This paper presents a rigorous derivation of Gassmann's equations, grounded in thermodynamic principles and conservation laws, addressing gaps and potential inconsistencies in the original formulation. It also explores Biot's poroelastic equations, demonstrating that Gassmann's equations are a specific case within Biot’s framework. The study affirms the robustness of Gassmann's equations when assumptions are met, and symbolic Maple routines are provided to ensure reproducibility of the results.

We developed a deep learning model that uses hyperspectral imaging data to predict key physical rock properties, specifically density, slowness, and gamma-ray values. Our model successfully learned to translate hyperspectral information into predicted physical properties. Tests on independent data gave accurate results, demonstrating the potential of hyperspectral data for mapping physical rock properties.

Original geochemical data for the vast Cenozoic arc magmatism of Iran introduce three distinct rock series rooted in the mantle wedge. The LILE-rich and LILE-poor series show wet-slab melt metasomatism and dry-slab melt metasomatism signatures respectively. The third series rich in incompatible elements, ITE-rich, indicate the input of asthenosphere as well. Eocene-Early Miocene ages for the three series imply that the metasomatic events predate Eocene and the three series occur intermittently.

Local seismic tomography yields the highest-resolution 3D Q_p model in CSES. Low Q_p anomalies along faults and basins indicate high medium fragmentation, thick sediments, or fluid richness. Tengchong volcano's westward dipping high attenuation suggests magma flow. Most M6+ earthquakes occur in low attenuation zones or anomaly boundaries. The 2008 Wenchuan M_S 8.0 and 2013 Lushan M_S 7.0 epicenters were separated by a low attenuation area, indicating future major earthquake risks.

Our simulation considers the Mesozoic subduction of the Izanagi slab, which plays an irreplaceable role in the formation of stagnant Pacific slab within the MTZ. The magmas of the Changbaishan volcano may primarily originate from the super-hydrous melts caused by the Pacific slab dehydration in the MTZ. The upward escape of the entrained oceanic asthenospheric material as well as the piling up and thickening of the subducted Pacific slab may play secondary roles.

In some situations where the crust plates collide to each other, they deform by creating folds and thrusts. Based on thrusts development direction, they are categorized into fore- or back-thrusts. We use numerical simulation to investigate their development over geological time-scales. We examine the importance of rock strength, friction, displacement type and geometry on back-thrusting with regard to the final geometry of the deformation, as well as the distribution of porosity and stresses.

There is still considerable controversy over the duration of the subduction-collision orogeny process of the Wushan-Shangdan Ocean. Here, we present new geochronological and geochemical data for Silurian granites from the North Qinling Orogen. The main conclusions are as follows: (1) the ocean had closed prior to 438 Ma; (2) The transition phase from syn-collision to post-collision took place between 429 and 421 Ma; (3) A three-stage tectonic model of the Wushan-Shangdan Ocean is proposed.

Our research aims to accurately differentiate the elastic properties of tight sands with thin shale beds and fractures. Traditional models struggle to distinguish between these two features. We developed a hybrid rock physics model. Our model's reliability is validated against well log data, revealing distinct anisotropic characteristics for thin shale beds and fractures. This model helps identify fractures more accurately, improving geophysical exploration.

Obtaining reliable estimates of the subsurface state distributions is essential to determine the location of e.g. potential nuclear waste disposal sites. However, providing these is challenging since it requires solving the problem numerous times yielding high computational cost. To overcome this, we use a physics-based machine learning method to construct surrogate models. We demonstrate how it produces physics-preserving predictions, which differentiates it from purely data-driven approaches.

In this manuscript, we investigated the kinematics and dynamics of strike-slip damage zones using laboratory mechanical tests and analogue modelling techniques. The results underline the importance of a multi-scale approach (from crustal to outcrop-scale) to improve the understanding of such deformation processes, deriving fundamental correlations with the physical and mechanical properties of the model materials applied in the experiments.

West Norwegian 'diamond facies' eclogite contains tiny mineral inclusions of quartz and amphibole lamellae that are not stable in the diamond field. Low trace amounts of water in the lamellae-bearing host minerals suggest that the inclusion microstructure was not formed by fluid infiltration but by dehydration during early exhumation of these rocks. Some samples with higher water content argue that a late fluid overprint was spatially restricted and obliterated evidence of extreme metamorphism.

At any scale, the limited size of a study area introduces a bias in the interpretation of linear features, defined as right-censoring bias. We show the effects of not considering such bias and apply survival analysis techniques to obtain unbiased estimates of multiple parametrical distributions in three censored length datasets. Finally, we propose a novel approach to select the most representative model from a sensible candidate pool using the Probability Integral Transform technique.

Our study investigates the statistical relationship between geological faults and earthquakes in the Southwestern Swiss Alps. We analyze how the fault size and earthquake rupture are related and find differences in how faults at different depths rupture seismically. While shallow faults tend to rupture only partially, deeper faults are more likely to rupture along their entire length, potentially resulting in larger earthquakes.

We assessed the poro-perm relations of both host rocks and fault rocks of Mesozoic carbonate rocks, by integrating a laboratory petrophysical studyn with a digital image analysis. Three different protocols were employed to compute permeability: i) Effective Medium Theory on laboratory data, ii) constant crack aperture and iii) crack density values from 2D images. Carbonate host rocks did not show a clear poro-perm trend due to the presence of stiff, sub-rounded pores and of small vugs.