Deciphering the internal composition of large-scale fault zones helps to better understand the various geologic factors that govern their seismic rupture behavior. We used new detailed geologic, structural, and geomorphologic map of an excellent natural laboratory in the Southern Yangsan Fault (SYF) in the southeastern part of the Korean Peninsula to elucidate the fault zone architecture and its controls

Hydrothermal circulation through oceanic crust, and all the transfers of mass and heat caused by this circulation, are controlled by the evolving permeability of the altered basaltic rocks at in-situ pressures (P) and temperatures (T). Numerical models designed to elucidate these processes therefore rely on knowledge of the rock-matrix permeabilities as a function of P and T and degree of hydrothermal

The Cenozoic evolution of the Altyn Tagh Fault (ATF) is still under debate. Here, we present new paleomagnetic rotation evidence on curvatures south of the ATF in the northeastern Tibetan Plateau to shed new light on this issue. A total of 498 core samples representing 53 sites and 6 time intervals (a-f) were collected from the post-Oligocene sequence at the Heishiqiu locality that in the junction

We propose a new Bayesian approach to estimate continuous crustal strain-rate fields from spatially discrete displacement-rate data, based on Global Navigation Satellite System (GNSS) observations, under the prior constraint on spatial flatness of the strain-rate fields. The optimal values of the hyperparameters in the model of strain-rate fields are determined by using Akaike's Bayesian Information

The Sea of Marmara is a tectonically active basin that straddles the North Anatolian Fault Zone (NAFZ), a major strike-slip fault that separates the Eurasian and Anatolian tectonic plates. The Main Marmara Fault (MMF), which is part of the NAFZ, contains an approximately 150 km long seismotectonic segment that has not ruptured since 1766. A key question for seismic hazard and risk assessment is whether

The exposure of gabbroic sequences at Oceanic Core Complexes (OCC) along ultraslow- to slow-spreading ridges permits the study of the processes forming the lower oceanic crust. On top of the Atlantis Bank OCC along the ultraslow-spreading Southwest Indian Ridge, IODP Expedition 360 drilled Hole U1473A, mainly composed of primitive olivine gabbros interspersed with more evolved Ti-Fe oxide-bearing gabbros

Located in the northern end of the Manila Trench, the deformation front (DF) off southwestern Taiwan is considered as a potential area for generating hazardous earthquakes and tsunamis. However, this area has been relatively seismically quiet, and the seismogenic structure has been unclear, particularly in the middle-to-lower crust. On February 10, 2017, an Mw5.3 earthquake occurred in the near-shore

The northern Central America region (Honduras and Nicaragua) is characterized by geotectonic units delimited by strike-slip fault systems and shortening zones of poorly constrained ages. The eastern portion of the Chortís block, named the “Dipilto micro-block” or “Patuca” is one of these units that besides with the Siuna Serpentinite Mélange, provides evidence for Early Cretaceous arc-continent collision

To explore the role of the olivine grain size and crystal preferred orientation (CPO), on the evolution of the microstructure and the mechanical behavior of upper mantle rocks up to large strains, we performed axial extension experiments at 1200 °C, 300 MPa confining pressure, and constant displacement rate leading to strain rates ~10−5 s−1 on three natural peridotites: a fine-grained mylonitic harzburgite

On October 30, 2020, an earthquake with a magnitude of 6.8 (Mw) struck the northern coast of Samos Island in the Kuşadası Gulf. The solution to the focal mechanism indicates that the earthquake of 30 October 2020 occurred on a normal fault with nodal planes of E-W strike; thus, indicating extension in N-S direction. The fault plane solutions show a N-S trending extension for normal faults, which are

The groundwork for the northeast Atlantic opening was laid during the latest Jurassic to mid-Cenozoic. The period is well-investigated on the Norwegian and UK continental margins at which the tremendous petroleum potential to a large extent resulted from the latest Jurassic to mid-Cenozoic development. Harsh ice conditions have made investigations of the NE Greenlandic margin more difficult. Based

Central and Southern Africa is home to major Archean Cratons, flanked by Proterozoic mobile belts. The region is characterized by anomalously high topography and shallow Curie depth (Zb). Factors controlling topography and Zb anomalies in old continental crusts remain poorly understood. In this study, we present high-resolution Moho undulation (Zm) derived with gravity spectral technique. Archean Cratons

This study presents the first analysis of the anisotropy of magnetic susceptibility (AMS) coupled with anisotropy of P-wave velocity (APV) in sedimentary rocks from a passive continental margin. In the Otway Ranges, Australia, the Lower Cretaceous sediments deposited during a period of subsidence and structural quiescence display triaxial-magnetic fabrics typical of extensional deformation. The extensional

