270 
small fissures parallel to the main lines of reef. Iron pyrites is plentiful 
throughout the reefs, and may also be seen in the dyke itself below water- 
level. It commonly occurs in very small crystals, either cubical or elon¬ 
gated prisms (needle pyrites). 
The Assuring of the dyke appears to have been due to movements within 
the dyke caused by shrinkage, as no evidence of their existence in the 
adjacent strata was obtained, and the reefs appear to become very broken 
towards the edges of the dyke. Near the circumference of the dyke, con¬ 
centric breaks are noticeable. 
The first work done on these fissure reefs was in 1865, when the Girl’s 
Reef was found “ cropping out on the surface about 2 feet in thickness, 
containing very good gold. On either side of the prospecting claim are 
leases—-Tubal Cain, Aulcan, and others. Some very rich leaders have 
been found by trenching (in the Tubal Cain claim).”* During 1866, the 
Girl’s Reef Company and Tubal Cain Company were formed, the deepest 
workings at that time being shafts of 60 feet in depth. Long adits were 
driven, and very rich blocks of stone proved and worked. The Tubal 
Cain Company erected a battery in 1866. 
A T ery little information concerning these old workings is now obtain¬ 
able; and, as they were at the time of the survey mostly closed, their nature 
and extent could not be fully ascertained. The record of some yields is 
attached (Appendix A). 
The Tubal Cain engine-shaft was sunk near the northern edge of the 
dyke to a depth of 310 feet. A level was opened out at 300 feet, and in 
the east cross-cut at 50 feet from the shaft a reef 4 feet wide was cut, and 
drives north 50 feet, and south 100 feet, put in along it. A winze, sunk 
to a depth of 8 feet, at 20 feet north of the cross-cut on this reef, yielded 
1 ton of stone, which gave 8 oz. of gold. Work in the winze was 
suspended on account of the water proving too heavy, and the mine, which 
had during the previous six months paid ^£1,200 in dividends, closed 
down. To a depth of 300 feet, over 30,000 oz. of gold is reported to have 
been obtained from this dyke. 
The following information about the accessible workings was obtained. 
The old Tubal Cain adit was driven in an easterly direction, the entrance 
being in Silurian strata. Sixty feet from the entrance the western edge of the 
dyke, here decomposed, was struck. At 200 feet in, a break, concentric 
with the north-western edge of dyke, was met, and a drive was put in south¬ 
westerly along this for a distance of 100 feet, where the Girl’s Reef 
was struck. Much slipping and faulting movement is indicated by 
the striated and slickensided surfaces in this drive. The drive was 
turned south-easterly along the Girl’s line of reef. When cut, the reef 
was small and dipped west at 70°. One hundred feet along the 
drive a new make of stone comes in on the eastern side; this was followed 
for over 100 feet, and averaged 2 ft. 6 in. in width, with a dip of 56° 
west. The drive was put in on the hanging wall, leaving the 
reef standing the greater part of its length. The face of the drive is 
350 feet from the cross-cut. Thirty feet from the face the drive was 
turned westerly away from the line of reef. No stoping was done on 
this level, nor was any connexion made with the surface workings. 
* Dicker’s Mining Record, N ov. 7, 1866. 
