Pyroclastic currents are described as gravity currents, and the classic conceptual model gives a first-order importance to the density of such currents. This directs quantitative models to assume specific flow structures (shallow water or equilibrium turbulent boundary layer), which may apply to restricted volcanic areas independently of source dynamics, or may correspond to source dynamics separate

Remarkably regular load structures are recognized in the late Vistulian (~15 ka BP) fluvial deposits exposed at the Gołąb site (eastern Poland). A mud layer, sandwiched between non-deformed sand, exhibits the unusual morphology of a 3D sine wave with parallel crests and troughs. Such structures are reported for the first time, remarkably differing from those previously described as having perfect linearity

More accurate normal fault mapping and more recently constrained extension rates in southern and central Tibet allow to better discuss the mechanical processes responsible for the distribution of extension in Tibet. First, we show that the location of the rifts in southern Tibet south of the Karakorum-Jiali fault zone (KJFZ) does not exactly correspond to that of the rigid Indian lower lithosphere

The association between Large Igneous Provinces (LIPs) and mass extinctions and anoxic events is attributed to the radical climatic changes in Earth. Even though the Early Cretaceous Paraná–Etendeka Igneous Province has a comparable erupted volume (>1 Mkm3) to other LIPs (e.g., Deccan, Emeishan and Siberian Traps), it remains controversial why this LIP did not contribute to a mass extinction and whether

In the northeastern (NE) Japan arc, active faults have a characteristic effect upon the short-wavelength Bouguer anomaly (SWBA). Here, we create a SWBA map based on the Fourier analysis of the latest gravity dataset and evaluate the relationship between the SWBA and active faults in the arc. Ultimately, we found that active faults are associated with negative regions or grooves in the SWBA and that

The relationships between tectonics, climate and sedimentation are important for understanding landscape evolution. In order to elucidate these relationships, we conducted a detailed survey of the thickness of terrace deposits and the altitude of terrace surfaces along the Liyuan River valley, in the Northeast (NE) Tibetan Plateau. We have dated the formation ages of terraces T3 and T4 to 42 ± 3.2

We investigate the variations in the state of isostatic compensation of the Mariana subduction system. We first calculate and analyse the gravity-derived crustal thickness and non-isostatic topography of this region. The Mariana back-arc spreading centre and West Mariana Ridge are both close to Airy isostatic compensation. In contrast, the Mariana Trench axis is associated with a clearly defined zone

Carbonate-associated sulfate (CAS) is an important proxy for reconstructing marine sulfur cycling throughout Earth's history. In order to assess the impact of carbonate neomorphism on δ34SCAS data, a mineralogical-spatial transect from early diagenetic limestone into low-temperature hydrothermal dolostone was analyzed in the middle Triassic Latemar platform interior, northern Italy. This study addresses

We present structural analysis and zircon and monazite geochronology of the Greater Himalayan Sequence (GHS) in the Kali Gandaki valley, central Nepal. Although the foliation is moderately NE-dipping, the upper GHS shows a top-to-WNW shear sense, whereas the lower GHS developed top-to-SW ductile shear zones. Quartz fabrics from mylonitic gneisses indicate deformation temperature from >650°C to ~450°C

We identify two piercing point pairs along a ~500 km transect of the arcuate strike-slip Denali fault to document long-term slip partitioning. Geochemical and isotopic similarity between Foraker and Panorama-Schist Creek-Nenana Plutons suggest ~155 km of right-lateral displacement on the western Denali fault since 37 Ma at a rate of ~4.2 mm/year. The eastern Denali fault Maclaren-Cottonwood Terrane

Paleo-Pacific subduction generated a prolonged active continental margin along the coast of the South China Block (SCB). A Triassic magmatic gap was argued to have occurred and was ascribed to flat-slab subduction of an oceanic plateau. We study for the first time a >330-m-long core of typical arc volcanics dated at ca. 218 Ma from the Meiji Atoll in the southern South China Sea (SCS). Paleomagnetism

Despite considerable progress in restoring rifted margins, none of the current kinematic models can restore the Mesozoic motion of the Iberian block in full agreement with the circum-Iberian geology. This conflict requires a revision of the kinematic description at the onset of divergence. The circum-Iberian region has a unique geological dataset that allows calibration and testing of kinematic reconstructions

