Multiple sulfur isotopes and metal trap evolution in sediment hosted ore systems

• Applicant: Joseph Magnall, Ph.D.
• Subject Area: Geology
• Term: since 2023
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 521731309

The sustainable development of critical raw materials (CRMs) is one of the major challenges facing society as we transition towards a green, digital, and circular economy. Sediment hosted base metal deposits are typically high grade and moderate to high tonnage systems, meaning that metal can be extracted with lower environmental cost relative to other types of mineral deposit. In these deposits, the main ore minerals are sphalerite (ZnS) and galena (PbS). Therefore, in order to make a high grade deposits, you not only need large amounts of metals but also equally large amounts of reduced sulfur. The mineral deposit is then formed where hot fluids carrying the Zn (and Pb) encounter rocks that contain large volumes of S. The formation of sediment hosted deposits only happened during specific periods of geological history, and there are no such deposits forming in todays oceans. The reasons for this are not clear, but we do know that high grade ore formation depends on the optimization of key processes, which in ancient sedimentary basins likely involved microbial activity. Microbes played a particularly important role in taking sulphate from ancient seawater and making reduced sulfur, which is required for concentrating the metals. In this project, we seek to develop new techniques for tracing microbial activity and reduced sulfur generation around ancient sediment hosted ore deposits. In doing so, this will help us to understand why and how high grade deposits are located where they are, thereby improving the discovery of new deposits.

• DFG Programme: Priority Programmes
• Subproject of: SPP 2238: Dynamics of Ore-Metals Enrichment - DOME
• Co-Investigators: Professorin Dr. Sarah Anne Gleeson; Professor Dr. Harald Strauß