Search

Summary: A novel, monolithic DC‐magnetron sputtered TiN+MgGd coating, only 3to5 μm thick, effectively protects steel substrates from corrosion. This achievement is due to alloying of TiN with MgGd, which not only maintains the renowned wear resistance of TiN coatings, but potentially improves it through optimized deposition parameters. The key to the enhanced corrosion resistance lies in the addition of magnesium (Mg) and gadolinium (Gd). It reduces the coating's free corrosion potential, thereby mitigating the driving force for galvanic corrosion between coating and substrate. Moreover, at specific Mg to Gd ratios, a cathodic protection effect can be observed. Crucially, the presence of Gd is essential for this performance. It imparts hydrophobicity to the coating surface, reinforces a passivating layer and significantly enhances defect tolerance. This discovery paves the way for a sustainable alternative to electroplated chromium or combined electroplating and PVD, offering superior corrosion protection with minimal coating thickness. [ABSTRACT FROM AUTHOR]

U–Pb dating of hydrothermal and hydrothermal accessory minerals is challenging because they often contain high concentrations of common Pb, low U concentrations, and they can be altered and fractured. Photomicrography, Bayesian regression, and trace element and isotope ratio maps have effectively been used to overcome these problems in dating such minerals. A new software, Brama (Bayesian regression and age mapping application) for LA-ICP-MS U–Pb data, performs outlier processing, baseline correction, isotope calculation and Bayesian regression by matching the laser ablation position of the line scan with the time-resolved signal of the plasma mass spectrometry data generated from quadrupole instruments, resulting in high resolution spatial maps of trace element and isotope ratios as well as age results. The software-derived data can also be used in the Tera–Wasserburg and Wetherill methods to calculate mineral ages. We demonstrate the key advantages and potential applications of Brama with two examples of LA-ICP-MS calcite and apatite U–Pb dating. [ABSTRACT FROM AUTHOR]

We study the effects of pore fluid pressure (Pf) on the pre‐earthquake, near‐fault stress state, and 3‐D earthquake rupture dynamics through six scenarios utilizing a structural model based on the 2004 Mw 9.1 Sumatra‐Andaman earthquake. As pre‐earthquake Pf magnitude increases, effective normal stress and fault shear strength decrease. As a result, magnitude, slip, peak slip rate, stress drop, and rupture velocity of the scenario earthquakes decrease. Comparison of results with observations of the 2004 earthquake support that pre‐earthquake Pf averages near 97% of lithostatic pressure, leading to pre‐earthquake average shear and effective normal tractions of 4–5 and 22 MPa. The megathrust in these scenarios is weak, in terms of low mean shear traction at static failure and low dynamic friction coefficient during rupture. Apparent co‐seismic principal stress rotations and absolute post‐seismic stresses in these scenarios are consistent with the variety of observed aftershock focal mechanisms. In all scenarios, the mean apparent stress rotations are larger above than below the megathrust. Scenarios with larger Pf magnitudes exhibit lower mean apparent principal stress rotations. We further evaluate pre‐earthquake Pf depth distribution. If Pf follows a sublithostatic gradient, pre‐earthquake effective normal stress increases with depth. If Pf follows the lithostatic gradient exactly, then this normal stress is constant, shifting peak slip and peak slip rate updip. This renders constraints on near‐trench strength and constitutive behavior crucial for mitigating hazard. These scenarios provide opportunity for future calibration with site‐specific measurements to constrain dynamically plausible megathrust strength and Pf gradients. Plain Language Summary: Large volumes of fluid can lead to high‐pressures that weaken rocks in fault zones and influence earthquake rupture. While fluids are critical to understanding behavior at subduction zones, where the largest earthquakes in the world occur and where tsunami generation increases hazard, measuring fluid and fluid pressure directly across an entire megathrust currently is not possible. Here, we use supercomputers to model the devastating 2004 Mw 9.1 Sumatra‐Andaman earthquake in 3‐D in order to isolate the role of fluid pressure on earthquake behavior. By first building a reliable base model and then varying fluid pressure to generate six earthquake scenarios, we find that fluid pressure is likely very high, and also that the way that fluid pressure varies with depth can greatly influence the earthquake and associated hazard. Fluid pressure controls location of the largest and fastest fault slip along the megathrust, and the possibility for a devastating tsunami. Key Points: Three‐dimensional dynamic rupture modeling of megathrust earthquakes under varying pore fluid conditions reveal very high pre‐earthquake fluid pressureWhen pore fluid pressure increases with the lithostatic gradient, peak slip and peak slip rate occur at shallower depths, controlling hazardApparent co‐seismic principal stress rotations and heterogeneous absolute post‐seismic stress states reflect aftershock focal mechanisms [ABSTRACT FROM AUTHOR]

The primary geological conditions for hydrothermal systems can be reconstructed using fluid inclusions, which generally requires that fluid inclusions trapped a single homogeneous phase and experienced no mass and volume changes after entrapment (Roedder's Rules). However, heterogeneous entrapment and post-entrapment modifications have been frequently identified in fluid inclusion studies, making the recovery of primary fluid properties from fluid inclusion data challenging or impossible. In this study, we constructed a specific tool, FlincPro, for the calculations of ideal and nonideal Fl uid inc lusion Pro perties in the H 2 O-NaCl system (ideal here refers to fluid inclusions that adhere to Roedder's Rules). Multiple modules have been developed to quantify the variations of fluid inclusion properties caused by heterogeneous entrapment, volume contraction/expansion, and water loss. The developed software illustrates possibilities in the variation of fluid inclusions in a specific assemblage with the input of a certain starting point. We found that compositions of the vapor endmember fluid are more significantly affected by heterogeneous entrapment than the liquid endmember, as the latter may have several orders of magnitude higher salinity and density. Homogenization pressure and temperature of halite-bearing fluid inclusions trapped on the halite liquidus will increase sharply with the addition of halite, but the homogenization behavior will not be changed. Volume contraction/expansion are effective ways to change the homogenization behaviors, especially for high salinity fluid inclusions. Water loss is not likely to cause the homogenization behavior change from total homogenization by vapor disappearance to total homogenization by halite dissolution for a halite-bearing fluid inclusion without additional volume contraction. Low-salinity and low-density fluid inclusions with total homogenization temperature around the critical temperature of water are least affected by post-entrapment modifications. Therefore, the interpretation of fluid inclusions formation depends on more parameters, e.g., petrographic observations, density and composition variations in fluid inclusion assemblages, and geological information, than only microthermometric data. [ABSTRACT FROM AUTHOR]

We present a systematic examination of the volatile (Cl, F, Br, S) and trace element (Na, Mg, V, Mn, Fe, Sr, Y, Zr, Ba, REEs, Th, U) abundances in apatite from 29 samples from base to top of the Layered Series in the Skaergaard intrusion, East Greenland. Apatite occurs as an interstitial phase in the lower zones, but joins the liquidus assemblage late in the crystallisation history (c. 90% crystallised), defining the base of Upper Zone b. The apatite can be classified as fluorapatite with low Cl/F ratios (< 0.4), confirming previous result. The REE content of interstitial apatite decreases from the base up to the middle part of the intrusion, followed by an increase towards the base of Upper Zone b. When apatite becomes a primocryst (liquidus phase) it shows significant difference in composition, including elements such as REEs + Y, Cl, Sr, and Eu compared to interstitial apatite. Whilst Sr and Eu are enriched in primocryst, the other REEs + Y and Cl are depleted compared to interstitial grains. Whilst the REE composition of primocryst apatite can be explained by fractional crystallisation of the Skaergaard parental magma, the peculiar trend and enrichment of REEs in interstitial apatite can be reproduced using a simple mass balance model (i.e. a simple mass balance equilibrium model where the bulk concentration of an element is evenly distributed between all phases in the final cumulate rock according to the respective partitioning coefficients). In this regard, the difference in composition between interstitial and primocryst apatite is explained by different formation environments (i.e. crystallising (late) from trapped liquid vs. main magma). Compared to primocryst apatite, interstitial apatite in Skaergaard is more REE (and Cl) rich due to crystallisation and continued reaction with a highly fractionated trapped interstitial melt. During crystallisation and continued reaction with the interstitial melt and sub-liquidus equilibration, Sr and Eu partition into plagioclase, depleting interstitial apatite in Eu and Sr compared to primocryst apatite. The mass balance model demonstrates that the REE content of interstitial apatite can be attributed to partitioning competition within the present mineral assemblage during crystallisation of the interstitial melt and diffusive re-equilibration. In this regard, the proportion of trapped interstitial melt relative to the proportion of different primocryst minerals is crucial. It is shown that especially the modal abundance of clinopyroxene exerts strong control on the distribution of REE in interstitial apatite. [ABSTRACT FROM AUTHOR]

