Age determination of linear surface features using the Buffered Crater Counting approach - Case studies of the Sirenum and Fortuna Fossae graben systems on Mars

Our case studies showed that the BCC approach provides equivalent or even more precise age results compared to the conventional stratigraphic approach. Here, we found that the investigated section of Sirenum Fossae is younger than previously thought. The derived formation age from the BCC analysis is 3.44-0.25+0.1Ga which corresponds to Late instead of Early Hesperian. Fortuna Fossae formed shortly after the emplacement of its now-fractured geologic host unit (Late Hesperian). Ages derived from BCC analysis vary between 3.53-0.11+0.06Ga and 3.50-0.11+0.07Ga. Furthermore, we recommend the use of crater ejecta blankets to position them in the stratigraphic sequence in order to improve crater statistics. However, the accuracy of the results depends on the extent and preservation state of the continuous ejecta blankets in the region of interest. Thus, the applied buffer width has to be chosen carefully according to investigated crater sizes and local observations.