Kirkland Lake Gold Inc.

Teck-Hughes

The Teck-Hughes mine is bounded on the west by Kirkland Lake Gold and by the Lake Shore mine to the east. The mine began production in 1917 and had produced 3,688,664 ounces of gold at a recovered grade of 0.38 oz/T when the mine ceased operating in 1968.

The mine ranks third among the seven mines of Kirkland Lake in terms of total ounces produced, but had an average recovered grade considerably below the camp wide average of 0.46 oz/T. In the latter years of operation the mine relied heavily on lower grade "slough ore" which had caved from the hangingwalls of open stopes.

In 1911 three claims (Tl 6624-Tl 6626), which were to form the most important part of the mine, were staked by Stephen Orr and three neighboring claims (Ll 238-Ll 240) were staked by John Reamsbottom. In 1912 gold was discovered in claim Ll 238 by James A. Hughes and Sandy McIntyre. Prospecting and surface trenching were carried out by Teck-Hughes Gold Mines Limited and a 35-foot shaft was sunk.

In 1913 No.1 Shaft was sunk to 212 feet and 203 feet of drifting was carried out on the 200-foot level. No.2 Shaft was sunk to a depth of 75 feet with 500 feet of lateral development on the 75-foot level by Teck-Hughes Gold Mines Limited. From 1914 to 1915 the No.3 Shaft was sunk to 124 feet and an 85-foot winze was developed from the second level. 1,360 feet of lateral development in No.1 and No.3 shafts were carried out by Nipissing Mining Company (under option from Teck-Hughes Gold Mines Limited).

From 1915-1917 the underground workings were dewatered and the No.3 shaft was deepened to 400 feet with a winze to 600 feet, and 1,804 feet of lateral development was carried out. In 1917, a 50-ton mill was installed and milling began. This work was completed by Teck-Hughes Gold Mines Limited.

As with other major mines in Kirkland Lake, the most important structure at the Teck-Hughes mine is the Main Break. This structure and the veins related to it yielded most of the gold in the mine. The mineralized structure was mined as the No.3 vein from surface to the 6105 foot level, the deepest level at the mine. Longitudinal sections reveal that stoping on the No.3 vein was almost continuous from surface to near the 3000 foot level. Diamond drilling defined the Main Break down to 6650 feet, however there was insufficient ore to warrant development below the 6105 foot level. Grade and production both decreased below 3 000 feet. This decrease in ore with depth has been suggested to be directly related to a decrease in the proportion of augite syenite to syenite porphyry with depth (Charlewood, 1964).

The No.4 break lies about 600 feet south of the Main Break and is generally believed to be the westerly extension of the South (No.1) vein of Lake Shore. Although this structure contains some low gold values, no ore has been mined along it in the Teck-Hughes mine. This fault may merge with the No.6 break at depth and has never been identified in the western portions of the mine.

From 1938 onwards, veins in the hanging wall of the Main Break became an important source or ore. These hanging wall veins are typical of other such veins in the Kirkland Lake camp which drape off the Main Break and dip flat to the south, generally between 30 and 50 degrees.

The relatively late discovery and subsequent mining of hanging wall veins can be attributed to a number of factors. Firstly, mining was concentrated on the Main Break where stoping was extensive, and easily traced. Secondly, many of the initial diamond drill holes testing for ore associated with the Main Break were not extended any significant distance into the hangingwall. In later years, improvements in diamond drilling and reduced drilling costs, increasing realization of the significance of the hangingwall veins, and the depletion of Main Break ore led to more and more exploration holes probing the hangingwall of the Main Break revealing numerous significant ore-bearing veins

The above summary of the history of the Teck-Hughes 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.