layered organo-sedimentary structures tagged posts

Earth’s Oldest Stromatolites and the Search for Life on Mars

Hand sample of Dresser Formation stromatolite, showing a complex layered structure formed of hematite, barite, and quartz, and a domed upper surface (arrow).

The earliest morphological traces of life on Earth are often highly controversial, both because non-biological processes can produce relatively similar structures and because such fossils have often been subjected to advanced alteration and metamorphism. Stromatolites, layered organo-sedimentary structures reflecting complex interplays between microbial communities and their environment, have long been considered key macrofossils for life detection in ancient sedimentary rocks; however, the biological origin of ancient stromatolites has frequently been criticized...

Read More