Reporters learned from the University of Science and Technology of China, the university’s school of earth and space science Professor Huang Fang team set up a high-precision copper-zinc isotope analysis method, on the basis of cooperation with foreign counterparts, through high temperature and high pressure experimental lithography, accurately determined the copper and zinc isotope balance coefficient between silicate melt and metal melt, and its constraints on the composition and formation of the moon’s core. The results of the study were published in the international geochemistry journal Geochemistry Vision Newsletter.
The Great Collision hypothesis holds that the moon was formed from a Mars-sized planet and a large collision between the primitive Earth 4.5 billion years ago. After the collision, the material splashes into space, gathers in the lunar orbit to form a hot melting lunar magma ocean, from which the structure of the moon’s nucleus, lunar crust, and the moon’s crust is separated. It is generally believed that the volatile effect of a major collision alters the elements and isotope composition of the moon, but little is known about the separation of the lunar ring, especially the process of lunar nuclear formation, mainly due to a lack of understanding of the behavior of elements and isotope geochemicals.
Copper (Cu) and zinc (Zn) are both volatile elements, which can limit the volatile effect during collision, and pro-iron-pro-sulfur elements, as well as nuclear-tidium-separation processes. Therefore, it can be used to explore the effects of lunar nuclear separation on the chemical composition of the moon.
It was found that sulfur-containing metal melts were significantly rich in light copper and zinc isotopes compared to silicate melts, while the fractionation between sulfur-free metal melts and silicate melts was smaller. The results are a good illustration of the difference in the composition of metal stable isotopes between the Earth and the moon. Large zinc isotope fractionation between months and ground clearly reflects the effects of the volatile process; although copper is less volatile than potassium and calcium, the difference in copper isotope composition between the moon and the ground is greater than that of potassium and calcium isotopes. This may be because the moon’s copper isotope composition is not only controlled by the volatile effect of a major collision, but also by the separation of sulfur-containing metal melts from the moon’s magma ocean when the moon’s nucleus is formed;