The result of U–Pb dating of minerals in a lunar meteorite, Kalahari 009 is reported. Analyses of five grains associated with basaltic clasts give an age of 4.35 ± 0.15 billion years. These are thought to represent the crystallization ages of parental basalt magma, making Kalahari 009 one of the oldest known mare basalt. This suggests that mare basalt volcanism on the Moon started as early as 4.35 billion years ago.
- Kentaro Terada
- Mahesh Anand
- Yuji Sano
