536 Transactions. — Geology. 



some of the writers, myself included, to interpret the sections 

 in conformity with the Cretaeeo-Tertiary theory of the Geo- 

 logical Survey. According to this theory the Weka Pass 

 Stone is the equivalent of the Waitaki Stone. Below the 

 Weka Pass Stone there is a succession of beds closelv re- 

 sembling those found below the Waitaki Stone, and containing 

 a Secondary fauna : therefore the theory was held to be 

 proved. But this contention overlooked the manifest fact 

 that the succession of fossiliferous Tertiary beds which under- 

 lie the Waitaki Stone in Otago and South Canterbury overlie 

 the Weka Pass Stone at Weka Pass, forming the Mount 

 Donald and Mount Brown Ranges. 



The Geological Survey has always acknowledged that the 

 Mount Donald beds overlaid the Weka Pass Stone, but has 

 not recognised that the Mount Donald, Mount Brown, or 

 Hutchinson Quarry beds underlaid the Waitaki Si one, as I 

 have shown to be the case at Kakanui and Wharekuri. 



The resemblance of the sequence and character of the 

 rocks of the Waipara and Oamaru formations was noticed 

 by Sir Julius von Haast. That writer, when discussing the 

 Oamaru formation in 1879, said, ::: "The beds belonging to the 

 Oamaru formation resemble often in sequence and character 

 of the rocks those of the preceding Waipara formation. They 

 in most instances begin with littoral deposits and end with 

 calcareous strata, the latter formed in deeper water." 



In this district there are three easily recognised marine 

 formations — namely, (1) Motanau beds, of Older Pliocene 

 age ; (2) Oamaru series, of Miocene age ; (3) Waipara series, 

 of Upper Cretaceous age. These formations are met in the 

 order named on the railway-line between Waipara Station 

 and the upper end of Weka Pass. 



Motanau Beds. 



At 42 miles 30 chains from Christchurch, after the line 

 leaves the gravel terrace of the Waipara, there appear in the 

 railway cuttings brown sands with layers of hard flaggy sand- 

 stone, often pebbly and gritty, and generally calcareous. The 

 dip of these beds is easterly at very low angles, and, proceed- 

 ing along the railway-line, sandstones, sandy clays, and shell- 

 beds succeed each other for a distance of three-quarters of a 

 mile. 



In the cutting between the 12^-mile and the 43f-mile 

 posts there are a number of conspicuous oyster-shell beds 

 occurring throughout a thickness of about 100 ft. These 

 marine beds end at a point 10 chains north of the 43-mile 



* Haast, "Geology of Canterbury and Westland," 1S7<J, p. 305. 



