Borup Fiord Pass

Borup Fiord Pass is a glacier-carved valley on Ellesmere Island in Nunavut, Canada, leading south into Esayoo Bay, part of Borup Fiord. It is known for a natural spring that brings subsurface fluids to the surface, sometimes through glacial ice. The pass is especially significant as the only known place where sulfur from a natural spring is deposited over ice. At the spring, hydrogen sulphide in the water is transformed into stable deposits of elemental sulfur, most commonly, or gypsum, through a process often associated with microbes such as bacteria.

Nunavut · Canada