Kerr (Addison)

Location: Mc Garry Township
Years of Operation: 1911, 1938 – 1996
Tons Milled: 40,336,512
Ounces of Gold Produced: 10,457,441






Kerr Addison Head FrameCopyright: G. Hamden

Kerr Addison Head Frame
Copyright: G. Hamden


Kerr Addison Mine (Producer)
Partial history as of 1979


LOCATION:  Approximately  V*  mile north-northwest of Virginiatown,  7*  mile  northwest of the tip of the Northeast Arm of Larder  Lake,  in central McGarry Township.  Main shaft on boundary between patent ed  claims  L1751  (HJB30)  and  L1850  (HS166); underground  workings  in  patented  claims  L1848 (HS165),  L1850  (HS166)  and  L1905  (HJB29). Latitude 48.140, Longitude 79.580 . Map reference: ODM 50a, Township of McGarry.

GEOLOGY:  The  Larder  Lake  “break”, striking N600E through the centre of the property and dipping 75- 800N, represents the faulted contact between Timis kaming  metasediments  on  the  north and  Keewatin metavolcanics  on  the  south.  In  the vicinity of the mine workings, the hanging wall of the “break” con sists  of  intensely  sheared  greywacke.  The footwall comprises  a  highly  altered green  and  brown  “car bonate  zone”, up to 600 feet in width, which con tains irregular lenses of talc-chlorite schist and small irregularly shaped  bodies of altered syenite intrusive rocks.  South  of this  zone  are  bedded  tuffs.  Inter- banded with the tuffs, and lying south of them, are basic lava flows. The  orebodies  are  of two different types. The car bonate type consists of irregular lenses of gold-bear ing quartz stockworks lying with in the highly altered and  brecciated  carbonate  zone.  Gold occurs in the free  state  randomly  distributed  throughout  the quartz. The flow type of orebody consists of lenses of  mineralized  and  silicified flow rock lying in the less  altered  flows  and  tuffs south of the carbonate zone.  Pyrite  mineralization,  which  is  uniformly disseminated  throughout  the  ore  zone,  contains most of the gold. The fracturing that permitted the formation of ore bodies can  nearly all  be associated with movements along the  Kerr-Addison Fault and subsidiary faults, all  of  which  are  components  of  the  Larder  Lake “break”.

ECONOMIC  FEATURES:  The  mine  is Canada’s  largest gold  producer.  The  average  recovered  grade of the 34,228,275  tons  of  ore  milled  during  the  period 1938-1973 was  0.27  ounce  of Au per ton. Ore re serves  in  1976  stood  at  502,560  tons  averaging 1510.611  ounce of Au  per ton and 330,170 tons aver aging  0.238  ounce of Au  per ton (Canadian  Mines Handbook 1977-78, p.172). OWNERSHIP: Kerr Addison Mines Limited.

HISTORY:  1906-1907:  Kerr-Addison  and  Reddick claim groups staked. Surface work done. 1908-1911:  Reddick  and  Kerr-Addison  properties acquired by Associated Goldfields Mining Company Limited.  Diamond-drilling  and  shaft  (No.2)  to 86 feet with  2,200 feet of lateral development on 83- foot level. 1920-1921:  Shaft  (No.1)  to  325  feet with  1,085 feet of lateral development on levels at 60, 175 and 300 feet.  During  the  period  1914-1921  more than 16,000  feet of diamond-drilling failed  to  intersect any orebodies. Work by Associated Goldfields Min ing Company Limited. 1936:  Large  scale  sampling  from  four  adits,  400 feet  apart,  driven  into  the  hillside.  Results  not encouraging. One deep diamond-drill hole intersect ed  150  feet of  ore  grade  material.  No.1  Shaft  de- watered  and  workings  resampled.  Shaft  deepened to 716 feet with new level at 500 feet. 1937-present:  No.3 Shaft to 3,995 feet with an  in ternal  shaft  from  3,850-foot  level  to  a  depth  of 6,022  feet.  Underground  development  totalled 477,596 feet on 39 levels. 500-ton mill installed and commenced production in 1938. Capacity expanded to  a  maximum  of  4,556  tons  per  day  in  1960. Production steadily declined since 1961 to 935 tons per day at end of 1975.


Years Gold Silver Ore Milled Recovered Grade
(ounces)  (ounces) (tons) (ounce of Au per ton)
1911, 1936 – 9,652,173 531,561 35,040,174 0.28

In  1976, the mill was handling ore at an average rate of 730 tons per day.

Canadian  Mines  Handbook  1977-78, p.172.
OBM 1909, Vol.18, pt.1,p.130, 131.
ODM  1924,  Vol.33,  pt.3,  p.23  (Kerr  Addison; Reddick).
ODM 1941, Vol.50, pt.7, p.64-75.
ODM 1964, MRC3, p.35, 36.
Resident  Geologist’s  Files,  Ontario  Ministry  of Natural Resources, Kirkland Lake.

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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