The South Pole-Aitken (SPA) is the largest and deepest basin on the Moon, theoretically opening a window into the lunar lower crust and likely into the upper mantle. However, compositional information of the SPA basin was mainly obtained from orbital remote sensing. Chang’E-4 landed in the SPA Basin, providing a unique chance for in situ probing the composition of the lunar interior. The landing site is located on ejecta strips radiating from Finsen crater, which lies ~135 km to the northeast. The lunar surface at the landing site consists of a very homogenous regolith overlain by few scattered rocks.
Source:
https://phys.org/news/2019-11-olivine-norite-yutu-crystallized-spa-impact.html