11 
Great caution should be observed in these mines in approaching the old 
alluvial workings as the levels are extended for very great bodies of water 
have accumulated in the old ground. 
The work now being done on this field may open up a new quartz 
mining area, although this is. not the first attempt to develop it, as some 
work was done in this direction over 30 years ago. 
The Old Hall Mine. 
The Old Hall mine is situated in a narrow valley, the lower portion 
of which is cut out of Ordovician rocks. The upper part is in a capping 
of basalt. It is close to and on the east side of the township. 
The shaft is sunk to a depth of 130 feet to the main level, and it is 
still about 15 feet above the creek level. At 116 feet northward from the 
shaft is a short crosscut. The beds consist of grey and black ribbony 
schists with a dip of 85 deg. W. Small quartz spurs occur. A band of 
material with much iron pyrites through it and carrying gold was worked 
here. At the end of the crosscut, harder sandstone is present. 
At about 127 feet north of the shaft is a rise of 23 feet, and over this 
rise about three feet of auriferous material—a mixture of graphite, quartz, 
and iron pyrites—was worked. (This is the country rock much contorted 
and crushed and cut through by quartz veins). Stoping has been carried on 
for 40 feet south of the rise, and north of the rise the stopes extend for 
20 feet to a fault wall showing graphite which cuts through the reef with¬ 
out displacing it. At this point the auriferous lode material was 8 feet 
wide. 
About 150 feet in, a crosscut has been put through the reef which strikes 
about north and south and dips 84 deg. W. At 270 feet, a crosscut is 
driven 25 feet to the east. This shews the reef to have been faulted 
and thrown 7 feet to the east looking north. The strike of this fault 
is north-east. The reef is 2 feet thick, but from this point northward the 
channel has been followed without any valuable quartz development. At 
488 feet is the end of the level. The west wall is well marked and dips 
84 deg. to the west. In the channel, there is about 20 inches of crushed 
country, with thin quartz veins. 
At the surface a strong outcrop of the reef shews about 2 chains south 
of the shaft. Its strike is about north and south, and it dips 84 deg. 
W., and the quartz ranges in thickness from 1 ft. 6 in. to 3 feet. To 
properly test the value of this reef it would be necessary to deepen 
the shaft and to drive levels along the lode. The country rocks here are 
alternating black and grey slaty beds very much crushed and distorted near 
the walls of the lode. Until some fossils are obtained there will be diffi¬ 
culty in determining their proper horizon. The line of reef worked appears 
to be to the east of that worked in the Port Arthur group of mines. Mr. 
Ponsonbv and his manager supplied much of the data. 
[Report sent in /d.5.07.] 
THE DUNOLLY GOLDFIELD AND THE NEW BIRTHDAY 
MINE, GOLDSBOROUGH. 
By E. J. Dunn , F.G.S., Director , Geological Survey. 
One of the broad features of the Dunollv gold-field is that there is 
a considerable extent of alluvial ground that has proved extremely rich. 