The San Pedro porphyry Cu‐(Mo) deposit, located in the San Rafael Massif (Argentina), is characterized by multiple stockwork vein generations developed in a subvolcanic intrusion with porphyry‐type alteration and mineralization, as well as associated polymetallic veins. Previous works reveal that the intrusive rocks related to the San Pedro porphyry (263 Ma) show comparable trace element signatures to giant porphyry deposits elsewhere (i.e., high Sr/Y and low Y). The fluid inclusions investigated in this study show that typical early, high‐temperature magmatic fluids (up to 685°C; 81.3 wt% equiv. NaCl) evolved to lower‐temperature, moderately saline fluids (up to 454°C; 52.4 wt% equiv. NaCl) due to fluid–rock interaction. The waning stage of the system is characterized by secondary, aqueous inclusions that represent dilution by meteoric fluids (up to 390°C, 16.9 wt% equiv. NaCl). Fluid inclusions were studied from two veinlet generations (A and B veinlets) related to potassic alteration and analyzed by LA‐ICP‐MS. The trace element signatures in the fluid inclusions suggest that there were two pulses of magmatic fluids that subsequently evolved under similar physicochemical conditions. The Cu concentration in the earliest fluid is between 0.3 and 0.85 wt% and within the concentrations found in other mineralized porphyry systems in the world. However, in contrast to economic porphyry systems, where a significant change in Cu concentration during fluid evolution is observed, there is no distinct change in the fluid Cu concentration at the San Pedro deposit, which would indicate that Cu and Mo precipitation was ineffective in the hydrothermal system. [ABSTRACT FROM AUTHOR]

DC-PVD TiMgGdN coatings with excellent corrosion properties have been successfully developed using a powder metallurgy TiMgGd target while maintaining the well known tribological properties of TiN. In this study, TiMgGdN coatings were compared with TiMgN coatings using identical deposition parameters to investigate the influence of Gd on the corrosion behavior. For this purpose, a TiMg powder metallurgical target was used with an identical Ti/ Mg ratio as the TiMgGd target. The coatings were comprehensively analysed by different analytical methods such as X-Ray Diffraction (XRD), Scanning Electron Microscopy (SEM), X-Ray Photonelectron Spectroscopy (XPS) and Glow Discharge Optical Emission Spectroscopy (GDOES) regarding their chemical, structural and microstructural characteristics. The corrosion properties were investigated using the neutral salt spray test (NSS test) in 5 % NaCl solution as well as with potentiodynamic tests in 0.5 % NaCl solution saturated with Mg(OH) 2. Based on the findings of this study, it can be concluded that the excellent corrosion performance along with the mechanical properties are supported by the Gd addition to the coatings. The TiMgN coatings show a change in chemical composition, microstructure as well as in hardness after corrosive exposure, which cannot be observed on TiMgGdN coatings. Consequently, alloying TiMgN with Gd maintains the stability of the coating during corrosive exposure. The analytical results show that the excellent corrosion performance and stability of the TiMgGdN coatings are due to a stable and stronger passivation layer by the formation of Mg(OH) 2 and Gd 2 O 3 on the TiMgGdN surface. Furthermore, the Gd 2 O 3 contributes to a strong hydrophobic effect. Regarding the microstructure, TiMgGdN coatings are seemingly denser compared to the TiMgN coatings, which positively influences the corrosion resistance of this coating. • The addition of Gd leads to an increase in coating density. • The TiMgN coatings show a degradation of the coating under corrosive exposure. • The chemical degradation of the TiMgN coatings depends on the microstructure. • The TiMgGdN coatings show high chemical stability under corrosive exposure. [ABSTRACT FROM AUTHOR]

The Skaergaard intrusion in East Greenland hosts mineralisation of platinum group elements and gold that is characterised by a remarkably low amount of sulphides (about 0.02 wt% sulphide) and a very high metal/sulphur ratio. Here we present the first quantitative analyses of sulphur (S), copper (Cu), lithium (Li) and other trace elements from melt inclusions in plagioclase to trace their evolution in the magma and to constrain the formation of the mineralisation. The concentration of these elements in the melt inclusions varies considerably within each sample. The S content in melt inclusions ranges from 165 to 320 ppm in the lower part of the intrusion, but increases to 349–512 ppm immediately below the mineralisation interval. In the same interval, the Li content increases from 22–43 to 40–69 ppm and Cu ranges from 118 to 1586 ppm with no systematic variations. Across the mineralisation, the Li content drops an order of magnitude to 4–7 ppm and S drops to 250–326 ppm. We explain these compositional changes as reflecting the magmatic evolution as the result of fractional crystallisation below, and coinciding aqueous fluid exsolution and sulphide saturation across the mineralisation. Normally the S content of basaltic magmas is much higher at sulphide saturation. We propose that sulphide saturation is possible, nevertheless, mostly due to the high Cu content and high Cu/Fe in the evolved ferrobasaltic melt resulting in a lowering of the S concentration required for sulphide saturation. The relationship between exsolutions of aqueous fluids and sulphides remains unknown. [ABSTRACT FROM AUTHOR]

An operator-in-the-loop study was conducted in support of control room modernization for a nuclear power plant. The study featured a benchmark comparison on a glass-top simulator of three variants of a turbine control system (TCS): (1) the existing analog TCS, (2) a proposed stand-alone digital TCS with two displays, and (3) the digital TCS with the addition of a third display consisting of a system overview screen. TCS prototypes were developed to allow formative evaluation of operator preferences and performance during realistic turbine scenarios in the full-scope simulator. The study revealed that completion of turbine startup was several minutes faster with the digital TCS variants than with the conventional analog TCS. Eye-tracking fixations were more widely distributed in the overview versus stand-alone TCS condition, suggesting the overview screen was cueing reactor operators to verify values across the boards. There was no significant difference in workload or situation awareness across the three interfaces. Reviewing key plant parameters showed smoother transitions during load-following for the digital-versus-analog TCS. Despite some performance advantages for the digital TCS variants, operators preferred the existing analog TCS. Open-ended responses suggested this finding may be more an artifact of familiarity than a reflection of dissatisfaction with the new TCS. The study provides compelling evidence that the new digital TCS was used successfully by the operators, suggesting high usability for the digital TCS design. Further advantages were realized through the addition of the system overview screen to provide crews with at-a-glance indicators of key turbine parameters. [ABSTRACT FROM AUTHOR]

From integrated textural and compositional studies of auriferous and barren pyrite/marcasite in the epithermal Axi gold deposit, China, we have identified a relationship between multiple gold mineralizing events, mafic magma recharge, and fluid-rock reactions. Three generations of pyrite (Py1–3) and four generations of marcasite (Mar1–4) record episodic gold mineralizing events, followed by silver-copper-lead-zinc-cadmium enrichment. The gold mineralizing events are recorded by high concentrations of subnanometer-sized gold in Py1, Py3, and Mar3 (max. = 147, 129, and 34 ppm, med. = 39, 34, and 12 ppm). Based on previous Re-Os age determinations of pyrite and U-Pb zircon ages of the andesitic wallrock, these gold events slightly postdate pulsed mafic magma recharge and represent the incursion of Au-As-S-rich magmatic volatiles into circulating meteoric water. Silver-Cu-Pb-Zn-Cd enrichment in Py2, Mar2, and Mar4 are consistent with quiescent degassing and gradual Ag-Cu-Pb-Zn-Cd enrichment in an evolved felsic magma. Barren Mar1 records the dominance of meteoric water and a limited magmatic fluid contribution. High-Co-Ni-V-Cr-Ti contents in porous cores of Py1 and Mar2 are attributed to wall rock alteration and dissolution-reprecipitation. The results provide convincing evidence that the metal budget (especially for Au, Ag, Cu, Pb, Zn, Sb) of the hydrothermal fluids and sulfides in epithermal systems are controlled by the influx of magmatic fluids and associated magma, whereas the enrichment of certain fluid-immobile elements, such as Co, Ni, V, Cr, and Ti, is caused in part by fluid-rock interaction. [ABSTRACT FROM AUTHOR]

Robust U–Pb dating of accessory minerals (e.g., apatite, titanite, wolframite, and cassiterite) by LA-ICP-MS is often impeded by variable contents of common Pb in matrix-matched reference material (RM). Therefore, common Pb needs to be corrected in these RMs analyses that are used as standards to calibrate isotope fractionation during data reduction. In this study, a novel stand-alone computer program (called Isoclock) focused on the deduction of common Pb from RM, and the corrected RM were used for isotope fractionation. A new common Pb correction method was introduced into the program that allows the deduction of common Pb not only in 206Pb and 207Pb, but also in 208Pb, so that both U/Pb and Th/Pb age calculations can be performed. The software contains several processing steps for the raw files of different mass spectrometers. The processing interface contains data import and view, background correction and filtering of outliers, calculation of common Pb for RMs, fractionation calibration, and age calculation. Isoclock is written using the free and open-source Python language and can either run the code directly or by using a graphical interface. Finally, we discuss the main advantages of this software and its geological application using six examples of apatite, cassiterite, titanite, monazite and wolframite U–Pb dating. [ABSTRACT FROM AUTHOR]

The kinematic rupture process of the 2011 M 9.0 Tohoku earthquake is inverted with an elliptical-patches method, using a genetic algorithm, for the purpose of rapid and robust estimation of the source parameters of a mega-earthquake. We use the ground-displacement field provided by a continuous GPS network and the ground-velocity field recorded by acceleration networks. In addition to the typical inversion procedure in which a data duration long enough to cover the whole rupture process is used, inversions based on shorter signals, giving an incomplete view over the ground shaking sequence, are also carried out. How fast can a robust estimation of the source parameters be obtained? Using the elliptical approximation, we find that robust solutions of M ~ 9.0-earthquakes are rather quickly obtained regardless of the frequency band and the elliptical patch description. It is also confirmed that, because of the absence of off-shore recording stations on the east side of the fault, some uncertainties in the rupture process cannot be completely removed. In fact, at the very low frequencies considered, the western part of the fault (deeper portion) contributes more significantly to the recorded signals than does the other end close to the trench. This problem also prevents refinement of the description of the rupture process, in particular when using more than one ellipse. [ABSTRACT FROM AUTHOR]