The Tanlu Fault Zone in eastern China stretches more than 2,400 km and is a significant, active, feature in the tectonics of East Asia. Here, we show the results of local earthquake travel-time tomographical approach based on a comprehensive and systematic set of seismic data collected from 2008 to 2018 along the Central South Segment of the Tanlu Fault Zone. According to the model, the uppermost 0–10 km

The Himalaya, a leading example of active mountains, is jointly shaped by intense tectonics, extreme climate and surface denudation. However, the causal relationship among these agents remains controversial. In this work, by an integrated analysis of bedrock channels and valley hillslopes using process-based models, we discover 3D-linear correlations in logarithmic space among precipitation-estimated

Collision-related porphyry Cu deposits (PCDs) are restricted to previous magmatic arcs, in which sulfide-rich lower crust occurred. Fertile adakite-like porphyries associated with PCDs have higher K2O contents and K2O/Na2O ratios than barren porphyries emplaced in the same arc. The elevated K2O/Na2O ratios of fertile porphyries reflect substantial inputs of coeval hydrous, oxidized ultrapotassic melts

The Jianchuan Basin is a key region for determining the spatial-temporal evolution of paleodrainage and tectonic at the southeastern Tibetan Plateau. New detrital zircon U-Pb geochronology and paleocurrent data from Eocene formations in this basin suggest that the sediment sources switched from the remote sources (including Hoh-Xil, Songpan-Ganzi, North Qiangtang, Yidun and western Yangtze terranes)

Absolute dating helps to define the age and duration of orogen building. Here we present new U–Pb ages of syn-faulting calcites collected in the northern foreland basin of the Pyrenees. The studied area underwent deformation during the Eocene growth of the belt. This orogenic growth is considered to have persisted until the Late Oligocene, after which post-orogenic processes prevailed. Microstructural

Graphite deposits may form alternatively by metamorphism of sedimentary rocks and from fluids. Both types occur in supracrustal successions within the Lewisian Complex of Northwest Scotland, and similarly in Palaeoproterozoic supracrustal rocks across the North Atlantic region in Canada, Greenland and Scandinavia. Carbon isotope compositions show that the graphite in Scotland had a mixed origin from

Graphite impacts crustal rheology and electric conductivity in the lower crust. In a combined geophysical and geological study from the Proterozoic Lofoten-Vesterålen Complex, Norway, we show the enrichment of graphite resulted in zones with strong schistosity and a sharp strain gradient towards host massive granulite gneiss. Increased graphite content resulted in high-conductivity zones with true

In East Greenland, sedimentation during the Middle Devonian-earliest Carboniferous interval was characterized by the Old Red Sandstone Molasse Basin deposits. The continental succession recorded folding and intrabasinal unconformities associated with the activation of extensional detachments and core complex formation which post-dated high-P granulite facies metamorphism at c. 403 Ma. The extensional

The establishment of the course of the modern Yangtze River is a topic of ongoing debate, with the formation of the Three Gorges, incised in the Huangling Massif, representing the key event under discussion. Downstream of the Three Gorges, the Cenozoic succession of the Jianghan Basin has been investigated to detect the moment of incision into the Three Gorges. Detrital apatite fission-track data from

Fault- and fracture-hosted multi-stage mineral assemblages that formed by fracture reactivation and fluid migration, constitute archives of the tectonic evolution of Precambrian cratons. Complex intergrowth patterns of these mineral records often hinder absolute dating of mineralization events for geological models. We apply LA-ICP-MS/MS in situ Rb-Sr dating of single crystal growth zones in sub-mm-wide

The effects and timing of the evolution of siliceous sponge and radiolarians on the mode of silica burial and oceanic silica cycling in the early Cambrian are still controversial. Bedded cherts of the lower Cambrian Yurtus Formation deposited in a subtidal shelf environment. They display diagnostic sedimentary features, including intraclastic chert grains, edgewise chert breccias, weakly compacted

The conventional mechanism for dolomitization in evaporitic basins is by drawdown-related reflux of brines, but it seems that ascending brines were responsible in the case of basal Zechstein (Wuchiapingian) strata. Dolomite of basinal sections of the Zechstein Limestone in SW Poland show mostly fabric-destructive dolomitization and wide δ18OVPDB and δ13CVPDB ranges (−3.78 to 6.47‰ and −1.64 to +5.3‰

