Wright – Hargreaves

Location: Teck Township
Years of Operation : 1921 – 1965
Tons Milled: 9,934,327
Ounces of Gold Produced: 4,821,296

 

 

 

 

 

Wright Hargreaves Gold MineEddie Duke Photo

Wright Hargreaves Gold Mine
Eddie Duke Photo

 

Reproduced with Permission of Kirkland Lake Gold

Wright-Hargreaves

The Wright-Hargreaves mine is located to the east of Lake Shore in the central portion of the Kirkland Lake camp. It ranks second to Lake Shore in terms of gold production and grade, having produced 4,817,680 ounces of gold at a grade of 0.49 oz/T.

This was the first discovery of gold in the Kirkland Lake camp, made on claim L1830 by W.H. Wright in 1911. In 1913 a shaft (Wright-Hargreaves No.1) was sunk to 85 feet with 110 feet of drifting on the 75-foot level. From 1916-1921 the No.1 shaft was deepened to 400 feet, No.2 Shaft to 320 feet, No.3 Shaft to 425 feet, and a total of 3,900 feet of lateral development took place. In 1921 a mill was constructed and milling started at 175 tons per day.

The mine was developed down to the 8200 foot level, the deepest development in the Kirkland Lake camp. Diamond drilling below the 8200 foot level revealed several high-grade intersections persisting several hundred feet below the level. However, the cost to develop these intersections at such deep levels proved to be too high, and mining was not continued.

The Main Break is the most prominent structure crossing the Wright-Hargreaves property. This structure has been traced, as a consistently strong fault, down to the 8100 foot level, and by diamond drilling below this. A significant amount of ore was mined from this structure, however, most of the tonnage came from the North vein. The North vein branches off the Main Break to the north just to the west of the property boundary with Lake Shore. Stoping on the North vein was extensive to about the 4500 foot level and development was to the 6600 foot level. Below this level, mining was concentrated along ore-bearing fractures of the North vein zone known as the North Heading Vein, North vein, and North D Vein. These veins are typically dipping near 75° south.

Another significant mineralized structure is the South vein-fault which branches off the south side of the Kirkland Lake fault in the western portion of the mine. As with many of the other mines in the camp there are also numerous veins which branch or splay off the main structures and form along tension fractures in the wedge of ground between major faults.

Post-ore faulting at Wright-Hargreaves has been well documented by the mine’s former chief geologist, Harold Hopkins (Thomson, 1950). The Lake Shore fault is the most important post-ore fault in the western portions of the mine. This fault strikes 012- 025° and dips steeply to the east near surface, becomes vertical with depth, then by the 5000 foot level dips to the west. This cross-fault has several important faults branching off the east side including the F and L faults.

A series of four major north-dipping “strike” faults have been numbered 1, 2, 6 and 5. Nos. 1 and 2 faults generally dip at 45°, or less, to the north and displace the Main Break and other vein zones some 150 and 300 feet respectively with reverse movement (hangingwall displaced over the foot wall). The No.6 strike fault has the smallest displacement averaging around 80 feet (again reverse movement), although it has a steeper dip of around 65°. The No.5 strike fault is the most important of these faults and outcrops on surface as the Murdock Creek fault. It can be traced to the east across the Sylvanite and Toburn workings. The fault dips at about 45° north on the Wright-Hargreaves property, but the dip appears to steepen with depth. Displacement on this fault has a maximum of 700 feet (reverse movement) on the Wright-Hargreaves property.

Most of the ore mined at Wright-Hargreaves was found within syenite porphyry with veins north of the Main Break below the 6600 foot level mainly in tuff, greywacke, conglomerate and granite porphyry located in the footwall of the main syenite porphyry plug. The Main Break is located within syenite porphyry throughout the mine. The north veins below the 6600 foot level are much less continuous than veins in the upper levels hosted by syenite porphyry.

The above summary of the history of the Wright-Hargreaves Mine is taken from: STILL, A.C. 2001 Structural setting and controls of gold mineralization at the Macassa Mine, Kirkland Lake, Ontario. Unpublished Masters of Science Thesis, Queens University 151p

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Wright-Hargreaves Mine (Past Producer)

MAIN METALS:

Au, Ag

LOCATION:

Immediately  north  of  Kirkland  Lake,  in eastern  Teck  Township.  Patented  claims  L1829- L1831  and  L2103.  No.4  (main)  Shaft  in patented claim  L1829.  Latitude  48.150,  Longitude 80.040 . Map  reference:  ODM  1945-1,  Township  of  Teck.

