This project investigates the geological processes that lead to the formation of primary resources of industrial metals such as copper, lead, zinc, molybdenum or gold in the Earth’s interior. Several PhD students funded by this project cooperate to understand why some metals are selectively enriched in certain small areas of the Earth's crust, in 100- to 10'000-fold higher concentration compared to normal rocks, and why this occurred only in some locations and at certain periods in the evolution of our planet. Understanding the formation of mineral resource is the foundation for discovering new deposits, which is essential for Switzerland as well as global technical development. Our research also trains students to acquire the geological understanding they need to work successfully and responsibly with the international resource industry. Collaboration with colleagues from resource-rich but economically less-developed countries contributes to mutual awareness of technical and cultural needs in different societies.
Ore formation involves chemical dissolution of trace metals by water-rich fluids or magmatic melts, followed by concentrated re-deposition of metallic minerals in selected areas of the Earth's crust. Our research starts with geological observations and sampling in the field, commonly in regions with known mineral occurrences. Samples are then analysed in the laboratory by different methods. Micro-analysis of tiny relicts of ore-forming solutions enclosed inside minerals is a technique that was developed by our group at ETH Zurich and is now used worldwide. With isotopic analyses of minerals containing radioactive elements we can determine when an ore vein formed, or how long it took for a magma to crystallise. The different field- and lab-based results are linked by computer simulations of the overall process to predict, for example, the flow directions of ore-mineralising fluids beneath a volcano. The same computer models can also be applied to study volcanic eruptions, or the extraction of geothermal energy from the Earth's interior. Technical details about this research and about training in resource geology can be found at www.geopetro.ethz.ch/research/orefluids. Zurich's new Earth Science Information and Exhibition center, focusTerra, contains an attractive display about mineral resources, which explains some results from this research in readily understandable form (www.focusterra.ethz.ch).