260 Geology of 



CHAPTER VI. 



"Waihao Foemation. 



I hate given this name to a series of beds of considerable thickness 

 reposing upon the crystalline metamorphic schists or the gneiss 

 granite formation, from which they are distinguished by having 

 undergone only partial metamorphism ; the line drawn, however, is 

 arbitrary, principally along the direction of the Southern Alps, where 

 these formations gradually blend with each other. The character of 

 the rocks in the eastern division, as I shall show in the sequel, is 

 however far more distinct and constant, and, in many respects, different 

 from that of the rocks of the central chain ; but the latter, in their 

 turn, often assimilate in their upper portion to those of the next, or 

 Mount Torlesse formation, so that it is very often impossible to find the 

 boundary line between them. Captain Hutton has named the same 

 beds, occurring in Otago, the Kakanui formation, but as I find that 

 our boundaries, where the rocks cross the "Waitaki, do not entirely 

 agree, so that he might include beds which I consider to belong to the 

 next, or Mount Torlesse formation, I have thought it more convenient 

 to give to that formation, occurring in the Province of Canterbury, a 

 local name, selecting it from the Biver "Waihao, where the rocks are 

 largely developed and show well their peculiar structure. 



Extent. 

 Starting £rom the northern boundary of the former united Province 

 of Canterbury, this zone begins below the junction of the Otira with 

 the Taramakau, where it covers a rather narrow belt of country 