The seismic vulnerability of masonry aggregates is assessed with an approach based on the discrete element method. In that purpose, a quasi-static push-over procedure has been developed, in which a load pattern, based on the building first mode of vibration, is applied to the studied structure. Using this approach, the magnitude of the horizontal load to be applied for the building to collapse is obtained after a short computation time, as well as a detailed description of the failure mechanism. These results can be useful, for instance, for identifying the weakness of a structure or for comparing quantitatively the vulnerability of different structures. The beneficial and negative effects on the seismic response of the aggregation are assessed by subjecting isolated and aggregated buildings to both in-plane and transverse loads. As observed by engineers during post-seismic field missions, the buildings at the extremities of the aggregate are more prone to damage, because, contrary to the buildings inside the aggregate, they are not efficiently braced by the neighboring structures. [ABSTRACT FROM AUTHOR]

Petrographic investigations of white kakortokite (nepheline syenite) reveal two structurally different types of perthite grains, herein called type A and B. Type A is more common and consists of an intimate intergrowth of microcline and albite. Microcline in type A perthites consists of two irregular penetrative individuals which appear as elongated pointed bodies parallel to (010) intergrown with polysynthetic twinned albite, which occurs as serrated bodies elongated parallel to (010). In type B perthites, K-feldspar (microcline) shows tiled structure and albite appears as microcrystalline equigranular veinlets, penetrating the perthite grain often perpendicular to (010). A great compositional variation of the type A grains (from nearly 100% microcline to almost pure albite) excludes exsolution to be the main process responsible for the structure. On the other hand, a replacement process controlled by a simultaneous dissolution-precipitation can explain the structure of type A, which means that widespread Na-metasomatism (albitization) had to have taken place in the kakortokite. Due to the different twinning structure of K-feldspar (microcline) in type B, the albitization in these grains occurred by albite veining of the grains. [ABSTRACT FROM AUTHOR]

The Húsavík‐Flatey Fault Zone (HFFZ) is the largest strike‐slip fault in Iceland and poses a high seismic risk to coastal communities. To investigate physics‐based constraints on earthquake hazards, we construct three fault system models of varying geometric complexity and model 79 3‐D multi‐fault dynamic rupture scenarios in the HFFZ. By assuming a simple regional prestress and varying hypocenter locations, we analyze the rupture dynamics, fault interactions, and the associated ground motions up to 2.5 Hz. All models account for regional seismotectonics, topo‐bathymetry, 3‐D subsurface velocity, viscoelastic attenuation, and off‐fault plasticity, and we explore the effect of fault roughness. The rupture scenarios obey earthquake scaling relations and predict magnitudes comparable to those of historical events. We show how fault system geometry and segmentation, hypocenter location, and prestress can affect the potential for rupture cascading, leading to varying slip distributions across different portions of the fault system. Our earthquake scenarios yield spatially heterogeneous near‐field ground motions modulated by geometric complexities, topography, and rupture directivity, particularly in the near‐field. The average ground motion attenuation characteristics of dynamic rupture scenarios of comparable magnitudes and mean stress drop are independent of variations in source complexity, magnitude‐consistent and in good agreement with the latest regional empirical ground motion models. However, physics‐based ground motion variability changes considerably with fault‐distance and increases for unilateral compared to bilateral ruptures. Systematic variations in physics‐based near‐fault ground motions provide important insights into the mechanics and potential earthquake hazard of large strike‐slip fault systems, such as the HFFZ. Plain Language Summary: The Húsavík‐Flatey Fault Zone (HFFZ) is the largest strike‐slip fault in Iceland, located in the Tjörnes Fracture Zone in Northern Iceland where the largest earthquakes in Iceland have occurred. At present the seismogenic potential of HFFZ suggests that an earthquake of magnitude ∼7 is possible, which poses a high earthquake hazard in the region. In this study, we generate a set of plausible earthquake rupture scenarios on the HFFZ that account for multi‐physics, regional geology and topo‐bathymetry. We simulate the corresponding seismic ground motions by exploring various assumptions, for example, in terms of slipping fault geometry and hypocenter locations. Our simulated scenarios have comparable magnitudes with historic events. The physics‐based ground motion scaling conforms to new empirical ground motion models, but shows varying ground motion variability with distance. Our study provides an overview of multiple rupture scenarios on the HFFZ and suggests that an ensemble of physics‐based dynamic rupture scenarios can complement classical seismic hazard assessment methods to better characterize the hazard in tectonically and seismically complex regions, especially in data‐scarce regions. Key Points: Observational constrained dynamic rupture scenarios of the Húsavík‐Flatey Fault Zone match expected regional earthquake scaling and magnitudesSegmented fault geometry, hypocenter location, fault prestress and roughness affect rupture dynamics and ground motionsOur physics‐based scenarios show magnitude‐consistent average attenuation relationships and match empirical ground motion models [ABSTRACT FROM AUTHOR]

The article discusses a study that focuses on quartz-wolframite-molybdenite vein and scheelite in amphibolite horizons from Thrudvang peninsula in Skjoldungen, South-East Greenland. Topics mentioned include selected trails of 24 inclusions from three fluid inclusion assemblages used for microthermometry, a geological map of the peninsula of Thrudvang and the surrounding areas, and the behaviour of the fluid inclusions during the microthermometric experiments.

Yersinia adhesin A (YadA) belongs to a class of bacterial adhesins that form trimeric structures. Their mature form contains a passenger domain and a C-terminal β-domain that anchors the protein in the outer membrane (OM). Little is known about how precursors of such proteins cross the periplasm and assemble into the OM. In the present study we took advantage of the evolutionary conservation in the biogenesis of β-barrel proteins between bacteria and mitochondria. Wepreviously observed that upon expression in yeast cells, bacterial β-barrel proteins including the transmembrane domain of YadA assemble into the mitochondrial OM. In the current study we found that when expressed in yeast cells both the monomeric and trimeric forms of full-length YadA were detected in mitochondria but only the trimeric species was fully integrated into the OM. The oligomeric form was exposed on the surface of the organelle in its native conformation and maintained its capacity to adhere to host cells. The co-expression of YadA with a mitochondria- targeted form of the bacterial periplasmic chaperone Skp, but not with SurA or SecB, resulted in enhanced levels of both forms of YadA. Taken together, these results indicate that the proper assembly of trimeric autotransporter can occur also in a system lacking the lipoproteins of the BAM machinery and is specifically enhanced by the chaperone Skp. [ABSTRACT FROM AUTHOR]

Recent research indicated that auditory detection and localization of approaching vehicles play roles in pedestrian safety. The present study examined detection and localization of recorded sounds of approaching target vehicles in the presence of competing noise from a second vehicle. Forty-one adults completed an auditory vehicle detection task comprising competing and non-competing vehicle noise conditions. Auditory vehicle detection performance was significantly better in the non-competing condition than the competing condition. Specifically, participants performance in the non-competing condition included larger detection distances, and more accurate localizations. We conclude that auditory perception of vehicles suffers significantly when competing noise from a second vehicle is present, and we discuss implications for pedestrian safety. [ABSTRACT FROM AUTHOR]

Seismic design using maps based on 'risk-targeting' would lead to an annual probability of attaining or exceeding a certain damage state that is uniform over an entire territory. These maps are based on convolving seismic hazard curves from a standard probabilistic analysis with the derivative of fragility curves expressing the chance for a code-designed structure to attain or exceed a certain damage state given a level of input motion, e.g. peak ground acceleration (PGA). There are few published fragility curves for structures respecting the Eurocodes (ECs, principally EC8 for seismic design) that can be used for the development of risk-targeted design maps for Europe. In this article a set of fragility curves for a regular three-storey reinforced-concrete building designed using EC2 and EC8 for medium ductility and increasing levels of design acceleration $$(\hbox {a}_\mathrm{g})$$ is developed. These curves show that structures designed using EC8 against PGAs up to about 1 m/s $$^{2}$$ have similar fragilities to those that respect only EC2 (although this conclusion may not hold for irregular buildings, other geometries or materials). From these curves, the probability of yielding for a structure subjected to a PGA equal to $$\hbox {a}_\mathrm{g}$$ varies between 0.14 ( $$\hbox {a}_\mathrm{g}=0.7$$ m/s $$^{2})$$ and 0.85 ( $$\hbox {a}_\mathrm{g}=3$$ m/s $$^{2})$$ whereas the probability of collapse for a structure subjected to a PGA equal to $$\hbox {a}_\mathrm{g}$$ varies between 1.7 $$\times 10^{-7}$$ ( $$\hbox {a}_\mathrm{g}=0.7$$ m/s $$^{2})$$ and 1.0 $$\times 10^{-5}$$ ( $$\hbox {a}_\mathrm{g}=3$$ m/s $$^{2})$$ . [ABSTRACT FROM AUTHOR]

