Early oxidation of the martian crust triggered by impacts
|Author(s)||Deng Zhengbin1, 3, Moynier Frederic1, Villeneuve Johan2, Jensen Ninna K.3, Liu Deze1, Cartigny Pierre1, Mikouchi Takashi4, Siebert Julien1, Agranier Arnaud5, 6, Chaussidon Marc1, Bizzarro Martin1, 3|
|Affiliation(s)||1 : Univ Paris, Inst Phys Globe Paris, CNRS, F-75005 Paris, France.
2 : Univ Lorraine, CRPG UMR 7350, CNRS, F-7358 Vandoeuvre Les Nancy, France.
3 : Univ Copenhagen, Ctr Star & Planet Format, Globe Inst, Copenhagen, Denmark.
4 : Univ Tokyo, Univ Museum, Tokyo, Japan.
5 : Univ Bretagne Occident, Lab Geosci Ocean, UMR CNRS 6538, Plouzane, France.
6 : Inst Univ Europe Mer, Plouzane, France.
|Source||Science Advances (2375-2548) (Amer Assoc Advancement Science), 2020-10 , Vol. 6 , N. 44 , P. eabc4941 (9p.)|
|WOS© Times Cited||2|
Despite the abundant geomorphological evidence for surface liquid water on Mars during the Noachian epoch (>3.7 billion years ago), attaining a warm climate to sustain liquid water on Mars at the period of the faint young Sun is a long-standing question. Here, we show that melts of ancient mafic clasts from a martian regolith meteorite, NWA 7533, experienced substantial Fe-Ti oxide fractionation. This implies early, impact-induced, oxidation events that increased by five to six orders of magnitude the oxygen fugacity of impact melts from remelting of the crust. Oxygen isotopic compositions of sequentially crystallized phases from the clasts show that progressive oxidation was due to interaction with an O-17-rich water reservoir. Such an early oxidation of the crust by impacts in the presence of water may have supplied greenhouse gas H-2 that caused an increase in surface temperature in a CO2-thick atmosphere.