GEOLOGIC AND GEOMORPHOLOGICAL INTERPRETATION OF THE MARE ORIENTALE IMPACT BASIN REGION OF EARTH’S MOON

The Mare Orientale impact basin is a multi-ring impact structure located in the Southern equatorial region of Earth’s Moon and covers 2.48 million square kilometers of the lunar surface. The rocks in the area are composed of basaltic lava flows and basement rock displaced by impact events that range in age from 4.5 to 1 Ga. This vast history makes the geology and geomorphology of the area broadly defined, with multiple lava flows, craters, and ejecta blankets from over one hundred geologic events.

In order to interpret the geology of the area, multiple datasets were compiled in ArcMap and ArcGIS Pro. The topography of the region was constructed by the combination of two high-resolution lunar digital elevation model from the NASA Goddard Space Flight Center using the Lunar Orbiter Laser Altimeter and SELENE Terrain Camera. From the digital elevation model, a hillshade map of the area was constructed to visually convey the topographic complexity of the surface. Analyses of the Unified Geologic Map of the Moon from the United States Geological Survey Astrogeology Science Center provided data used to determine lithology and ages of the geologic formations in the area. These data allowed for a more informed cartography based on age relationships and morphology. The union of the topography and Unified Geologic Map of the Moon were used to construct a hypothesized geologic cross-section of the multi-ringed impact basin. The asymmetric ejecta blanket boundaries provided the key to understanding the subsurface structure of the basin, as well as the hypothesized trajectory of the meteorite that created the Mare Orientale impact basin.