SUPRA-GLACIAL SULPHUR SPRINGS AND ASSOCIATED BIOLOGICAL ACTIVITY

This paper describes newly discovered supra-glacial sulphur springs in the Canadian High Arctic. The location represents a unique occurrence of springs discharging from the surface of a large ice sheet and precipitating 'travertine-like' deposits of native sulphur, gypsum and calcite as well as releasing H2S. The presence of sulphur in three oxidation states indicates a complex series of redox reactions. Physical and chemical conditions of the spring water and surrounding environment argue for biologically mediated reactions. Bacteria counts of 2 to 3 x 104 cells/ml, as well as SEM images of biofilm and individual cells confirm bacteria are present in the spring system.

Sulphur is most likely derived from thick evaporite (anhydrite) beds of the underlying Otto Fiord Formation. Geological constraints suggest a circulation depth of greater than 1.5 km, implying a topography driven flow system, with an active biological community, may operate within an area covered by extensive ice sheets and thick (> 500 m) permafrost.