Magnetochemistry of the Apollo landing sites

A coherent magnetochemical picture of lunar samples is presented which was determined from a synthesis of available magnetic-property data and corresponding chemical and petrographic data for soils and rock samples collected at the Apollo landing sites. The magnetic properties of the samples are correlated with Al/Si ratio as well as with telescope spectral reflectivity curves, and magnetochemical diagrams based on composition-sensitive magnetic parameters describing the Fe metal and Fe(2+) contents are used to classify the samples. It is shown that the relative metal-fraction size distribution and magnetic stability for different rock types and soils of varying Al/Si values are reflected in a plot of the ratio of saturation isothermal remanence to saturation magnetization vs the ratio of remanent coercive force to coercive force. It is concluded that all the Apollo landing sites have distinct telescope curves correlated with petrology, chemistry, Al/Si values, and magnetic properties. The established correlations suggest the possibility of estimating the magnetic properties of the regolith from remote-sensing observations.