became
known as an indicator. It represents really the main channel of
drainage from a wide and long extent of gold-slate, and having no point
of obstruction to its circulation actually in it, along and down the
part mined, it contained no gold. The twist strain to the field had
arranged obstructive points on its eastern side, however, in the form
of wing-like " filter packs "— -settling pits;" and, in these, golden
fluids were stagnated and their gold precipitated. As with the fluids
from cyanide vats, nothing much would be precipitated without
obstruction—partial stagnation—of circulation, which is essential to
deposition in payable form; and this is why cyaniders pass the golden
waters from their vats through charcoal, &c.—that is, obstruct the circulation in the presence of precipitants.
The
indicator in the Black Horse mine deposited about £300,000 in value of
gold in one huge wing receptacle that formed a " settling pit," as it
were, on its side. This wing pitched to a point 600 or 700 feet south
in the 1,250-ft. level, and on to one of those parallel breaks in the
field which run to the north-east and underlie to the south-east. The
lowest 100 feet or so of this line of gold was in the old Egerton
Company's area, and, as the Black Horse traced and worked it down its
pitch to its boundary, the Egerton put up a rise from its nearest level
below, and quickly obtained about £20,000 in dividends.
In
working out the richer parts of the Egerton deposit hundreds of
thousands of tons of ore have been left, which, even now, would
probably keep hundreds of men employed if only a 100-head up-to-date
mill were set going.
As
previously remarked, the line of the Egerton run of gold was followed
north from the Rose shaft to a depth of 850 feet from the surface. It
was in the form of a wing make going out of the east side of a
vertical, which latter is evidently a southern continuation of the
indicator vertical in the Black Horse to the north. As with the more,
drooping wings of the Black Horse indicator, the richest gold was met
with in the wing parts nearest to the vertical, Fig. 6 (a). I
noticed similar lode structure in the Welcome lode formation, to the
north of lnglewood (b), and in the Scotchman's lode formation in
Stawell (c). In the Black Horse the relation of the wing receptacle to
the vertical channel was as in (d), Fig. 6, and here, again, the
greatest richness was found to be in stone nearest the vertical
channel. The structure of the Great Columbian, lnglewood, is shown in (e).
The
works in the winze down 120 feet below the 1,760-ft. level in the Black
Horse are well into another order of lode structure, more nearly
vertical and more closely associated with the indicator channel. In
fact, the management is, and has been for some time, working in the
northern end of that great series of ]ode formations which extends from
a point considerably south of the Rose workings for about 3,000 feet to
the vicinity of the winze. The late manager, Mr. Wm. Joseph, followed "
makes " of a vertical nature down from the 1,500-ft level, to the
1,760-ft. level (and below this by winze), and all of these showed that
the structure is becoming more nearly vertical*