Compared with solution ICP- MS, LA- ICP- MS studies have thus far reported comparatively few external reference data for accuracy estimates of experiments. This is largely the result of a paucity of available reference materials of natural composition. Here, we report an evaluation of natural glass (obsidian) as an inexpensive and widely available external reference material. The homogeneity of over forty elements in six different obsidian samples was assessed by LA- ICP- MS. Accuracy was tested with two obsidian samples that were fully characterised by electron probe microanalysis and solution ICP- MS. Laser ablation experiments were performed with a variety of ablation parameters (fluence, spot sizes, ablation repetition rates) and calibration approaches (natural vs. synthetic reference materials, and different internal standard elements) to determine the best practice for obsidian analysis. Furthermore, the samples were analysed using two different laser wavelengths (193 nm and 213 nm) to compare the effect of potential ablation-related phenomena (e.g., fractionation). Our data indicate that ablation with fluences larger than 6 J cm−2 and repetition rates of 5 or 10 Hz resulted in the most accurate results. Furthermore, synthetic NIST SRM 611 and 612 glasses worked better as reference materials compared with lower SiO2 content reference materials (e.g., BHVO-2G or GOR128-G). The very similar Si O2 content of the NIST SRM glasses and obsidian (i.e., matrix and compositional match) seems to be the first-order control on the ablation behaviour and, hence, the accuracy of the data. The use of different internal standard elements for the quantification of the obsidian data showed that Si and Na yielded accurate results for most elements. Nevertheless, for the analysis of samples with high Si O2 concentrations, it is recommended to use Si as the internal standard because it can be more precisely determined by electron probe microanalysis. At the scale of typical LA analyses, the six obsidian samples proved to be surprisingly homogenous. Analyses with a spot size of 80 μm resulted in relative standard deviations (% RSD) better than 8% for all but the most depleted elements (e.g., Sc, V, Ni, Cr, Cu, Cd) in these evolved glasses. The combined characteristics render obsidian a suitable, inexpensive and widely available, external quality-control material in LA- ICP- MS analysis for many applications. Moreover, obsidian glass is suited for tuning purposes, and well-characterised obsidian could even be used as a matrix-matched reference material for a considerable number of elements in studies of samples with high SiO2 contents. [ABSTRACT FROM AUTHOR]

The peralkaline Ilímaussaq Intrusion of the Gardar Province in South Greenland consists of several intrusive phases that have been related to different magmatic pulses and igneous cumulate processes. The lowermost exposed part of the intrusion is kakortokite, a eudialyte‐nepheline syenite, with distinctive sub‐horizontal layering which passes upwards into lujavrite, a fine‐grained melanocratic eudialyte‐nepheline syenite. Along the contact between kakortokite and lujavrite lies a transitional layered kakortokite, which has been defined previously based on textural and mineralogical criteria. However, published literature presents conflicting descriptions of this sequence in terms of thickness, layering, contacts, and mode of origin. Our own and previous field and petrographic investigations suggest that parts of the eudialyte‐rich zones in the transitional layered kakortokite comprise metasomatized and partially assimilated naujaite autoliths, a sodalite‐rich eudialyte nepheline syenite, detached probably from the roof of the intrusion. Here, we focus on the nature of the transitional layered kakortokite and conclude, in contrast to the conventional model, that it was formed by metasomatic transformation and assimilation of naujaite autoliths. We propose that the breakdown and replacement of sodalite locally increased chlorine and sodium concentrations, which may have catalyzed the precipitation of eudialyte. In detail, we suggest that the uppermost four eudialyte‐rich horizons were strongly influenced by metasomatic processes caused by mineral‐melt reaction, and were not simply the result of conventional igneous magmatic cumulate formation, as has been inferred for the underlying kakortokite layered units. Recognition of a significant metasomatic process has important bearing on the distribution of minerals with specific elements, like REE in eudialyte, both from a petrological and an economic perspective. [ABSTRACT FROM AUTHOR]

Abstract: Pedestrians must use a variety of cues when making safe decisions, many of which require processing of auditory information. We examined detection and localization of approaching vehicles using auditory cues. 50 adults ages 18–49 were presented with actual sounds of vehicles approaching at 5, 12, 25, and 35mph. Three indices were of interest: the distance at which vehicles were detected, participants’ decision regarding the direction from which vehicles were approaching, and their determination of the vehicles’ arrival at their location. Participants more easily detected vehicles moving at higher speeds and vehicles approaching from the right. Determination of the direction of approach reached 90% accuracy or better when vehicles were traveling at, or greater than, 12mph, and were more approaching from the right. Determination of vehicle arrival deteriorated significantly as speeds increased. Implications of the use of auditory cues in pedestrian settings, and future directions, are discussed. [Copyright &y& Elsevier]

Abstract: The Yuchiling Mo deposit, East Qinling, China, belongs to a typical porphyry Mo system associated with high-K calc-alkaline intrusions. The pure CO2 (PC), CO2-bearing (C), aqueous H2O-NaCl (W), and daughter mineral-bearing (S) fluid inclusions were observed in the hydrothermal quartz. Based on field investigations, petrographic, microthermometric and LA-ICP-MS studies of fluid inclusions, we develop a five-stage fluid evolution model to understand the ore-forming processes of the Yuchiling deposit. The earliest barren quartz±potassic feldspar veins, developed in intensively potassic alteration, were crystallized from carbonic-dominant fluids at high temperature (>416°C) and high pressure (>133MPa). Following the barren quartz±potassic feldspar veins are quartz-pyrite veins occasionally containing minor K-feldspar and molybdenite, which were formed by immiscible fluids at pressures of 47–159MPa and temperatures of 360–400°C. The fluids were characterized by high CO2 contents (approximately 8mol%) and variable salinities, as well as the highest Mo contents that resulted in the development of quartz-molybdenite veins. The quartz-molybdenite veins, accounting for >90% Mo in the orebody, were also formed by immiscible fluids with lower salinity and lower CO2 content of 7mol%, at temperatures of 340–380°C and pressures of 39–137MPa, as constrained by fluid inclusion assemblages. After the main Mo-mineralization, the uneconomic Cu-Pb-Zn mineralization occurred, as represented by quartz-polymetallic sulfides veins consisting of pyrite, molybdenite, chalcopyrite, digenite, galena, sphalerite and quartz. The quartz-polymetallic sulfide veins were formed by fluids containing 5mol% CO2, with minimum pressures of 32–110MPa and temperatures of 260–300°C. Finally, the fluids became dilute (5wt.% NaCl equiv) and CO2-poor, which caused the formation of late barren quartz±carbonate±fluorite veins at 140–180°C and 18–82MPa. It is clear that the fluids became more dilute, CO2-poor, and less fertile, with decreasing temperature and pressure from quartz-pyrite to late barren veins. Molybdenite and other sulfides can only be observed in the middle three stages, i.e., quartz-pyrite, quartz-molybdenite and quartz-polymetallic sulfide veins. These three kinds of veins are generally hosted in potassic altered rocks with remarkable K-feldspathization, but always partly overprinted by phyllic alteration. The traditional porphyry-style potassic–phyllic–propylitic alteration zoning is not conspicuous at Yuchiling, which may be related to, and characteristic of, the CO2-rich fluids derived from the magmas generated in intercontinental collision orogens. Among the fluid inclusions at Yuchiling, only the C-type contains maximum detectable Mo that gradationally decreases from 73ppm in quartz-pyrite veins, through 19ppm in quartz-molybdenite veins, and to 13ppm in quartz-polymetallic sulfide veins, coinciding well with the decreasing CO2 contents from 8mol%, through 7mol%, to 5mol%, respectively. Hence it is suggested that decreasing CO2 possibly results in decreasing Mo concentration in the fluids, as well as the precipitation of molybdenite from the fluids. This direct relationship might be a common characteristic for other porphyry Mo systems in the world. The Yuchiling Mo deposit represents a new type Mo mineralization, with features of collision-related setting, high-K calc-alkaline intrusion, CO2-rich fluid, and unique wall-rock alterations characterized by strong K-feldspathization and fluoritization. [Copyright &y& Elsevier]

Membrane-embedded β-barrel proteins are found in the outer membranes (OM) of Gram-negative bacteria, mitochondria and chloroplasts. In eukaryotic cells, precursors of these proteins are synthesized in the cytosol and have to be sorted to their corresponding organelle. Currently, the signal that ensures their specific targeting to either mitochondria or chloroplasts is ill-defined. To address this issue, we studied targeting of the chloroplast β-barrel proteins Oep37 and Oep24. We found that both proteins can be integrated in vitro into isolated plant mitochondria. Furthermore, upon their expression in yeast cells Oep37 and Oep24 were exclusively located in the mitochondrial OM. Oep37 partially complemented the growth phenotype of yeast cells lacking Porin, the general metabolite transporter of this membrane. Similarly to mitochondrial β-barrel proteins, Oep37 and Oep24 expressed in yeast cells were assembled into the mitochondrial OM in a pathway dependent on the TOM and TOB complexes. Taken together, this study demonstrates that the central mitochondrial components that mediate the import of yeast β-barrel proteins can deal with precursors of chloroplast β-barrel proteins. This implies that the mitochondrial import machinery does not recognize signals that are unique to mitochondrial β-barrel proteins. Our results further suggest that dedicated targeting factors had to evolve in plant cells to prevent mis-sorting of chloroplast β-barrel proteins to mitochondria. [ABSTRACT FROM AUTHOR]

The article highlights the notable musical compositions of German composer Karlheinz Stockhausen. It highlights the inspiration he undertook for creation of music for the "Licht Cycle" opera. It also highlights the Stockhausen's ways for expression of musical notation, and depiction of spiritualism in the music he create.

