Paleo-Hydrothermal Predecessor to Perennial Spring Activity in Thick Permafrost in the Canadian High Arctic, and Its Relation to Deep Salt Structures: Expedition Fiord, Axel Heiberg Island, Nunavut

Figure 7

Outcrop-scale features of the WGVA site. (a) Partial overview of the site showing metal gossan (upper left) and hydrothermal veining in wallrock. (b) Outcrop within the exposure in (a) containing zoned calcite-quartz vein hosted in partial epidotized wallrock showing the relative size of vein structures (M. Zentilli for scale). (c) Individual vein showing early brown carbonate (“cal1”) crystals symmetrically lining wallrock contacts, with a vuggy infilling white (sparry) calcite (“cal2”) and quartz. Epidotized wallrock containing minor secondary vein splays occurs in the vein selvage. (d) Enlarged view of vein showing early brown carbonate crystals radiating from vein margins symmetrically towards the vein centre containing euhedral terminations and open space in this example. (e) “Zebra” texture showing alternating layers of carbonate- and sulfide-rich hydrothermal mineralization (white-tan) with wall-rock septae (grey). (f) Contorted “zebra” texture indicating post-crystallization deformation. (g) Enlarged view of sulfide-rich host rock layers separated by hydrothermal carbonate. (h) Botryoidal masses of pyrite-marcasite.

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