Benthic mat observations
The morphology of shallow water microbial mats at Lake Fryxell is
influenced by the nucleation of gas bubbles on the mats (Wharton et al.
1982, Wharton et al. 1994). Gas bubbles build up in mats and induce
buoyant delamination of mat layers, creating microbial mat liftoff
structures. Liftoff mat was present to 6.4 m depth in 2006 (7.0 m depth
in 2012; Figure 2A-B). Liftoff was not present below 7.0 meters in 2006
and was also absent from the deeper transect starting at
~8.5 m in 2012. Video footage throughout the 2012
oxycline shows ridge-pit and prostrate mat overlying discrete cm-scale,
mineralized topographic highs or knobs (Figure 2C).