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direction. In other words, the strike is reasonably constant in direction, 

 being very generally N. 15° E., but varying locally from N. to N. 30° E. 



The rocks of the series are of very variable strength, the weakness of 

 some bands being due, apparently, in great part to their shattered nature. 

 The argillites are invariably traversed by innumerable joints, and so also 

 are the greywackes as a rule, but in places they are unjointed except on a 

 large scale. The greywackes with few joints are very strong, forming some 

 of the highest ridges and peaks. They weather spheroidally, and, when 

 broken, present an appearance similar to that of an even-grained igneous 

 rock. The shattered grey- 

 wackes have in some places 

 been rendered equally strong 

 by the deposition of inter- 

 lacing quartz veins filling 

 the joint-planes. 



Corresponding to the 

 regular strike and the steep 

 dip of the strata and their 

 varying strength, there is a 

 well-marked arrangement of 

 ridges and valleys parallel 

 to the strike. This may 

 easily be recognized on a 

 map, and in the field it is 

 found to be the dominant 

 feature of the topography. 

 In fig. 1 the straight and 

 parallel courses of the 

 Orongorongo and Wainuio- 

 mata are especially notice- 

 able. Parallel to these the 

 entrance to Port Nicholson 

 and the Evans Bay - Lyall 

 Bay depression will be 

 noted. On the Wellington 

 Peninsula itself (see also 



fig. 2) one continuous valley, occupied by the Karori, Makara, and Ohariu 

 Streams, is well marked. The position of another is indicated by the 

 settlements of Karori and Khandallah ; it continues southward some 

 distance, and its northward continuation is the Porirua Valley. Even the 

 high bluff of Cape Terawhiti is almost cut off from the neighbouring land 

 by a deep north-south valley. 



KAUKAU 

 ANDNXW 



/ 



. PO&T 

 1WARRA 



NICHOLSON 



TONGUE POINT 



5 MILES 



PS»Cf»s>fi<af t 



Fig. 1. — Locality-map of the Wellington District. 



Land Features. 



The adjustment of stream-courses to structure, an arrangement which, 

 with exceptions that will be noted, has been retained by existing streams, 

 points to prolonged exposure to subaerial denudation for the duration of 

 at least one nearly completed earlier cycle of erosion. The existing topo- 

 graphy is composite, and has been developed during an uplift of at least 

 800 ft., and perhaps of 1,000 ft. or more. The amount of uplift seems 

 to have been nearly uniform, although probably not quite uniform, 

 over the area studied. During the uplift pauses occurred, some of which 



