Park. — The Great Ice Age of New Zealand. 595 



The Rev. James Christie* has stated that Saddle Hill owes its dis- 

 tinctive form to ice erosion ; and after a careful examination of its topo- 

 graphy I am entirely at one with him. The seaward slopes of Saddle Hill 

 exhibit beautiful, smooth, undulating contours, and I am satisfied that 

 the two main knobs of the hill, as well as the small knob lying to the east 

 of these, are roches moutonnees in a good state of preservation. 



Waihola Lake, and the Taieri Basin, of which it is a part, are good 

 examples of U-shaped valleys, as also is the Kaikorai Valley, which heads 

 into a fine glacial cirque at the source of the Leith Stream. The Toko- 

 mairiro is also a glacial basin. It is a continuation of the Taieri Basin, 

 and is separated from the Clutha glacial valley by some low ice-shorn 

 hummocky hills. 



At Wingatui, following the foot of the mica-schist hills, there is a 

 deposit of brick-clay some 50 ft. thick, consisting of thin horizontal alter- 

 nating layers of rock-flour and gritty clay. The material is not residual, 

 but aqueous, and is almost identical with the fine bedded glacial clays at 

 Lake Hayes and Kawarau Falls, near Lake Wakatipu. The existence of 

 the glacial moraines at AUanton, a few miles to the south, and at Fern- 

 town, a few miles to the north, and the existence of an ancient glacier 

 in the Taieri Basin, are strongly suggestive of the glacial origin of these 

 clays. 



The slopes and crests of Flagstaff, Swampy Hill, Pine Hill, and of 

 Otago Peninsula, when viewed from almost any standpoint, exhibit smooth, 

 sweeping contom's, domed crests, and truncated spurs, in many places 

 dissected by the later streams draining the slopes. Moreover, the higher 

 slopes of Swampy Hill, facing the Upper Leith ; the slopes of the Otago 

 Peninsula behind Anderson's Bay ; and the higher slopes of Sidey's Hill, 

 opposite Abbotsford, are excavated into tiers of more or less parallel 

 shelves — a feature that I have shown is often associated with ice erosion 

 in the Wakatipu region. 



No one has ever claimed that the Otago Harbour is a submerged valley 

 of fluviatile erosion. Such a hypothesis would at once be faced with 

 insuperable difficulties, not the least being a satisfactory explanation of 

 the sudden cessation, or ending, of the valley at Dunedin without leaving 

 a trace of its former existence to the westward of the city. It seems not 

 improbable that -the site of North Dunedin, embayed as it is on three sides 

 with encircling hills, was a glacial basin from which one stream of ice 

 passed seaward through the gap between Lawyer's Head and St. Clair, 

 while another stream flowed down Otago Harbour. 



As a matter of fact Otago Harbour consists of two distinct basins — 

 namely, the Dunedin Basin and the Port Chalmers Basin — which are 

 separated by a chain of islands that extend from side to side with only 

 narrow, shallow channels between them. 



The Leith is obviously a young stream that has eroded its present 

 narrow rift-like gorge down to the floor of the Dunedin cirque since the 

 glacial period. 



Mr. Christie has expressed the opinion that Otago Harbour was the 

 work of ice erosion. I am so far in agreement with him in believing that 

 the harbour was occupied by a glacier which deepened it and moulded the 

 adjacent hills, imparting to them the flowing contours and beautiful 

 catenary curves that are so conspicuous on each side. 



* J. Christie, Olago Daily Times, May, 1909. 