High precision isotope ratio and trace element determination can be achieved with modern quadrupole ICP-MS provided that short and long-term instrument performance is accurately monitored. Here we present results for the isotope ratios 6Li/7Li, 147Sm/149Sm, 160Dy/161Dy, 207Pb/206Pb, 208Pb/206Pb, 206Pb/204Pb and 235U/238U with which we determined long-term isotope ratio stability of relevance to both trace element and isotope determination. With respect to trace element determination, we first present long-term observations regarding oxide formation rates of Ba and Nd on light REE and heavy REE, as well as Zr on Ag. These showed good correlations and could be used to correct effectively the interference. The efficacy of this correction was demonstrated with analyses of the rock reference material BHVO-2 at both low and high oxide formation rates. Next, we studied the long-term reproducibility of a Dy isotope ratio that was measured to correct for the isobaric interference on Gd. It was found that, regardless of tuning condition, the ratio reproduced very well (0.58% RSD, 1 s) and that the estimate of the Gd concentration did not suffer from the large correction (> 10%) caused by the Dy isobar. Long-term reproducibilities of Li, Sm and U isotope ratios, required for accurate mass bias correction when isotopically enriched internal standards of these elements are employed, were measured in the rock reference materials AGV-2 and JA-3 over a time period of up to 3 years. As expected, the Li isotope ratio showed the largest variability (RSD = 7%), but the other two ratios had relative external reproducibilities of only 1.01% (1 s, U) and 0.67% (Sm). The mass bias-induced scatter in measurements for Sm and U was so small that the internal standard correction was effective, even for samples with high concentrations of these elements. With regard to Pb-isotope ratio determination, we also present long-term reproducibility for NIST SRM 982, run as an unknown and two accuracy tests for Pb separated from granitoids and from meteorites. It is demonstrated that the obtained ratios, including those involving 204Pb, are accurate relative to MC-ICP-MS determinations and of comparable precision to conventional TIMS analysis. The excellent agreement between all data sets shows the potential of modern quadrupole ICP-MS instrumentation for Pb-isotope determination, particularly for samples with very low Pb content. [ABSTRACT FROM AUTHOR]

PVD-TiMgGdN coatings have been successfully developed by the authors using an industrial DC-magnetron PVD unit. The coatings reveal excellent corrosion protection capabilities for mild steel substrates for at least 800 h in the neutral salt spray test (NSS). MgGd was added to the TiN matrix by using segmented (Seg.) multi-component targets, consisting of segments of pure Ti and of a Mg- 30 wt.-% Gd alloy. The Seg. targets caused an increased defect density due to droplets forming at the gaps between the segments which leads to an unsatisfactory wear performance. To overcome the low mechanical and wear properties by keeping the coatings excellent corrosion performances stable, a TiMgGd target with a specific Ti:Mg:Gd ratio was manufactured by powder metallurgy (PM) technology processed out of pure metal powders. In the present work, the properties of the corrosion and wear performance of DC-PVD-TiMgGdN coatings, which were synthesized onto corrosive mild steel substrates by using a Seg. target and a PM target of comparable Ti:Mg:Gd ratios together with identical deposition parameters, are compared with each other. The coatings were characterized regarding their microstructural, mechanical, physical and corrosion properties. Furthermore, ball on disk wear tests were conducted by reciprocal dry sling SRV III tests. It is shown that the excellent corrosion performance, could significantly be boosted by using the PM TiMgGd sputter target. Moreover, a remarkable increase in wear resistance of the TiMgGdN coatings can be examined by the use of a PM sputter target. It was found that the chemical properties of the TiMgGdN coatings as well as the nitrogen gas flow have a major influence on the mechanical coating properties and on the resulting microstructure, which directly correlates with the corrosion and wear properties. • Different microstructural properties of PM coating in comparison to Seg. coatings • Hardness values of the PM coatings are increased in comparison to Seg. coatings. • The PM coatings show grain refinement in comparison to the Seg. coatings. • The friction coefficient of PM TiMgGdN coatings is lower in comparison to Seg. coatings. • Substrate protection by DC-MS-TiMgGdN coatings up to 800 h in salt spray test [ABSTRACT FROM AUTHOR]

Abstract: The solubility of molybdenum (Mo) was determined at temperatures from 500°C to 800°C and 150 to 300MPa in KCl–H2O and pure H2O solutions in cold-seal experiments. The solutions were trapped as synthetic fluid inclusions in quartz at experimental conditions, and analyzed by laser ablation inductively coupled plasma mass spectrometry (LA ICPMS). Mo solubilities of 1.6wt% in the case of KCl-bearing aqueous solutions and up to 0.8wt% in pure H2O were found. Mo solubility is temperature dependent, but not pressure dependent over the investigated range, and correlates positively with salinity (KCl concentration). Molar ratios of ∼1 for Mo/Cl and Mo/K are derived based on our data. In combination with results of synchrotron X-ray absorption spectroscopy of individual fluid inclusions, it is suggested that Mo-oxo-chloride complexes are present at high salinity (>20wt% KCl) and ion pairs at moderate to low salinity (<11wt% KCl) in KCl–H2O aqueous solutions. Similarly, in the pure H2O experiments molybdic acid is the dominant species in aqueous solution. The results of these hydrothermal Mo experiments fit with earlier studies conducted at lower temperatures and indicate that high Mo concentrations can be transported in aqueous solutions. Therefore, the Mo concentration in aqueous fluids seems not to be the limiting factor for ore formation, whereas precipitation processes and the availability of sulfur appear to be the main controlling factors in the formation of molybdenite (MoS2). [Copyright &y& Elsevier]

Metal evolution in a composite granitic pluton was tracked by analyzing melt inclusions in 11 quartz samples from 7 zones at the Timbarra gold deposit, Australia. We present the first quantitative microanalyses of gold (Au) in granitic silicate melt inclusions using laser ablation inductively coupled plasma mass-spectrometry and show how Au and other metals become enriched during fractional crystallization in a granite intrusion. Au was enriched during fractionation from a monzogranite to a highly fractionated alkali-feldspar granite. Similar enrichment behavior for other metals implies that no gold-enriched precursor melt is required and fractional crystallization can enrich the Au concentration to economic levels. The low content of accessory oxides and sulfides, the absence of early Cl- bearing fluids, the volatile content in the melt, and a prolonged crystallization constitute important factors for extensive metal enrichment during crystal fractionation. These characteristics play a crucial role in felsic, highly fractionated plutons and their associated deposits such as intrusion-related Au deposits. The gold enrichment during fractionation also implies that Au is directly sourced from the granites. [ABSTRACT FROM AUTHOR]

In this study, the author queried senior undergraduate business students in 4 different majors regarding their perceptions of how helpful 25 different pedagogical strategies were in facilitating their learning. The author sought to determine whether certain pedagogical strategies proved to be more successful within specific business-major curricula than others. The business majors gave different ratings to almost half of the pedagogical strategies used in the study. These results should be useful to business faculty members in developing and selecting pedagogical strategies that facilitate student learning. [ABSTRACT FROM AUTHOR]

Presents a demographic and administrative analysis of pretrial diversion cases in the U. S. federal court system from 1995 to 1999. History of pretrial diversion in the federal courts; Details of diversion procedures; Methodology of recording pretrial services data; Association between major offense, criminal history, pretrial diversion.

AbstractAs the nuclear industry develops new advanced reactor technologies, many companies are embracing this advancement by pursuing the development of microreactors. The term microreactor generally refers to a nuclear reactor with an operating power of 20 MW(thermal) or less. The power range of microreactors makes them appealing for many use cases, such as powering remote communities, mining sites, and military bases. Most of the microreactor designs being pursued are expected to incorporate remote facility operations into the final product. However, no framework has yet been developed to determine what remote operations systems require for reliable, resilient, and secure operation of a microreactor.This work identifies the research needs for challenges that are unique to remote operations and monitoring for microreactors, specifically regarding instrumentation and control, communication methods, regulatory requirements, and operational policies. The types of commands and sensor measurements that must be transmitted between the facilities, as well as methods for verifying the trustworthiness of these signals, are assessed. This work evaluates the security, reliability, and performance requirements that must be met when considering the selection of communication hardware and protocols for use in remote operations.Also, an assessment was performed to study how remote operations fit within current regulatory requirements and what may need to be updated in regulatory policy to allow for remote operation. Finally, the operational contingencies unique to remote operations that must be in place for responses to abnormal events are identified. This paper identifies the challenges and research opportunities within the areas of importance for the design of remote operation systems. [ABSTRACT FROM AUTHOR]

• Laozuoshan is the only large gold skarn deposit in Northeast China. • New mineralogical, isotopic, and fluid inclusion data were obtained. • Ore fluids and metals were derived principally from a magma source. • Fluid-rock interactions and cooling exert principle controls on gold precipitation. The Laozuoshan mine, located in the central Jiamusi block, is the largest gold skarn deposit in Northeast China. It comprises three ore zones (East, Middle, West) with complex stratigraphic and structural controls. The skarn-type orebodies mainly occur in the East and Middle ore zones along the contact zones between Hercynian granite and Precambrian metasedimentary rocks. The earliest stage of alteration is characterized by potassium hornfels. Subsequently, prograde skarn formation occurred, characterized by garnet in the grossular-andradite series and pyroxene in the hedenbergite-diopside series. This was followed by a retrograde skarn overprint of hydrous silicates and ore minerals. Three types of garnet with distinct textures and elemental compositions are recognized, which indicate fluctuating physicochemical conditions in the hydrothermal fluids. The fluids associated to the prograde skarn are characterized by high temperature and high salinity, which underwent fluid boiling that led to precipitation of minor pyrite and arsenopyrite. The main gold and sulfide mineralization is related to the retrograde skarn overprint, where cooling and strong fluid-rock interactions occurred. Gold precipitation is estimated to have occurred at temperatures of 380–470 °C, based on the arsenopyrite geothermometer and fluid inclusion microthermometry. The fluid inclusion and C-O isotope data indicate that the ore-forming fluids were dominated by magmatic water during the prograde skarn stage and the main ore-forming stages. Mixing between meteoric and magmatic fluids occurred during the latest stages of the retrograde skarn formation. Both sulfur and lead isotope compositions of sulfides support a magmatic origin for the ore-forming materials. On the basis of the available geological and geochemical evidence, we propose that the Laozuoshan deposit is a reduced gold skarn deposit, genetically related to the granitic pluton. [ABSTRACT FROM AUTHOR]

