Surges in volcanic activity on the Moon about two billion years ago

The history of mare volcanism critically informs the thermal evolution of the Moon. However, young volcanic eruptions are poorly constrained by remote observations and limited samples, hindering an understanding of mare eruption flux over time. The Chang'e-5 mission returned the youngest lunar basalts thus far, offering a window into the Moon's late-stage evolution. Here, we investigate the mineralogy and geochemistry of 42 olivine and pyroxene crystals from the Chang'e-5 basalts. We find that almost all of them are normally zoned, suggesting limited magma recharge or shallow-level assimilation. Most olivine grains record a short timescale of cooling. Thermal modeling used to estimate the thickness and volume of the volcanism sampled by Chang'e-5 reveals enhanced magmatic flux similar to 2 billion years ago, suggesting that while overall lunar volcanic activity may decrease over time, episodic eruptions at the final stage could exhibit above average eruptive fluxes, thus revising models of lunar thermal evolution.

Automated summary

This study investigates the mineralogy and geochemistry of lunar basalts from the Chang'e-5 mission, revealing limited magma recharge or shallow-level assimilation in most crystals. Thermal modeling shows an enhanced magmatic flux around 2 billion years ago, suggesting episodic eruptions at the final stage could have above average eruptive fluxes, revising models of lunar thermal evolution.