258 Transactions. — Geolotjy. 



3. Unfortunately another gully follows, and the next cutting 

 shows the following rocks, dipping 20° E.S.E. : — 



Feet. 

 9. Brown sandstone ... ... ... 10 



8. Bust-coloured rubbly limestone with beds of 



sand and broken shells ... ... 18 



7. Brown sandstone ... ... ... 25 



A gully now follows, and the section is continued in the next 

 cutting as follows : — 



Feet. 

 6. Sandy clay ... ... ... ... ? 



5. Bust-coloured rubbly calcareous sandstone ... 20 

 4. Soft brown sandstone ... ... ... 15 



3. Bust-coloured sandy limestone with beds of 



sandstone ... ... ... .. 30 



2. Soft brown sandstone with calcareous bands 50 



1. Bust-coloured sandy limestone and sandstone, 

 the sandstones increasing in importance 

 upwards ... ... ... ... 25 



These rusty limestones, from 8 to 1, form what are known 

 as the Mount Brown beds, the total thickness of which is here 

 between 200 and 250 feet. These beds rest unconformably on 

 laminated argillaceous sandstones with grey calcareous bands, 

 which get more numerous downwards. Very fortunately, this 

 is well seen in the section a little south of the Weka Pass Hotel, 

 and also a little south of the 44th milestone from Christchurch. 

 (Plate XIV., fig. 2.) 



The rocks on both sides the plane of discordance dip 20° 

 E.S.E., while the plane of discordance itself dips, roughly, 30° 

 in about the same direction, but is irregular. At first sight it 

 might be thought that this plane of discordance was a fault ; 

 but the low hade, the uneven surface, and the absence of any 

 friction breccia, show, I think, that such is not the case. It 

 seems to me that the older series was horizontal when the newer 

 series was deposited on its denuded edges, and that both have 

 been tilted since. 



Dr. Hector has always maintained that the Mount Brown 

 beds rested unconformably on the lower rocks in the Waipara 

 District,* while I have held t lie contrary view. I now gladly 

 acknowledge that I have been wrong, and that the Mount Brown 

 beds must be separated from the underlying series. 



2. These underlying rocks in the Weka Pass are as follows : — 

 5. Laminated argillaceous sandstones with grey calca- 

 reous bands, which get more numerous downwards. 

 4. Blue sandy marl and sandstones. 



* See Hector, "Prog. Rep. Geol. Surv., 1868-9," p. 12 : also Sir J. von 

 Haust, " Reports, Geological Explorations, 1870-71," p. 14. 