Fault‐damage zones comprise multiscale fracture networks that may slip dynamically and interact with the main fault during earthquake rupture. Using 3D dynamic rupture simulations and scale‐dependent fracture energy, we examine dynamic interactions of more than 800 intersecting multiscale fractures surrounding a listric fault, emulating a major listric fault and its damage zone. We investigate 10 distinct orientations of maximum horizontal stress, probing the conditions necessary for sustained slip within the fracture network or activating the main fault. Additionally, we assess the feasibility of nucleating dynamic rupture earthquake cascades from a distant fracture and investigate the sensitivity of fracture network cascading rupture to the effective normal stress level. We model either pure cascades or main fault rupture with limited off‐fault slip. We find that cascading ruptures within the fracture network are dynamically feasible under certain conditions, including: (a) the fracture energy scales with fracture and fault size, (b) favorable relative pre‐stress of fractures within the ambient stress field, and (c) close proximity of fractures. We find that cascading rupture within the fracture network discourages rupture on the main fault. Our simulations suggest that fractures with favorable relative pre‐stress, embedded within a fault damage zone, may lead to cascading earthquake rupture that shadows main fault slip. We find that such off‐fault events may reach moment magnitudes up to Mw ≈ 5.5, comparable to magnitudes that can be otherwise hosted by the main fault. Our findings offer insights into physical processes governing cascading earthquake dynamic rupture within multiscale fracture networks. Plain Language Summary: Large geological faults are surrounded by many small fractures of different sizes and orientations, forming a fracture network around the main fault. The characteristics of an earthquake and its size may depend on the orientation of the main fault (and surrounding fractures) within the ambient stress field. Can a small (initial) rupture within a fracture network start a domino‐like (cascading) earthquake across the entire fault network? How does the compounded earthquake process depend on fracture orientation, local stress, and rupture starting point? To address these questions, we study earthquake rupture physics in a complex fault‐zone model comprising over 800 multiscale fracture planes surrounding a main fault. Using 3D dynamic rupture simulations and supercomputing, we explore how different ambient stress orientations, earthquake hypocenters, and levels of fault loading affect earthquake dynamics in fracture networks. The simulations demonstrate that cascading rupture in a fault zone is possible under certain conditions. Our results provide important insights into the physics of cascading earthquakes in multiscale fracture systems and hence are useful for advancing seismic hazard assessment for both natural and induced earthquakes. Key Points: We perform 3D dynamic rupture simulations in a network of >800 fractures and a listric main fault, assuming scale‐dependent fracture energyCascading rupture is possible under high fracture connectivity if a subset of fractures is favorable with respect to the ambient stressWe demonstrate the feasibility of dynamic rupture cascade irrespective of hypocenter locations within the fracture network [ABSTRACT FROM AUTHOR]

Tsunamigenic earthquakes pose considerable risks, both economically and socially, yet earthquake and tsunami hazard assessments are typically conducted separately. Earthquakes associated with unexpected tsunamis, such as the 2018 Mw7.5 strike-slip Sulawesi earthquake, emphasize the need to study the tsunami potential of active submarine faults in different tectonic settings. Here, we investigate physics-based scenarios combining simulations of 3D earthquake dynamic rupture and seismic wave propagation with tsunami generation and propagation. We present time-dependent modeling of one-way linked and 3D fully coupled earthquakes and tsunamis for the ∼ 100 km long Húsavík–Flatey Fault Zone (HFFZ) in North Iceland. Our analysis shows that the HFFZ has the potential to generate sizable tsunamis. The six dynamic rupture models sourcing our tsunami scenarios vary regarding hypocenter location, spatiotemporal evolution, fault slip, and fault structure complexity but coincide with historical earthquake magnitudes. Earthquake dynamic rupture scenarios on a less segmented fault system, particularly with a hypocenter location in the eastern part of the fault system, have a larger potential for local tsunami generation. Here, dynamically evolving large shallow fault slip (∼ 8 m), near-surface rake rotation (± 20 ∘), and significant coseismic vertical displacements of the local bathymetry (± 1 m) facilitate strike-slip faulting tsunami generation. We model tsunami crest to trough differences (total wave heights) of up to ∼ 0.9 m near the town Ólafsfjörður. In contrast, none of our scenarios endanger the town of Akureyri, which is shielded by multiple reflections within the narrow Eyjafjörður bay and by Hrísey island. We compare the modeled one-way linked tsunami waveforms with simulation results using a 3D fully coupled approach. We find good agreement in the tsunami arrival times and location of maximum tsunami heights. While seismic waves result in transient motions of the sea surface and affect the ocean response, they do not appear to contribute to tsunami generation. However, complex source effects arise in the fully coupled simulations, such as tsunami dispersion effects and the complex superposition of seismic and acoustic waves within the shallow continental shelf of North Iceland. We find that the vertical velocity amplitudes of near-source acoustic waves are unexpectedly high – larger than those corresponding to the actual tsunami – which may serve as a rapid indicator of surface dynamic rupture. Our results have important implications for understanding the tsunamigenic potential of strike-slip fault systems worldwide and the coseismic acoustic wave excitation during tsunami generation and may help to inform future tsunami early warning systems. [ABSTRACT FROM AUTHOR]

From California to British Columbia, the Pacific Northwest coast bears an omnipresent earthquake and tsunami hazard from the Cascadia subduction zone. Multiple lines of evidence suggests that magnitude eight and greater megathrust earthquakes have occurred ‐ the most recent being 321 years ago (i.e., 1700 A.D.). Outstanding questions for the next great megathrust event include where it will initiate, what conditions are favorable for rupture to span the convergent margin, and how much slip may be expected. We develop the first 3‐D fully dynamic rupture simulations for the Cascadia subduction zone that are driven by fault stress, strength and friction to address these questions. The initial dynamic stress drop distribution in our simulations is constrained by geodetic coupling models, with segment locations taken from geologic analyses. We document the sensitivity of nucleation location and stress drop to the final seismic moment and coseismic subsidence amplitudes. We find that the final earthquake size strongly depends on the amount of slip deficit in the central Cascadia region, which is inferred to be creeping interseismically, for a given initiation location in southern or northern Cascadia. Several simulations are also presented here that can closely approximate recorded coastal subsidence from the 1700 A.D. event without invoking localized high‐stress asperities along the down‐dip locked region of the megathrust. These results can be used to inform earthquake and tsunami hazards for not only Cascadia, but other subduction zones that have limited seismic observations but a wealth of geodetic inference. Plain Language Summary: The largest earthquakes on Earth occur along faults that develop between two tectonic plates that come into contact. Termed megathrust earthquakes, these catastrophic events are responsible for generating both strong ground‐shaking and tsunamis. The Cascadia megathrust fault straddles the Pacific coastline of North America and from evidence in both the United States and Japan, we know this fault last slipped in 1700 A.D. We have combined models of strain buildup (geodetic coupling models) with state‐of‐the‐art 3‐D computer simulations to understand the potential hazard of a future earthquake in Cascadia and show what factors might lead to the fault slipping its entire length. We compare our simulations to geologic measurements of permanent ground movement from 1700 A.D. Our results demonstrate that no matter where the earthquake is allowed to start, coupling models showing strain accumulation to the top of the fault easily leads to big earthquakes. We also look into what 1700 A.D. event may have looked like and show several scenarios that fit the geologic data very closely. This work represents the first set of 3‐D simulations that use the laws of physics to see what may control the size of future earthquakes in Cascadia. Key Points: We design the first fully dynamic 3‐D earthquake simulations based on geodetic coupling models for the Cascadia megathrustSegmentation in the stress drop is needed to produce subsidence amplitudes consistent with observed megathrust earthquakesDynamic rupture simulations demonstrate how fault friction and stress levels may control margin‐wide rupture [ABSTRACT FROM AUTHOR]