We establish a high-resolution magnetic isochron pattern in the East Subbasin (ESB) of the South China Sea (SCS) based on recently collected magnetic data, which provides an updated age of seafloor spreading in the ESB and reveals a new type of ridge reorientation. Seafloor spreading in the ESB initiated at Chron 11n.1r (29.7 Ma) and ceased shortly after Chron 5Br (15.6 Ma). Successive ridge jumps

The Archean-Proterozoic transition heralded a number of fundamental changes on Earth, including the oxygenation of the atmosphere, a marked emergence of continents above sea-level, and an increase in δ18O of felsic magmas. The potential drivers for the latter are changes in the composition of supracrustal material or increased crustal reworking. Although the onset of subduction-induced continental

The Capitanian (late middle Permian) and end-Permian mass extinctions were particularly severe from a palaeoecological perspective. Previous studies of their expressions on land underscored their impacts on plants and vertebrates, but the effects on the continental invertebrate infauna remain poorly understood. A multiproxy analysis from the Iberian Basin (Central Spain) reveals a dramatic decrease

The Xigaze fore-arc basin in southern Tibet records important information related to subduction of the Neo-Tethys and subsequent collision between India and Asia. We present field observations, together with new apatite fission track and zircon (U-Th)/He (ZHe) thermochronology data, from a ~25 km SW-NE transect in the central Xigaze fore-arc basin around Sangsang to elucidate the burial and exhumation

A widespread provenance shift recorded by passive margin strata of western Laurentia, from predominant Stenian (1.2–1.0 Ga) detrital zircon age components to their absence, occurred during the Neoproterozoic–Cambrian Sauk transgression and is commonly used as a ca. 540 Ma chronostratigraphic marker throughout the west/south-western United States. However, in Neoproterozoic–Cambrian strata of this region

Olivine-hosted melt inclusions (MIs) from tephra of the recent 2013–2018 activity at Mt. Etna were investigated for assessing the chemical evolution of magmas and quantifying their pre-eruptive volatile budget. Microanalyses revealed two types of MIs present in all investigated eruptions; the inclusions, particularly the less evolved ones, appear to have experienced water loss coupled with SiO2 depletion

Knowledge of the Guiana Shield evolution during the Gondwana break-up is key to a better understanding of craton dynamics and margin response to transtensional opening. To improve this knowledge, we investigated the dynamics and thermal evolution of French Guiana, using several low-temperature thermochronology methods applied to basement rocks, including apatite and zircon (U-Th)/He and apatite fission

As a proxy for the lithospheric strength at the time of loading, the effective elastic thickness of the lithosphere (Te) can aid in understanding the structure and evolution of the lithosphere. Here, we obtain spatial variations in Te of Amerasia Basin and surrounding regions using the fan-shaped Morlet wavelet method. Our results show that variations in Te generally agree well with tectonic provinces

The Taiwan–Ryukyu arc–trench junction area is a seismic active region and has high potential to generate large earthquakes. However, the detailed deep structures are not fully revealed because of data resolution problems. The Taiwan Integrated Geodynamic Research (TAIGER) project collected two wide-angle and multichannel seismic profiles across the Taiwan mountain belt (T5) and the western end of the

The Oligocene represents a transitional phase from a “hot-house” to a “cold-house” climate. Central Asia has undergone substantial environmental changes and tectonic events; however, we know little about how these tectonic events shaped the climate and biodiversity in Central Asia. Here, we present a detailed study on the early Oligocene palaeobotanical record in Kazakhstan using various qualitative

Here, we present the detrital zircon age spectra for five (n = 36, 68, 66, 41, 29) red quartzite gastroliths collected from the top of the Upper Jurassic Morrison Formation in the eastern Bighorn Basin, Wyoming, USA. The detrital zircon age spectra reveal geon 17 maximum depositional ages, and age peaks that are Yavapai (geon 17), Penokean (geon 18) and Archean (>geon 25). The colour, texture, composition

