Ring-Moat Dome Structures (RMDSs) are small circular mounds of diameter typically about 200 m and ∼3-4 m in height, surrounded by narrow, shallow moats. They occur in clusters, are widespread in ancient Imbrian-aged mare basalt host units and show mineralogies comparable to those of their host units. Based on these close associations and similarities, a model has been proposed for the formation of

A catalogue of mercurian craters that retain their central peak or peak-ring structure was created to aid target prioritisation for the Mercury Imaging X-ray Spectrometer (MIXS), now on its way to Mercury aboard BepiColombo. Preliminary analysis of the MIXS crater catalogue suggested a potential spatial correlation between an abnormally high spatial density of peak-ring basins and a region of Mercury

We integrate high-resolution full-waveform velocity models with seismic reflection images to map the peak ring and impactite stratigraphy at the Chicxulub structure. International Ocean Discovery Program/International Continental scientific Drilling Program Site M0077 provides ground truth for our interpretations. The peak ring is narrower (∼10 km width) where it is high relief (600-700 m below seafloor)

To establish a consistent framework for seismic wave propagation that accommodates the effects of stress changes, it is critical to take into account the different definitions of stress and their corresponding effects on seismic quantities (e.g., wave speeds) as dictated by continuum mechanics. Revisiting this fundamental theoretical foundation, we first emphasize the role of stress within various

In hard rock settings, reflection seismic surveys are often acquired on crooked roadways. Acquisition geometry-related noise resulting from these crooked profiles obscures the final image in places where there are crossline dipping reflectors. This noise can be prevented with cross-dip moveout (CDMO) corrections. The conventional practice is to apply corrections on straight processing lines; however

Seismic anisotropy, wave attenuation, and dispersion are critical phenomena of wave propagation in real media. Full-wavefield modeling of wave behavior in such media plays an important role in investigating dynamic features of the earth’s interior and in full-waveform inversion of anisotropic parameters and velocity dispersion. We have developed a numerical scheme to model the full-waveform response

The singly and multiply scattered waves generated from interfaces of a fractured medium have strong energy, and their propagation directions contain information of fracture parameters. To exploit the useful information in the scattered waves, a fracture scattering imaging method is developed based on reverse time migration and angle decomposition. In this method, a fracture-parameter-related local

We have developed an inversion method for recovery of the geometry of an arbitrary number of geologic units using a regularized least-squares framework. The method addresses cases in which each geologic unit can be modeled using a constant physical property. Each geologic unit or group assigned the same physical property value is modeled using the signed distance to its interface with other units.

Gravity gradiometry inversion can provide important knowledge about a salt body and can assist in subsalt imaging. However, such inversions are faced with difficulties associated with the lack of response from the nil zone in which the salt density is nearly identical to that of the background sediments and weak signals from the deeper portion of the salt. It is well understood that such difficulties

Self-organizing maps (SOMs) are a type of unsupervised artificial neural networks clustering tool. SOMs are used to cluster large multivariate data sets. They can identify patterns and trends in the geophysical maps of an area and generate proxy geology maps, known as remote predictive mapping. We have applied SOMs to magnetic, radiometric, and gravity data sets compiled from multiple modern and legacy

Hydrocarbon source rocks can be adequately approximated as transversely isotropic (TI) media. The elastic properties of a TI medium are defined by five stiffness parameters: c11, c33, c44, c66, and c13. The laboratory estimation of c11, c33, c44, and c66 is straightforward, with each of the stiffness parameters determined by a single velocity measurement in an orthogonal direction. For c13, we need

Airborne electromagnetic (AEM) methods have been more and more widely used in mineral exploration, environmental and engineering studies, and ground water investigation. However, compared with ground-based electromagnetic (EM) methods, such as magnetotelluric or controlled-source EM, AEM methods generally produce large amounts of data, which leads to very costly 3D EM inversions. We have developed

When the shield machine passes through the clay layer, the clay debris cut by the cutter head usually adheres to the surface of the cutter head and is easy to form mud cakes after extrusion, which affects the safety and efficiency of construction. For the structure made of different materials, due to the different surface properties, the adhesion characteristics of clay are also different. So, selecting