On 14 November 2016, the Northern part of New Zealand's South Island was struck by the Mw7.8 Kaikōura earthquake, an event of unprecedented geometric complexity rupturing at least 21 segments of the contractional North Canterbury and of the Marlborough fault systems. Geological, geodetic, tsunami and seismic data reveal puzzling features as well as observational difficulties of the event leading to competing views on its key features, such as the role played by the Hikurangi subduction interface, the exact rupture sequence, and the higher than expected local tsunami. We present a dynamic rupture model of the 2016 Mw 7.8 Kaikōura earthquake to unravel the event's riddles in a physics-based manner and provide insights on the mechanical viability of competing hypotheses proposed to explain them. The event is modeled using the open-source software SeisSol (www.seissol.org), based on a arbitrary high-order accurate DERivative Discontinuous Galerkin method (ADER-DG). We verify our model with strong ground-motions, high rate GPS, long-period teleseismic and tsunami data. Our model reproduces key characteristics of the event and constraints puzzling features inferred from high-quality observations including a large gap separating surface rupture traces, the possibility of significant slip on the subduction interface, the non-rupture of the Hope fault, and slow apparent rupture speed. We show that a rupture cascade sequentially breaking the Papatea and Kekerengu faults is dynamically consistent with regional stress estimates and a crustal fault network geometry inferred from seismic and geodetic data. A coseismically triggered tsunami caused by the rare occurrence of an earthquake starting on-land and crossing to two faults off-shore matches local tide gauge data.We find, that such complex rupture cascade links the crustal fault system when operating at low apparent friction thanks to the combined effects of overpressurized fluids, low dynamic friction and stress concentrations induced by deep fault creep. Understanding the physical conditions that allow rupture cascades on complex fault systems advances our ability to quantify earthquake hazard, especially to evaluate the possibility of extreme events on real fault networks. [ABSTRACT FROM AUTHOR]

The 2004 Mw 9.1-9.3 Great Sumatra-Andaman Earthquake is one of the strongest and most devastating earthquakes in recent history. It generated a powerful tsunami, causing more than 220,000 fatalities. Despite its huge spatial extent, the analysis of the earthquake is impeded by a lack of near-source observations. Static ground-deformation data, polluted by significant after-slip in the near-source region, and teleseismic data do not fully constrain the source, leading to significant differences in its characterization. Specifically, the tsunamigenic aspects of the earthquake, such as the large but mostly horizontal seafloor displacements and potential splay fault activation, remain puzzling.In this study, we investigate the earthquake using high-resolution 3D dynamic rupture simulations. We use the open-source software SeisSol (www.seissol.org) which is based on an arbitrary high-order accurate DERivative Discontinuous Galerkin method (ADER-DG). We account for complex megathrust-splay fault geometries, high resolution topography and bathymetry, 3D subsurface structure and off-fault plasticity. We resolve the full frictional sliding process as well as the seismic wave field in the to-date longest (500 s) and largest (1500 km) dynamic rupture earthquake scenario.We discuss macroscopic earthquake source characteristics inferred from a smoothly initialized model, in which we prescribe regional, smoothly varying fault pre-stresses constrained by earthquake focal mechanisms, interacting with frictional fault conditions changing only depth-dependently. The interplay of complex fault geometry and simple pre-stress state yields good agreement of ground-deformations in the near field and very long-period teleseismic data. We are specifically interested in the effects of off-fault plasticity: overall reducing rupture speed but increasing or decreasing fault slip depending on regional stress orientation in conjunction with the fault geometry. We then refine the regional stress state based on static inversion and mechanical viability arguments to fully capture dynamic features such as lower slip release in the Southern megathrust and slow rupture velocity at around 8° latitude. Our models are verified by generating synthetic geodetic, teleseismic and tsunami records, employing off-line coupling of SeisSol to established global seismic wave propagation and tsunami simulation tools. [ABSTRACT FROM AUTHOR]

The Laozuoshan deposit, located in the central Jiamusi Block of north‐east China, is characterized by two types of mineralization, including principal skarn‐type Au mineralization occurring along the contact zone between granite and migmatite, and minor auriferous quartz‐arsenopyrite veins hosting in plagiogranite and granite. Re–Os dating of auriferous pyrrhotite and arsenopyrite were performed to determine the metallogenic ages of the Laozuoshan gold deposit. Analyses of arsenopyrite from quartz vein‐type ores yield a weighted average model age of 89.0 ± 3.1 Ma (mean standard weighted deviation（MSWD） = 9.3), which is within uncertainty in agreement with the 187Re/188Os versus 187Os/188Os isochron age of 93.2 ± 2.6 Ma (MSWD = 1.3) and the 187Re versus 187Os isochron age of 97 ± 14 Ma (MSWD = 7.4). Pyrrhotite samples from skarn‐type ores have model ages from 82.6 Ma to 424.8 Ma, indicating an unclosed Re–Os isotope system. However, the skarn‐type Au mineralization likely occurred during the Permian following the emplacement of the Laozuoshan granite. Results of laser ablation inductively coupled plasma mass spectrometry (LA‐ICP‐MS) trace element analysis show that element contents in sulphides from different types of ores are systematically different. Au, Ag, Bi, Pb, Co, and Ni are significantly enriched in skarn‐type arsenopyrite. These data suggest that the Laozuoshan deposit formed from two gold mineralization events. Combined with previous studies, we suggest that the skarn‐type Au mineralization was associated with the subduction of the Panthalassic oceanic plate, whereas the rollback of the Palaeo‐Pacific Plate was responsible for the quartz vein‐type Au mineralization in the Laozuoshan deposit. The multiple mineralization events have important implications for regional exploration. [ABSTRACT FROM AUTHOR]

We present petrological data and seven Lu-Hf garnet-amphibole-whole rock ages obtained from a single garnet-hornblende-mica schist sample from the Isua supracrustal belt (West Greenland). Garnets grew during prograde metamorphism toward regional amphibolite-facies peak conditions, and a mylonitic foliation formed during and after garnet growth. Garnet crystals show typical prograde zoning with no visible traces of a relict garnet generation. They do show various degrees of retrogression. While some crystals are perfectly euhedral with only minor chemical alteration along cracks, others are elongated in the foliation and either grew in this shape or were deformed. Six garnet splits were separated from crushed single crystals and one from a crushed bulk sample. Individual three-point garnet-hornblende-whole rock ages scatter between 2.603 ± 0.018 Ga and 2.432 ± 0.059 Ga for single garnets. The garnet split from the bulk sample defines an age of 2.463 ± 0.031 Ga, the data point farthest from the regression line for all data points (2.551 ± 0.074 Ga, mean square of weighted deviates = 25). We interpret these data to indicate partial retrogression of a Neoarchean garnet population not significantly older than the oldest obtained three-point age. Well-preserved garnet zoning, regional peak temperatures well below the closing temperature of the Lu-Hf system, and the small scatter of Lu-Hf ages preclude an interpretation of the observed metamorphism and deformation as being Eoarchean in age. [ABSTRACT FROM AUTHOR]

The Zhob ophiolite comprises the Naweoba, Omzha and Ali Khanzai blocks, which are surrounded by the sediments of the Alozai Group and Loralai Formation. The Ali Khanzai Block contains metamorphic, ultramafic, gabbroic, volcanic and volcaniclastic rocks with associated chert. The Zhob manganese deposits found in the Ali Khanzai Block, occur in banded, lenticular and massive forms within red to brown coloured metachert. Braunite and pyrolusite are the main constituent manganese-bearing minerals with minor hausmannite, hematite and barite while quartz is the major gangue mineral with some carbonate minerals. Geochemical evidence from the major oxides indicates that the manganese mineralization and associated metachert at Zhob were formed by hydrothermal activity with little contribution from contemporaneous volcanic materials and this is confirmed by high Fe/Mn and low Co/Zn ratios and trace element patterns. These deposits formed along with seafloor spreading centres and were later obducted as part of Ali Khanzai Block of Zhob ophiolite. [ABSTRACT FROM AUTHOR]

[Display omitted] • Contour figures constructed to systematically illustrate fluid inclusion properties. • Evolution paths for nine types of fluid inclusions with variable trapping conditions. • Overestimated fluid salinity and correction of halite-bearing fluid inclusions. • Details for fluid inclusions formed in the Vapor + Halite region. Previous studies revealed very complicated phase ratios and microthermometric behavior of fluid inclusions, which can be attributed to the various phase relations in the H 2 O-NaCl system and different evolutionary paths after their entrapment at different conditions. This numerical calculation work aims at presenting a comprehensive illustration of fluid inclusion formation in the H 2 O-NaCl system and facilitating the interpretation of microthermometric data. We firstly illustrate a series of contours figures in the pressure–temperature projection for fluid salinities at 0.1, 1, 10, 30, 50, and 70 wt% NaCl, for the bubble curve and the dew curve, and for the halite liquidus of the H 2 O-NaCl system to demonstrate the changes of salinities and densities that lead to the variations of room-temperature phase ratios of fluid inclusions. Then we comprehensively construct the evolutionary paths of fluids trapped at variable conditions. Isochores of the entrapped halite-undersaturated fluids may intersect the vapor + liquid surface of the H 2 O-NaCl system on the dew curve, the bubble curve, or the locus on the critical curve, or intersect the bubble curve of the vapor + halite region. Isochores of the entrapped halite-saturated fluids may intersect the bubble curve of the vapor + liquid surface at elevated temperature, the dew curve of the vapor + liquid surface, the halite liquidus, or their junction. After the intersections, the fluid inclusions evolve in the two-phase regions (vapor + liquid, liquid + halite, or vapor + halite), and the detailed evolution of fluid pressure, temperature, density, salinity, and phase ratios of the coexisting two phases are systematically discussed. Evolutionary paths of the halite-saturated fluids and the extremely low salinity fluids will eventually intersect the vapor + liquid + halite surface and then evolve to room temperature. The evolutionary paths above define nine types of fluid inclusions with characteristic phase ratios and microthermometric behavior, making a necessary complement to previous studies for the understanding of fluid inclusion formation and interpretation of microthermometric data. For the first time, we present the evolutionary path for a halite-bearing fluid inclusion that experiences partial homogenization by halite dissolution and total homogenization by liquid disappearance. Underestimation of the homogenization temperature is inevitable for vapor-rich fluid inclusions formed in the vapor + halite region, therefore, such fluid inclusions, typically formed in very shallow porphyry systems, provide invalid temperature information for fluid evolution. The residual vapor phase at halite dissolution for halite-bearing fluid inclusions may lead to an over-estimation of the bulk fluid salinity by over 3 % at elevated temperature conditions. The contour figures can facilitate the understanding of post-entrapment modifications of fluid inclusions which alters fluid inclusion phase ratios and homogenization behavior. [ABSTRACT FROM AUTHOR]

