Fossil microorganisms and formation of Early Precambrian weathering crusts

Life on early Earth

“…All the weathering crusts (a specific type of continental geological formation) examined from the Baltic Shield contain many micro-organisms, which suggests that Archean land was colonized by them and, probably, by fungi. 6,7 The appearance of eukaryotes (i.e., plants and animals) in the geological record is a very important problem. We see no reason to distrust the data of Timofeev showing that that spherical forms up to 0.1-0.15mm in diameter and tubes up to 0.03-0.04mm across are probably the remains of eukaryotic organisms.…”

Bacterial-Paleontological Study of Early Precambrian Weathering Crusts

“…Weathering profiles in all geological settings are reliable witnesses of continental regimes and in the Precambrian structures they often give unique information about continental features which led to biosphere development (Rozanov et al, 2008). Complex of diverse fossil microorganisms in ancient weathering crusts was discovered in result of electronic-microscope investigations, and conclusion about possibility of land colonization by microbes from the very beginning of geological annals was made (Rozanov et al, 2008;Astafieva et al, 2009). …”