258 
REPORT OX THE DISCOVERY OF AURIFEROUS QUARTZ AT 
A DEPTH OF 4,156 FEET IN THE NEW CHUM 
RAILWAY MINE, BENDIGO, WITH PHOTOGRAPH 
(PLATE XXXII.). 
By E. J. Dunn , F.G.S., Director of the Geological Survey. 
A development fraught with importance is that at a depth of 4,156 feet in 
this mine, and 800 feet below the last body of quartz of a payable nature, 
excellent-looking quartz of great size and in centre-country (the anticline) 
has been sunk through in the winze. The slate and sandstone are highly 
mineralized. The quartz also carries sulphides, and, what is more 
important, gold. 
In no part of the mine have the appearances for gold been more favour¬ 
able than in the bottom of the winze: The quartz resembles a broken 
saddle reef, and is in centre-country. The winze passed through over 
20 feet of quartz, and what appears to be spurrv country; while a leg 
occurs on the W. side. Further work is necessary to definitely settle the 
nature of the quartz body, and also to prospect it, so as to determine 
whether or not there is sufficient gold present to be payable. Even at this 
great depth 7 dwts. of gold per ton is considered worth working. Should 
this body of quartz prove payably auriferous it adds enormously to the 
proved resources in gold of this State, and it is certain to exert a powerful 
influence in the further development of the Bendigo gold-field. 
Then as to the possibility of working at such depths, it is to be noted 
that in the bottom of the winze, 4,156 feet from the surface, the rocks are 
cool and the water cool, while the supply of air is excellent. The rocks 
and the water are cooler at the bottom of the winze than at the bottom of 
the shaft, 3,900 feet deep. There appears to be no reason why the shaft 
should not be continued to 5,000 feet or more in depth, and the conditions 
then as regards temperature should) be such that mining can be carried on 
satisfactorily and without undue distress to the miner. With the cheapened 
methods, of producing ice, the air that would be sent below might be cooled 
and filtered. As this is the deepest body of quartz carrying gold that has 
vet been opened up in Victoria, the accompanying photograph has been taken 
of it—see Plate XXXII. 
The quartz is highly mineralized, sulphide of iron predominating, and 
particles of fine gold being visible. The country rock surrounding the 
quartz is grey sandstone and black slate, through the former of which iron 
pyrites are abundantly disseminated. 
The quartz vein on the right of the photograph conforms to the bedding 
of the country, and is apparently the W. leg. 
[.Report sent in tth April, 1905.] 
REPORT ON ROCKS FROM BENDIGO. 
By D. J. Mahony , B.Sc., late Lecturer and Demonstrator in Geology , 
Melbourne University. 
The specimens consist of 14 rocks, with slices prepared from them 
for microscopic examination, and were chosen from the collection made 
by Mr. H. S. Whitelaw, at Bendigo. These rocks were collected from 
three situations, viz., two from the 296-feet level, New Chum Railway 
mine; five from depths ranging from 3,860 feet to 4,025 feet in the New 