The destructive 2023 moment magnitude (Mw) 7.8-7.7 earthquake doublet ruptured multiple segments of the East Anatolian Fault system in Turkey. We integrated multiscale seismic and space-geodetic observations with multifault kinematic inversions and dynamic rupture modeling to unravel the eventsÕ complex rupture history and stress-mediated fault interactions. Our analysis reveals three subshear slip episodes during the initial Mw 7.8 earthquake with a delayed rupture initiation to the southwest. The Mw 7.7 event occurred 9 hours later with a larger slip and supershear rupture on its western branch. Mechanically consistent dynamic models accounting for fault interactions can explain the unexpected rupture paths and require a heterogeneous background stress. Our results highlight the importance of combining near- and far-field observations with data-driven and physics-based models for seismic hazard assessment. [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • The Bake is exceptional for its higher native gold proportion in southeastern Guizhou district. • Post-mineralization shear zone has led to the Au remobilization. • In-situ sulfur isotope signatures suggest gold was derived from deeply sourced auriferous metamorphic fluids. Abstract The Bake gold deposit is exceptional for its high native gold abundance relative to the other orogenic gold deposits in the southeastern Guizhou district. The grades of gold can be up to 2 to 3 wt% in bonanza ore, and native gold preferentially occurs within voids and fractures in pyrite, arsenopyrite and quartz. Gold content can be up to 6.9 ppm in hydrothermal pyrite, however, the majority of the pyrite analyses have Au contents less than 1 ppm (mean = 0.32 ppm) based on LA-ICPMS analyses. Meanwhile, EMPA reveals that arsenopyrite has a maximal Au content of up to 0.14 wt%, but most analyses are below detection limit (0.01 wt%). Moreover, native gold grains in cataclastic pyrite and arsenopyrite are commonly high-purity with fineness ranging from 949 to 977. Given that paragenetically early hydrothermal pyrite and arsenopyrite contain variable but relatively high gold concentrations than later generations of sulfide, it is suggested that early invisible gold may have been remobilized to form at least part of the microscopic visible gold. Post-mineralization shear zones, which cut the vein-bearing anticline, may have led to the deformation of the lode quartz vein system on the macro level, and microscopically, sulfide fragmentation and elemental remobilization. Although diagenetic pyrite from unaltered host rocks is enriched in invisible gold with mean values at 0.83 ppm, evidence supporting the release of Au from them is weak. Corresponding evidence comes from the distinct sulfur isotope signatures in different pyrite generations. Diagenetic pyrite has δ34S values in the narrow range of +9.27‰ to +10.75‰, whereas hydrothermal pyrite shows a broad range (+6.81‰ to +17.42‰), based on LA-MC-ICPMS analyses. The Mesoproterozoic Lengjiaxi Group underlying the Xiajiang Group is most likely the source region, on the basis of geological background and assuming the metamorphic devolatilization model. [ABSTRACT FROM AUTHOR]

Tsunamigenic earthquakes pose considerable risks, both economically and socially, yet earthquake and tsunami hazard assessments are typically conducted separately. Earthquakes associated with unexpected tsunamis, such as the 2018 MW 7.5 strike-slip Sulawesi earthquake, emphasize the need to study the tsunami potential of active submarine faults in different tectonic settings. Here, we investigate physics-based scenarios combining 3D earthquake dynamic rupture with tsunami generation and propagation for the ~100 km long Húsavík-Flatey Fault Zone in North Iceland using time-dependent one-way linked and 3D fully-coupled earthquake-tsunami modeling. Our analysis shows that the HFFZ has the potential to generate sizeable tsunamis. The six dynamic rupture models sourcing our tsunami scenarios vary regarding hypocenter location, spatio-temporal evolution, fault slip, and fault structure complexity but coincide with historical earthquake magnitudes. We find that the earthquake dynamic rupture scenarios on a less segmented fault system, particularly with a hypocenter location in the eastern part of the fault system, have a larger potential for local tsunami generation. Here, dynamically evolving large shallow fault slip (~8 m), near-surface rake rotation (±20°), and significant coseismic vertical displacements of the local bathymetry (±1 m) facilitate strike-slip faulting tsunami generation. We model tsunami crest-to-trough differences (total wave heights) of up to ~0.9 m near the town Ölafsfjöröur. In contrast, none of our scenarios endanger the town of Akureyri, which is shielded by multiple reflections within the narrow Eyjafjöröur Bay and by Hrísey Island. We compare the modeled one-way linked tsunami waveforms with simulation results using a 3D fully-coupled approach. We find good agreement in the tsunami arrival times and location of maximum tsunami heights. While seismic waves result in transient motions of the sea surface and affect the ocean response, they do not appear to contribute to tsunami generation. However, complex source effects arise in the fully-coupled simulations, such as tsunami dispersion effects and complex superposition of seismic and acoustic waves within the shallow continental shelf of North Iceland. We find that the vertical velocities of near-source acoustic waves are unexpectedly high - larger than those corresponding to the actual tsunami - which may serve as a rapid indicator of surface dynamic rupture. Our results have important implications for understanding the tsunamigenic potential of strike-slip fault systems worldwide and the co-seismic acoustic wave excitation during tsunami generation and may help to inform future tsunami early warning systems. [ABSTRACT FROM AUTHOR]

The junction of the southeastern Guizhou, the southwestern Hunan, and the northern Guangxi regions is located within the southwestern Jiangnan orogen and forms a NE-trending ∼250 km gold belt containing more than 100 gold deposits and occurrences. The Pingqiu gold deposit is one of the numerous lode gold deposits in the southeastern Guizhou district. Gold mineralization is hosted in Neoproterozoic lower greenschist facies metamorphic rocks and controlled by fold-related structures. Vein types present at Pingqiu include bedding-parallel and discordant types, with saddle-reefs and their down limb extensions dominating but with lesser discordant types. The major sulfide minerals are arsenopyrite and pyrite, with minor sphalerite, galena, chalcopyrite, and rare pyrrhotite, marcasite, and tetrahedrite. Much of the gold is μm- to mm-sized grains, and occurs as fracture-controlled isolated grains or filaments in quartz, galena, sphalerite, pyrite, and wallrock. Three types of fluid inclusions are distinguished in hydrothermal minerals. Type 1 aqueous inclusions have homogenization temperatures of 171–396 °C and salinities of 1.4–9.8 wt% NaCl equiv. Type 2 aqueous-carbonic inclusions yield final homogenization temperatures of 187–350 °C, with salinities of 0.2–7.7 wt% NaCl equiv. Type 3 inclusions are carbonic inclusions with variable relative content of CO 2 and CH 4 , and minor amounts of N 2 and H 2 O. The close association of CO 2 -rich inclusions and H 2 O-rich inclusions in groups and along the same trail suggests the presence of fluid immiscibility. The calculated δ 18 O H2O values range from 4.3‰ to 8.3‰ and δD H2O values of fluid inclusions vary from −55.8‰ to −46.9‰. A metamorphic origin is preferred on the basis of geological background and analogies with other similar deposit types. Two ore-related sericite samples yield well-defined 40 Ar/ 39 Ar plateau ages of 425.7 ± 1.7 Ma and 425.2 ± 1.3 Ma, respectively. These data overlap the duration of the Caledonian gold mineralization along the Jiangnan orogen, and suggest that gold mineralization was post-peak regional metamorphism and occurred during the later stages of the Caledonian orogeny. Overall, the Pingqiu gold deposit displays many of the principal characteristics of the Bendigo gold mines in the western Lachlan Orogen (SE Australia) and the Dufferin gold deposit in the Meguma Terrane (Nova Scotia, Canada) but also some important differences, which may lead to the disparity in gold endowment. However, the structural make-up at deposit scale, and the shallow mining depth at present indicate that the Pingqiu gold deposit may have considerable gold potential at depth. [ABSTRACT FROM AUTHOR]

The Advanced Reactor Control and Operations (ARCO) facility was constructed in January 2018 to serve as a test bed for advanced reactor control rooms and operator support systems. Since then, it has supported human-machine interface user experience research, fault detection and mitigation technology development, control room concept of operations development, and remote operations research. ARCO serves as the control room for the Compact Integral Effects Test (CIET) facility, which replicates the primary-side flow paths and thermal-hydraulic behavior of a fluoride-salt-cooled high-temperature reactor (FHR) using simulant fluids and scaling principles. New reactor designs feature different operating conditions and scenarios than those in existing reactors. ARCO supports the research and development of digital tools for operator communications, intuitive real-time data analysis, online health monitoring and prognostics, and control room cybersecurity. By integrating these different technologies, ARCO acts as a prototypical control system to iteratively develop methods and tools of operation in advanced small modular nuclear reactors. This paper describes the features of and challenges to operating advanced small modular reactors underlying the design basis for ARCO and its operator support systems. [ABSTRACT FROM AUTHOR]