Qiao et al., Sosigenes pit crater age 1 2 The role of substrate characteristics in producing anomalously young crater 3 retention ages in volcanic deposits on the Moon: Morphology, topography, 4 sub-resolution roughness and mode of emplacement of the Sosigenes Lunar 5 Irregular Mare Patch (IMP) 6 7 Le QIAO1,2,*, James W. HEAD2, Long XIAO1, Lionel WILSON3, and Josef D. 8 DUFEK4 9 1Planetary Science Institute, School of Earth Sciences, China University of 10 Geosciences, Wuhan 430074, China. 11 2Department of Earth, Environmental and Planetary Sciences, Brown University, 12 Providence, RI 02912, USA. 13 3Lancaster Environment Centre, Lancaster University, Lancaster LA1 4YQ, UK. 14 4School of Earth and Atmospheric Sciences, Georgia Institute of Technology, Atlanta, 15 Georgia 30332, USA. 16 *Corresponding author E-mail:
[email protected] 17 18 19 20 Key words: Lunar/Moon, Sosigenes, irregular mare patches, mare volcanism, 21 magmatic foam, lava lake, dike emplacement 22 23 24 25 1/51 Qiao et al., Sosigenes pit crater age 26 Abstract: Lunar Irregular Mare Patches (IMPs) are comprised of dozens of small, 27 distinctive and enigmatic lunar mare features. Characterized by their irregular shapes, 28 well-preserved state of relief, apparent optical immaturity and few superposed impact 29 craters, IMPs are interpreted to have been formed or modified geologically very 30 recently (<~100 Ma; Braden et al. 2014). However, their apparent relatively recent 31 formation/modification dates and emplacement mechanisms are debated. We focus in 32 detail on one of the major IMPs, Sosigenes, located in western Mare Tranquillitatis, 33 and dated by Braden et al.