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 8

Reflected light photomicrographs summarizing textural and compositional characteristics of sulfides in vein margins associated with vein carbonates and laminated sedimentary wall rocks. (a) Recrystallized (former framboids) subhedral pyrite (subhed-py) in early brown carbonate (“cal 1”) surrounded in later carbonate (“cal 2”) containing euhedral pyrite (euhed-py). (b) Cataclastic pyrite in wall rock. (c-d) Plumose, porous, pyrite-marcasite intergrowths showing massive domains of pyrite alternating with polycrystalline domains of marcasite. (d) Same area as (c) but in crossed nicols to emphasize anisotropy of marcasite; enclosed dark material is calcite. Dark areas within pyrite-marcasite intergrowths are porosity. (e) Subhedral pyrite polycrystalline aggregate with sphalerite core. (f) Pyrite framboid in black layer of “zebra” rock (Figure 7(g)). (g) Recrystallised pyrite (former framboid) along vein-wallrock margin enclosed within early brown carbonate domain (“cal 1”).

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