IN THE SOUTH ISLAND OF NEW ZEALAND, ETC. 107 
explanation being that the matter carried down by the glacier is 
so enormous as completely to fill up the bottom of the Tasman 
Valley as the glacier slowly retreats, which can plainly be seen 
by the successive heaps of terminal moraine all down the 
valley. The cUbris brought down by the Mueller Glacier is 
immediately washed away by the Hooker Eiver ; there is no 
room in this valley for its deposition. 
In the ice age, or glacial period, of Hew Zealand, which is 
placed by Capt. Hutton in the older Pliocene, this glacier with 
its tributaries, the Hooker and Mueller, combined on the west, 
and the Murchison and Jollie on the east, was over 40 miles 
longer than it is at present, and its terminus was at the 
southern end of Lake Pukaki. All down the sides of the 
Valley of the Tasman you can see the lateral moraines in 
several series, the largest and highest being quite 200 feet 
above the present level of the lake ; while the great terminal 
moraine, though perhaps not quite so high as that at Tekapo, 
represents a far greater accumulation, for the Pukaki Lake is 
much the deeper. How this is exactly the same phenomenon 
on a larger scale presented by the present terminus of the 
glacier — a hole blocked with morainic deposit brought forward 
by the glacier and dropped at the snout. Hor is there here 
any rock-basin ; nothing but the considerable slope of the 
Mackenzie Plains to the gorge of the Waitaki 14 miles distant, 
where the three rivers, Tekapo, Pukaki and Ohau, unite. How 
I understand that this great hole, the Pukaki Lake, does not 
show a depth below the level of the rock bottom of the 
Waitaki; and were it so, though the weight of the ice must 
have been enormous, and far above computation, still I think 
it open to question whether ice descending at such a small 
angle (not more than one degree from the nevd even were the 
mountains double their present height) could have possibly dug 
these great holes, supposing the ice to be armed with the so- 
called “ digging tools,” which I maintain are non-existent, or at 
any rate extremely problematical. 
How Mr. Alexander McKay, F.G.S., Geologist to the Hew 
Zealand Government, firmly maintains that, in Hew Zealand at 
least, these lake basins are due not to the digging power of ice, 
but to great earth movements. This South Island is crossed by 
three great geological faults. In the north-east of the island 
are the great lvaikouras nearly 10,000 feet high, separated into 
two ranges by the cleft through which the Clarence Eiver runs. 
Here one can plainly trace two great faults, one on each side of 
the mountains, one up the Piver Awatere, and the other up the 
