Lagain A. auteur aut IRD Bouley S. auteur aut IRD Baratoux David auteur aut IRD Costard F. auteur aut IRD Wieczorek M. auteur aut IRD text journalArticle eng text/pdf born digital access Ages of geological units of planetary bodies are determined from impact crater counts on their surface. These ages are model-dependent, and several models largely used in the community assume a constant production function and a constant cratering rate over the last 3 Ga. We have mapped the population of small impact craters (>200 m in diameter) formed over a population of large impact craters (>5 km in diameter) with layered ejecta on Acidalia Planitia, Mars. We have deduced the age of each large impact crater under the assumption of a constant impact rate and constant production function. The impact rate inferred from this set of ages is, however, not constant and show a significant increasing during the last similar to 1 Ga compared to chronology models commonly used. We interpret this inconsistency as an evidence for temporal variations in the size-frequency distribution (SFD) of impactors in the main belt, consistent with recent studies argued for a late increasing of the large impactor flux on Earth and the Moon. specialized Impact craters Mars Impact rate Layered ejecta craters 060 020 180 art. 104755 [11 p.] 2020 0032-0633 https://www.documentation.ird.fr/hor/fdi:010077879 10.1016/j.pss.2019.104755 0032-0633 [F B010077879] https://www.documentation.ird.fr/hor/fdi:010077879 https://www.documentation.ird.fr/intranet/publi/2020/02/010077879.pdf Accès réservé (Intranet de l'IRD) IRD - Base Horizon / Pleins textes 2020-03-11 2025-02-24 fdi:010077879 fre