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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]
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 ...
While the stromatolites are in an environment containing oxygen, Hynek said he believes the layers farther down in the rock have little to no access to oxygen and are actively formed by microbes ...
Sea spray containing marine microorganisms, including prokaryotes, can be swept high into the atmosphere where they become aeroplankton, and can travel the globe before falling back to earth. The earliest evidence for life on earth comes from biogenic carbon signatures and stromatolite fossils discovered in 3.7 billion-year-old rocks.
Pia (1927) erected the group to contain calcareous algal fossils that contain no visible cellular structure but which he presumed represented cyanobacteria based on comparisons to modern examples. He divided the taxon into two groups: the stromatolithi and the oncolithi .
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Graphic representation of carbon, hydrogen, nitrogen, oxygen, phosphorus, and sulfur. CHNOPS and CHON are mnemonic acronyms for the most common elements in living organisms. "CHON" stands for carbon, hydrogen, oxygen, and nitrogen, which together make up more than 95 percent of the mass of biological systems. [1] "CHNOPS" adds phosphorus and ...
Hydrogen isotope biogeochemistry (HIBGC) is the scientific study of biological, geological, and chemical processes in the environment using the distribution and relative abundance of hydrogen isotopes. Hydrogen has two stable isotopes, protium 1 H and deuterium 2 H, which vary in relative abundance on the order of hundreds of permil.