412 Transactions. — Geology. 



question/'^ And, further, when discussing the geology of Wai- 

 apu Valley he refers to the rocks representing the Amuri lime- 

 stone as belonging to the " Cretaceous" period.! 



In December of 1874 I made a collection of Tertiary 

 marine shells from certain sandy clays in the lower part of 

 the Maungapakeha Valley. These clays rested unconformably 

 on soft shaly claystones containing fragments of a fibrous shell 

 which, I have no doubt, belonged to the genus Inoceravius. 

 On a subsequent visit to this district I found that the Ino- 

 cerarmis beds were associated with grey chalky clays, which 

 are now known throughout the North Island as hvdraulic 

 limestone. 



In 1888, in my report " On the Probable Discovery of Oil 

 and Coal in Wairarapa North County," | after speaking of the 

 occurrence of hydraulic limestone on Ika Farm, I state that 

 " this limestone is associated with the younger members of 

 the Upper Secondary rocks"; and in the argillaceous mem- 

 bers of these rocks I found that fragments of Inoceramus were 

 not uncommon. 



In the South Island the conformable relations of the 

 Amuri limestone to the underlying Secondary beds have been 

 acknowledged by every one, but different opinions are enter- 

 tained by the Geological Survey and Captain Hutton as to 

 the interpretation of the sections at Waipara and Weka 

 Pass. 



The chief point of contention is concerning the relations 

 of the Weka Pass stone (Oamaru stone) to the Anmri lime- 

 stone. 



In South Canterbury and North Otago the Oamaru series 

 consists of the following members in descending order : — 

 (a.) Oamaru stone. 

 {h.) Marly and sandy clays. 



(c.) Marly greensands, often with calcareous concre- 

 tions. 

 (d.) Quartz grits, fireclays, and coal. 



At Waipara and Weka Pass the Weka Pass stone, which 

 has always been acknowledged to be the equivalent of the 

 Oamaru stone, rests directly upon the Amuri hmestone. The 

 Weka Pass stone forms a sloping plane deeply dissected by 

 streams, and in following round the contours of the valleys 

 is always found resting on a level or nearly level surface of 

 Amuri limestone, thereby presenting at many places the ap- 

 pearance of complete stratigraphical conformity. 



Since 1873 Captain Hutton has consistently maintained 



• Reps. Geol. ExpL, 188G-87, p. 218. 



t Loc. cit., p. 218. 



J Reps. Geol. Expl., 1887-88, p. 24. 



