Extended Data Fig. 6: An anchor point for the early lunar impact flux by the Apollo basin.
From: KREEP-like lithologies in the South Pole–Aitken basin reworked by the Apollo basin impact at 4.16 Ga
The new calibration point of lunar impact flux based on the isotopic age of the Apollo basin and the representative crater density at the Apollo basin (red dot; see Methods). The classic crater chronology model42 (black line) and a recently updated version using the calibration point established for the CE-560,73 and CE-6 mare basalts20 (red line) are shown for comparisons. Calibration points (blue dots) are established from Apollo and Luna samples include crater densities59,74, and radiometric ages61. The production densities use the N(1) value, which is the spatial density of craters with diameters of ≥1 km per square kilometer.
