486 
tions, like a line struck diagonally across a chess hoard, but fol- 
lowing the sides of the squares , and giving to the cliffs which bound 
these valleys a peculiar rectangular appearance, resembling ruined 
masonery on a gigantic scale. 
With the exception of the Hurunui valley none of the radiat- 
ing valleys runs directly across the main chain, which at the heads 
of the Rakaia and Waimakariri, stands up like a wall barring all 
further progress. Haast’s Pass, the lowest, and probably the easiest 
of all, does not extend across the northern branch of the chain, 
but leads to the coast by following the westerly course of the Ilaast 
river . 1 Arthur’s Pass does not, as it were, cross the range in a 
dii'ect line as does that by the Hurunui, but leads along it from 
one radiating valley to another; the Waimakariri and the Terama- 
kau overlapping each other to the extent of about 20 miles. Thus 
it will be understood that the three passes occur under three distinct 
sets of conditions. Haast’s Pass, at the head of the Wanaka Lake, 
is both in the line of one of the great radiating valleys and also 
in the direction of the axis of the great foldings of the strata, these 
i 
two causes in combination having formed an unusually low gap in 
the mountains. The Hurunui Pass, on the other hand, is one of 
the fractures running directly across the range, whilst Arthur’s 
Pass 2 is a fissure parallel to the planes of stratification, from which 
the rock already bruised and shattered, when the surface of the 
country was crushed up into the huge foldings before referred to, 
has been gradually removed by glacial action and by the weather- 
ing process constantly going on over the whole face of nature. 
The general features of the Geology of the Southern Alps have 
been established by Dr. Haast’s and Dr. Hector’s researches in the 
provinces of Canterbury and Otago 3 and maybe illustrated by the 
accompanying sections. 
1 Haast’s Pass lias not yet been opened, even for foot traffic; but it will pro- 
bably one day become a very important line of communication between the West 
Coast of Canterbury and the northern part of the Otago Province. 
2 1866 a bridle road was opened over Arthur’s Pass, descending into the Tera- 
makau by the gorge of the Otira. See Appendix. 
3 Dr. J. Haast, Report on the Geological Survey of the Pronvince of Canter- 
