dc.contributor.author | Planavsky, Noah J. | en_NZ |
dc.contributor.author | Reinhard, Christopher T. | en_NZ |
dc.contributor.author | Isson, Terry T. | en_NZ |
dc.contributor.author | Ozaki, Kazumi | en_NZ |
dc.contributor.author | Crockford, Peter W. | en_NZ |
dc.coverage.spatial | United States | en_NZ |
dc.date.accessioned | 2020-08-25T02:25:21Z | |
dc.date.available | 2020-08-25T02:25:21Z | |
dc.date.issued | 2020 | en_NZ |
dc.identifier.citation | Planavsky, N. J., Reinhard, C. T., Isson, T. T., Ozaki, K., & Crockford, P. W. (2020). Large mass-independent oxygen isotope fractionations in mid-Proterozoic sediments: Evidence for a low-oxygen atmosphere? Astrobiology, 20(5), 628–636. https://doi.org/10.1089/ast.2019.2060 | en |
dc.identifier.uri | https://hdl.handle.net/10289/13753 | |
dc.description.abstract | Earth's ocean-atmosphere system has undergone a dramatic but protracted increase in oxygen (O₂) abundance. This environmental transition ultimately paved the way for the rise of multicellular life and provides a blueprint for how a biosphere can transform a planetary surface. However, estimates of atmospheric oxygen levels for large intervals of Earth's history still vary by orders of magnitude-foremost for Earth's middle history. Historically, estimates of mid-Proterozoic (1.9-0.8 Ga) atmospheric oxygen levels are inferred based on the kinetics of reactions occurring in soils or in the oceans, rather than being directly tracked by atmospheric signatures. Rare oxygen isotope systematics-based on quantifying the rare oxygen isotope ¹⁷O in addition to the conventionally determined ¹⁶O and ¹⁸O-provide a means to track atmospheric isotopic signatures and thus potentially provide more direct estimates of atmospheric oxygen levels through time. Oxygen isotope signatures that deviate strongly from the expected mass-dependent relationship between ¹⁶O, ¹⁷O, and ¹⁸O develop during ozone formation, and these "mass-independent" signals can be transferred to the rock record during oxidation reactions in surface environments that involve atmospheric O₂. The magnitude of these signals is dependent upon 𝘱O₂, 𝘱CO₂, and the overall extent of biospheric productivity. Here, we use a stochastic approach to invert the mid-Proterozoic Δ¹⁷O record for a new estimate of atmospheric 𝘱O₂, leveraging explicit coupling of 𝘱O₂ and biospheric productivity in a biogeochemical Earth system model to refine the range of atmospheric 𝘱O₂ values that is consistent with a given observed Δ¹⁷O. Using this approach, we find new evidence that atmospheric oxygen levels were less than ∼1% of the present atmospheric level (PAL) for at least some intervals of the Proterozoic Eon. | en_NZ |
dc.format.mimetype | application/pdf | |
dc.language.iso | en | en_NZ |
dc.publisher | Mary Ann LIebert | |
dc.rights | This is an author's accepted version of an article published in Astrobiology. © 2020 Mary Ann LIebert, Inc. Final publication is available from Mary Ann Liebert, Inc., publishers http://dx.doi.org/10.1089/ast.2019.2060 | |
dc.subject | Atmospheric oxygenation | en_NZ |
dc.subject | Precambrian | en_NZ |
dc.subject | Proterozoic | en_NZ |
dc.subject | Triple oxygen | en_NZ |
dc.title | Large mass-independent oxygen isotope fractionations in mid-Proterozoic sediments: Evidence for a low-oxygen atmosphere? | en_NZ |
dc.type | Journal Article | |
dc.identifier.doi | 10.1089/ast.2019.2060 | en_NZ |
dc.relation.isPartOf | Astrobiology | en_NZ |
pubs.begin-page | 628 | |
pubs.elements-id | 255940 | |
pubs.end-page | 636 | |
pubs.issue | 5 | en_NZ |
pubs.publication-status | Published | en_NZ |
pubs.volume | 20 | en_NZ |
dc.identifier.eissn | 1557-8070 | en_NZ |