Fossilized fountain conduit
Location:
Sirmilik
Glacier, Bylot Island, Nunavut, Canada
A series of dark rings connected by dark lines in the center of the photo represents a fortuitous exposure of an abandoned conduit that probably fed a surface fountain on Sirmilik Glacier (46201, B37). The exposure is in the side of a deep valley thermally eroded into the snout area of Sirmilik Glacier, the same valley described in image 0026. The curvilinear shape of the structure is probably related to differential flow rates at different levels of the glacier (i.e., flowing faster near the surface than at the base). The circular structures are likely related to thermal erosion by water that was swirling due to Coriolis forces during ascent of water from the base or descent of water from the surface, producing this cross section of a "corkscrew." The black material that defines the various fractures in the valley side comprises mostly organic debris, dominated by the algae Ancyclonema nordenskioldii. Many of the low-angle structures dipping to the left may be inactive thrust faults in this zone of compressive flow near Sirmilik's snout.
Updated 08/27/2009 CAB