19
MINES AND PROSPECTS

This section of the report supplies information on the mines and mineral
claims in the gold belt, and as the belt has not been traced satisfactorily
northwest of the Island Mountain mine nor southeast of Grouse creek,
only those properties that lie within these limits are included. The order
ae the deposits are taken up is from northwest to southeast in the

elt.

ISLAND MOUNTAIN MINES COMPANY, LIMITED

The holdings of the Island Mountain Mines Company, Limited, are
northwest of the foot of Jack of Clubs lake. Underground exploration for
lode gold began here in the seventies and several unprofitable attempts at
mining had been made by 1890. After forty years of relative inactivity,
exploration began again and underground development has been steady
since 1932. In 1933 a valuable ore-body was discovered consisting of gold-
bearing pyrite replacing limestone. Production on a 50-ton basis began in
November, 1934, the ore being treated in a cyanide mill.

There are many old workings consisting of open-cuts, shallow shafts,
and short adits, mostly caved and inaccessible, on the eastern and north-
eastern slope of Island mountain. The newer workings are adits driven
westward into the mountain from 80 to 650 feet above Jack of Clubs lake
(See Figure 2). The main adit is 80 feet above the lake and the next most
extensive adit, known as the Mid Lake, is 320 feet above the lake.

The newer underground workings are in the Barkerville gold belt and
mainly in the Rainbow member. The rocks are so much disturbed by
faulting that the detailed geology has not been worked out satisfactorily.
The rocks are mainly argillites and argillaceous quartzites, all somewhat
sheared. There are also several bands of impure limestone. The main adit
supplies the most complete geological section. The rocks strike northwest
and dip 45 degrees northeast. The section is given below. The widths
given are the widths at right angles to the strike.

Feet wide
Calcareous and argillaceous quartzite .............ceucecceeeecs 300
White limestone and argillaceous and siliceous limestone........ 30-80
Argillaceons qiartZike: vacpicjey via Hafele sperswwpsie sows p vaGe ee ART ee 150
@alcareoush@uartzitel jt cornet ran OR eo eae ee 10-20
Ar Pula CeOUSEOUALCZILE , lors vcs, clone ire ste terete eee ee Chee 150
Argillacsous: limestone tii2..\cce cit hase «occ Seasalion 10
Argillaceous quartzite and argillite ............02ceseeeeeeccene 300
rArsiilaceons: limestone racisccateio sire shavereccitalnverstavew erate cnrarevefeieiere oslaleres 20-60
Arpiliaceous’ quartzite! 2s. Seta hee eB oehece cee ee ee 50
Creyiguambziger £75. perjekieie new Gait ssskl sale talticte 1a%. Se eo aS 50

The white limestone near the top of the section is the one in which
the largest replacement ore-body occurs. A few bands of soft, dark greenish
grey rock in the upper half of the section may have been crystalline igne-
ous rocks originally, but those examined in thin section appeared to be
altered sediments although they could not be named definitely.

The rocks and mineral deposits are cut by faults. The largest fault
strikes about north 15 degrees west and dips 45 to 60 degrees east.
Neither the offset nor the direction of movement on this fault has been
determined. Faults of similar strike and dip in the workings of the Cariboo
Gold Quartz mine have offset the beds 400 to 1,000 feet and in all cases the