586 



Transactions. 



Si 



Eh 



Ph 

 < 



% 



O 



o 



o 

 o 



I— t 



1-1 



o 



CO 



d 



I made a careful examination of this coastal shelf in 

 1887 and again in 1888, and on these occasions satisfied 

 myself that it was not an uplifted marine platform of 

 erosion. 



Maritime platforms are distinguished by their uniform 

 height and a uniform shelving gradient towards the sea. 

 The Terawhiti shelf varies greatly in height, and its surface 

 is undulating. 



At the time of my earlier examinations I was unable to 

 find a satisfactory solution of the origin of this coastal 

 terrace ; but I now think that an ice-sheet or glacier flowing 

 through the depression occupied by Cook Strait would be 

 able to excavate the fringing platform we now see. 



The Terawhiti shelf has a singular resemblance to the 

 Crown Terrace, a glacier platform that fringes the north side 

 of the Arrow Basin, in the Wakatipu region. 



After passing Cape Terawhiti, Mana Island is seen lying 

 at the entrance to Porirua Harbour. This island is flat- 

 topped, its shape being almost identical with that of the 

 flat ice-shorn islands in Lake Wakatipu. 



Pig. 4. — Showing Mana Island, as seen from Cook Stkait. 



Passing over to Queen Charlotte Sound, we find that the 

 long, narrow, descending spurs that separate the numerous 

 arms or inlets that open out of the main soimd are worn 

 down into long, tapering wedges, the crest of which, at their 

 lower end, is frequently truncated and terraced. 



Fig. 5. — Showing Wedge-shaped Spur separating Arms of 

 THE Sea in Queen Charlotte Sound. 



These wedge-shaped spurs are quite a conspicuous feature 

 in the land forms. They have a curious resemblance to the 

 tapering spur lying between the two arms of Moke Lake, in 

 the Wakatipu district. 



Proceeding through the sounds towards Cape Jackson, we 

 pass Jackson's Hump, which, whether viewed from the east 

 or the west side, is seen to be a perfect dome. This well- 

 known landmark is situated on the narrow peninsula on 

 ihe extreme end of which lies Cape Jackson. 



^ 



^ 



srr 



/r£ 



Fig. 6. — Showing Jackson's Hump, viewed from the East Side. 



