New constraints on Archean Atmosphere
A recent study about Archean Atmosphere is published today in Science. This study involving Pascal Philippot from IPGP was performed on rocks drilled by IPGP in Australia in 2004.
Article at a glance
The first life on Earth blossomed up during the Archean, between 3.8 and 2.4
billion years ago, at a time when climatic conditions were made favourable
by the absence of any major glaciations. Researchers at the CRPGCNRS
University of Lorraine (France), in collaboration with the University
of Manchester (UK) and the Institut de Physique du Globe of Paris, have
measured the pressure of nitrogen (N2, which forms 78 % of the present-day
atmosphere) and the isotopic composition (15N/14N ) of this element in the
Archean atmosphere by analyzing water bubbles trapped in rocks formed
near the surface of the Earth 3.5 billion years. These measurements provide
important clues to reconstruct ancient climatic conditions, including the level
of ancient atmospheric carbon dioxide (CO2), a major greenhouse gas in the
atmosphere, as well as the strength of the Earth’s magnetic field at that time.