The MacKenzie occurrence is situated in the Duckling Creek area of the Swannell Ranges (Omineca Mountains), approximately 11 kilometres northeast of Old Hogem and 39 kilometres west of Germansen Landing.
The area is underlain by Middle Triassic to Lower Jurassic Takla Group volcanics, which have been intruded to the north and west by mesozonal plutonic rocks assigned to the Late Triassic to Early Cretaceous Hogem Intrusive Complex. The plutonic rocks form an elongate batholith, extending from Chuchi Lake north to the Mesilinka River. The structural setting of the batholith and the intruded Takla Group is one of vertical tectonics associated with graben development (Bulletin 70).
Takla Group rocks in the area of the occurrence are predominantly basaltic in composition and host abundant, though erratically distributed, epidote (with or without pyrite) as veinlets, stringers, pods and patchy replacements. These rocks are cut by numerous pre-Hogem pyroxene porphyry ‘feeder’ dikes. Hogem Complex intrusions range in composition from monzonite through syenite and are potassic altered, locally hosting up to 50 per cent pink feldspar as veins and envelopes several centimetres wide around fractures. Dikes of fine- to medium-grained syenite porphyry cut the volcanic rocks in the area. Near the contact, a dark hybrid rock of uncertain composition has been mapped. It is, however, almost certainly related to the emplacement of the intrusions.
The MacKenzie showing is reported to consist of two showings separated by 250 metres of clay material. The north showing consists of massive pyrite-chalcopyrite exposed in a creek cutbank. The host was described as an intensely fractured, chlorite-rich, intermediate to mafic intrusive rock with a late potassic overprint consisting of mainly of potassium feldspar veins. Eastfield Resources Ltd.’s 2000 drill program indicated the area to consist of intensely potassium-altered intrusive rock. A 1.6-metre channel sample taken across this zone assayed 2.68 per cent copper, 16.1 grams per tonne silver and 0.4 gram per tonne gold (Property File - Page, J.W., 1999).
The south showing consists of a 1-metre wide massive chalcopyrite lens dipping into the creek bank. A sample of this material yielded 20.75 per cent copper, 127.6 grams per tonne silver and 6.8 grams per tonne gold (Property File - Page, J.W., 1999).
Work History
In 1970, Donna Mines held the property as the Duckling claims and conducted geochemical sampling and trenching and drilled three diamond-drill holes on the Discovery zone (093N 089) located 1.9 kilometres east of the Mackenzie showing. They followed up in 1971 with an 8-kilometre ground magnetic survey. In 1981, Dimac Resource Corp. staked the Duckling claim and followed up by taking 13 rock and 45 soil samples. In 1987, Cathedral Gold Corporation conducted mapping and geochemical survey consisting of 55 rock and 326 soil samples on its Ling claims, which covered much of the same ground as the previous Duckling claims. Cathedral followed in 1989 by taking 73 rock and 163 soil samples. In 1999, Lysander Minerals Corp. staked the Duck claims where the Mackenzie showings occur. Eastfield Resources Ltd., under a 2000 option agreement with Lysander (see Lorraine, MINFILE 093N 002), completed an initial diamond drilling program on the MacKenzie zone. A total of 352 metres of thin-wall BQ diamond drillcore was obtained from five holes drilled. No significant economic results were obtained although strongly altered intrusions were intersected. A small, 91-sample soil program carried out simultaneously with the drill program indicated that significant soil copper anomalies exist in this area. In 1991, Manson Creek Resources conducted an exploration program consisting of 84 soil samples east of Duckling Creek.
In 2000, J.W. Morton on behalf of Eastfield Resources Ltd. and Lysander Minerals Corporation conducted a reconnaissance drill program to test the copper and gold mineralization discovered in 1999 within the Mackenzie zone located in the southeastern corner of the Lorraine property in the Duckling Creek area. Drilling, totalling 352 metres, was completed over five holes. The most significant drilling intercepts occurred within drillhole MAC 2000-1. Soil samples (91) were taken for assay and located a coherent 200-metre long copper-gold anomaly.
Additional exploration was undertaken in 2004 in the MacKenzie area and was successful in outlining several 1-kilometre long copper-in-soil geochemical anomalies. Two lines of induced polarization geophysical surveying were also completed in this area, which was also successful in indicating several moderate-level anomalies and one strong anomaly. Two new mineralized showings were also discovered in the southern portion of the grid, with grab rock samples from these assaying 0.84 per cent copper and 2.4 grams per tonne gold and a second assaying 0.75 per cent copper and 2.22 grams per tonne gold (Assessment Report 27782). In 2004, Eastfield Resources described the Mackenzie occurrence as consisting of three massive sulphide pods occurring along a 1-kilometre structure with select samples indicating grades of 10 to 20 per cent copper and 6 to 14 grams per tonne gold. These bodies are small, averaging 1 to 2 metres wide and have limited strike and dip dimensions where tested. Disseminated mineralization was observed in rocks peripheral to these bodies.
In 2005, on the MacKenzie, Teck Cominco outlined several strong induced polarization chargeability anomalies associated with linear resistivity high features. Five core holes, spaced 750 metres to 1.5 kilometres apart, tested some of these targets. Pyrite was generally encountered, apparently associated with feldspar and hornblende phyric intrusions. Two holes in the central part of the grid intersected moderate potassium alteration and minor copper mineralization.
See Lorraine (MINFILE 093N 002) for further details
