Reconstructing Precambrian pCO2 and pO2 Using Paleosols
Nathan D. Sheldon, R. L. Mitchell, Rebecca Dzombak
Abstract
Paleosols formed in direct contact with the Earth's atmosphere, so they can record the composition of the atmosphere through weathering processes and products. Herein we critically review a variety of different approaches for reconstructing atmospheric O2 and CO2 over the past three billion years. Paleosols indicate relatively low CO2 over that time, requiring additional greenhouse forcing to overcome the 'faint young Sun' paradox in the Archean and Mesoproterozoic, as well as low O2 levels until the Neoproterozoic. Emerging techniques will revise the history of Earth's atmosphere further and may provide a window into atmospheric evolution on other planets.
Topics & Concepts
PrecambrianPaleosolArcheanAtmosphere (unit)Early EarthAstrobiologyEarth scienceGeologyWeatheringEarth (classical element)GeochemistryEnvironmental sciencePaleontologyMeteorologyGeographyAstronomyPhysicsLoessPaleontology and Stratigraphy of FossilsMethane Hydrates and Related PhenomenaGeological and Geochemical Analysis