The South Chile ridge (SCR) intersects the Patagonian trench around 46°09′S, forming the triple junction among the Antarctic, Nazca, and South America plates. Subduction of the SCR since ~18 Ma produced the opening of a slab window beneath Patagonia and a noticeable magmatic gap in the cordillera, profuse volcanism and topographic uplift in the retroarc. To study seismicity distribution and present-day

An updated GPS velocity field and set of focal mechanism solutions have allowed us to quantify the detailed tectonic deformation of Northeast Tibet. By employing block kinematic modelling, we show how the relative motion of modelled blocks is accommodated by deformation on major fault structures across the region, from the Eastern Kunlun Range to the Qilian Shan, with the slip rate decrease from the

The arcuate tectonic structure is a prominent feature of the northeast Tibetan plateau, the dynamics of which is still not well constrained. In this study, 3-D high-resolution numerical models are systematically conducted to investigate the arcuate tectonics and dynamics. The models highly emphasize the significance of lateral heterogeneities, indicating that the pre-existing strong blocks within the

Recently, a number of research findings have come to light about the age of plate tectonics, and energies are needed to operate it. The aim of present study is to investigate whether the energy of plate tectonics process was different during the Phanerozoic (Pz) and in earlier eons, and if there is such a discrepancy, whether it can be justified by changes in the processes that able to move the plates

The appraisal of geothermal sites along Gulf of Suez, is important to develop the renewable energy resources in Egypt. An integrated approach based on remote sensing, Geographic Information System and geophysical methods were used to predict the ubication of promising geothermal sites. Multi‐source datasets were selected, analysed and integrated to develop a Geothermal Potential Model. Information‐Value

We describe a singular structure in Upper Cretaceous rocks of the Eaux‐Chaudes massif of the western Pyrenees, consisting of a kilometre‐scale fold nappe with a sheared overturned limb. High ductile strain attests a deformation style rarely reported for the alpine Pyrenees, and peak temperature in Upper Cretaceous carbonates is estimated by Raman spectroscopy of carbonaceous material palaeothermometry

The Salt Range in Pakistan exposes Precambrian to Pleistocene strata outcropping along the Salt Range Thrust (SRT). To better understand the in‐situ Cambrian and Pliocene tectonic evolution of the Pakistan Subhimalaya, we have conducted low‐temperature thermochronological analysis using apatite (U‐Th‐Sm)/He and fission track dating. We combine cooling ages from different samples located along the thrust

Evaluation of the regional geotectonic impact of the High Arctic Large Igneous Province (HALIP) in the present‐day northern Atlantic region has been hindered by poor correlation between the Svalbard–Barents Shelf region and eastern North Greenland. New sedimentological and biostratigraphic data from Peary Land and Kronprins Christian Land (Kilen), North Greenland reveal that the Lower Cretaceous palaeogeographic

We present the first results of OSL‐dated fluvial sands extracted from a riverside cave in the tropical Andes. The excellent agreement between the ages of the various samples allowed the calculation of a late Quaternary valley incision rate forced by ongoing uplift of an active Subandean fault‐propagation fold in NE Peru. A structural cross‐section was constructed to understand the relationship between

We have reinterpreted the causative fault parameters of the 2005 Zarand earthquake in the light of a new imagery study using Interferometric Synthetic Aperture Radar (InSAR). By conducting a joint inversion of two InSAR datasets, we can characterize the rupture as it relates to complex local structures. At first, the mainshock ruptured a nearly pure reverse fault, dipping ~65° NNW in the basement below

S‐type granitic gneiss is a major rock type in exposed Phanerozoic basement areas. However, it is hardly used to decipher the metamorphic evolution of such areas formed by the collision of tectonic plates. It is demonstrated by thermodynamic modelling of the metamorphism of common to evolved S‐type granite that mineralogical key patterns can elucidate the baric nature of granitic gneiss. Low‐ to medium‐grade

Exceedingly strong aeolian dust activity has occurred in inland Asia. Comparisons of the late Cenozoic sedimentation rates between aeolian and fluvial‐lacustrine sequences around the northern Tibetan Plateau suggest that aeolian process has played an important role in the erosion, weathering and deposition of sediment. However, recognizing dust as an important source in fluvial‐lacustrine sequences

