https://agupubs.onlinelibrary.wiley.com/doi/epdf/10.1029/2020JE006589, this reference paper cited in the space.com report is very interesting reading. I note some comments.
".2. Background 2.1. Formation of the Lunar Crust and Mantle from a Magma Ocean The early Moon is thought to have formed from a giant impact with the Earth, and its current crust and mantle are products of a global magma ocean. Estimates of the magma ocean's depth range from several hundred km to the entire Moon (e.g., Steenstra et al.,2020; Wood etal.,1970). As the LMO cooled, minerals fractionally crystallized in a specific sequence depending on melt composition, pressure, oxygen fugacity, and temperature...The thorium anomaly across SPA reflects emplacement of deep SPA ejecta: Integrating elemental abundances with mineralogy, impact models, and geologic context, it was demonstrated that the Th enhancement associated with the South Pole-Aitken Basin is the result of SPA ejecta sourced from ~50–100 km beneath the preimpact surface. The pattern of Th abundance across SPA reflects the distribution of the SPA ejecta blanket convolved through ~ 4 billion years of subsequent geologic processing including impact cratering, volcanic resurfacing, and regolith development. These observations are inconsistent with previous hypotheses for the SPA Th anomaly including localized volcanic emplacements, Mg-suite intrusions, and antipodal basin ejecta...Because this downwelling is thought to occur during or shortly after LMO crystallization (within ~10 Myr), this places tight constraints on the timing of SPA formation relative to this sequence. Alternatively, this may reveal an underestimate in the timescale of cumulate mantle overturn, or imply that overturn did not occur or was not completely efficient in redistributing and sequestering late magma ocean cumulates in the deep lunar interior"
Various timescales used to create the Moon from the giant impact and subsequent evolutionary events that follow, are difficult to determine here. The giant impact model for the origin of the Moon features a proto-Moon forming near the Roche limit of some 3 earth radii or so and a proto-earth that is spinning much faster than the Earth's 24 hour length of day today. Some reports suggest less than 6 hour day, others suggest 1.5 hour day. The Moon's lunar period is much shorter too, <= 21 hours. *Tight constraints* should apply to all of the postulated lunar evolutionary model used to explain our origins today.
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