Hidden magma tracked

Despite being hidden deep underground, magma has an incredibly strong influence not only on the planet but on its inhabitants too. But our understanding of the natural force is limited to its behaviour close to the surface; we have not been able to track the movements of magma at such great depths – until now. A research team from the University of Geneva have discovered an innovative technique to estimate the volume and magma flow required for the construction of magma chambers. The technique makes use of tiny crystals of the mineral zircon, which is found in solidified magma. “The zircon crystals that are found in solidified magma hold key information about the injection of molten rock into a magma chamber before it freezes underground,” said Professor Urs Schaltegger. Zircon contains radioactive elements that allow researchers to determine its age, which they did by pairing data collected using natural samples and numerical simulation. “Modelling meant that we could establish how the age of crystallised zircon in a cooled magma reservoir depends on the flow rate of injected magma and the size of the reservoir,” said researcher Guy Simpson. The resulting model is able to determine with great accuracy the age, volume and injection rate of magma that has accumulated at inaccessible depths. The researchers have concluded that the formation of Earth’s crust, volcanic super eruptions and mineral deposits occur under very specific conditions. “When we determine the age of a family of zircons from a small sample of solidified magmatic rock, using results from the mathematical model we have developed, we can tell what the size of the entire magma chamber was, as well as how fast the magma reservoir grew,” said Professor Luca Caricchi. “This information means that we can determine the probability of an explosive volcanic eruption of a certain size to occur. In addition, the model will be of interest to industry because we will be able to identify new areas of our planet that are home to large amounts of natural resources such as copper and gold.” Editorial: Look out for an in depth on this soon