Aqueously altered igneous rocks sampled on the floor of Jezero crater, Mars
Kenneth A. Farley, K. M. Stack, David L. Shuster, B. Horgan, J. A. Hurowitz, Jesse Tarnas, Justin I. Simon, V. Z. Sun, Eva L. Scheller, Kelsey Moore, S. M. McLennan, Paulo Vasconcelos, R. C. Wiens, A. H. Treiman, L. E. Mayhew, Olivier Beyssac, T. V. Kizovski, Nicholas J. Tosca, Kenneth H. Williford, L. S. Crumpler, L. W. Beegle, J. F. Bell, B. L. Ehlmann, Yang Liu, J. N. Maki, M. E. Schmidt, Abigail C. Allwood, H. E. F. Amundsen, R. Bhartia, Tanja Bosak, A. J. Brown, B. C. Clark, A. Cousin, O. Forni, T. S. J. Gabriel, Y. S. Goreva, Sanjeev Gupta, Svein‐Erik Hamran, C. D. K. Herd, Keyron Hickman‐Lewis, J. R. Johnson, Linda C. Kah, P. B. Kelemen, K. M. Kinch, Lucia Mandon, N. Mangold, Cathy Quantin‐Nataf, M. S. Rice, P. St. J. Russell, Sunanda Sharma, Sandra Siljeström, A. Steele, R. Sullivan, M. Wadhwa, B. P. Weiss, Amy J. Williams, Brittan Wogsland, Peter A. Willis, T. A. Acosta-Maeda, Pierre Beck, Karim Benzerara, Sylvain Bernard, Aaron S. Burton, Emily Cardarelli, Baptiste Chide, Elise Clavé, E. A. Cloutis, B. A. Cohen, Andrew D. Czaja, Vinciane Debaille, E. Dehouck, Alberto González Fairén, David Flannery, Stephanie Fleron, Thierry Fouchet, J. Frydenvang, Bradley Garczynski, Erin Gibbons, Elisabeth M. Hausrath, Alexander G. Hayes, Jesper Henneke, John Leif Jørgensen, Evan M. Kelly, J. Lasue, Stéphane Le Mouëlic, Juan Manuel Madariaga, S. Maurice, Marco Merusi, Pierre‐Yves Meslin, S. M. Milkovich, Chase Million, R. Moeller, Jorge I. Núñez, A. Ollila, Gerhard Paar, D. A. Paige, David A. K. Pedersen, P. Pilleri, C. Pilorget, P. Pinet
Abstract
The Perseverance rover landed in Jezero crater, Mars, to investigate ancient lake and river deposits. We report observations of the crater floor, below the crater's sedimentary delta, finding that the floor consists of igneous rocks altered by water. The lowest exposed unit, informally named Séítah, is a coarsely crystalline olivine-rich rock, which accumulated at the base of a magma body. Magnesium-iron carbonates along grain boundaries indicate reactions with carbon dioxide-rich water under water-poor conditions. Overlying Séítah is a unit informally named Máaz, which we interpret as lava flows or the chemical complement to Séítah in a layered igneous body. Voids in these rocks contain sulfates and perchlorates, likely introduced by later near-surface brine evaporation. Core samples of these rocks have been stored aboard Perseverance for potential return to Earth.