Evidence of a Limited Biosphere 1.4 Billion Years Ago
Louisiana State University and McGill University
https://www.mcgill.ca/newsroom/channels/news/billion-year-old-lake-deposit-yields-clues-earths-ancient-biosphere-288081
https://www.lsu.edu/mediacenter/news/2018/07/23gg_hayles_bao_nature.php
The paper is:
Crockford, P.W., Hayles, J.A., Bao, H., Planavsky, N.J.,
Bekker, A., Fralick, P.W., Halverson, G.P., Bui, T.H.,
Peng, Y. and Wing, B.A., 2018. Triple oxygen isotope
evidence for limited mid-Proterozoic primary productivity.
Nature, Letter | Published: 18 July 2018
https://www.nature.com/articles/s41586-018-0349-y
Yours,
Paul H.