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Very few Archean stromatolites contain fossilized microbes, but fossilized microbes are sometimes abundant in Proterozoic stromatolites. [16] While features of some ancient apparent stromatolites are suggestive of biological activity, others possess features that are more consistent with abiotic (non-biological) precipitation. [17]
The hydrogen ions are used to react with carbon dioxide to produce ... Stromatolites provide ancient ... Some microalgae contain substances of high biological ...
The stromatolites found today are almost all carbonate rocks (made of limestone), but these structures are mostly composed of the minerals gypsum and halite (rock salt), Hynek said.
These possible biosignatures include: (a) microfossils and stromatolites; (b) molecular structures and isotopic compositions of carbon, nitrogen and hydrogen in organic matter; (c) multiple sulfur and oxygen isotope ratios of minerals; and (d) abundance relationships and isotopic compositions of redox-sensitive metals (e.g., Fe, Mo, Cr, and ...
Stromatolites are alternating layers of cyanobacteria and sediments. The grain size of sediment portion of stromatolites is affected by the depositional environment. During the Proterozoic, stromatolites' compositions were dominated by micrite and thinly laminated lime mud, with thicknesses no greater than 100 microns. [3]
Stromatolites, bioherms (domes or columns similar internally to stromatolites) and biostromes (distinct sheets of sediment) are among such microbe-influenced build-ups. [3] Other types of microbial mat have created wrinkled "elephant skin" textures in marine sediments, although it was many years before these textures were recognized as trace ...
Pages in category "Stromatolites" The following 7 pages are in this category, out of 7 total. This list may not reflect recent changes. ...
Hot mineral water that contains hydrogen carbonate and calcium ions has the most optimal range. [14] [15] This case is similar to the origin of life in hydrothermal vents, but with hydrogen carbonate and calcium ions in hot water. [16] [17] At a pH of 9–11, the reactions can take place in seawater.