PROCEEDINGS OF SECTION C. 439 
On the coast between Waikawau and Tapu the slaty shales 
are intruded by eight dyke-like masses of hornblende-andesite, 
which are well exposed in the road cuttings. 
Liuture Prospects of the Thames Goldfield. 
Up to to the present time the mining operations on this field 
have been almost exclusively confined to a small area on the 
foreshore, embracing altogether little more than a square mile of 
country. I have already pointed out that the auriferous series, 
with its gold-bearing veins, possess a general N.N.E. or N.E. 
strike, and a reference to the accompanying map will show that 
it passes as a narrow belt, about a mile and a quarter wide, 
north-eastward to the upper parts of Tararu and Otonui streams, 
and thence onward in the direction of Mercury Bay. I am 
fully convinced that the prospects of finding payable gold in the 
forest country just indicated are sufliciently encouraging to 
warrant the thorough exploration of that portion of the field. 
The country is broken and heavily timbered, but these obstacles 
could easily be overcome by a judicious expenditure in making 
pack or even blaze-tracks in the more inaccessible parts. 
Coming back to the limits of the present goldtfield, it is obvious 
on all sides that the mining of the past has been confined to the 
winning of gold from the veins near, or only a few hundred feet 
below the surface. Yet veins carrying payable gold have in 
many instances been proved to live into the “low levels,” the 
term generally applied to the country below 400 feet. A large 
and wealthy area of deep ground exists between the Saxon mine 
and the Big Pump, and even a larger and richer between the old 
Queen of Beauty mine and Hape Creek, extending right across 
Block No. XX VII. The neglect of this rich ground is no doubt 
due to the fact that hitherto the gold has always been found 
accessible to the surface, and, in consequence, mining companies 
have not considered it necessary to incur expenditure in seeking 
gold at lower levels ; but as the accessible gold must soon become 
exhausted, the working of the deep ground must attract the 
attention of the mining community at an early date, and it 
would, I think, be a matter for regret if its development is lett 
to foreign skill and capital rather than to local enterprise. As the 
lower levels are opened out, the Thames will become one of the 
richest and most productive goldfields in Australasia. 
8.—COAL: ITS ORIGIN AND PROCESS OF 
FORMATION. 
By James MELvIN. 
