Hyperfine Interact (2008) 182:87–101 DOI 10.1007/s10751-008-9714-9 Mössbauer spectroscopy of magnetic minerals in basalt on Earth and Mars H. P. Gunnlaugsson · H. Rasmussen · L. Kristjánsson · S. Steinthorsson · Ö. Helgason · P. Nørnberg · M. B. Madsen · S. Mørup Published online: 4 October 2008 © Springer Science + Business Media B.V. 2008 Abstract Mössbauer spectroscopy of iron–titanium containing spinel phases is re- viewed. New techniques are presented for determination of their composition us- ing room-temperature Mössbauer spectroscopy. An example of thermal alteration processes is described. The speciality of olivine-containing basalt is briefly discussed with regard to its magnetic properties. Keywords Basalt · Mössbauer spectroscopy · Titanomaghemite 1 Introduction Mössbauer spectroscopy has proved to be a valuable tool in geology giving informa- tion about various aspects of the iron mineralogy that in turn can provide insight into H. P. Gunnlaugsson (B ) Department of Physics and Astronomy, Aarhus University, Ny Munkegade, 8000 Århus C, Denmark e-mail: hpg@phys.au.dk H. Rasmussen · P. Nørnberg Department of Earth Sciences, Aarhus University, Ny Munkegade, 8000 Århus C, Denmark L. Kristjánsson · S. Steinthorsson · Ö. Helgason Science Institute, University of Iceland, Dunhaga 3, 107 Reykjavík, Iceland M. B. Madsen Earth and Planetary Physics, Niels Bohr Institute, University of Copenhagen, Juliane Maries Vej 30, 2100 Copenhagen Ø, Denmark S. Mørup Department of Physics, Technical University of Denmark, Building 307, 2800 Kgs. Lyngby, Denmark