Cotton. — Notes on Wellington Physiography . 



263 



to the west, and finds its way to the sea as a tributary of the Karori, having 

 thus a roundabout course eight miles in length. As indicated in fig. 2, the 

 capture of the Silver Stream by the Karori is a double one, two branch 

 ravines of the Karori tributary having successively tapped the course of 

 the Silver Stream. The floor of the old Long Valley here stands about 840 ft. 

 above sea-level. The deepening of the captured stream at the elbow of 

 capture is 400 ft. or 500 ft. Northward from this divide the Kaiwarra. 

 which here occupies the Long Valley, descends somewhat rapidly in a trench 

 incised in an older mature valley-floor. At the upper reservoir (U.R. in 

 fig. 2) it follows entrenched meanders of small radius, and a portion of the old 

 flood-plain on which the meanders originated remains as a bench far above 

 the present stream and at a height of 660 ft. above the sea. At this point a 

 mature dry valley on a level with the old flood-plain bench, evidently the 

 old stream-course, swings off to the north, while the course of the Kaiwarra. 

 flowing north-east, is a young gorge. The sketch, fig. 12, shows the old 

 valley and the young gorge of the Kaiwarra. 



Following the old dry valley mentioned above, we find ourselves in the 

 broad mature valley occupied by the settlement of Karori. It has been 

 invaded by the head of the Karori Stream from the south-west, as well 



Fig. 12. — Capture of the " Long Valley " Stream by the Kaiwarra. 



Upper reservoir on the left : young gorge of the Kaiwarra below the upper-reservoir 



clam on the light. 



as by the Kaiwarra from the north-east. The north-eastward continuation 

 of the now broad and mature Long Valley through Ngaio and Khandallah 

 is evident, but between Karori and Ngaio the floor of it has been almost 

 completely gouged out by the numerous young deep-gorged tributaries 

 of the middle Kaiwarra. Overlooking the Kaiwarra there are, however, 

 abundant stream-deposits in Karori, and a bed of gravel on the western 

 slope of the Tinakori hills at a height of 600 ft. 



The lower Kaiwarra leaves the Long Valley by a steep-walled gorge, and 

 crosses the scarp of the Wellington fault. The north-eastward continua- 

 tion of the valley is occupied next by a short obsequent stream, a tributary 

 of the Kaiwarra. Farther on, at Khandallah, it is crossed by a stream 

 which joins the Ngahauranga near its mouth. Still farther to the north- 

 east the valley has been invaded by the Ngahauranga, a stream which, 

 owing its activity to its position on the fault-scarp, has worked back in a 

 profound gorge along a nearly straight course at right angles with the 



