Prior to 1999, little exploration had been done to test for potential mineralization south of the main ore horizon. Drifting and mining on the Main and `04 Break systems by the various mines in Kirkland Lake was sufficient to maintain production. It was not until 1999 that Kinross Gold planned an aggressive exploration program testing potential mineralization south of the `04 Break at the Macassa Mine. An initial drill hole returned 0.78 ounces of gold per ton over 12 feet of core, 600 feet south of the `04 Break. The intersection was comprised pyrite-rich mineralization, distinctly different from the quartz veining associated with the `04 Break. Shortly thereafter Kinross terminated operations at Macassa and follow up drilling was never completed.
After purchasing the Macassa Mine property – along with four contiguous former producers (Kirkland Minerals, Teck Hughes, Lakeshore and Wright Hargreaves) in 2001, Kirkland Lake Gold began dewatering the underground workings at the Macassa Mine. Once the -4700 foot level was dewatered in 2003, an exploration program was initiated to not only follow up on the Kinross drill hole, but also to test further south, within the technical limits of large electric hydraulic drills.
In November of 2003, the fourth drill hole of this program intersected multiple mineralized zones up to 1,600 feet south of the `04 Break indicating the presence of significant gold mineralization well south of the `04 Break. The furthest south of these zones became the Lower D Zone, which is now accepted as the first zone discovered comprising the South Mine Complex (SMC).
As drilling continued to further test the Lower D Zone to the east, a series of new mineralized zones were discovered including the New South Zone in July of 2005. Drill hole 50-627 intersected a 90.4 foot section grading 2.3 ounces of gold per ton (opt); a follow-up wedged hole intersected the same mineralized zone and returned 1.43 opt over 125 feet of core length. Subsequently, in December 2005, the company began development of a 2,400 foot cross-cut heading south from the 5,300 foot level to intersect the newly discovered mineralization and provide drilling platforms for high productivity air drills. Approximately one year later, a similar south cross-cut was started from the 5,000 foot level to provide additional drill platforms and assist with future ventilation and mining requirements.
The SMC represents an entirely new mineralized system in the Kirkland Lake mining camp. It is characterized by generally shallowly dipping (25°-50°) structurally controlled zones of finely disseminated pyrite, visible gold and tellurides. This is in contrast to the steeply dipping (70°-80°) quartz vein hosted gold of the Main and '04 Break that put Kirkland Lake on the map. The new zones being developed in the SMC on 5300 and 5000 foot levels are hosted primarily by moderately southeast to south-southwest dipping dark grey to grey brown alkaline tuff, and by several phases of porphyritic intrusives, the most common of which is syenite porphyry. The SMC also exhibits a higher grade than what has been historically mined in the Kirkland Lake camp. It has been intersected as deep as the -6500 foot elevation and as high as the -4700 foot elevation over a strike length in excess of 2,000 feet. Gold mineralization in the SMC area occurs in a complex interconnected network of narrow, east to northeast trending shallow south dipping shear zones and auriferous alteration. It consists of wide, gold-bearing alteration and mineralization halos, in contrast to the narrow quartz vein systems associated with the Main and ’04 Breaks. The overall mineralized corridor is coincident with the area of abundant sill-like syenite intrusions and trachyte which collectively widen to the northeast, and occurs in bedded tuffs. The mineralized corridor and the area of syenite intrusions on the 5300 level are separated from the `04 Break in their footwall to the northeast by a wide expanse of fresh tuff lacking any significant mineralized shear zones, larger igneous bodies, or significant areas of bedding in the tuff.
Understanding how the SMC formed and its relationship to the `04 and Main Break is of great importance from an exploration standpoint. The Kirkland Lake Gold exploration team believes the SMC formed as a result of linking structures between the `04/Main Break structures and a yet to be defined structure south of the SMC. Such linking zones, on a smaller scale, are not uncommon in the Kirkland Lake camp, and have been historically mined at the past producing Wright Hargreaves property between the Main and South Breaks. Identification of potential new linking structures throughout the Kirkland Lake camp will be the focus of exploration for many years to come.
As of December 31, 2011, current reserves and resources in the South Mine Complex include:*
As of December 31, 2011, current reserves and resources in the Main, '04 and related structures, not including the South Mine Complex:*
*See Kirkland Lake news release dated May 30th, 2012, a copy of which has been filed on SEDAR for further particulars. The contents of the above reserve and resource statements have been verified and approved by the Company's Chief Exploration Geologist, Stewart Carmichael, P.Geo, a “qualified person” for the purpose of National Instrument 43-101, Standards of Disclosure for Mineral projects.
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