50 PROCEEDINGS OF THE ROYAL SOCIETY OF QUEENSLAND. 
Mr. Dickson found in India that the distance between successive 
shoots was usually approximately equal to the average length of the 
shoots. 
In some of the Hart’s Range mines, notably the Spotted Tiger and 
the Pannikin, the entire worked length has carried payable mica, and 
might be considered one shoot. Over 300 feet have been worked out in the 
Old Billy Hughes Mine, leaving only quartz and eutectic quartz-felspar 
blows as pillars. These occur with great frequency and regularity every 
30 feet or so. The New Billy Plughes Mine is on a different shoot on the 
same lode higher up in the mountain. 
Few of the mica occurrences have been followed up by exploratory 
work. The mica-bearing lens occurring on the surface has been worked 
out, and the mine lias been abandoned as of no further use. “Where 
it be, there it be” has been the motto of the prospector. 
Sporadic occurrence and apparently complete cutting out of ‘ ‘ lode ’ ’ 
is characteristic of all pneumatolytic minerals associated with pegmatites 
and deposited by emanations from pegmatites. It is the same with 
wolfram, tin, molybdenite. I have seen many tin mines in North Queens- 
land which have been abandoned three or more times after a bunch of 
tin ore has been taken out, all trace of ore having vanished. Enter- 
prising prospectors entering these “shows” often pick up clues which 
lead them to another bunch of ore. So it is with mica. 
Mica apparently occurs in book form only in pegmatites in the 
crystalline gneisses and associated very old formations, because it is only 
in these formations that the plasticity of the rocks, caused by high 
temperature and pressure, has sealed up all cracks and fissures, thereby 
allowing pent up gases and mineralisers to act in the manner outlined. 
V. MICA MINES OF CENTRAL AUSTRALIA. 
(See plate II. and plate III.) 
It is not within the scope of this paper to describe all the mica mines 
of the Territory or even to enumerate them. That has been done in my 
official reports, the principal of which may in due course be published 
by the government. The object of this paper is to bring to light certain 
conclusions of a theoretical nature, based on observations, conclusions 
which could not be properly and fully dealt with in official reports. 
There are many hundreds of muscovite mines in the Hart’s Range 
(see plate II.), most of them worked to a standstill and abandoned. The 
most notable of these is the Spotted Tiger Mine, which has twice in its 
history been abandoned as useless, only to be taken up again and found 
richer than ever. It has produced over 300 tons of fine commercial 
mica, not clear mica, but spotted ; and it is still producing. 
Nearby is the Billy Hughes Mine, at an elevation of about 3,000 
feet above sea level, on the steep slopes of Mt. Palmer, in the central 
portion of the Hart’s Range metamorphic complex. On and near the 
slopes of the same mountain are the Disputed, the Rex, the Spotted Dog, 
the Ulgarna, the Caruso, the Rising Sun, and many smaller deposits. 
About four miles north-east of Mt. Palmer, on the slopes of Mt. Brady, 
are situated the Central mine and man}' smaller “shows.” East and 
west of these centrally situated important mines, for a distance of 30 to 
40 miles either way, i.e., both east and west, the hillsides are studded 
with mica mines, and scrap-mica carried by the wind sparkles in the sun 