The national baseline aeromagnetic survey of Britain allows a uniform assessment of the shallow and deep magnetic properties of the British tectonic terranes. The most significant is that associated with destruction of early Palaeozoic oceanic lithosphere across the Iapetus Suture separating Baltica and Avalonia from the Laurentian terranes. Here a formal 3D inversion of a continuous swathe of the

The Tian Shan mountain range maintains high topography across the Eurasian continent despite being distal to any modern plate boundary. Previous studies of the Tian Shan have revealed a history of mountain building in response to India-Asia collision which has overprinted much of its Mesozoic history. The Karatau and Talas ranges in the north-western Tian Shan represent a unique opportunity to investigate

Pre-existing faults in the mechanical basement are believed to play an important role in controlling deformation of the thin-skinned Jura Mountains fold-and-thrust belt, which constitutes the northernmost extension of the European Alps. We use brittle-viscous analogue models to investigate the influence of frontal and oblique basement steps on the subsequent evolution of structures during thin-skinned

Granular materials are a useful analogue for the Earth's crust in laboratory models of deformation. Constraining their mechanical properties is critical for such model's scaling and interpretation. Much information exists about monomineralic granular materials, such as quartz sand, but the mechanical characteristics of bimineralic mixtures, such as commonly-used quartz sand mixed with gypsum powder

To better constrain the heat source of the geothermal system and lithospheric thinning mechanism of the Paleo-Pacific subduction zone, data from 35 broadband magnetotelluric (MT) stations were collected in 2020 along a 180-km-long NW-trending profile in the Cathaysia Block. Based on the measured data, we obtained the lithospheric electrical structure of the Cathaysia Block in South China using the

To assess the geometry of cracks in highly altered peridotites, we analyzed the ultrasonic velocity of serpentinized dunites and harzburgites collected by the Oman Drilling Project (Holes BA1B, 3A, and 4A). First, we estimated the hydrated fraction from grain density to obtain the porosity-free matrix velocity, which indicated complete serpentinization at shallow depths and decreasing hydration at

The Jiaodong Peninsula of eastern China is densely populated and prone to frequent moderate-strong earthquakes that are mostly distributed along a group of northeastern oriented Mesozoic-Cenozoic faults. An improved understanding of the seismic velocity structure in the area is of great significance for the roles that the faults played in the formation and evolution of the various tectonic features

Clay-mineralogy study of Taiwanese river-mouth sediments, recent deep-water seafloor sediments around Taiwan, along with sediments collected from the Tainan shelf edge, have been investigated to access the source and transport of detrital fine-grained sediments. We determined the clay mineralogy in both hemipelagites and turbidites in the top 50 cm of the deep-sea sediment cores to infer how sediments

Anisotropy of magnetic susceptibility (AMS) analyses and structural observations of Triassic flysch in the Tsetang area, SE Tibet, were carried out to assess the Cenozoic tectonic evolution and kinematics of deformation of the eastern Tethyan Himalaya Thrust Belt. We analysed a total of 202 standard-sized specimens from four sample sites across the Renbu–Tsetang Thrust from north to south. Rock magnetism

The Keping fold-and-thrust belt (FTB) is located along the southern foreland of the Chinese Tian Shan, consisting of 3–6 rows of E- to NE-trending thrusts. Determining the time of thrusting and folding within the Keping FTB is crucial to understand the process and characteristic of tectonic deformation along the southern Tian Shan foreland. Here, we present new deformation ages of four thrusts within

The control exerted by the Mesozoic basin configuration on the Cenozoic tectonic evolution of the Catalan Coastal Ranges has been frequently recognized as a key factor to explain its present-day structure. However, details of this structural inheritance and its evolution through geological time is still under discussion. In this work we present two structural cross-sections based on fieldwork, well

This paper analyses the process and depth of formation of chromite crystals occasionally including ultrahigh pressure (UHP) minerals, recovered from some investigated ophiolites. We present direct microstructural evidence for crystallization of chromite ores from the Semail ophiolite, in place they are exposed. Similar crystal preferred orientation in olivine-rich layers and in septa from chromite

The axial fault-bounded depression of the South Kenya rift (SKR) locally displays anomalously wide sectors resulting from the presence of one (or many) elevated and offset block(s) on the flanks of the main trough. Very little attention has been paid so far to the nature of the driving mechanisms responsible for these atypical rift patterns. New insights are supplied by the Natron-Ol Doinyo Ogol rift

