Here, we conducted spectroscopic measurements on high-pressure, high-temperature fluids and melts to study how halogens, in particular bromine, can be incorporated in subduction zone fluids and melts. We find that a gradual evolution of bromine speciation with liquid composition enables the incorporation of high amounts of Br in both phases. Thus, bromine and, by extension, chlorine are expected to be efficiently recycled from the slab towards the volcanic arc.

In carbonate rocks, fault zones influence the fluid flows and lead to important diagenetic processes modifying reservoir properties. The aim of this study is to identify the impact of two polyphase fault zones on fluid flows and reservoir properties during basin history. We determined petro-physic and diagenetic properties on 92 samples. This study highlights that fault zones acted as drains at their onset and induced fault zone cementation, which has strongly altered local reservoir properties.

Sandbox models investigated extension and inversion of salt-bearing rifts such as those found in the Moroccan High Atlas, North Africa. Sand packs were stretched and the structural lows were filled with a salt analog. Models were then subjected to additional extension and loading that remobilized the salt into diapirs. During shortening the distribution of the salt in the overburden governed the structural styles and trends in the supra-salt strata, strongly decoupled from subsalt deformation.

This paper uses seismic reflection methods to image and better constrain fault and basin architecture at depth in a region of northern Australia thought to be highly prospective for oil and gas as well as sediment-hosted lead–zinc mineralisation. A better understanding of these architectural constraints is essential for the delineation of fluid pathways, barriers, and potential traps where these commodities may have accumulated.

We explore pre-existing fabric in metabasalts replete with a wide range of crisscross fractures/faults, hosting quartz veins of variable orientations and thicknesses in the Chitradurga region, India. The fractures are identified as components of a riedel shear system. We evaluate reactivation potential of fractures and conclude that episodic changes in fluid pressure conditions triggered fault-valve action, thereby reactivating fabric and fractures, leading to vein emplacement in the region.

Pangea was assembled during Devonian to early Permian times and resulted in a large-scale and winding orogeny that today transects Europe, northwestern Africa, and eastern North America. This orogen is characterized by an S shape corrugated geometry in Iberia. This paper presents the advances and milestones in our understanding of the geometry and kinematics of the Central Iberian curve from the last decade with particular attention paid to structural and paleomagnetic studies.

To place constraints on the mantle deformation beneath the Central Alps and the greater Alpine region, we analysed the appropriate seismic signal recorded by more than 100 stations, belonging to AlpArray and to other permanent networks. We took a picture of the imprinting that Alpine orogen history and related subductions left at depth, with a mainly orogen-parallel mantle deformation from Western Alps to Eastern Alps, but also N to S from the Po Plain to the Rhine Graben.

A chronostratigraphic study was conducted on Carboniferous rocks of SW Iberia. Terrigenous strata with a maximum depositional age of ca. 303 Ma unconformably overlie marine deposits and volcanic rocks dated at ca. 335–331 Ma. Lying below this unconformity, the marine deposits are intruded and overlain by a ca. 317 Ma porphyry. Detrital zircon populations from marine deposits indicate derivation from Laurussian terranes, while the terrestrial rocks are related to Laurussia and Gondwana sources.

We study the Iberian plate motion, from the late Permian to middle Cretaceous. During this time interval, two oceanic systems opened. Geological evidence shows that the Iberian domain preserved the propagation of these two rift systems well. We use geological evidence and pre-existing kinematic models to propose a coherent kinematic model of Iberia that considers both the Neotethyan and Atlantic evolutions. Our model shows that the Europe–Iberia plate boundary was made of two rift systems.

In this paper, we present newly developed numerical models to simulate episodic growth of geological faults. This growth of faults occurs during the seismic cycle, with spontaneously generated primary and secondary fault structures. With these models we are able to show the evolution of complex fault geometries. Additionally, we can quantify the impact of earthquakes on fault growth.

At the St. Johns Dome, Arizona, CO₂ naturally occurs in the subsurface, but there are travertine rocks on the surface which are an expression of CO₂ leakage to the surface. These travertine deposits occur along faults, zones where the rock layers are fractured and displaced. In our research, we use geomechanical analysis to show that the CO₂ leakage occurs at points where the faults are likely to be permeable due to the orientation of the geological stress field in the subsurface.

