Open access Ultraviolet Photooxidation of Smectite‐Bound Fe(II) and Implications for the Origin of Martian Nontronites . V. B. Rivera Banuchi ,W. Liu ,N. Yee ,C. Legett ,T. D. Glotch ,S. M. Chemtob , First Published:?2 May 2022. Key Points . Ultraviolet (UV) irradiation of initially ferrous smectites of varying iron content p...