Rock-forming minerals behave elastically, a property that controls their ability to support stress and strain, controls the transmission of seismic waves, and influences subsequent permanent deformation. Minerals are intrinsically anisotropic in their elastic properties; that is, they have directional variations that are related to the crystal lattice. We explore this directionality and present new ways of visualising it. We hope this will enable further advances in understanding deformation.

In this paper, we investigate the physical mechanisms of tectonic nappe formation by high-resolution numerical modeling. Tectonic nappes are key structural features of many mountain chains which are packets of rocks displaced, sometimes even up to 100 km, from their original position. However, the physical mechanisms involved are not fully understood. We solve numerical equations of fluid and solid dynamics to improve our knowledge. The results are compared with data from the Helvetic Alps.

This study presents an approach that combines equilibrium thermodynamic modelling with oxygen isotope fractionation modelling for investigating fluid–rock interaction in metamorphic systems. An application to subduction zones shows that chemical and isotopic zoning in minerals can be used to determine feasible fluid sources and the conditions of interaction. Slab-derived fluids can cause oxygen isotope variations in the mantle wedge that may result in anomalous isotopic signatures of arc lavas.

We present a first application of seismic attributes, a well-known technique in the oil and gas industry, to vintage seismic reflection profiles in a seismotectonic study. Our results improve data interpretability, allowing us to detect peculiar geophysical signatures of faulting and a regional seismogenic layer. We suggest a new tool for both seismotectonic research and assessments of the seismic hazard, not only in the central Apennines (Italy), but also in seismically active areas abroad.

Time-domain electromagnetic (TEM) geophysics data originally collected for mining purposes were reprocessed and inverted. The new inversions were used to construct a 3D model of the subsurface geology to facilitate hydrogeological investigations within a DANIDA-funded project. Improved resolutions from the TEM enabled the identification of possible paleovalleys of glacial origin, suggesting the need for a reevaluation of the current lithostratigraphy of the Voltaian sedimentary basin.

The Patos-Marinza oil field in Central Albania (40.71° N, 19.61° E) is one of the largest onshore oil fields in Europe. More than 7 million oil barrels are extracted per year from sandstone formations in western Albania. The regional seismicity culminated in December 2016, when a seismic sequence developed in the oil field, triggering the opening of a public inquiry. We take advantage of the Sentinel-1 radar images to show that a strong subsidence, probably induced, is taking place in the field.

The Barents Sea and Fennoscandia were home to large ice sheets around 20 000 years ago. After the melting of these ice sheets, the land slowly rebounded. The rebound speed is determined by the viscosity of the deep Earth. The rebound is ongoing and causes small changes in the Earth’s gravity field, which can be measured by the GRACE satellite mission. We use these measurements to obtain the viscosity of the upper mantle and find that it is 2 times higher in Fennoscandia than in the Barents Sea.

Here we discuss the validity of so-called “break-up” markers along the Newfoundland margin, challenging their perceived suitability for plate kinematic reconstructions of the southern North Atlantic. We do this on the basis of newly available seismic transects across the Southern Newfoundland Basin. Our new data contradicts current interpretations of the extent of oceanic lithosphere and illustrates the need for a differently constraining the plate kinematics of the Iberian plate pre M0 times.

We propose a methodology for the identification of rock types using geophysical and geological information. It relies on an algorithm used in machine learning called self-organizing maps, to which we add plausibility filters to ensure that the results respect base geological rules and geophysical measurements. Application in the Yerrida Basin (Western Australia) reveals that the thinning of prospective greenstone belts at depth could be due to deep structures not seen from surface.

This study investigates Cenozoic deformation during cooling and exhumation of the Tauern metamorphic and structural dome, Eastern Alps, through Th–Pb dating of fissure monazite-(Ce). Fissure (or hydrothermal) monazite-(Ce) typically crystallizes in a temperature range of 400–200 °C. Three major episodes of monazite growth occurred at approximately 21, 17, and 12 Ma, corroborating previous crystallization and cooling ages.

The metamorphism of the Pulo do Lobo unit (SW Iberian Massif) is described in this paper. To this end, three different and complementary methodologies have been applied. The new results reported here contribute to the knowledge of the metamorphic conditions of the Pulo do Lobo unit in relation to its deformation. Furthermore, the results are compared in order to assess the reliability of the different methods applied.

