Planetary surface dating from crater size–frequency distribution measurements: Multiple resurfacing episodes and differential isochron fitting

The analysis of crater size–frequency distributions and absolute densities forms the basis of current approaches for estimating the absolute and relative ages of planetary surfaces. Users of the Neukum system of crater dating have conventionally used a cumulative presentation of the data, but because of the recent proliferation of interest in identifying resurfacing ages, it is worth emphasising the utility of the differential presentation of crater data in identifying resurfacing events and, particularly, in distinguishing the signature of short-lived events, such as volcanic flows, from long-acting processes, such as aeolian erosion. rk describes some additional considerations for making isochron fits to differentially plotted crater populations with respect to the removal of a binning bias for incrementally/differentially plotted data. rtmann approach has not typically employed the fitting of isochrons, but differential fitting would be a natural choice for this system, and is implemented in the Craterstats software. sed calculation of the martian epoch boundary times in both chronology systems is provided.