We use a sediment core from the Gobi Desert (Ejina Basin, NW China) to illustrate the landscape history of the area. During 2.5 million years a sediment package of 223 m thickness has been accumulated. Various sediment types document that the area turned from a playa environment (shallow water environment with multiple flooding events) to an alluvial–fluvial environment after the arrival of the Heihe in the area. The river has been diverted due to tectonics.

Coal is an important source rock for natural gas recovery, and its frictional properties play a role in induced seismicity. We performed experiments to investigate the frictional properties of bituminous coal, and our results show that the frictional strength of coal became significantly weakened with slip displacement, from a peak value of 0.5 to a steady-state value of 0.3. This may be caused by the development of shear bands with internal shear-enhanced molecular structure.

This work studies intensively the flow in fractures with finite hydraulic conductivity intersected by a well injecting/producing at constant pressure. We demonstrated that during the bilinear flow regime the transient propagation of isobars along the fracture is proportional to the fourth root of time. Moreover, we present relations to calculate the termination time of bilinear flow under constant injection/production well pressure. Our results can be utilized to estimate the fracture length.

In this paper, a novel methodology of 3D geologic model uncertainty assessment that considers both input data and prior knowledge is developed and applied to characterize fault zones – areas of damaged rock surrounding a fault surface that are important to subsurface engineering projects. The results of the study demonstrate how existing frameworks can be expanded to incorporate new types of information to arrive at a realistic and straightforward model of fault zone geometry in the subsurface.

This study evaluates the buffering of seawater oxygen isotopes at midocean ridges, using a process-based model of hydrothermal circulation and reactive transport of oxygen isotopes. The buffering intensity shown by the model is significantly weaker than previously assumed. Oxygen isotopes of oceanic crust are consistently relatively insensitive to seawater isotopic composition, which explains the ancient oceanic crust without invoking a constant seawater oxygen–isotopic composition through time.

Normal faults often reactivate under compression, in a process called inversion. The 3D geometry of these structures (and the effect on resultant inversion structural style) is often not considered. Using seismic reflection data, we examine how stresses form different inversion styles that are controlled by the geometry of the pre-existing structure. Geometrically simple faults are preferentially reactivated; more complex areas are typically not reactivated and instead experience bulk uplift.

We present a high-resolution 3D analysis of the physicochemical characteristics of two sandstone cubes at the submeter scale. Our study provides insight into the spatial distribution and the controlling factors of small-scale heterogeneity in sandstone media. A comprehensive physicochemical data set is provided, which may help to evaluate the degree of uncertainty that should be considered in field-scale property models.

Simulations of seismic waves are very important; they allow us to understand how earthquakes spread and how the interior of the Earth is structured. However, whilst powerful, existing simulation methods usually require a large amount of computational power and time to run. In this research, we use modern machine learning techniques to accelerate these calculations inside complex models of the Earth.

At the bottom of the mantle (2850 km depth) two large volumes of reduced seismic velocity exist underneath Africa and the Pacific. Their reduced velocity can be explained by an increased temperature or a different chemical composition. We use the gravity field to determine the density distribution inside the Earth's mantle and find that it favors a distinct chemical composition over a purely thermal cause.

In the first kilometers of the subsurface, temperature anomalies due to heat conduction rarely exceed 20–30°C. However, when deep hot fluids in the shallow crust flow upwards, for example through permeable fault zones, hydrothermal convection can form high-temperature geothermal reservoirs. Numerical modeling of hydrothermal convection shows that vertical fault zones may host funnel-shaped, kilometer-sized geothermal reservoirs whose exploitation would not need drilling at depths below 2–3 km.

We present an open-source tool to model ambient seismic auto- and cross-correlations with spatially varying source spectra. The modeling is based on pre-computed databases of seismic wave propagation, which can be obtained from public data providers. The aim of this tool is to facilitate the modeling of ambient noise correlations, which are an important seismologic observable, with realistic wave propagation physics. We present a description and benchmark along with example use cases.

This paper reports a multiproxy approach to reconstruct the depth, timing, and extent of the past fluid flow during the formation of a fold-and-thrust belt in the Northern Apennines, Italy. The unique combination of paleopiezometry and absolute dating returns the absolute timing of the sequence of deformation. Combined with burial models, this leads to predict the expected temperatures for fluid, highlighting a limited hydrothermal fluid flow we relate to the large-scale subsurface geometry.