A geochemical investigation of perennial spring activity and associated mineral precipitates at Expedition Fiord, Axel Heiberg Island, Canadian High Arctic

Two groups of perennial springs are observed in the Canadian High Arctic at Expedition Fiord on Axel Heiberg Island. Saline discharge (∼1.3--2.5 molal) produces a variety of calcite (travertine) and gypsum-rich precipitates. Field observations, laboratory experiments, and geochemical modeling of the waters reveal that calcite precipitation is controlled primarily by CO2 degassing, but alternating light (sparite calcite crystals) and dark (amorphous micritic calcite spheres coated by organic material and trace metals) laminae are present. Evaluation of the geochemical environment in conjunction with field observations suggest that micrite layer formation may be influenced by microbial activity, although their presence has yet to be confirmed.;In addition, discharge from two springs at Colour Peak leads to the precipitation of metastable calcium carbonate crystals (0.25--0.5 cm long) on terraced and steep mound slopes that form during winter months. Background literature and field observations suggest that this mineral may be ikaite (CaCO 3·6H2O). The precipitation of this mineral may provide information regarding its environmental growth constraints and opportunities.