GEOLOGY:

Almost  all  of  the three  claims  straddling the  “Main  Break”  is  underlain  by  the  main  Al goman  syenite  porphyry stock  in  the camp. Other rock  types  encountered  underground  include Timiskaming  conglomerate  and  greywacke,  and Algoman augite syenite. The  Kirkland  Lake  Fault  or “Main  Break” trends N670E  through  the  centre  of  the  property.  It bisects  the  syenite  porphyry  stock  along  its long
axis  and,  in  section,  parallels  the  north contact of the  stock.  In  spite of a  southerly dip in part of its downward  course,  post-ore  faults  have  moved  the structure  northward,  so  that at  depth  the fault  is still  almost  vertically  beneath  its  position  on  surface.  Other  ore-bearing  structures  are  found  not only  in  faults  that  have  branched  off  the  “Main Break”,  but  also  in parallel faults and tension fractures.  Fissure-filling  gold-bearing  quartz  veins are  the  most  common  type  of vein; the larger ore bodies on the various faults are of this type. Lodes,
stockworks,  and  breccia  and  gash  veins  are  found on subsidiary structures. Numerous  post-ore  faults  occur  on  the  property. The strike and transverse faults have different characteristics.  Most  of  the  strike  faults  dip  north, exhibit  shearing,  and  contain  late  quartz  and  cal
cite.  On  the  transverse  faults,  brecciation  rather than  shearing  is  more  common  and  gouge  is often present;  these  faults  rarely  contain  quartz and calcite.  The  north-northeast-trending  Lake  Shore Fault  (a  transverse fault), which enters the property  in  the  southwest corner,  is  the  most important post-ore fault. Although  much  ore  was  mined  from  the  Kirkland Lake Fault, the most productive structure has been
the  North  Vein, which branches off the north side of the main fault just west of the Wright-Hargreaves property.

OWNERSHIP:

Wright-Hargreaves Mines Limited.

HISTORY:

1911:  First discovery  of gold  in  the  Kirkland  Lake  camp  made  in  claim  L1830  by  W.H. Wright.
1913:  Shaft  (Wright-Hargreaves  No.1)  to  85  feet with  110 feet of drifting on  the  75-foot level and another  shaft to  20  feet  by “Cartwright interests”
(ODM 1914, Vol.23, pt.1, p.169).
1916-1921:  No.1  Shaft deepened to 400 feet, No.2 Shaft  to  320  feet,  No.3  Shaft  to 425  feet,  and  a total of 3,900 feet of lateral development. In 1921, mill  completed  and  milling started at  175 tons per day.  Work  by  Wright-Hargreaves  Mines  Limited.
1922-1965:  Mine  serviced  by four shafts  and  two winzes.  The  No.4  Shaft,  started  in  1931,  became the main production shaft and eventually reached a depth  of 4,089 feet.  The  No.6 Winze,  collared on the  7,050 foot level, took the workings to a  depth of 8,100 feet (and continued to 8,222 feet). Under ground  development  was  carried  out on  57  levels and, during the  life of the mine, totalled: 257,623 feet  of  drifting,  92,200  feet  of  crosscutting,  and 82,669  feet  of  raising.  Mill  capacity  reached  a maximum  of  1,200-1,250  tons  per  day  in  1940. The  mill  closed  in  1957  and  from  that time  until mining operations  ceased in  1965, ore was shipped to the Lake Shore mill.

PRODUCTION:

Year Gold Silver Ore Milled Recovered Grade
(ounces) (ounces) (tons) (ounce of Au per ton)
1921-1965 4,817,680 853,643 9,734,402 0.49

REFERENCES:

CIMM  1948,  Structural  Geology  of Canadian Ore Deposits, Vol.1, p.644-653.
ODM 1923, Vol.32, pt.4, p.39-41.
ODM 1928, Vol.37, pt.2, p.125-133.
ODM 1948, Vol.57, pt.5, p.161-176.
ODM 1964, GC 11, p.41-44.
ODM 1964, MRC3, p.73, 74.
ODM 1965, Vol.75, p63-65.

Gordon, J.B., Lovell, H.L., de Grijs, Jan, and Davie, R.F.
1979:  Gold  Deposits of Ontario,  Part  2:  Part of District of Cochrane,  Districts of Muskoka,  Nipissing,  Parry  Sound,  Sudbury,  Timiskaming,  and  Counties  of Southern  Ontario;  Ontario  Geological  Survey,  Mineral  Deposits  Circular  18,  253p.

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