Two-billion-year-old volcanism on the Moon from Chang’e-5 basalts

Abstract

The Moon has a magmatic and thermal history that is distinct from that of the terrestrial planets1. Radioisotope dating of lunar samples suggests that most lunar basaltic magmatism ceased by around 2.9–2.8 billion years ago (Ga)2,3, although younger basalts between 3 Ga and 1 Ga have been suggested by crater-counting chronology, which has large uncertainties owing to the lack of returned samples for calibration4,5. Here we report a precise lead–lead age of 2,030 ± 4 million years ago for basalt clasts returned by the Chang’e-5 mission, and a 238U/204Pb ratio (µ value)6 of about 680 for a source that evolved through two stages of differentiation. This is the youngest crystallization age reported so far for lunar basalts by radiometric dating, extending the duration of lunar volcanism by approximately 800–900 million years. The µ value of the Chang’e-5 basalt mantle source is within the range of low-titanium and high-titanium basalts from Apollo sites (µ value of about 300–1,000), but notably lower than those of potassium, rare-earth elements and phosphorus (KREEP) and high-aluminium basalts7 (µ value of about 2,600–3,700), indicating that the Chang’e-5 basalts were produced by melting of a KREEP-poor source. This age provides a pivotal calibration point for crater-counting chronology in the inner Solar System and provides insight on the volcanic and thermal history of the Moon.

Cratering Records in the Chang'e‐5 Mare Unit: Filling the “Age Gap” of the Lunar Crater Chronology and Preparation for Its Recalibration

“…It is no surprise that the age of a certain surface sampling site will be under debate for years or decades. The situation may be similar with the Chang'e-5 samples, albeit some preliminary radio-isotopic ages around 2.0 Ga have been recently reported (Che et al, 2021;Li et al, 2021).…”

Chang’E-5 reveals the Moon's secrets to a longer life

“…The age on Zr-rich minerals from the Science study 2 agrees well with the robust 2,030 ± 4 Ma age. 3 Zirconium-bearing minerals were only <5 mm wide, thus the $3-mm spot size of one study, 3 compared with $7 mm in the other, 2 also provided additional accuracy by avoiding terrestrial, laboratory-derived Pb contamination along grain boundaries. Irrespectively, the two independent laboratories in Beijing arrived at indistinguishable ages within uncertainty.…”

“…The 2 Ga Chang'E-5 age squarely fills this gap and anchors the cratering chronology curve. 2,3 A mechanism for young volcanism Dating the youngest mare basalts thus begs the question of how volcanic activity on the Moon was sustained for so long. The small Moon is less than 30% the radius of Earth.…”

“…Nonetheless, three isotopic systems (U-Pb, Sm-Nd, and Rb-Sr) all consistently indicate that the young Chang'E-5 basalts formed by the melting of the lunar mantle. 3,4 How did the interior of the Moon keep warm for so long? On the same day as the second geochronology study, 3 two other studies were published in Nature 4,5 that investigated two possible mechanisms for how volcanic activity on the Moon lasted as late as 2 Ga.…”

“…3,4 How did the interior of the Moon keep warm for so long? On the same day as the second geochronology study, 3 two other studies were published in Nature 4,5 that investigated two possible mechanisms for how volcanic activity on the Moon lasted as late as 2 Ga.…”