Faults form due to stresses caused by crustal processes. As faults influence the stress field locally, fault interaction leads to local variations in the stress field, but this is difficult to observe directly. We describe an outcrop of one fault abuting into another one. By careful measurement of structures in the overlapping deformation zones and separating them using published relative age data, we show a rotation in the local stress field resulting from the faults growing to each other

In Los Humeros, through field structural–geological mapping and analogue experiments, we show a discontinuous and small-scale (areal size ~ 1 km²) uplift of the caldera floor due to the emplacement of multiple shallow (< 1 km) magmatic bodies. These results allow for a better assessment of the subsurface structure of Los Humeros, with crucial implications for planning future geothermal exploration, which should account for the local geothermal gradient affected by such a shallow heat source.

In this field-based study, geological structures and hydrothermal alterations in one of the least known geological terrains in Sweden are investigated. The area is located above the polar circle in northwestern Sweden that produces a significant portion of the iron and copper in the EU. A new tectonic model based on field evidence and microstructures is presented and it is shown that minerals typical for iron and copper–gold deposits can be linked to different phases of the structural evolution.

Injection of vertical sheets of magma (dyke swarms) controls tectonic and volcanic processes on Earth and other planets. Yet we know little of the 3D structure of dyke swarms. We use seismic reflection data, which provides ultrasound-like images of Earth's subsurface, to study a dyke swarm in 3D for the first time. We show that (1) dyke injection occurred in the Late Jurassic, (2) our data support previous models of dyke shape, and (3) seismic data provides a new way to view and study dykes.

Knowledge about physical properties at depth is crucial to image and understand structures linked with orogenic processes. We examined seismic velocities from core and downhole data from the COSC-1 borehole, Sweden, and calibrated our results with laboratory measurements on core samples. Despite a strong mismatch between the core and downhole velocities due to microcracks, mafic units are resolved at all scales, while at sample scale, strong seismic anisotropy correlates with the rock foliation.

Hydraulic stimulation summarizes fracture initiation and reactivation due to high-pressure fluid injection. Several borehole intervals covering intact rock and pre-existing fractures were targets for high-pressure fluid injections within a decameter-scale, crystalline rock volume. The observed induced seismicity strongly depends on the target geology. In addition, the severity of the induced seismicity per experiment counter correlates with the observed transmissivity enhancement.

The characterization of fractures is crucial for a wide range of pertinent applications, such as geothermal energy production, hydrocarbon exploration, CO² sequestration, and nuclear waste disposal. We estimate fracture parameters based on waves that travel along boreholes (tube waves) using a stochastic optimization approach.

We have developed a model of the Earth's structure in the upper 500 km beneath the central and eastern Mediterranean. Within this model, we can see parts of the African tectonic plate that have sunk underneath the European plate over the past tens of millions of years. This model was constructed using seismic waveform tomography by matching the seismograms from many earthquakes recorded at the surface to synthetic seismograms that were generated by simulating earthquake wave propagation.

A magnitude 5.3 reverse-faulting earthquake in September 2018 near Lake Muir in southwest Western Australia was followed after 2 months by a collocated magnitude 5.2 strike-slip event. The first event produced a ~ 5 km long and up to 0.5 m high west-facing surface rupture, and the second triggered event deformed but did not rupture the surface. The earthquake sequence was the ninth to have produced surface rupture in Australia. None of these show evidence for prior Quaternary surface rupture.

Long-term monitoring of CO₂ of onshore storage has to consider thousands of years as a medium lifetime of the storage. In this wide time interval, the stress and strain properties of the reservoir change and earthquakes could occur. Therefore, we have to identify those fault sets which can be reactivated by changing the stress conditions. We need to know the role of active fault sets and model the changing conditions to prevent induced seismicity.

The Alboran Sea is one of the most active region of the Mediterranean Sea. There, the basin architecture records the effect of the Africa–Eurasia plates convergence. We evidence a Pliocene transpression and a more recent Pleistocene tectonic reorganization. We propose that main driving force of the deformation is the Africa–Eurasia convergence, rather than other geodynamical processes. It highlights the evolution and the geometry of the present-day Africa–Eurasia plate boundary.