Hurron.—-On the Silt Deposit at Lyttelton. 418 
widely extended a deposit, resting on such different rocks, could be formed 
in the way suggested by Dr. von Haast; and it is also difficult to under- 
stand why, on this hypothesis, the deposit should be found only on the 
coast near the mouths of the great rivers from the Waimakariri to the 
Waitaki, and not elsewhere. 
In the second place the limit in height of the deposit must be noticed. 
In the “ Transactions of the New Zealand Institute,” vol. vi., 1878, p. 423, 
Dr. v. Haast says that on Banks Peninsula it extends to a height of 800 
feet above the sea; and in his Report on the Geology of Canterbury he says 
that at Timaru it reaches to near the summit of Mt. Horrible, which is 
1,272 feet high. No other data can be obtained at present, and the 
difficulty here is to explain why, on the subaérial hypothesis, its height on 
Banks Peninsula should be limited to 800 feet, notwithstanding that grass 
grows, rain falls, and the wind blows at much greater altitudes. 
In the third place the silt deposit is not confined to the slopes. At 
Oamaru it covers the very highest points of Oamaru Cape, as may be seen in 
fig. 7, page 55, of my report already quoted ; and in many parts of Banks 
Peninsula it is better developed on the ridges than in the valleys, as the 
accompanying sketch of the cliffs between Little Akaloa and Mackintosh 
Bay will show (fig. 2) ; so that the action of rain in its formation must be 
eliminated. 
Little Sandy’s Mackintosh 
loa. Head. Bay. 
[74 
AE AEE DS 
WE - ff S CA pan AN 
ber Se T ^A 
AMIGA USE DARIO SONS 
Fig. 2, a, silt deposit ; b, volcanic rocks. 
The last point to be noticed is the fossils eontained in the deposit. 
Usually it is quite unfossiliferous, but Dr. von Haast states that moa bones 
and land shells have been found in it somewhere on Banks Peninsula, but 
no definite locality is named. The occurrence of land shells is remarkable 
considering how rare they are now in New Zealand, and that they are 
almost entirely confined to the bush. I have never heard of any land shells 
having been found on grass land except in crevices of limestone, or under 
blocks of the same rock; and there is no limestone on Banks Peninsula, 
while, according to Dr. von Haast's hypothesis, the formation accumulated 
on open grass land. 
At Oamaru marine shells of still living species are found in the lower 
part of the deposit up to a height of 60 feet above the sea. A list of the 
species will be found at page 70 of my *' Report on the Geology of Otago," 
1875. 
