Abstract The mantle source and formation mechanism of the recently discovered ∼120 Ma lunar volcanic glass beads (VGBs) in Chang’e‐5 samples remain elusive. By systematically comparing the compositions of ∼120 Ma VGBs with those of ancient Apollo VGBs, we propose a distinctive metasomatized mantle source characterized by low‐Ti but enriched in Na2O, K2O, and incompatible trace elements. Modeling of multiple saturation points suggests an olivine‐orthopyroxene‐dominated mantle source partially molten at 7.7–15.2 kbar and 1,387–1,448°C. The metasomatism of highly evolved ∼2.0 Ga Chang’e‐5 basalt in the mantle source is the most plausible scenario for the unique composition of ∼120 Ma VGBs. Radiogenic heating simulations indicate that the prolonged accumulation of radiogenic heat from unerupted and highly evolved Chang’e‐5 basalt‐like materials within mantle source could create localized thermal anomalies, triggering partial melting of the metasomatized mantle. This model shed new lights on the mechanism sustaining lunar volcanic activity.
Observations from the Little Bunker
Last updated: August 18, 2025 04:13 PM
Atmospheric CO₂
425.4 ppm
+18.4
ppm/year
Atmospheric CH₄
1934.91 ppb
+9.11
ppb/year
Global Temperature
+1.48 °C
Peak: +1.73°C
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8.1 billion
+67
million/year