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Formation and stability of oxygen‐rich bubbles that shape photosynthetic mats
Author(s) -
BOSAK T.,
BUSH J. W. M.,
FLYNN M. R.,
LIANG B.,
ONO S.,
PETROFF A. P.,
SIM M. S.
Publication year - 2010
Publication title -
geobiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.859
H-Index - 72
eISSN - 1472-4669
pISSN - 1472-4677
DOI - 10.1111/j.1472-4669.2009.00227.x
Subject(s) - microbial mat , photosynthesis , carbonate , millimeter , photic zone , geology , cyanobacteria , chemical physics , chemistry , paleontology , botany , biology , phytoplankton , organic chemistry , nutrient , bacteria , physics , astronomy
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 13 C.