Cotton. — Notes on Wellington Physiography. 



253 



The diagram (fig. 6) is an attempt to explain graphically the evolution 

 of Miramar Peninsula. It does not appear that the channel thus blocked 

 had ever the importance of the present entrance, which has from the 

 first been the main channel, and is the continuation of the Hutt Valley. 



Mr. Elsdon Best has drawn the writer's attention to an authentic Maori 

 tradition, first put in writing about 1850, which relates some episodes in the 

 history of the locality some seventeen generations ago (i.e. about the end of 

 the fifteenth century). It appears that before that period Evans Bay and 

 Lyall Bay were connected by a channel, which was probably kept open by 

 the tide through the growing sand-bar. The tradition relates that, when a 

 party of Maoris had retired to the island (Miramar Peninsula is clearly 

 indicated) with all the available canoes, another party, pursuing them, were 

 compelled to build rafts to effect the crossing. An account is given also of 

 an event which appears to have been an earthquake accompanied by 

 elevation of the land. By that movement the channel was finally closed. 



Fig. 6. — Diagram of Evolution of Miramar Peninsula (a Land-tied Island). 



In the lower diagram Evans Bay (opening to Port Nicholson) is on the left, and Lyall 

 Bay (opening to the ocean) on the right. Spurs running down both to Evans Bay 

 and to the ocean have been cut back by marine erosion, and rock platforms indi- 

 cating their former area have been exposed by a recent movement of elevation. 

 These are much more extensive at the seaward end, but even on the shore of 

 Evans Bay a moderate amount of cutting has been done by the waves raised on the 

 waters of Port Nicholson by the prevailing north wind. The sand-bar joining the 

 island to the mainland must have been formed at an early stage, for the spurs 

 running down into it have been almost completely protected from marine erosion. 

 The upper diagram is a restoration of the initial form of Miramar " island." 



The case of Miramar Peninsula is therefore one where island-tying has been 

 assisted by a slight movement of the land.* It seems probable that with- 

 out a slight movement of elevation a shallow channel would always have 

 been kept open through the bar by the tide. 



In a quaint paper by Crawford, f entitled " Port Nicholson, an 

 Ancient Fresh-water Lake," the view was advanced that the present 

 entrance had been opened quite recently by the sea, and that over a 

 dam of boulders in the Evans Bay -Lyall Bay channel the waters of a 

 fresh-water lake formerly escaped and cascaded down to join the " great 

 Cook Strait liver." 



The small channel appears to have been formed by the drowning of 

 two small streams, one flowing north and the other south, separated by 

 a low divide which is evidently not deeply buried, for the spurs running- 

 down from opposite sides into the sand-bar are not widely separated. 



* See Gulliver, loc. cit., p. 200. 



t Trans. N.Z. Inst., vol. 6, 1874, p. 290. 



