McKay. — On the Age of the Napier Limestone. 871 



During the 5th, 6th, and 7th September last I examined 

 Scinde Island, and agree with Captain Hutton that there is an 

 upper and a lower limestone in Scinde Island, but saw no reason 

 to suppose that these were unconformable to each other. To 

 me, the evidence was quite clear that the lower limestones and 

 overlying sands are connected by passage beds, and shade into 

 one another. I further found that, not the northern, but the 

 western side of Scinde Island showed the presence of the younger 

 series ; and I could not arrive at the conclusion that the lower 

 beds are the equivalents of the Te Aute limestone, nor of any 

 formation containing no more than 35 per cent, of recent species. 

 The upper beds, I admit, resemble the shell limestones of the 

 mainland to the W. and N.W. of the Ahuriri Plain, but I was 

 forced to the conclusion that either the upper limestones are not 

 the same as those on the mainland already mentioned, or that 

 the lower limestone was not the Te Aute limestone, and in all 

 these conclusions differ from the opinions of Captain Hutton. 



To try to solve the various problems thus requiring to be 

 considered, I went to Petane, and thence by coach to the 

 Mohaka Valley, spending two days to the west and north of 

 the river-crossing, and the other available day on the Te Waka 

 Eange ; the sequence to the eastward I but partly observed. I 

 traced the tertiary sequence, as here represented, to its base in 

 the Kiwi Eange, and further to the north along the Taupo Eoad. 

 I found strata rich in fossils in this direction, on the north- 

 western side of this part of the Mohaka Valley, and was able 

 thus to refer nearly a thousand feet of strata to the Pareora 

 series of the Geological Survey classification. 



The fossils of this part of the tertiary sequence are abundant 

 in the Mohaka river-bed, near the bridge and crossing of the 

 Taupo Eoad ; but I did not content myself with these, but sought 

 out the fossiliferous beds in section. 



These lower beds are characteristic, and not difficult to be 

 distinguished from those that over-lie on the south-east side of 

 the valley. They are brown, green, or grey sands, or fine grit, 

 with concretions or beds of harder and more calcareous material 

 full of shells. In then.' upper part, the brown sands alternate 

 with lighter-coloured sandy clays. They dip a little to the S. of 

 E. at moderate angles, 20° to 25°. Eastward of the Mohaka 

 these are followed conformably by a great thickness, more than 

 1,000 feet, of light-grey sandy beds of a more argillaceous type 

 than the last brown sand bed appearing in the Mohaka east 

 bank, at the crossing. This series is closed by a bed of brown 

 sand of considerable thickness, which shows on the western 

 brow of the Titiokura saddle, by which the Napier-Taupo Eoad 

 reaches the Mohaka. These appear to be the gritty sandstones, 

 " No. 9," of Mr. Percy Smith's map, and the " grey and brown 

 sandstones " of Captain Hutton. Fossils are rare, and I collected 



