336 Transactions. 



the beds towards the end of the year 1912, and this paper gives an account 

 of his conclusions arrived at on that occasion. I must take this opportunity 

 to express my obligation to Mr. W. F. Kobinson, Lecturer on Surveying 

 at Canterbury College, who accompanied me on the visit, and gave material 

 assistance in determining the relative position of various points of import- 

 ance, and to whom I am indebted for the sketch of the locality on page 339. 



Position and General Features op the Locality. 

 (See map and topographic sketch.) 



EedclifE Gully is situated on the south bank of the Rakaia River, about 

 fifteen miles above the Gorge Bridge, and forms part of Mr. Gerard's Double 

 Hill Station. On the opposite side of the Rakaia lies Lake Coleridge, and 

 the pipe-line of the power scheme connected with it reaches the Rakaia 

 about two miles below the mouth of the gully, so that if at any future occasion 

 it is intended to apply this power for the manufacture of calcium carbide 

 or other calcium compound the position is eminently favourable for carrying 

 it to a successful issue. 



The level of the bed of the Rakaia is at this spot approximately 1,260 ft. 

 above the sea, while the highest point of the limestone exposure is 3,060 ft. 

 The mountains in the immediate vicinity reach to nearly 7,000 ft., and 

 about five miles to the south-east is Mount Hutt (7,180 ft.), the highest 

 of all the peaks in the range which rises directly from the Canterbury Plains. 

 At the head of the gully is RedclifE Saddle (2,980 ft.), from which an easy 

 track leads south to the head of a branch of the North Ashburton. This 

 pass forms a well-marked depression in the range which bounds the Rakaia 

 on the south, and shows in its flowing contours and U-shaped cross-section 

 unmistakable signs of severe glacial erosion ; glacial shelves are common, 

 and morainic matter is scattered over the surface and at times masks with 

 a covering of variable thickness the limestones and beds associated with them. 

 Signs of glaciation are also clearly visible on the main valley of the Rakaia 

 in the vicinity. Stranded lateral moraines; roches moutonnees rising from 

 the floor of the valley ; the silt-filled lake-bed which has been now drained 

 by the erosion of the river ; and the imposing wall-like sides of the valley 

 with its steep even slopes rising to 2,000 ft. above its floor ; the truncated 

 spurs; and just across the river the great barrier of glacial drift, full of 

 scratched stones, forming the dam across the lower end of the lake, and 

 through which passes the pipe-line for the power scheme — all furnish un- 

 doubted proofs of the severity of the glaciation. It is evident from the 

 slope of the glacial shelves in the Redcliff Pass and from the general form 

 of its valley that an overflow of ice from the basin of the Rakaia took place 

 at the height of the glaciation. On the shoulder of the spur from Mount 

 Hutt which juts out into the angle between the tributary valley and the 

 main stream this action is very pronounced. One can easily picture the 

 great ice-stream impinging on this part of the mass of Mount Hutt, and 

 causing pronounced abrasion as the ice was packed at the angle before it 

 flowed away either down the main stream or was diverted towards the 

 Ashburton.* The thickness of ice must have reached 2,000 ft., and it pro- 

 ))ably exceeded this amount. 



The block of reddish limestone from which this locality takes its name 

 lies a little back behind the general line of the valley-walls, and no doubt 



* A similar overflow of ice must have occurred higher up the Rakaia Valley, at the 

 junction of the Lake Stream with the main river. 



