Recent Tectonic Activity in and Around the Posidonius Crater, Moon

Abstract

Tectonic structures such as wrinkle ridges, lobate scarps, small-scale graben, and tectonic pits reveal the recent lunar activity and complex deformational processes. Despite numerous studies, the northeastern region of the Mare Serenitatis basin, including the Posidonius crater, has yet to be studied in detail. This research presents a comprehensive analysis of tectonic structures in this region, revealing ∼808 km of wrinkle ridges, ∼286 km of lobate scarps, ∼346 km of small-scale graben, and ∼269 tectonic pits. We identified 412 craters deformed by wrinkle ridges, 55 craters by lobate scarps, and 108 craters by small-scale graben, suggesting extensive recent deformation. Chronological analysis of wrinkle ridges and lobate scarps revealed young ages ranging from ${\sim 29}_{-9}^{+10}$ Ma to ∼120 ± 30 Ma close to the crater, whereas Posidonius crater resurfaced floor age tend to $\sim {2.8}_{-0.5}^{+0.4}$ Ga. Our study suggests that the blind thrust fault deformed the western floor of the Posidonius crater, with small-scale graben with pits plausibly developed during the reactivation. Orthogonal transitions that occur between adjacent wrinkle ridges and lobate scarps in the study area could be a splay fault of the blind thrust fault and likely formed during the reactivation. This reactivation plausibly resulted from a combination of recession stresses, diurnal tidal stresses, and global contraction. Additionally, a combination of complex processes─intrusion, subsidence, and tectonics associated with the blind thrust fault plausibly influenced Rima Posidonius. Overall, this study suggests that the northeastern region of the Mare Serenitatis basin witnessed recent tectonic activity and could be a potential site for future exploration missions.