G. A. Cotton — Blorl^ Mountains in Nevj Zealand. 279 



a distance of nearly 30 miles. From the crest line of this por- 

 tion of the Kakanni fault scarp, the back slope of a great 

 tilted block descends gently to the northeast as a somewhat 

 undulating, stripped plateau surface and dips beneath marine 

 strata near the coast. A branch of the Maniototo depression 

 extends towards the coast as a fault angle along the base of 

 the Kakanui fault scarp, forming Shag Yalley. Its south- 

 western side is a gently sloping and slightly undulating stripped 



Fig. 19. 



Fig, 19. The scarp of the northern highland with Mount Ida in the center, 

 as seen from subdued hills of covering beds in the Maniototo depression, just 

 east of the northern end of Rough Ridge. 



plain descending from the Barewood Plateau. In the fault 

 angle some remnants of marine covering strata are preserved. 



4. Drainage. 



The Central Otacjo Chain of Dej}res8ions. — The main lines 

 of drainage in the chain of depressions of Central Otago appear 

 to be entirely consequent on the deformation ; but this state- 

 ment does not exclude the possible occurrence of " anteconse- 

 quent" streams. The existence of true antecedent streams is 

 not very probable. 



The Manuherikia depression is traversed longitudinally by 

 the Manuherikia River, flowing south westward to join the 

 Clutha (or Molyneux) River. The head of the Manuherikia 

 occupies the fault angle at the base of the Hawkdun fault 

 scarp, and its largest tributary, the Dunstan Creek, coming in 



