Speight, Cockaynk, Laii^g. ---lloimf Arroir^niith Di.<<fHrf. 333 



came through the Kakaia Gorge on to the plains near the Point Station. 

 Haast says that they extended several miles on to the plains, but I am in- 

 clined to think that the evidence for this extreme extension is of a some- 

 what doul)tful character, and what he took for morainic accumulations 

 are fluvio-glaciul deposits such as are formed by the powerful streams 

 issuing from the edge on an ice-sheet or glacier. In the neighbourhood of 

 the Point Station there are very extensive areas covered with reassorted 

 detritus arranged in iri'egular heaps of the Drumlin type, showing that 

 the glacier reached almost to that point, and so must have been over sixty 

 miles in length. 



In the Rangitata Valley there are undoubted signs of glaciation where 

 the river debouches on to the plains. 



Thus the valleys of the Rakaia and Rangitata were filled with exceed- 

 ingly large glaciers of the ordinary type, but there is no indication that 

 they approached even distantly to the character of an ice-sheet. In the 

 Lake Heron Valley, with its flat floor and wide cross-section, and its 

 relatively higher altitude, they possessed in certain respects a remote 

 resemblance to an ice-sheet of very small dimensions. The area of land 

 in this valley formerly covered with glaciers extended twenty miles in 

 length by at least eight in breadth ; but it must be regarded as a great 

 basin filled principally with snow and neve fields at the height of the 

 glaciation rather than a true ice-sheet. 



(b.) Old Moraines. * 



The chief morainic accumulations are those of the Hakatere and its 

 tributary valleys. Here for over several square miles the floor is covered 

 with irregular heaps of angular material forming the terminal moraines 

 of ancient glaciers ; fairly extensive accumulations occur at various points 

 in the Cameron Valley and at its outlet, in the Upper Ashburton Valley, as well 

 as on the north side of Lake Heron, on the slopes of the Sugarloaf, but these 

 are insignificant when compared to the square miles of debris lying to the 

 south of the lake, and forming the great dam which acts as the containing- 

 wall on that side. This great deposit stretches across the floor of the 

 valley, and also extends down it for several miles towards the Clent Hills 

 Station and the Ashburton River, especially on the north-west side of the 

 valley. At one place this has been cut through by a former river-channel 

 which drained the lake, and has left as proofs of its former existence high 

 terraces on either side of its bed. In the floor of the great deserted channel 

 a tiny stream meanders, an insignificant remnant of the great river which 

 at one time flowed from the front of the glacier and for a time served as the 

 means of discharge for the surplus water of the greater Lake Heron. 



The next extensive deposit is that which stretches from Hakatere 

 Station right through lo the Potts River. For miles the floor of this stream- 

 deserted valley is covered with heaps of angular material. It forms a 

 great barrier across the upper end of the Pudding Stone Valley and on the 

 low saddles which lead to the small valleys behind Mount Possession Station. 

 These were terminal moraines of the ice as it halted in its retreat from the 

 eastern hills of the area. 



Apart from these, the only morainic accumulations of any extent are 

 those lateral moraines which mark the high ice-level on the valley-sides. 

 They are common up the Rangitata and in the valley leading from Haka- 

 tere to the Potts, and occasionally in other places. A frequent position is 



