Fig. 2
Morphologically different terrains and the new division of geological units in the study area. (a) Geological units defined in our study and their absolute model ages (see Fig. 3). Unit boundaries of Av, AHv, lHt, and lHl are from Tanaka et al.13, with lHl unit further divided into HNlsm and HNldm and lHt renamed as lNt based on AMA analysis and distribution of geomorphological features; (b) map of pitted-cone density, polygonal troughs, and etched flows; (c) MOLA elevation map58, (d) map of crater density, pancake-like and rampart craters; (e) THEMIS-IR mosaic of night-time images (100 m/pixel)61. The software ArcGIS 10.1 (https://www.esri.com/) was used to create the maps in the figure.
