33'2 Transactions. 



reaffirmed his belief in a necessary unconformity on palaeontological grounds, 

 which he therefore placed, with Hutton, between the Amuri limestone and 

 Weka Pass stone, and cited unconformities on the same horizon in other 

 districts, and the controversy shifted to these. 



Thomson (1913) described new fossil-localities in the Weka Pass stone 

 at Onepunga and in the Mount Brown beds near the junction of the Weka 

 Creek and the Weka Pass Stream. He expressed the opinion that " although 

 a classic locality for the determination of the relationships of the Cretaceous 

 and Tertiary beds, the Middle Waipara and Weka Pass district is not well 

 suited, owing to its poverty in molluscs, to become the standard of reference 

 for the Tertiaries of New Zealand." 



Morgan (1915) described the section exposed in the gorge of the Weka 

 Pass Stream near the railway-viaduct and in its upper valley, agreeing with 

 the explanation of the structure put forward by Marshall, Speight, and 

 Cotton, and devoted special attention to the contact of the Amuri lime- 

 stone and the Weka Pass stone. The conclusion, stated to be tentative, 

 was that the facts appeared to be clear proof of at least local unconformity. 

 The same writer in 1916 (1916b) described the contact in the country between 

 the Weka Creek and the Waipara River, recording the occurrence of small, 

 extremely black, phosphatic pebbles in the glauconitic sandstone to a height 

 of 4 ft. above the Amuri limestone surface, also one or two quartz pebbles 

 and a pebble of flint, and also worm-borings now filled with glauconitic 

 matter in the Amuri limestone. He noted that in the gorge of the Waipara 

 River there was no sign of visible unconformity, but considered that it was 

 still possible to accept the Amuri limestone and Weka Pass stone contact 

 as representing a stratigraphical break. He cited a contact visible in a 

 small gorge of Weka Creek as very satisfactory proof of the unconformity 

 maintained by Hector and McKay as present between the " grey marls "" 

 and Mount Brown beds. Sections were also given showing the Quaternary 

 age of some of the faults of the district. 



Speight in 1915 discussed the geology of the intermont basins of 

 Canterbury with a view to arriving at a proper conclusion as to the pre- 

 Notocene physiography, and whether or not the present Notocehe beds 

 were originally laid in discontinuous deposits or are the remains of a widely 

 distributed cover which once masked the greater part of the surface of the 

 country. He concluded in favour of the latter view, with the restriction 

 that they did not form a complete veneer over the whole surface, but that 

 elevations that survived the prior period of erosion projected like islands 

 through/ the Tertiarv sea, and mav in some cases have been sufficientlv 

 high to form sanctuaries for the Antarctic element in the New Zealand flora. 



Marshall in 1916 described the minute structure of the younger lime- 

 stones of New Zealand, including specimens of the Amuri limestone and the 

 Weka Pass stone from the Weka Pass. He found the Amuri limestone to 

 consist mainly of very finely grained calcite, with fairly numerous, isolated 

 chambers of Glohigerina. Near the contact it contained a considerable 

 number of grains of quartz sand and some glauconite, as well as some brown 

 mica, together with different and larger species of Foraminifera, including 

 CristeUaria and Rotalia. These characters, emphasized to a greater extent, 

 were the features that distinguished the overlying Weka Pass stone from 

 normal Amuri limestone. Tl\e microscopic structure and relations of these 

 limestones served to indicate a strong resemblance between these stones 

 near their contact, and such differences as there were would be a natural 

 result of the shallowing of the water and of an increase in the velocity of 

 the ocean currents. The depth of deposit of the Amuri limestone, a pure 

 Glohigerina ooze, was estimated at from 600 to 2,500 fathoms. Its age was 

 considered to be Miocene. 