This paper presents a detailed case study of decorated dislocations of olivine with C-type fabric in the Lüliangshan garnet peridotite from the North Qaidam ultrahigh-pressure (UHP) metamorphic belt in NW China. Electron backscatter diffraction (EBSD) measurements reveal a weak C-type fabric in olivine, i.e., the crystallographic [100] axes form a weak point maximum subnormal to the foliation while

Lithospheric rheological heterogeneities across a rift play a significant role in intraplate deformation and seismic activity. The Kachchh rift in the northwestern part of the India has not only experienced lithospheric stretching but also witnessed large magnitude devastating earthquakes. Here, we present the results of a magnetotelluric (MT) investigation carried out in the southeastern part of the

This study examines the scaling relationship between fault length and displacement for the purpose of gaining a better understanding of the evolution of normal faults within the central Kenya Rift. 620 normal faults were manually mapped from a digital elevation model (DEM), with 30 m2 resolution and an estimated maximum displacement of ~40–~6030 m and fault lengths of 1270 ‐ 60,600 m. To assess the

The closure of Mianlue Ocean lead to the collisional assembly between the North China Block (NCB) and the South China Block (SCB). But the timing of initial continental collision remains unclear, with the proposed ages ranging from the Late Permian to the Late Triassic. This study presents stratigraphic, sedimentological, tectonic subsidence, and provenance data from the Triassic strata in the Zigui

Orthopyroxene is the second most abundant mineral in the upper mantle and, like olivine, can form crystallographic preferred orientations (CPO) during mantle deformation that may influence mantle seismic anisotropy. Here we use a compilation of 21 peridotites in which both olivine and orthopyroxene CPOs are preserved to document the range of orthopyroxene CPO types and to explore their effects on seismic

Intragranular boundaries are important features of polycrystalline materials and impact on many physical and chemical properties. Knowledge of their physical orientation is often crucial to explain such properties. However, it has proved difficult to determine the complete orientation of intragranular boundaries, which involves the misorientation angle and axis about which the adjacent crystal lattices

Costa Rica is a seismically active region located in a subduction zone. Combining earthquake data from the National Seismological Network and several Central American catalogs from 1522 to 2020, we present a new estimation for the Gutenberg-Richter relationship. The seismic catalog compiled with ~122,000 earthquakes was studied by calculating the magnitude of completeness (Mc) and by applying a space-time

The convergence between the Eurasian Plate and the Philippine Sea Plate results in rapid uplifting of the Taiwan Orogen. To study the mountain building in Taiwan, we present three transects of shear wave velocity across the Taiwan mountain belt with joint inversion of teleseismic Rayleigh wave H/V ratios and phase velocities derived from ambient noise tomography. The Particle Swarm Optimization algorithm

The structural evolution of the Larnaka Ridge is studied using high-resolution multichannel seismic reflection profiles and multibeam mosaics of the seafloor. Multibeam maps revealed the presence of two families of en-échelon tension cracks (young and old) on the seafloor north of the ridge. Rose diagram on the young tension cracks revealed that most lineations are oriented NW–SE, where the instantaneous

Multichannel seismic reflection profiles show that the Outer Cilicia Basin evolved mainly during the uppermost Messinian–Quaternary as an asymmetric piggyback basin on the hanging wall of the large south-verging Kyrenia thrust culmination, following the partitioning of the much larger Miocene basin. A major north-verging backthrust and several similarly-verging smaller splays developed during the deposition

The formation of curved orogens (oroclines) is commonly attributed to buckling around a vertical-axis in response to orogen-parallel compression. Nonetheless, the viability of this mechanism in a three-dimensional stratified lithosphere is controversial. Here we use numerical models to assess how the horizontal stratification of the lithosphere affects buckling processes. Our three-dimensional models

Earthquake gates are fault geometric complexities, common in natural fault systems, that conditionally impede earthquake ruptures. This study centers on modeling of multicycle dynamics of the Pingding Shan earthquake gate along the central Altyn Tagh Fault in northwest China. The earthquake gate includes three geometric complexities: a prominent restraining bend, a 4-km wide stepover to the east, and

The June 12, 2017 Karaburun-Lesvos (North Aegean Sea) earthquake occurred along the NW-SE trending Lesvos fault, along the southern strand of the North Anatolian Fault Zone. In the present study seismotectonic aspects of the 2017 Karaburun-Lesvos earthquake and its aftershock sequence are studied. A rupture model based on finite source analysis of the teleseismic waveforms has shown that the earthquake

