09/2019 Geochemists measure new composition of Earth’s mantle
Researchers suspect greater dynamics than previously assumed between the Earth’s surface and its mantle / Study published in “Nature Geoscience”
What is the chemical composition of the Earth’s interior? Because it is impossible to drill more than about ten kilometres deep into the Earth, volcanic rocks formed by melting Earth’s deep interior often provide such information. Geochemists at the Universities of Münster (Germany) and Amsterdam (Netherlands) have investigated the volcanic rocks that build up the Portuguese island group of the Azores. Their goal: gather new information about the compositional evolution of the Earth’s mantle, which is the layer roughly between 30 and 2,900 kilometres deep inside the Earth. Using sophisticated analytical techniques, they discovered that the composition of the mantle below the Azores is different than previously thought –suggesting that large parts of it contain surprisingly few so-called incompatible elements. These are chemical elements which, as a result of the constant melting of the Earth’s mantle, accumulate in the Earth’s crust, which is Earth’s outermost solid layer.
The researchers conclude that, over Earth’s history, a larger amount of Earth’s mantle has melted – and ultimately formed the Earth’s crust – than previously thought. “To sustain the material budget between Earth’s mantle and crust, mass fluxes between the surface and Earth’s interior must have operated at a higher rate,” says Münster University’s Prof. Andreas Stracke, who is heading the study.
As the material below the Azores rises from very deep within Earth’s mantle – and is unexpectedly similar to most of its upper part – the composition of Earth’s entire mantle may differ from current thinking. “Our results have opened up a new perspective,” says Andreas Stracke, “because we will now have to reassess the composition of the largest part of the Earth – after all, Earth’s mantle accounts for over 80 percent of Earth’s volume.” The study has been published in the journal “Nature Geoscience”.
07/2019 Welcome Malcolm Massuyeau
We welcome Malcolm Massuyeau as a new postdoc at the Institute for Mineralogy.
07/2019 Welcome Hadi Omrani & Sepideh Mehrani
We welcome Hadi Omrani and Sepideh Mehrani from Golestan University, Gorgan, Iran, who will be working with Michael Bröcker.
06/2019 Magnetism discovered in the earth's mantle
New findings on the Earth’s magnetic field: researchers show that the iron oxide hematite remains magnetic deep within the Earth’s mantle / Study published in "Nature" journal
The huge magnetic field which surrounds the Earth, protecting it from radiation and charged particles from space – and which many animals even use for orientation purposes – is changing constantly, which is why geoscientists keep it constantly under surveillance. The old well-known sources of the Earth’s magnetic field are the Earth’s core – down to 6,000 kilometres deep down inside the Earth – and the Earth’s crust: in other words, the ground we stand on. The Earth’s mantle, on the other hand, stretching from 35 to 2,900 kilometres below the Earth’s surface, has so far largely been regarded as “magnetically dead”. An international team of researchers from Germany, France, Denmark and the USA has now demonstrated that a form of iron oxide, hematite, can retain its magnetic properties even deep down in the Earth’s mantle. This occurs in relatively cold tectonic plates, called slabs, which are found especially beneath the western Pacific Ocean. The results are published in the current issue of "Nature".
04/2019 "DOME" SPP coordinated by Uni Potsdam, WWU, GFZ and Uni Freiburg just approved
The Deutsche Forschungsgemeinschaft (DFG) has just approved 14 new SPPs for the year 2020. One of the SPPs approved is the programm „Dynamics of Ore-Metals Enrichment“ (DOME) which is coordinated by Prof. Max Wilke of the Institute of Geosciences, University of Potsdam. Prof. Carmen Sanchez-Valle is part of the steering committee.
03/2019 Welcome Håkon Austrheim
We welcome Håkon Austrheim from the University of Oslo, Department of Geosciences, Norway.