the
faces of stone in sight, governed values in stocks, as the time when
all stock-holders treated their mines, as if " they would be worked out
next week."
Here,
in Clunes, a golden mile has been worked to varying depths for yields
in gold equal to about £5,000,000. The lode structure of this golden
mile has much in common with other of our State's golden miles, more
particularly as regards its detail features of deposition, and the
ship-shape form in length of the lode-gridironed area. Indeed, most of
these favoured golden miles in our State show lode systems, somewhat
similar in shape to that of one long narrow boat, upside down, on
another long and narrow boat, the length to the north. The only
difference would be in the proportion of length to depth, the depth of
the golden miles being equal to, if not longer than, their longitudinal
extent. I have noticed in the detail structure of large and small
formations of quartz in lode lines, that the length bears a
relationship to the depth ; in fact, when I have ascertained the length
of a "make " (or " block," as miners call these quartz occurrences), I
know pretty well how deep it extends.
It
was not until comparatively late in its reign of mining prosperity that
Climes managers got a notion of the arrangement of the most favoured
parts of its great system of lodes. Experience proved that the lode
structure is in the form of a series of saddles and legs, resulting
from the application of force exercising a slight twist strain as it
corrugated the rock-beds. Only at intervals did the cracking favour the
saddle form of lode formations, and the legs from each apex went down
to the east and west until they joined other fractured lines associated
with the troughs in the strata between the arches of the saddles. Up
through the system of fractures a rush of hot fluid rock had come, from
depths a couple of miles or more down, perhaps, forcing its way along
lines of least resistance, which proved to be. as far as concerns the
area entered by the pick, from one leg line to the other leg line. This
material possibly came out at and spread over the original surface. It
brought great quantities of sulphide, principally mundic, with it, and
we may find, some day, that it brought up gold and silver also. Mr.
Luke, late a mining manager on the field, informed me that in places in
the mines it fills almost all the space between the walls of a lode
line, leaving room only for a little stone on its hanging and foot-wall
sides. I found several samples of this rock along the line of mullock
heaps, and Mr. Luke identified them as being similar to the intrusive
rock he had met with in deep workings.
The
wear of ages has lowered the surface to just below the cap of an arch
in the Clunes sedimentary rock-beds, and the outcrops of the quartz
legs were exposed. These are known as the Welcome Lode ; then, going
west, the Eastern Lode, the Old Man Lode, the Robinson's Lode, and the
Western Lode.
The
whole area occupied by them is permeated with innumerable lines of
underground drainage, namely, lines of smaller fractures running more
nearly vertical than horizontal, all feeding into the main lines of
drainage represented by the legs. They are to be seen in the
rock-faces on the surface, red with rusted (oxidized) sulphide of iron,
in some instances containing a small vein of quartz, in others none ;
and I notice that the most highly-mineralized lines are encased in the
well-known gold-slate. They form part of the system of drainage which
concentrated part of its gold in rich deposits (shoots) in the various
lines and fish-shaped "makes" of its main lodes. There are many patches
of gold remaining in these underground lines, at points of obstruction
to circulation, similar to those being unearthed on
