The effects of the target material properties and layering on the crater chronology: the case of Raditladi and Rachmaninoff basins on Mercury

TL;DR

This study determines the ages of Raditladi and Rachmaninoff basins on Mercury using crater chronology, revealing their relatively young ages and suggesting recent volcanic activity, while emphasizing the importance of target layering in age estimates.

Contribution

It introduces a method to incorporate terrain layering and properties into crater-based age determination for planetary surfaces.

Findings

Rachmaninoff basin age ~3.6 Ga

Raditladi basin age ~1.1 Ga

Evidence of recent volcanic activity on Mercury

Abstract

In this paper we present a crater age determination of several terrains associated with the Raditladi and Rachmaninoff basins. These basins were discovered during the first and third MESSENGER flybys of Mercury, respectively. One of the most interesting features of both basins is their relatively fresh appearance. The young age of both basins is confirmed by our analysis on the basis of age determination via crater chronology. The derived Rachmaninoff and Raditladi basin model ages are about 3.6 Ga and 1.1 Ga, respectively. Moreover, we also constrain the age of the smooth plains within the basins' floors. This analysis shows that Mercury had volcanic activity until recent time, possibly to about 1 Ga or less. We find that some of the crater size-frequency distributions investigated suggest the presence of a layered target. Therefore, within this work we address the importance of considering terrain parameters, as geo-mechanical properties and layering, into the process of age determination. We also comment on the likelihood of the availability of impactors able to form basins with the sizes of Rachmaninoff and Raditladi in relatively recent times.