Se eee

207

_ Some fracturing has followed sulphide deposition, and carbonate solu-
tions have deposited a second generation of siderite, possibly accompanied
by calcite, in the fractures so formed.

The tenor of the ore is remarkably uniform. No attempt was made
by the writer to sample the individual zones. The management states
(Lay, 1930) that the approximate average assay of more than one hundred
samples from Nos. 2, 3, and 4 mineralized zones was: silver, 7 ounces a ton;
lead, 15 per cent; and zine, 7-5 per cent, across a width of 8 feet.

It is evident that mineralization in these deposits was controlled to a
large extent by the structure of the folded limestone beds. In general the
mineralized beds strike approximately east and dip north at an angle
roughly the same as that of the northern slope of Fergusons Hill. The
underground workings, consisting of four main adits, Nos. 1, 2, 4, and 5,
were driven from the north slope of the hill to probe the continuation of
these beds at depth. No. 1 adit, whose portal is close to the lowest outcrop
of the No. 3 mineralized zone, exposes almost continuous sulphides for a
length of 140 feet. A crosscut from this adit shows Nos. 2 and 3 zones to
be see mineralized across a combined stratigraphic thickness of about
15 feet.

No. 2 adit, at the same level as No. 1, was driven on the lowest
exposure of mineralized zone No. 4. This zone has a slightly flatter dip
than the hillside, so that its lower parts have been removed by erosion.
An eastward-trending drift from this adit, driven just under, and parallel
with, the surface of the hill, shows evidence of almost continuous mineral-
ization throughout its length of 70 feet. A crosscut 60 feet long intersects
No. 3 mineralized zone, which at this point is about 3 feet wide and
contains abundant galena and sphalerite associated with pyrite and
pyrargyrite.

No. 4 adit was driven from 85 feet below the level of Nos. 1 and 2 adits.
Drifting east and southwest from the portal has exposed Nos. 2 and 3
mineralized zones, which here cannot be accurately distinguished from one
another, for a length of 250 feet. Crosscutting 90 feet south from the
portal has penetrated a sphalerite deposit that may represent part of No. 1
mineralized zone. Short drifts have followed this zone for 50 feet, and
have disclosed two disconnected mineralized lenses each with a maximum
width of about 4 feet and a length of 20 feet.

No. 4 adit is connected with No. 1 adit by a raise 130 feet long. For
most of its length this raise lies in No. 2 mineralized zone.

No. 5 adit, 80 feet below No. 4, consists of about 600 feet of main
crosscut and 800 feet of exploratory workings therefrom. When visited in
1946 and 1947, the portal was caved and the workings could not be
examined. It is understood, however, that although beds were penetrated
that were believed to represent continuations of the mineralized zones. no
appreciable evidence of mineralization was encountered. The dump from
this adit contains a considerable amount of sheared schistose limestone,
but no sulphide and relatively little quartz-siderite rock.

The apparently abrupt disappearance of mineralized bodies such as
those contained in Nos. 2 and 3 mineralized zones, which, between No. 4
adit and the summit of Fergusons Hill, maintain a fairly uniform composi-
tion across a width of as much as 200 feet, a thickness of 8 feet or more,

—

_—s