THE CADIA RIDGEWAY DISCOVERY STORY
The discovery story of the Cadia Ridgeway gold-copper porphyry deposit can be found here.
THE STORY OF KIDD CREEK MINE – THE DEEPEST BASE METAL MINE IN THE WORLD
How two large international mining companies dismissed the site of the now 150 million tonne Kidd Creek Mine, the deepest base metal mine in the world, is now a lesson for us all in the mining industry today.
The enormity of the Kidd Creek deposit speaks for itself. With mined ore and reserves in excess of 150 million tonnes, and copper and zinc grades of 2.5% and
6%1 respectively, the Kidd Creek Mine is one of the largest VMS deposits in the world.
How did two separate companies dismiss such a deposit on multiple occasions?
Texas Gulf Sulphur Co. (Texas Gulf) conducted electromagnetic (EM) surveys over the site of the now Kidd Creek Mine on the first day of an extended geophysics program, recording a very large and strong anomaly. Texas Gulf dismissed the anomaly on the basis of its size and strength, and classified it as a low priority on the probable assumption that it was caused by the adjacent graphitic shale conductor.
Canadian Nickel, the exploration arm of International Nickel*, detected the Kidd Creek anomaly too, and “rejected it as having no economic significance on the account of its extraordinary size and absence of any associated magnetic feature”2.
Texas Gulf began a drilling program over other anomalies in the area, totalling 59 holes over a four-year period, without success. This was during a downturn of the industry in the area, where imminent mine closures threatened the existence of the nearby township of Timmins.
The eventual discovery of the Kidd Creek deposit is owed to the persistence and dedication of the exploration team of Texas Gulf. Senior exploration geologist Walter Holyk developed and successfully applied an alternative syngenetic model for VMS deposits that directly led to the discovery of Kidd Creek. Holyk’s working hypothesis contradicted well-held theories at the time, whereby VMS deposits had exhalative origins rather than replacement deposits that were related to granites1.
Four years after the EM surveys were conducted, Holyk’s working hypothesis and syngenetic model was proved correct when the first hole was finally drilled at the Kidd Creek anomaly, recording 8.37% zinc, 1.24% copper and 3.9 ounces per tonne of silver over 177 m. With samples displaying solid copper nearing a foot in length, the ‘size of the prize’ for Texas Gulf was beginning to become evident.
* Interestingly, International Nickel was historically associated with the Kempfield Polymetallic Project.
Exploring for base metals, International Nickel drilled some of the earliest diamond holes at Kempfield. Despite recording up to 5% zinc over short intervals of one metre, International Nickel elected to abandon any further exploration programs.
For information regarding Argent Minerals methodical approach to exploration, and the Kempfield depositional hypothesis formulated by Dr Vladimir David and Professor Ross Large, click here.
- Evans, A M and Moon, C J, 2006. A volcanic-associated massive sulphide deposit – Kidd Creek, Ontario, in Introduction to Mineral Exploration, 2nd Edition(ed: C Moon, M Whateley and A M Evans), pp 358 – 381 (Blackwell: Malden).
- Hester, B W, 1991. Discovery of the Kidd Creek Mine near Timmins, Ontario, in Case Histories of Mineral Discoveries, Volume 3 (ed: V F Hollister), pp 111-113 (Society of Mining, Metallurgy, and Exploration).