INSET: USGS IMAP 740: Geologic map of the Grimaldi quadrangle of the Moon

The Grimaldi quadrangle lies at the southwest margin of Oceanus Procellarum about 1,000 km east of Orientale, the youngest of the lunar multi-ringed basins. The distal ends of the ejecta blanket surrounding the Orientale basin partly covers the western third of the quadrangle. The relatively small, two-ring Grimaldi basin is in the northwest corner of the quadrangle, and the Humorum...