Formation and stability of oxygen-rich bubbles that shape photosynthetic mats
Bosak T, Bush JW, Flynn MR, Liang B, Ono S, Pertoff AP, Sim MS. 2010. Formation and stability of oxygen-rich bubbles that shape photosynthetic mats. Geobiology. 8:45-55
Gas release in photic-zone microbialites can lead to preservable morphological biosignatures. Here, we investigatethe formation and stability of oxygen-rich bubbles enmeshed by filamentous cyanobacteria. Sub-millimetricand millimetric bubbles can be stable for weeks and even months. During this time, lithifying organic-rich laminaesurrounding the bubbles can preserve the shape of bubbles. Cm-scale unstable bubbles support the growthof centimetric tubular towers with distinctly laminated mineralized walls. In environments that enable highphotosynthetic rates, only small stable bubbles will be enclosed by a dense microbial mesh, while in deep watersextensive microbial mesh will cover even larger photosynthetic bubbles, increasing their preservation potential.Stable photosynthetic bubbles may be preserved as sub-millimeter and millimeter-diameter features with nearlycircular cross-sections in the crests of some Proterozoic conical stromatolites, while centrimetric tubes formedaround unstable bubbles provide a model for the formation of tubular carbonate microbialites that are not markedlydepleted in 13C.
- Type
- Journal Article
- Authors
- Bosak, T.; Bush, J; Flynn, M.; Liang, B.; Ono, S.; Pertoff, A.; Sim, M.
- Units
- GRYN
- Keywords
- Cyanobacteria, microbialites, morphological biosignatures, Stromatolites