Etude par la méthode des traces nucléaires du sol de la Mer de la Fécondité (Luna 16)

Assuming an age for the basalts of Mare Fecunditatis of ~3.45 × 109 yr (papanastassiou and Wasserburg, 1972), the track-density levels observed in the basaltic fragments can well be explained according to the model of Comstocket al. (1971). On the other hand, in order to account for the very high track densities observed in the Luna 16 anorthites and those reported for the Apollo 15 long drill stem by crozazet al. (1972) the model would require a rate of solar flare activity much higher during the period 4.6-3.5 × 109yr than that observed today.