Speight. — Unrecorded Tertiary Outlier in Basin of the Rakaia. 357 



end of the Black Range and flowing south in a glacial trough ; and, secondly, 

 the Avoca River, which rises in glaciers on Mount Greenlaw and joins the 

 Harper about six miles below the tributary just mentioned. Although the 

 main stream is called the Harper, the amount of water properly belonging 

 to it is small as compared with the amount from its two main tributaries. 

 It also receives the overflow from Lake Coleridge just before it reaches the 

 Wilberforce. 



The only account of the district is that given by Haast,* who traversed 

 the whole length of the Avoca in the year 1866, but was prevented by bad 

 weather from ascending the Harper to its source. 



| It is in the stretch of the river-valley between the junctions of the Avoca 

 and the unnamed tributary with the Harper that it presents its most inter- 

 esting geological features. In this locality there is developed a series of 



M'Aigidus, 



Sketch-map of Harper River District. 

 Shaded portion indicates Tertiary beds ; dotted lines, probable lines of fault. 



Tertiary beds consisting of sandy clays with impure lignite, greensands, con- 

 cretionary sands, and layers of concretionary shell-beds. It was not found 

 possible under the weather conditions to detach specimens from the hard 

 layers in the time at the author's disposal, but frequent specimens of 



* J. Haast. Report on the Headwaters of the River Rakaia, 1866 : a report 

 published by the Provincial Government of Canterbury, and reproduced substantially 



in the same author's Geology of Canterbury and Westland, 1879. 



