Structural control of scarps in the Rembrandt region of 3 Mercury 4 5

1 Lobate scarps, thought to be the surface expression of large thrust faults, are the 2 most spectacular contractional tectonic features visible on Mercury. Most lobate scarps 3 follow a general and relatively simple pattern, with a roughly arcuate or linear form in plan 4 view, and an asymmetric cross section characterized by a steeply rising scarp face and a 5 gently declining back scarp. In this work, we study two peculiar and complex scarps in the 6 Rembrandt region of Mercury through MESSENGER imagery. On the one hand, the 7 formation of these scarps resulted in the deformation of features such as impact craters, 8 fractures, extensional faults, and volcanic plains, while on the other hand, the deformed 9 features partly influenced the formation of the scarps. Evidence for structural control on the 10 formation of the scarps includes their orientation, segmentation, bifurcation, change in 11 structural trend and dip orientation, and transition into high-relief ridges or wrinkle ridge 12 morphologies in some cases. Thus, these two lobate scarps provide examples of complex 13 geological relations among other features, expanding the recognized richness of mercurian 14 geology. Also, the southern scarp records a complex history of contraction, suggesting that 15 the development of some mercurian lobate scarps may be more complex than usually 16 thought. 17