Volcanism along the rings of the Crisium Basin on the Moon: Insights from M3 onboard Chandrayaan - 1

The Crisium Basin (17.0°N, 59.1°E) is a Nectarian multi-ring basin hosting extensive volcanism inside the basin center and along its four rings. The Crisium Basin is an essential proxy for understanding basin-related magmatic activity on the Moon. A detailed stratigraphy and chronology have been established for the Mare Crisium in several earlier studies. However, there has been no comprehensive study regarding the composition and emplacement timescales of the basalts along the rings of the Crisium Basin. The basalts along the rings of the Crisium Basin have been emplaced within Mare Undarum, Mare Spumans, Mare Anguis, Cleomedes Crater, and Lacus Bonitatis. Our recent study identified Marginis West as an episode of volcanism along the outermost ring of the Crisium Basin. This study, for the first time, examines the compositional diversity and ages of the basalts emplaced along the rings of the Crisium Basin to better understand its geological evolution. We report the youngest volcanic unit emplaced inside the Crisium Basin at ∼2.0 Ga inside Mare Anguis. Based on the spectral signatures, we report that the contemporaneously formed mare units within the Crisium Basin are compositionally different, displaying a westward increase in Ca, and large pre-existing crustal structures would have deeply influenced the volcanism within the basin in the region.