DOI 10.1016/j.chemgeo.2024.122239 Microbialites are microbial sedimentary structures that constitute some of the oldest traces of life on Earth. By their deposition in a wide range of sedimentary environments and their presence throughout most of geological time, the sedimentological and geochemical signatures they preserve represent important paleoenvironmental archives for understanding Earth's biological and geochemical co-evolution. Here we present a large microbialite collection containing >1370 curated specimens, covering all continents except Antarctica and spanning >3.5 Ga of Earth history, that is accessible to the international scientific community for examination and sampling at the Muséum National d'Histoire Naturelle (MNHN) in Paris, France. After cataloguing and evaluating the samples for their lithology, biogenicity, and inferred depositional environments, we characterized the collection for selected geochemical parameters, notably carbonate stable carbon and oxygen isotope ratios, as well as major, trace, and rare earth element compositions. Finally, we explore the different geochemical proxies analyzed with regards to their utility for reconstructing evolving Earth surface environments and/or microbial metabolisms via comparison of geochemical data from the MNHN Microbialite Collection to a compilation of similar proxy data for carbonates worldwide. We demonstrate that certain temporal trends previously recognized in carbonates worldwide (e.g., with respect to variations in C and O stable isotope compositions and redox sensitive trace element enrichments) are well reflected in this collection. Our findings highlight the utility of the MNHN Microbialite Collection and microbialites more generally for reconstructing the conditions associated with habitable environments in deep time and for tracing the response of microbial communities to the geochemical evolution of Earth's surface.
Microbialite, Stromatolite, Geochemistry, Paleoenvironments, Museum collection, Sample Curation
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Publisher's official version | 25 | 5 Mo | ||
Supplementary Fig. 1. Replicate measurements (n = 27) of the limestone reference material CAL-S. The obtained results agree well with the proposed values for CAL-S in Potts et al. (2002), in ... | 1 | 6 Ko | ||
Supplementary Fig. 2. PAAS-normalized europium anomalies in carbonate microbialites of the MNHN Microbialite Collection plotted against barium to samarium ratios before (A) and after (B) correction .. | 1 | 380 Ko | ||
Supplementary Fig. 3. δ18Ocarb (A) and δ13Ccarb (B), as well as uranium (C), vanadium (D), molybdenum (E), manganese (F), and iron (G) concentrations.... | 1 | 423 Ko | ||
Supplementary Fig. 4. δ18Ocarb (A) and δ13Ccarb (B), as well as uranium (C), vanadium (D), molybdenum (E), manganese (F), and iron (G) concentrations plotted against strontium to calcium ratios. | 1 | 423 Ko | ||
Supplementary Fig. 5. Iron (A) and total REE (B) concentrations plotted against magnesium to calcium ratios, as well as total REE concentrations plotted against strontium .... | 1 | 370 Ko | ||
Supplementary Fig. 6. Total REE concentrations (A), PAAS-normalized europium anomalies (B), PAAS-normalized lanthanum anomalies (C), PAAS-normalized cerium anomalies (D), .... | 1 | 437 Ko | ||
Supplementary Fig. 7. Total REE concentrations (A), PAAS-normalized europium anomalies (B), PAAS-normalized lanthanum anomalies (C), PAAS-normalized cerium anomalies (D), praseodymium to ... | 1 | 435 Ko | ||
Supplementary Fig. 8. Total REE concentrations (A), PAAS-normalized europium anomalies (B), PAAS-normalized lanthanum anomalies (C), PAAS-normalized cerium anomalies (D), ... | 1 | 435 Ko | ||
Supplementary Fig. 9. Total REE concentrations (A), PAAS-normalized europium anomalies (B), PAAS-normalized lanthanum anomalies (C), PAAS-normalized cerium anomalies (D), ... | 1 | 459 Ko | ||
Supplementary Fig. 10. Violin plots showing concentrations in the MNHN Microbialite Collection of selected redox-sensitive Al-normalized elements: iron (A),... | 1 | 455 Ko | ||
Supplementary Fig. 11. Evolution of iron to aluminum ratios (A), manganese to aluminum ratios (B), uranium to aluminum ratios (C), ... | 1 | 371 Ko | ||
Supplementary material 1. Supplementary Table 1. List of sample providers to the MNHN Microbialite Collection at the time of publication. *First name unknown. | - | 16 Ko | ||
Supplementary material 2. Supplementary Table 2. List of quaternary carbonate microbialite samples analyzed from the MNHN Microbialite Collection and plotted in Figure 6 as a function of their ... | - | 20 Ko | ||
Supplementary material 3. Supplementary Table 3. List of samples from the MNHN Microbialite Collection selected for plotting in Figure 7 due to their environmentally representative REE spectra, in ... | - | 18 Ko |
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