and Oamaruian. 



Marshall J in his paper on the " Relations between Cretaceous and 

 Tertiary Rocks " discusses at considerable length the views of different 

 New Zealand geologists as to the Waipara succession, and furnishes much 

 useful information as to the relationship between the Cretaceous and 

 Tertiary rocks in other parts of the globe. He reaffirms his belief in a 

 Cretaceo-Tertiary succession. 



I do not think that any useful object would be served by a further 

 discussion of the various points of disagreement between myself and Dr. 

 Marshall. Tire settlement of the Cretaceo-Tertiary can only be achieved 

 by a detailed geological survey of the Middle Waipara and Weka Pass 

 districts. The groups of beds recognized there, and their order of super- 

 position as agreed by all geologists, are — 



1. Greta beds 



2. Mount Brown beds 



3. Grey marls V Oamaruian (Miocene). 



4. Weka Pass stone 



5. Amuri limestone ' 



6. Glauconitic greensands • . Doubtful. 



7. Saurian beds ) 



8. Oyster-bed y Senonian. 



9. Quartz sands with brown coal ) 



*J. Park, Tertiary Fossils in the Weka Pass Stone, New Zealand, Geol. M<kj., 

 July, 1912, p. 336. 



t J- A. Thomson, Trans. X.Z. Inst., vol. 48, 1916, pp. 48-58. 

 t hoc. cit., pp. 100-19. 



