Details

Autor(en) / Beteiligte

• BOSAK, T
• BUSH, J.W.M
• FLYNN, M.R
• LIANG, B
• ONO, S
• PETROFF, A.P
• SIM, M.S

Titel

Formation and stability of oxygen-rich bubbles that shape photosynthetic mats

Ist Teil von

• Geobiology, 2010, Vol.8 (1), p.45-55

Ort / Verlag

Oxford, UK: Oxford, UK : Blackwell Publishing Ltd

Erscheinungsjahr

2010

Quelle

Wiley Online Library All Journals

Beschreibungen/Notizen

• Gas release in photic-zone microbialites can lead to preservable morphological biosignatures. Here, we investigate the formation and stability of oxygen-rich bubbles enmeshed by filamentous cyanobacteria. Sub-millimetric and millimetric bubbles can be stable for weeks and even months. During this time, lithifying organic-rich laminae surrounding the bubbles can preserve the shape of bubbles. Cm-scale unstable bubbles support the growth of centimetric tubular towers with distinctly laminated mineralized walls. In environments that enable high photosynthetic rates, only small stable bubbles will be enclosed by a dense microbial mesh, while in deep waters extensive 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 nearly circular cross-sections in the crests of some Proterozoic conical stromatolites, while centrimetric tubes formed around unstable bubbles provide a model for the formation of tubular carbonate microbialites that are not markedly depleted in ¹³C.