Two tectonic plates converge at subduction zones where the subducting plate bends. Flexural bending of a subducting plate at a trench results in pervasive normal faulting, providing conduits for plate hydration and influencing the water budget and seismic behavior of the plate interface. 2-D plate bending simulations have demonstrated high strains due to strong bending may result in loss of strength

The Ismetpasa segment of the North Anatolian Fault (NAF) is where an aseismic creeping behaviour is observed. As a result, earth scientists are focused on the Ismetpasa segment to understand and explain the nature of creep behaviour. The studies conducted on the segment are based on many different techniques such as simple measuring tape observations, InSAR and GNSS observations, depending on the technological

Naturally deformed dunite cores with a preexisting crystallographic preferred orientation (CPO), collected from a shear zone in the Josephine peridotite (southwest Oregon, USA), were deformed experimentally in triaxial compression. The compression axis was varied relative to the CPO geometry to measure the anisotropy in viscosity of these rocks. Deformation experiments were performed in a gas-medium

We show the results of a geophysical survey carried out in the Alalobeda (Alalobad) geothermal field (Afar, Ethiopia). The site is located on the western margin of the NW-SW Tendaho Graben, at the intersection with the NNE-SSW Main Ethiopian Rift. The survey included 121 Magnetotelluric (MT) and Time Domain Electromagnetics (TDEM) soundings, and 300 gravity records. We applied 3D MT and gravity inversion

Satellite image-based lineament mapping in combination with the normalised Stream Length Gradient Index (SL/K-index) is one of the most widely used methods to identify active faults in areas where other verification methods, such as faulted strata, geophysical subsurface data, or seismic activity in the upper crust, are unavailable, and to classify their degree of activity. The accuracy of this approach

The Pliocene-Quaternary evolution of the western margin of the Calabrian Arc has been investigated by analysing the configuration and distribution of local sedimentary basins and their relationship with shallow and deep tectonic structures. Research focussed on the evolution of the more recent offshore sedimentary basins located to the east of Sicily, along the Alfeo Fault System, using multichannel

The age of breakup which formed the Central-North Atlantic has been debated for many decades and is still subject to debate: from ca. 150 Ma to 110 Ma. To address this issue, we have carried out a thermochronological study of the eastern margin of the rifted Iberia-Newfoundland sector. New apatite fission-track (AFT) data acquired on samples from the footwall (Variscan basement) and one sample (Triassic

High-resolution P-wave velocity and anisotropy structure of the hitherto elusive uppermost mantle beneath the Indian shield and its surrounding regions are presented to unravel the tectonic imprints in the lithosphere. We inverted high quality 19,500 regional Pn phases from 172 seismological stations for 4780 earthquakes at a distance range of 2° to 15° with a mean apparent Pn velocity of 8.22 km/s

The 150 km long, 6 s TWT, 2D seismic profile KBF03A, which was acquired in 1994 and lies near the western edge of the Kaapvaal craton in South Africa, has been reprocessed using standard reflection seismic processing methods. The results exhibit a significant improvement in the imaging quality of the subsurface features and an evident boost in the signal-to-noise ratio. The improved seismic data, combined

Due to the subduction of the Paleo-Pacific Plate below the East Asian continent, the North China Craton (NCC) is considered to have been thinned in the Mesozoic, with the lithosphere of its east portion significantly thinned. As the eastern boundary of the NCC, The Tanlu Fault Zone (TLFZ) is one of the largest strike-slip fault systems in eastern Asia. Tanlu is believed to have recorded the destabilization

The crystalline basement of the Upper Rhine Graben is a major target for deep geothermal exploration due to the generally high reservoir temperatures and the increased radiogenic heat production. The geothermal potential is strongly dependent on the lithology because mainly the thermal but also the hydraulic properties are affected by the rock type. For this reason, the so far most detailed 3D model

Using lidar, photogrammetry and field studies, we investigate the structure and kinematics of the Hope, Kelly, and Alpine faults where they converge and intersect along the Australian-Pacific plate boundary in New Zealand. Approximately 50% of the reverse-dextral slip rate of the Alpine fault in the west transfers to the dextral central Hope Fault in the east via a horsetail splay zone of distributed

It has long been debated whether the formation of the Cenozoic Weihe and Shanxi grabens in North China was induced by the Indo–Asia collision or Pacific Plate subduction. Deciding between these two models requires precise knowledge of the timing of the graben formation. In this study, we used high-resolution magnetostratigraphy to suggest that the age of a ~ 1644-m thick syn-rift section conjoining