436 PROCEEDINGS OF SECTION C. 
meeting at Sydney, Professor Hutton describes a number 
of igneous rocks which are said to come from Waiotahi Creek, 
Karaka Creek, and other places on this goldfield. He mentions 
hornblende and enstatite-dacites, hornblende-andesite, augite- 
andesite, and enstatite-andesite. This is a subject to which I 
have devoted some study, and I regret that I am unable to 
confirm this author’s conclusions. As a result of the closest 
investigation, I have been unable to find any of the above rocks 
im situ within the boundaries of the goldfield. Rounded boulders 
of hornblende and augite-andesites are common enough in the beds 
of the Waiotahi and Karaka streams, but they are obviously derived 
from the overlying breccia and tuff formation, which, as I have 
pointed out, is often intruded by igneous dykes, and in places 
contains huge angular masses of solid lava many feet in diameter. 
I have also examined many of these so-called dykes, both in the 
mines and on the surface, and have no hesitation whatever in 
stating that they are all of clastic origin. The rocks composing 
these hard bands are generally extremely hard, and of a dark 
bluish-grey or green colour when obtained in the solid. They 
are highly felspathic, and hence very subject to decomposition 
near the surface, and usually contain disseminated nests and 
grains of iron pyrites, and not uncommonly well-developed prisms 
of hornblende. They are, in fact, indurated tufas of fine texture, 
the true character of which can only be determined by a close 
study of their disposition and arrangement in the field. 
The Character of the Auriferous Veins. 
So far as my observations go at present, I am inclined to think 
there are no true jsswre reefs on this goldfield, a circumstance 
which may be partly accounted for by the absence of intrusive 
dykes cutting through the auriferous strata. The gold-bearing 
veins occur as Jedded-segregations, possessing in most cases the 
strike and underlie of the country. A peculiarity of these 
deposits is that, while the foot-wall may be well defined, the lode- 
stuff is found to pass upward into the country without any 
approach to a hanging-wall or defined line of demarcation. They 
are also very irregular in character, being often elliptical in shape 
and subject to great variations in width. They often split into a 
number of parallel veins, and receive leaders or droppers from 
the hanging-wall side. The country has a general strike between 
N.N.E. and N.E., and the auriferous veins follow the same 
general course. The underlie of the veins is also dependent on 
the dip of the strata. Thus, where the dip is to the N.W., 
the veins underlie in that direction, and where it is to the 8.E., 
the veins also underlie that way. Looking at the section on the 
preceding page, it is obvious that the anticlinal arrangement of. 
the auriferous strata causes the repetition of the auriferous veins,. 
