Portal de Periódicos da CAPES

Non-KREEP origin for Chang’e-5 basalts in the Procellarum KREEP Terrane

2021; Nature Portfolio; Volume: 600; Issue: 7887 Linguagem: Inglês

10.1038/s41586-021-04119-5

1476-4687

Heng‐Ci Tian, Hao Wang, Yi Chen, Wei Yang, Qin Zhou, Chi Zhang, Honglei Lin, Chao Huang, Shitou Wu, Lihui Jia, Lei Xu, Di Zhang, Xiaoguang Li, Rui Chang, Yue‐Heng Yang, Lie‐Wen Xie, Dan‐Ping Zhang, Guangliang Zhang, Saihong Yang, Fu‐Yuan Wu,

Geology and Paleoclimatology Research

Mare volcanics on the Moon are the key record of thermo-chemical evolution throughout most of lunar history1-3. Young mare basalts-mainly distributed in a region rich in potassium, rare-earth elements and phosphorus (KREEP) in Oceanus Procellarum, called the Procellarum KREEP Terrane (PKT)4-were thought to be formed from KREEP-rich sources at depth5-7. However, this hypothesis has not been tested with young basalts from the PKT. Here we present a petrological and geochemical study of the basalt clasts from the PKT returned by the Chang'e-5 mission8. These two-billion-year-old basalts are the youngest lunar samples reported so far9. Bulk rock compositions have moderate titanium and high iron contents with KREEP-like rare-earth-element and high thorium concentrations. However, strontium-neodymium isotopes indicate that these basalts were derived from a non-KREEP mantle source. To produce the high abundances of rare-earth elements and thorium, low-degree partial melting and extensive fractional crystallization are required. Our results indicate that the KREEP association may not be a prerequisite for young mare volcanism. Absolving the need to invoke heat-producing elements in their source implies a more sustained cooling history of the lunar interior to generate the Moon's youngest melts.