Stromatolites as geochemical archives to reconstruct microbial habitats through deep time: Potential and pitfalls of novel radiogenic and stable isotope systems

Author(s)
Simon V. Hohl, Sebastian Viehmann
Abstract

Understanding the origin and evolution of life on Earth and potentially other planets in our solar system is of fundamental interest for humanity. For the longest time in Earth's history, life evolved in microbial communities. It is, however, still incompletely understood how, when and where such habitable environments formed and how microbial communities adopted to the drastic changes of the atmosphere-hydrosphere-lithosphere systems through deep time.

Stromatolites, i.e., lithified microbial mats that occur in sedimentary successions from at least 3.4 billion years ago until today, hold the geochemical key to our understanding of the evolution of microbial life on Earth and may also provide a blueprint for planetary studies. This review targets the potential and pitfalls of emerging and established isotope applications to stromatolites based on improved and newly developed analytical and technical capabilities in the last decades. We provide a comprehensive overview of present data and the interpretation of applications of radiogenic (Usingle bondPb, Rbsingle bondSr, Smsingle bondNd) and stable (O, C-N-S, Fe, Mo, Cr, U, Cd) isotope systems in stromatolites. Although the behaviour and fractionation processes of different isotope systems in stromatolites and microbial mats are incompletely understood, the different isotope proxies are used to better understand and reconstruct microbial habitats in stromatolite-forming environments through deep time. Primarily, radiogenic isotopes are used to directly date stromatolites and determine the source of elements in ancient stromatolite environments, while stable isotopes are used to understand redox conditions, metal availability, and (biogenic) metal cycling processes in microbial habitats. We provide deep insights into each isotope application in stromatolites and show their unique potential and future perspectives to bridge the gap between geochemistry and microbiology and to better understand the evolution of microbial life on Earth and beyond.

Organisation(s)
Department of Geology
External organisation(s)
Tongji University
Journal
Earth-Science Reviews
Volume
218
No. of pages
20
ISSN
0012-8252
DOI
https://doi.org/10.1016/j.earscirev.2021.103683
Publication date
07-2021
Peer reviewed
Yes
Austrian Fields of Science 2012
105128 Geomicrobiology, 105105 Geochemistry, 105127 Geochronology, 105121 Sedimentology
Keywords
ASJC Scopus subject areas
General Earth and Planetary Sciences
Portal url
https://ucrisportal.univie.ac.at/en/publications/aa4f002c-0c94-4b48-8cc3-0d646f02c925