The evolution of the Earth’s atmosphere studied using impact craters
An international team shows that rocks from the hydrothermal system formed following the impact of the Rochechouart asteroid around 200 million years ago contain traces of the atmosphere of that period in the Earth's history.
Artist's view of an asteroid crashing into Earth © Freepik
Publication date: 25/09/2023
Press, Research
Related teams :
Cosmochemistry, Astrophysics and Experimental Geophysics (CAGE)
Related themes : Origins, Earth and Planetary Interiors
Tracking the evolution of the composition of the Earth’s atmosphere allows following the entire geological history of our planet. However, geological samples that have trapped atmospheric signals are extremely rare.
An international team of researchers led by Guillaume Avice (IPGP-Université Paris Cité, CNRS), in collaboration with the University of Queensland (Australia), the University of Lorraine and the Natural History Museum in Vienna (Austria), shows that rocks from the hydrothermal system formed following the Rochechouart asteroid impact (France) some 200 Ma ago contain traces of the atmosphere from that period of Earth’s history.
Measurements of the elemental and isotopic composition of noble gases show that the atmospheric signal is essentially pure, and Argon-Argon dating confirms the age of this atmospheric signal.
Impact craters are therefore new targets for understanding the evolution of the Earth’s atmosphere over the long term, bearing in mind that a better knowledge of the past atmosphere is important for understanding future variations, particularly in the case of climate change.
Ref: G. Avice, M.A. Kendrick, A. Richard, L. Ferrière, Ancient atmospheric noble gases preserved in post-impact hydrothermal minerals of the 200 Ma-old Rochechouart impact structure, France, Earth and Planetary Science Letters, Vol. 620, 2023, DOI: 10.1016/j.epsl.2023.118351.
