14 The N.Z. Journal of Science and Technology. [Jan. 
scheelite, and pyrite in small amount.* In some places fragments of country, 
usually lenticular in shape, are included, and at some points the partial 
replacement of these and of the wall-rock was observed. An excellent 
example of this may be studied in the Federation adit, which was driven 
beneath outcrops of solid quartz, and at the calculated distance penetrated 
a zone of crushed country that had been strongly silicified. The whole of 
the ore has probably been formed by the replacement by quartz of the 
crushed country occurring along a fissure. 
The principal workings on the lode are in the Empire City Claim, 
where five adits have been driven. As will be seen from the following 
table, the lode steadily 
increases in size 
downward for 
240 ft. below 
outcrop :■—- 
Thickness of 
Lode. 
Length of 
Ore-body. 
Depth below 
Crest of Hill. 
Outcrop 
6 in. to 2 ft. 
. . 
No. 0 adit 
3 ft. to 6 ft. 
500 ft. 
70 ft. 
No. 1 adit 
3| ft. to 7 ft. 
1,100 ft. 
150 ft. 
No. 2 adit 
5 ft. to 10 ft. 
1,350 ft. 
195 ft. 
Intermediate 
6 ft. to 12 ft. 
, , 
240 ft. 
No. 3 adit 
See below 
, # 
255 ft. 
No. 4 adit 
Does not yet cut lode 
435 ft. 
No. 3 adit, 60 ft. below No. 2, has been driven 750 ft. in a formation 
consisting of crushed and sheeted country traversed by numerous stringers 
and veinlets of quartz. This zone apparently dips north-eastward at about 
30°, and is of unknown width (at least 80 ft.). The lode, which down to the 
intermediate below No. 2 adit consists of solid quartz, is below this point 
seamed with bands of crushed country. In depth these increase in number 
and thickness so that in No. 3 adit, only 15 ft. below, the lode consists of 
sheeted country as above described. 
The scheelite is irregularly distributed throughout the ore. A series of 
heads or cross-courses dipping southward, rarely at angles of more than 
30°, cross and usually dislocate the lode from a few inches to several feet. 
It is in the immediate neighbourhood of these, and especially on their 
hanging-wall side, that the scheelite occurs most abundantly. Masses of 
the mineral, containing but little quartz and weighing many pounds, have 
been found. In a general way the scheelite increases in amount from the 
surface downward, and the quartz veinlets cutting the formation in No. 3 
adit contain rather more of the mineral than the ore won from No. 2 adit. 
The schistose rocks of the district are deeply weathered, and along the 
fissure the oxidation of the ore and wall-rocks extends below No. 2 adit. 
In the intermediate below this drive the ore is in part oxidized, but the 
formation explored by No. 3 adit shows no trace of oxidation. There the 
quartz veinlets contain, in addition to scheelite and pyrite, an easily notice¬ 
able amount of calcite, a mineral that was not detected in the oxidized ore 
of the higher adits. Surface water percolates readily along and near the main 
fissure, and the oxidation of the ore can be ascribed only to its action. 
In the Golden Bar and Empire City Claims the ore occurs along the 
same fissure. In both claims the quartz is similiar ; but sampling shows 
that the ore of the former contains somewhat less gold and scheelite. Two 
adits have been driven in the Golden Bar 110ft. apart vertically; and in 
both of these the ore has a width of from 3 ft. to 6 ft., and is of average thick¬ 
ness at the ends of the drifts. The vein has been traced southward by means 
of trenches at short intervals nearly to Dead Horse Creek ; and here, in 
* Analyses made in Great Britain show that the scheelite concentrates from the 
Dominion and other New Zealand mines contain a little oxide of tin—usually not 
more than 0d0 per cent. 
