Trans. N.Z. Inst., Vol. WAX. 



Plate XXI. 



Fig. 1. — View of the basin taken from the summit of Castle Hill, looking south-east. 

 The limestone in the foreground is dipping towards the observer, the fields in 

 the middle distance arc probably based on greensands and tuff beds, and the 

 distant hills are the greywackes of Mount Torlesse. the ends of the spurs of 

 which are faceted either by glacial action or by faulting — in all probability the 

 latter. 



Fig. 2. — View of the basin looking south-west from the hill between Broken River and 

 Porter River. The limestone in the foreground forms here the lower gorge of 

 the Porter River, but it appears again farther up-stream after making a swing 

 round to the left, and is seen again in the distance forming the eastern face of 

 Castle Hill. The Pareora beds are seen between the two gorges ; the charac- 

 teristically terraced landscape reposes on these beds. The general conformity of 

 the stratification i.- clearly seen. Text fig. 4 follows along the eastern face of 

 Castle Hill as seen in the plate. 



Face p. 324.] 



