On the provenance of the Chang'E-5 lunar samples

China's Chang'E-5 (CE-5) mission has collected 1.731 kg samples from a young mare basalt unit (named P58/EM4) in the northeastern Oceanus Procellarum region of the Moon. Accurate tracing of the provenance of returned samples is essential for understanding their laboratory measurements, which can provide critical information about the Moon and the inner Solar System. In this article, the provenance, chemical composition, formation, and evolution processes of the regolith at the CE-5 landing site are analyzed by using remote sensing observations and crater ejecta deposition models. A comprehensive search based on crater ejecta thickness model shows that 1892 impact craters in P58 likely deposited similar to 0.56 m of primary ejecta at the landing site, whereas 4 impact craters outside P58 deposited similar to 0.05 m of distal ejecta that further excavated and reworked similar to 0.5 m thick local mare basalt. Twelve craters within 1 km from the CE-5 landing site are estimated to contribute similar to 0.49 m (similar to 88%) of the ejecta materials, and their ejecta source regions are investigated using the Maxwell Z model. Among these 12 craters, Xu Guangqi and a smaller crater near the landing site are the two most volumetrically significant contributors (similar to 0.3 m and similar to 0.12 m). Craters more than 1 km distant from the landing site deposited fewer exotic materials, but some of them could have delivered low-Ti materials to the sampling site. Finally, the regolith stratigraphy at the landing site is investigated based on the identified and assumed impact sequence by using a Monte Carlo-based ejecta ballistic sedimentation model. The results reveal a depth-varying FeO/TiO2 abundance profile at the landing site, suggesting that the sedimentation of distant ejecta can reduce FeO/TiO2 abundance of the underlying layer by similar to 1 wt.% at similar to 0.5 m depth. Our results provide key information on sample provenance and regolith stratigraphy of the landing site, which is crucial to deciphering the returned CE-5 samples. (C) 2022 Elsevier B.V. All rights reserved.