Biosignatures of Earth’s oldest fossils

The oldest putative fossils occur as hematite filaments and tubes in jasper-carbonate banded iron formations (BIF) from the 4280- to 3750-Ma Nuvvuagittuq Supracrustal Belt (NSB), Québec. If biological in origin, these filaments might have affinities with modern descendants; however, if abiotic, they could indicate complex prebiotic forms on early Earth. In this presentation, I will describe various microfossils, dubiofossils and pseudofossils that occur in the NSB jasper BIF. This will include descriptions of associated observations from mineralogy, sedimentology, petrology, and geochemistry. The latter in particular will include new observations of the organic geochemistry and trace metal composition of selected microfossils. The microstructures share resemblance to younger microfossils, modern Fe-oxidising bacteria from hydrothermal environments, and the experimental products of heated Fe-oxidizing bacteria. Collectively, the observations suggest a diverse microbial ecosystem on the primordial Earth, traces of which may be common on other planetary bodies with hydrothermalism, including Mars.

CAB YouTube channel

We invite you to watch this video as a preview of tomorrow’s seminar, recorded after the discovery was published. 

Short video (1:45min)

Long video (4:10min)