Recent  

Fast depletion of shallower deposits is pushing the mining industry to look for cutting-edge technologies for deep mineral targeting. We demonstrated a joint workflow including two state-of-the-art technologies: full-waveform inversion and reverse time migration. We produced Earth images with significant details which can help with better estimation of areas with high mineralisation, better mine planning and safety measures.

In this study we present a method to compute a reference pressure based on density structure in which we cast the problem in terms of a partial differential equation (PDE). We show in the context of 3D models of continental rifting that using the pressure as a boundary condition within the flow problem results in non-cylindrical velocity fields, producing strain localization in the lithosphere along large-scale strike-slip shear zones and allowing the formation and evolution of triple junctions.

Reactivation of tectonic faults can lead to earthquakes and jeopardize underground operations. The reactivation potential is linked to fault properties and the tectonic stress field. We create 3D geometries for major faults in Germany and use stress data from a 3D geomechanical–numerical model to calculate their reactivation potential and compare it to seismic events. The reactivation potential in general is highest for NNE–SSW- and NW–SE-striking faults and strongly depends on the fault dip.

Fluid flow through rock occurs in many geological settings on different scales, at different temperature conditions and with different flow velocities. Fluid is either in local thermal equilibrium with the host rock or not. We explore the parameters of porous flow and give scaling laws. These allow us to decide whether porous flows are in thermal equilibrium or not. Applied to magmatic systems, moving melts in channels or dikes moderately to strongly deviate from thermal equilibrium.

Three-dimensional backstripping based on the Archimedes principle restored changes through time in 3D subsurface evaporite thickness, 3D salt loss and gain, and 3D subsurface salt movement. The methodology presented is sensitive to any process that influences overburden thickness, in this case sedimentation, erosion and tectonics. The restoration approach can be integrated into existing backstripping workflows and can serve as a benchmark for physics-based numerical modelling of salt tectonics.

(1) Structural diagenesis analysis is performed on the ultra-deep tight sandstone. (2) Fracture and intergranular pores are related to the low in situ stress magnitudes. (3) Dissolution is associated with the presence of fracture.

The carbonates of the Malm are the main reservoir rocks for hydrothermal heat and power generation in southern Germany. To better understand these buried rocks, the carbonates exposed in northern Bavaria are often investigated. As the petrophysical properties of carbonates strongly depend on their subsidence history and maximum burial depth, we will investigate this issue by analyzing mudstones, which indirectly store this type of information and are found just below the Malm carbonates.

We introduce two up to 7 km long normal fault scarps near the city of Bar (Montenegro). The fact that these widely visible seismogenic structures have never been described before is even less surprising than the circumstance that they apparently do not fit the tectonic setting that they are located in. By quantifying the age and movement of the newly discovered fault scarps and by partly re-interpreting local tectonics, we introduce approaches to explain how this is still compatible.

The crystalline basement is considered a ubiquitous and almost inexhaustible source of geothermal energy in the Upper Rhine Graben. Interdisciplinary investigations of relevant reservoir properties were carried out on analogous rocks in the Odenwald. The highest hydraulic conductivities are expected near large-scale fault zones. In addition, the combination of structural geological and geophysical methods allows a refined mapping of potentially permeable zones.

Methods for mineral exploration play an important role within the EU. Exploration must be environmentally friendly, cost effective, and feasible in populated areas. Seismic methods have the potential to deliver detailed images of mineral deposits but suffer from these demands. We show the results for a sparse 3D seismic dataset acquired in Sweden. The 3D depth image allows us to track the known mineralizations beyond the known extent and gives new insights into the geometry of the deposit.

Triaxial compression tests at different effective stresses allow for analysing the deformation behaviour of Opalinus Clay, the potential host rock for nuclear waste in Switzerland. We conducted microstructural investigations of the deformed samples to relate the bulk hydro-mechanical behaviour to the processes on the microscale. Results show a transition from brittle- to more ductile-dominated deformation. We propose a non-linear failure envelop associated with the failure mode transition.

Volcanic eruptions are controlled by the presence of gas bubbles in magma, which, in excess, can cause explosions. Eruption models lack an understanding of how gas percolates in magma flowing in a conduit. Here we study gas percolation in magma associated with the 1994–1995 eruption at Mt. Unzen, Japan. The results show that the pathways for gas escape depend on the depth and ascent rate of magma. Pathways closed at depth but opened along fractures when magma ascended rapidly near the surface.