In situ cosmogenic 53Mn production rate from ancient low-denudation surface in tropic Brazil

Abstract: Preliminary results of 53Mn measurements for seven Brazilian haematites are presented. The production rate of 53Mn due to cosmic-ray induced disintegration of iron is estimated to be 103±19 atoms g(Fe)-1 yr−1 at sea level and high latitude. This is consistent with the only previously published measurement. The muon contribution to the total 53Mn production at the surface is estimated to be ∼7%. Cosmogenic-isotope dating employing 53Mn is applicable to any rock/mineral type that contains iron as a major constituent, such as haematite, goethite, pyroxene and olivine. The method has the potential to extend the time scale of cosmogenic exposure dating to >10Ma. [Copyright &y& Elsevier]