Morphostructural mapping of Borealis Planitia, Mercury

Orbital data from the MESSENGER spacecraft show that a significant portion of Mercury's northern hemisphere is covered by smooth plains, which are interpreted to be flood volcanic material and/or impact melt. The smooth plains show pervasive tectonic structures and encompass a broad raised bulge of uncertain geophysical interpretation. In this work, we focus on the mapping of all the morphostructures within the northern smooth plains, aiming at providing a useful dataset for further studies about the mapped area. The structural map is obtained through a twofold process: first with an automatic mapping, using an algorithm to identify all the lineaments from a DEM; and second with a visual inspection and classification of the results of the algorithm in a GIS environment. The final maps are drafted at two different scales, 1:300,000 and 1:600,000. With this approach, we mapped and characterized more than fifty thousand lines marking scarps on the surface, creating a database with several morphometric attributes for each of the identified scarps (e.g. length, azimuth, and height), which can be used for geostatistical study of smooth plains tectonics. Our structural map reveals that: (i) the area is broadly dominated by wrinkle ridges, ghost crater assemblages of lineaments, and scarps related to impact crater processes (e.g. radial faults, secondary crater chains, ejecta emplacement) and that (ii) the amount of strain was not evenly accommodated throughout the northern smooth plains.

Automated summary

Orbital data from the MESSENGER spacecraft reveals that a considerable portion of Mercury's northern hemisphere is covered by smooth plains, which are believed to be volcanic or impact melt material. Through a twofold process involving automatic mapping and visual inspection, a structural map of the northern smooth plains was created, detailing the various morphostructures including wrinkle ridges, ghost crater assemblages, and scarps related to impact crater processes. The mapping effort resulted in the identification and characterization of over fifty thousand scarps, each with their own morphometric attributes, providing valuable data for further geostatistical studies of smooth plains tectonics.