Geomorphological and mineralogical analysis of the lunar Robertson crater

Abstract

This study provides a comprehensive overview of the lunar Robertson crater of Copernican period located on the far side of the moon using multi-sensor satellite observations from combined Chandrayaan-I M3, LROC WAC Global Geomorphology and SELENE DTM mosaics. The analysis shows development of dynamic features, distribution of minerals, and topographic features during the crater formation. The crater preserves a complex geological evolution based on the mineralogical heterogeneity and distinct geomorphological features (such as accumulated melt flow at the crater floor, topographic undulations etc.) observed in a radial symmetry, which suggest formation through high energy impact processes. The detailed investigation of melt pool topography at the crater floor, highlights the formation and subsequent modifications of the transient cavity developed during simple to complex crater transition after the impact. The mineral species identified using the RELAB spectral library through the ‘spectral hourglass’ workflow show a distinct distribution, with Mg-spinel and olivine-rich lithologies concentrated in the central peak, while pyroxenes dominate the crater floor and surrounding rock rings. This pattern shows a complex mineral distribution, likely excavated from different depths as a result of the impact event. The dynamics of crater formation show a diameter respectively of 4.36 km and 5.73 km, assumed for chondrite and iron projectiles. Besides, CSFD measurements represent an absolute age of about 82 ± 4 Ma based on the 121 isochron fits to the differential data of post-impact craters that suggests recent resurfacing consistent with melt flow during the terminal stages of impact dynamics.