9621 Agnes Crossing, Lake Suzanneview, New Mexico Island 84604-9295.
Examining lunar samples from the Aitken Basin on the far side of the South Pole, researchers discovered significant differences in volcanic activity and crustal properties between the two
Examining lunar samples from the Aitken Basin on the far side of the South Pole, researchers discovered significant differences in volcanic activity and crustal properties between the two sides of the moon. These new findings shed light on the Moon’s geological history and improve methods for dating lunar craters.
The Moon exhibits a striking global dichotomy: its near and far sides differ in geomorphology, topography, chemical composition, crustal thickness, and volcanic activity.
To further investigate this contrast, Professor Egan Xu from the Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, and his team examined lunar soil samples collected from the South Pole-Aitken Basin (SPA) on the far side. These samples were obtained by the Chang’e-6 mission.
Their findings were published at: Science 15 November.
“The samples returned by Chang’e-6 offer the best opportunity to investigate the global dilemma of the moon,” said Professor Xu.
Volcanic activity shaped much of the lunar surface, with lava flows forming rocks called mare basalts. They are much more abundant on the near side, where they cover about 30% of the surface compared to only 2% on the far side. To fully understand this dilemma, it is important to examine samples taken from both sides of the Moon.
Chang’e-6 lunar soils contain two types of basalt: low titanium and very low titanium (VLT). The dominant low titanium basalt represents the local basalt unit around the settlement, while the VLT basalt may have been derived from a unit east of the settlement (Figure 1B).
High-precision Pb-Pb dating of Zr-bearing minerals and Rb-Sr dating of plagioclase and late-stage mesostasis of low-titanium basalts yield isochron ages corresponding to 2.83 Ga (Figure 2), indicating that “younger magmatism also occurred” . According to research, it is on the far side of the moon.
Compared to near-side samples returned by the Apollo and Chang’e-5 missions, the low titanium basalt of Chang’e-6 has a low μ value and 87Mr/86 Sr and a very high value of εNd (Fig. 3).), which indicates a very depleted mantle source.
The thickness of the Earth’s crust has been suggested as an important factor in explaining the asymmetry in the abundance of volcanism between the near and far sides of the Moon. However, this model has been questioned because the far-side SPA basin, which has an abnormally thin crust, appears to be a deep and significantly underfilled volcanism.
Based on the study of low titanium basalt Chang’e-6, Xu’s team suggested that the composition of the mantle source is another important factor controlling the occurrence of volcanic activity on the moon.
“Although the SPA basin has a thin crust, the depleted and resilient mantle resource beneath the SPA basin largely prevents partial melting,” Xu said. he said.
This study also provides an additional calibration point for lunar crater chronology at 2.83 billion years ago and suggests a steady flow of collisions from 2.83 billion years ago onwards. This new calibrated chronology model improves the age estimation tool based on cratering statistics for both the Moon and other terrestrial bodies, and also has additional implications for the evolution of Moon impactors, potentially related to early planetary migration in the early Solar System.
Source: Port Altele
As an experienced journalist and author, Mary has been reporting on the latest news and trends for over 5 years. With a passion for uncovering the stories behind the headlines, Mary has earned a reputation as a trusted voice in the world of journalism. Her writing style is insightful, engaging and thought-provoking, as she takes a deep dive into the most pressing issues of our time.
