562 Transactions. 



glaciers on the Barrier Kange. The snouts of the glaciers are 

 about 1,000 ft. above the valley-floor, and, as in the case of the 

 Rock Burn, the waters from their melting ice tumble down pre- 

 cipices into the valley below. This ice fills hanging valleys from 

 which ice was under other conditions supplied to the main valleys. 



From the head of the Hidden Falls Stream there is a low, flat 

 pass with mountain walls on either hand to the head of the 

 Olivine Stream. On the west side a mountain wall rises without 

 a break, but on the east deep valleys cut far into the hills, and 

 each appears to terminate beneath the snout of a glacier, though 

 we were unable to spend the time necessary to prove this in every 

 case. There can be no doubt that all the flat of this deep pass 

 was once covered by ice, for in many points of vantage on the 

 mountain-side perched blocks, evidently of a different nature 

 from that around them, are to be seen. A large mass of moraine 

 extends across the top of the Olivine Stream. This dammed 

 up the stream, and is the main cause of the formation of the wide 

 flat area of the pass beyond it. 



The Olivine Stream is in all essentials a duplicate of the Rock 

 Burn. Its main features are certainly due to glacial erosion. 



From the Olivine there is a low saddle leading to the valley 

 of Lake Alabaster. The slope on the Olivine side is extremelv 

 steep, and that stretching towards Lake Alabaster also appears 

 precipitous. On the saddle itself the effects of ice-action are 

 clear and pronounced. Rounded and worn rock-surfaces are 

 everywhere in evidence, though the actual grooves and polished 

 surfaces are here, as elsewhere, somewhat indistinct. 



The profound valley occupied by Lake Alabaster is entered 

 by the Pyke River from the north-east. This river is, at a 

 distance of twenty-five miles above Lake Alabaster, separated 

 from the waters of Big Bay by a flat area of morainic matter 

 no more than 200 ft. above sea-level. This morainic matter 

 fills a wide valley between the Skipper's and McKenzie Ranges. 

 The Pyke River, instead of following this obvious straight 

 course to the sea, turns sharply to the south-west towards Lake 

 Alabaster, joins the Hollyford River, and after a course of thirtv- 

 five miles enters the ocean near Martin's Bav. 



Evidently some special explanation of this eccentricitv 

 is required. The explanation is to be found in a considera- 

 tion of the movements of the ice of the great Hollyford glacier. 

 This prehistoric glacier received the ice from twenty-five miles 

 of mountain-ranges on either hand, and, judging from the depth 

 and width of its valley, must have attained enormous dimen- 

 sions. In the lower part of its course the ice-stream under- 

 went " diffluence," and a portion of it passed over a low saddle 

 then occupying the site of Lake Alabaster, and entered the 