Post‐collisional ultrapotassic magmatism received special attention because it is an important indicator for mantle geodynamics in a collisional orogen. So far, no mantle‐derived magmatism has been identified within the Himalayan belt, hindering our understanding of the architecture and thermal state of the deep‐seated lithosphere in this area during the orogenesis. Here, we report the first discovery

We used various fault models to calculate the stress change on Ridgecrest epicentral locations and surrounding fault systems. In general, the 2019 Ridgecrest earthquake sequence was triggered by past historical earthquakes. The computed stress changes in both foreshock and mainshock epicentral locations have exceeded the stress trigger threshold, which suggests that past historical earthquakes play

There is as yet no consensus as to the dominant source of sediment transported to the oceans: the steep tectonically active highlands, or the gently sloping lowlands? In this study, new Pb isotopic analyses of detrital K‐feldspar have been combined with published data to constrain sand supply in the Yangtze River, one of the largest fluvial sediment transport systems on Earth. Tributaries draining

2.9 Ga is an uncommon magmatic age in Archean evolution worldwide, especially in West Gondwana. We identified so far unknown 2.97–2.92 Ga high‐K calc‐alkaline magmatism in the Borborema Province, northeast Brazil. It appears to indicate that the transition to high‐K magmas occurred before c. 2.7 Ga in Earth's history. The 2.9 Ga protoliths were reworked and progressively changed composition to 2.65 Ga

The Rhodope Metamorphic Complex (RMC) in Bulgaria has been established as a Mesozoic ultra‐high‐pressure metamorphic province by findings of microdiamond in gneisses. Additionally, Variscan ultra‐high‐pressure metamorphism has been proposed for the Ograzhden/Vertiskos Unit in the Upper Allochthon of the RMC, based on findings of coesite, graphite pseudomorphs after diamond and indirect age constraints

New Cu isotope data obtained on chalcopyrite from the Black Mountain and the Broken Hill deposits in the medium‐ to high‐grade metamorphic Aggeneys‐Gamsberg ore district (South Africa) require a revision of our understanding of the genesis of metamorphic Broken Hill‐type massive sulphide deposits. Chalcopyrite from both deposits revealed unusually wide ranges in δ65Cu (−2.41 to 2.84‰ NIST 976 standard)

Thrusting and the associated folding are crucial geological processes accommodating the crustal shortening in a foreland setting. This work focuses on the late Quaternary thrusting of the Banfanggou fault (BF) in the southern Chaiwopu Basin, northern Chinese Tian Shan foreland. The outcrops at the Urumqi River in the western part of the southern margin of the basin show that the BF, dipping south with

Lower crusts of oceanic plateaus have been rarely studied and their nature remains unclear, due to low probability in preservation. Here we demonstrate that cumulates of the Pengco Complex in central Tibet represent the lower crust of an oceanic plateau generated at ~188 Ma. Mineral crystallization order and geochemistry support their formation via low‐P fractionation from anhydrous basaltic melts

1School of Ocean and Earth Science, Tongji University, Shanghai, China 2Key Laboratory of Ocean and Marginal Sea Geology, South China Sea Institute of Oceanology, Innovation Academy of South China Sea Ecology and Environmental Engineering, Chinese Academy of Sciences, Guangzhou, China 3Southern Marine Science and Engineering Guangdong Laboratory (Guangzhou), Guangzhou, China 4Department of Geology

The lower crustal domain of the Ivrea‐Verbano Zone (NW Italy) hosts five ~300‐m‐wide pipe‐like ultramafic intrusions that are metasomatized and exhibit Ni‐Cu‐PGE sulphide mineralization. To better constrain the role of metasomatism in the ore genesis, we studied the best‐preserved pipe at Valmaggia which was emplaced 249 Myrs ago. Phlogopite 40Ar/39Ar analyses show that the pipe was infiltrated by

Cooling related to moving rocks over an ~8.5 km vertically thick ramp in the Main Himalayan thrust (MHT) produced 0.8–2 Ma zircon (U–Th)/He (ZHe) and apatite fission track (AFT) ages from the Main Central thrust to 40 km south in central Nepal. The ramp size is controlled by thicker Proterozoic stratigraphy. ZHe ages in NW India and eastern Bhutan over a similar 40 km wide swath are 1.4–12 Ma. In addition