33 
The Birthday Tunnel Mine. 
The shaft is 496 feet deep. The reef is to the west of the shaft. A 
northern level has been driven for several hundred feet. In the stopes 
over this level extremely heavy gold has been found in the reef along the 
course of an olive-grey slate bed, which is apparently an indicator. I 
saw solid pieces of gold, up to 20 ozs. in weight, from the contact, and 
toe much care cannot be exercised in tracing out the course of such a bed, 
apd in following the line of its contact with the lode. As an indicatoi 
this slate bed is worth following, for, wherever quartz veins cross it, there 
is a likelihood of further rich deposition of gold having taken place. It 
is an interesting feature that, where the rich aggregation of gold occurs, it 
is in quartz that is highly fractured and crushed, as though the gold had 
been deposited subsequent to the quartz, and had crushed the quartz as it 
accumulated. The quartz is easily detached from the gold, which is of 
crystalline character. This gold appears to be due to secondary enrich¬ 
ment. 
There are several distinct quartz reefs within this lease, and these will 
be accurately laid down and their relations shown by Mr. W. Baragwanath, 
junior. 
Berringa appears to be a very important quartz mining field in its in¬ 
fancy. There are several known lodes, more or less parallel, and doubt¬ 
less many more to- be discovered, as they do not all show at the surface. 
The quartz bodies range from a few inches to many feet i|n width, and 
appear to carry some gold throughout, although in some mines large blocks 
of quartz are being left behind. There are two or three different sets of 
faults that dislocate the reefs, and that require to be well considered in the 
working of the mines. Centre-country occurs, and its importance as a 
datum requires to- be recognised, especially where indicators exist. The 
course of the anticlines, as far as ascertainable, will be indicated bv the 
survey being made. There appears to be no good reason why the dis¬ 
tance from the Birthday' Tunined to the Staffordshire Reef should not also 
be occupied by mines. 
As a field the features appear to be great abundance of quartz of a 
fair average quality and cheaply worked, and with heavv stamps, stone- 
breakers, automatic feeders, and everv appliance to economise in the mining 
and treatment, a yield of 3 or 4 dwts. of gold per ton should pav well. 
There is abundance of room for other mines than those at work, and 
also for the deepening and opening out on a, larger scale of the existing 
mines. Mr. Ditchburn, the mining manager, informs me the new lode 
in Williams Fancy is payable. Should it open up well in the levels 
to be driven north and south, it means a large increase to the crushing plant 
to deal with it. 
I am indebted to the mining managers of the several companies for 
much information and courtesv. 
\Report sent in 78th July , 7905.] 
THE UNION MINE, DIAMOND CREEK, NEAR 
MELBOURNE. 
(NO. l8 ON LOCALITY MAP.) 
By E. J. Dunn , F.G.S., Director , Geological Survey. 
The reef worked in this mine strikes about N. and S. (mag.), and dips 
to the east at about 45 deg., cutting through Silurian strata that dip to 
the west at about 60 deg. The country rocks consist of thick and thin 
bedded sandstones, inter-stratified with slates. In colour the beds are 
purple, grey, and brown. 
B 2 
