Researchers get beneath the surface of the earth Analysis of rock microstructures can lead to important insights into key processes in the lithosphere, the outer part of the earth’s crust. The Made-In-Earth project aims to develop new quantification approaches, helping build a deeper understanding of phase transitions in the lithosphere, as Professor Lucie Tajčmanová explains The analysis of
rock samples and the chemical composition of microstructures found on the earth’s surface can help scientists build a deeper understanding of processes in the earth’s interior. By analysing rock samples, researchers can identify certain minerals and investigate the way they are arranged, from which new insights can be drawn. “These minerals, their composition and the way they are arranged can indicate the peak pressure and temperature conditions under which the rock microstructure developed,” explains Professor Lucie Tajcmanová, the Principal Investigator of the Made-In-Earth project, an ERC-backed initiative based at ETH in Zurich. Researchers in the project are developing new quantification approaches to quantitatively understand the data from metamorphic rocks. “We focus on so-called metamorphic rocks, rocks that have somehow metamorphosed, or otherwise been modified, from their original state,” explains Professor Tajcmanová.
Rock metamorphosis This process of rock metamorphosis has an enormous impact on the earth’s surface. It is known that mineral reactions and phase transformations in the lithosphere help form mountain ranges, lead to volcanic eruptions,
38
and trigger earthquakes, underlining the wider importance of improving our understanding of geodynamic processes. “We are collaborating with people who are developing a new generation of geodynamic models, while we also work with researchers in other areas,” outlines Professor Tajcmanová. However, while fully aware of the project’s wider implications, Professor Tajcmanová says their research is largely fundamental in nature. “We are currently focusing more on developing theoretical methods and we analyse rock samples from all over the world. We have some samples from the Bohemian massif in the Czech Republic, as well as from the Alps, the Himalayas, India, Norway, and other regions,” she continues. Kaoko Belt (NW Namibia)
The project is focussing in particular on rocks that belong to the lithosphere, the outer part of the earth’s crust. Previously researchers compared the pressures and temperatures under which a rock developed to localise the area in which it was formed, but Professor Tajcmanová and her colleagues question the effectiveness of this approach. “With this approach it is assumed that rocks are like fluids, which is not true, as in fact they behave like solid phases with different mechanical properties. We are trying to develop new quantification approaches, a new way of thinking about how to look at certain observations in rocks,” she says. Researchers are developing theoretical approaches, coupling chemical and mechanical processes; a key first step in this work is in building new thermodynamic formulations. “This work is partly theoretical. With this ERC funding, we can really get into the fundamental equations and question whether they are appropriate or not,” continues Professor Tajcmanová. Researchers are looking at chemical distribution processes in rock microstructures, together with the squeezing effects of deformation, to build a more detailed picture of processes in the lithosphere. The rocks that researchers are analysing are very small, ranging from
EU Research
