A SPECTRUM OF TECTONISED BASIN EDGES ON MERCURY.

Lobate scarps on Mercury are generally accepted as being surface expressions of thrust faulting. This is taken as evidence of litho-spheric contraction on a global scale, reflecting either global cooling, leading to thermal contraction and internal phase changes; or tidal despinning, leading to collapse of an equatorial bulge; or a combination of both. It has been further suggested that the orientations of lobate scarps could reflect a pattern of mantle convection. Here we describe compressional tectonics local-ized along the interface between basin-fill and the inner walls of >200 km diameter impact basins. These are considerably larger than the ghost craters with deformed rims that have been the focus of other stud-ies . We draw attention to several ex-amples of outward-directed thrust faults following the inside of basin rims, mostly un-remarked in a global survey of >300 km basins by Fassett et al. 201