
The Kemess North deposits occur at the southern end of the Toodoggone formation, which describes a collection of occurrences and deposits found in Mesozoic volcanic rocks of the eastern Stikine Arch. The area is known for its gold-copper porphyry deposits and low sulphidation epithermal gold-silver vein deposits.
The Kemess North gold-copper mineralization forms an inclined tabular zone centered on the East Cirque porphyritic monzodiorite. Alteration and mineralization are associated with, and zoned both vertically and laterally from, the quartz diorite/quartz monzonite intrusive intersected at depth beneath the East Cirque.
The highest grade gold-copper zones occur at or near the quartz monzonite-Takla volcanic contact. This zone occurs mostly within the quartz monzonite stock and to a lesser extent within the andesite adjacent to the intrusive stock. The protolith is commonly completely replaced. The quartz monzonite/quartz diorite stock and associated quartz-magnetite zone is interpreted as the heat source driving the porphyry copper-gold system at Kemess North.
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