Georesources

More people than ever live in urban centres and use sophisticated technologies. Topic 8 will address one of the most fundamental challenges facing society: securing the future supply of energy and raw materials needed to sustain our 21st century infrastructure, to enable the transition from fossil and nuclear energy to renewables. In doing so, we want to achieve the targeted reduction of CO₂ emissions and also to support a growing circular economy. During this transition, geoscience solutions to sustainable energy, raw materials supply, and subsurface storage of waste will be required, with a growing emphasis on the deep subsurface.

Our research foci include:

• development and application of new technologies for georesources
• accessing clean geothermal energy as an integral part of the energy supply
• constraining the key processes that form high value ore deposits
• developing knowledge-based approaches for the safe disposal of waste from energy production
• designing new observational, experimental and simulation platforms to assess the coupled thermal, hydraulic, mechanical, chemical, and biological controls on resources
• integrating geodynamics as a fundamental control on the occurrence of resources and a defining boundary condition for safe subsurface utilization
• the role of biological-solid-fluid interactions and the deep biosphere in georesource systems

Geothermal energy is an important domestic source for the future energy mix. We aim to provide the geothermal solutions for thermal energy provision in cities (heating and cooling), and to constrain the key processes necessary for the exploitation of intermediate depth, deep, and superhot geothermal systems. Additionally, our research focusses on the minimization of risks related to the utilization of geothermal reservoirs. We will develop optimized production strategies to minimize the induced hazards associated with reservoir stimulation.

Subsurface storage of energy products (e.g., heat, synthetic gas, Hydrogen) and energy waste material (e.g., radioactive waste, CO2) will become increasingly important in the near future as the subsurface allows the safe and sustainable storage of large quantities of energy on different time scales. Our research focusses on the development of: i) strategies for underground heat and cold storage at different depths, ii) approaches for efficient and sustainable storage of hydrogen and synthetic gas, iii) research platforms offering geoscience solutions for the save and reliable storage of radioactive waste. Geochemical and petrophysical experiments and measurement will form the basis for advanced modelling of the key processes.

Within our carbon resources (i.e., hydrocarbon and gas hydrate) research, the interaction processes of deep organic fluids or hydrate phases with the host rock matrix, formation waters, and microbial communities are of central interest. We will also focus on the geomechanical and physical properties of hydrate-bearing sediments, a risk for slope stability.  

Of major interest are the following three broad groups of deposits:

Magmatic deposits related to mafic-ultramafic, alkalic-carbonatitic and felsic-pegmatitic intrusions provide much of the world’s Cr-Ni-PGE (platinum-group elements), REE, and Li-Nb-Ta supplies. To better constrain if an intrusion is barren or mineralized, research in ST8.2 focusses on processes that lead to the enrichment of metals in these systems. We combine geochemical/isotopic tracers of magma source and evolution with experiments that determine how metals behave during melting and crystallization.

Magmatic-hydrothermal deposits in subduction and collisional zones (e.g., Andean and Variscan belts) are major suppliers for Cu, Mo, Au, Ag, Sn, and W. Quantifying the processes of generation, emplacement, and degassing of fertile magmas in these systems and identifying the mechanisms of focused fluid flow and ore precipitation by physical and chemical fluid-rock interactions are key to guiding future exploration. Fundamental processes that are addressed include the importance of pre-enrichment in source areas for melt generation, the manner of volatile release from incrementally growing magmatic intrusions, and the role of fault structures in dynamic ore-forming hydrothermal systems.

Massive sulfide deposits in volcanic and sedimentary basins have the potential to host significant Cu, Zn, and Pb resources. Researchers in ST8.2 study the interactions of diagenetic and hydrothermal processes coupled to the 4D evolution of permeability and porosity that govern heat and fluid flow in volcanic and sedimentary systems. Other key aspects of our research are i) the role of biotic communities and organic material, ii) the sulfur cycle, iii) mobility of redox-sensitive metals.

Geodynamic drivers of energy and mineral systems like plate tectonics play a key role in energy and mass transfer within the Earth and controls the regional-scale distribution of resources. ST8.3 aims to identify crustal architecture and fault systems that control melt and fluid pathways and thereby provide a 4D-framework for integrating plate-boundary processes (magmatism, deformation, uplift and sedimentation) into mineral and energy system models. One focus of our research is to quantify the capacity of large-scale sedimentary basins for ore formation, geothermal energy, and storage of mineral and energy wastes which is directly linked to their geodynamic history, including far-field and near-field stresses, thermal regimes, and the development of heterogeneous physical rock properties. These data are critical for assessing potential risks in different systems, e.g., induced seismicity in response to reservoir utilization, thermal variation, and the long-term stability of repositories for nuclear waste.

Coupled Interactions of thermo-hydro-mechanical-chemical processes act over a large range of temporal and spatial scales and control the formation of energy and raw material resources. ST8.3 aims to develop new system models that integrate coupling, feedback and cascading effects into conventional THMC models of fluid flow, reactive transport and permeability evolution. This includes studying the role of organic-inorganic and microbial interactions, which can be particularly important for the formation of mineral and energy resources in sedimentary basins, and for developing strategies for energy production and storage potential.

Advanced Technologies for analysis and discovery are required to extract maximum value from the resources and to safeguard against the negative impacts of exploitation. In ST8.3, we advance technological applications on several fronts: i) fiber-optic distributed acoustic sensing (DAS) for real-time monitoring, imaging of the underground and exploration of geothermal and mineral systems, ii) multi-parameter sensor systems for exploration, assessment, and monitoring of deep geothermal and mineral resources, iii) analytical and experimental laboratories on-site and in the field, iv) underground research labs, v) advanced data concepts.