Scientists have discovered that magma deep within Earth can store significantly more oxygen than previously believed, challenging assumptions about the planet’s geological and atmospheric history. The research, led by teams from HPSTAR and Northwestern Polytechnical University, involved high-pressure experiments revealing that magma can absorb excess oxygen under extreme conditions.
High-Pressure Experiments Reveal Oxygen Storage Capacity
Experiments conducted by researchers at the Center for High Pressure Science and Technology Advanced Research (HPSTAR) and Northwestern Polytechnical University demonstrated that molten rock can absorb additional oxygen beyond its chemical composition. By heating synthetic basalt to 1200 to 1800 °C and pressures up to 7 gigapascals—the team found that magma retained 5.2% excess oxygen by weight at extreme conditions. This contrasts with control experiments without added oxygen sources, which showed lower levels of excess oxygen. The study, published in National Science Review, used piston-cylinder and cubic presses to replicate deep-Earth conditions.
The samples were subjected to pressures from standard atmospheric levels up to 7 gigapascals and temperatures ranging from 1200 to 1800 °C. After cooling the samples into glass, the team measured their chemical composition. Oxygen moved from a separate reservoir into the melt until the modeled system reached equilibrium, with simulated excess oxygen increasing from about 0.33% at atmospheric pressure to 2.12% at nine gigapascals. The study’s authors include Ho-Kwang Mao and Yanhao Lin of HPSTAR, Haiyang Niu of Northwestern Polytechnical University, Wim van Westrenen of Vrije Universiteit Amsterdam, Ruiheng Liu, and Peiyan Wu.
The research highlights that oxygen makes up more than half the atoms in Earth’s silicate interior. Simulations showed oxygen atoms forming peroxide-like bonds, altering the melt’s electronic properties.
Implications for Earth’s Atmospheric History
The findings suggest that magma could have transported oxygen from Earth’s interior to the surface, potentially influencing the planet’s atmospheric evolution. Researchers propose that rising magma might have released oxygen as pressure decreased, oxidizing the shallow mantle, crust, and atmosphere. This mechanism might account for a temporal overlap in Earth’s history: significant spikes in atmospheric oxygen around 2.5 to 2.0 billion years ago coincided with the formation of major large igneous provinces (LIPs). An approximate calculation indicates that if magma from that era emitted 0.27% of its mass as surplus oxygen, it might have provided the same amount of oxygen present in today’s atmosphere.
However, the research does not establish how much oxygen natural magmas carry or how much reaches the atmosphere.
Broader Cosmic Implications
The discovery has implications with implications for magma oceans, planetary differentiation and the atmospheres of other rocky worlds. The study also challenges existing models of magma oceans and volcanic degassing, suggesting that oxygen dynamics may have played a critical role in planetary evolution. According to SOURCE 3, the study highlights a possible significant transport mechanism whose impact still needs to be quantified, with consequences for magma oceans, planetary differentiation, and the atmospheres of other terrestrial planets.
While further research is needed to establish how much oxygen natural magmas carry and how much reaches the atmosphere, the findings open new avenues for exploring Earth’s geological history and the conditions necessary for life. The Center for High Pressure Science and Technology Advanced Research receives funding from the National Natural Science Foundation of China (U1530402 and U1930401). The collaboration involved researchers from HPSTAR, Northwestern Polytechnical University, and Vrije Universiteit Amsterdam, with the study credited to Yongjiang Xu, Haiyang Niu, Wim van Westrenen, Ruiheng Liu, Peiyan Wu, Ho-Kwang Mao and Yanhao Lin in National Science Review 2026.
Scientists discover a hidden oxygen reservoir deep inside Earth | Scientists Discover a Hidden Oxygen Source Deep Inside Earth | <a href="https://www.thebrighterside.