Fatigue fracture is the main failure form of mining drill pipe joints, which directly leads to the occurrence of drill pipe drop accidents. Based on the principle of engineering bionics, the spine structure and kinematic behavior characteristics of cheetah were studied; the bionic design and trial production of drill pipe joints were carried out. For the bionic drill pipe joint, it separates the torsion

CO2 geological sequestration in shale is a promising method to mitigate global warming caused by greenhouse gas emissions as well as to enhance the gas recovery to some degree, which effectively addresses the problems related to energy demand and climate change. With the data from the New Albany Shale in the Illinois Basin in the United States, the CMG-GEM simulator is applied to establish a numerical

Ice-nucleating particles (INPs) initiate the primary ice formation in clouds at temperatures above ca. −38 ∘C and have an impact on precipitation formation, cloud optical properties, and cloud persistence. Despite their roles in both weather and climate, INPs are not well characterized, especially in remote regions such as the Arctic. We present results from a ship-based campaign to the European Arctic

Atmospheric chromophoric organic matter (COM) plays a fundamental role in photochemistry and aerosol aging. However, the effects of photodegradation on chemical components and photochemical reactivity of COM remain unresolved. Here, we report the potential effects of photodegradation on carbon contents, optical properties, fluorophore components and photochemical reactivity in aerosol. After 7 d of

The Pearl River Delta (PRD) region in South China is faced with severe ambient tropospheric ozone (O3) pollution in autumn and summer, which mostly coincides with the occurrence of typhoons above the Northwest Pacific. With increasingly severe O3 pollution in the PRD under the influence of typhoons, it is necessary to gain a comprehensive understanding of the impact of typhoons on O3 transport, production

Using borehole-constrained 3D reflection seismic data, we analyse the importance of sub-salt, salt, and supra-salt deformation in controlling the geometries and the kinematics of inverted structures in the Danish Central Graben. The Danish Central Graben is part of the failed Late Jurassic North Sea rift. Later tectonic shortening caused mild basin inversion during the Late Cretaceous and Paleogene

Abiotic methane has been increasingly detected at the surface of Earth and other terrestrial planets, exerting a strong effect on the study of chemolithoautotrophic life and thus astrobiology. In contrast, abiotic methane generation in subduction zones, which is intimately linked to questions such as the mechanisms of deep carbon mobility, has received scarce attention. Experiments elucidated the significant

Chemolithotrophic microorganisms are key primary producers in hydrothermal environments. However, the complex thermal and compositional gradients that frequently describe these settings commonly obfuscate which reactions are fueling such complex ecosystems. Nonetheless, potential sources of microbial energy can be identified by combining analytical geochemical data from hydrothermal systems and thermodynamic

Overwhelming numbers of detrital zircon (dZr) U—Pb ages have been acquired all over the globe in the last few decades, opening new horizons for employing big data approaches. However, several impediments such as frequent publication of heavily filtered data tables with omitted analyses, failure to cite the logic on "best age" computation, and generally the lack of uniformity among data treatment approaches

Angle-domain common-image gathers (ADCIGs) that can be used for migration velocity analysis and amplitude-versus-angle analysis are important for seismic exploration. However, because of the limited acquisition geometry and seismic frequency band, ADCIGs extracted by reverse time migration (RTM) suffer from illumination gaps, migration artifacts, and low resolution. We have developed a reflection angle-domain

The time-lapse seismic method plays a critical role in reservoir monitoring and characterization. However, time-lapse data acquisitions are costly. Sparse acquisitions combined with postacquisition data reconstruction could reduce costs and facilitate more frequent applications of the time-lapse seismic monitoring. We have developed a sparse time-lapse seismic data reconstruction methodology based

As large earthquakes in contractional fold-and-thrust belts are usually associated with complex ruptures along multiple faults or fault splays, the evaluation of potential rupture extent and relevant hazards continues to be challenging. We present a case study on the geometry and kinematic evolution of the southern Junggar fold-and-thrust belt, northern Tian Shan, where the 1906 M 8 Manas earthquake

The location of the suture zone between the South China Block (SCB) and the Indochina Block (IB) is disputed. Recently, along the Song Chay (Chay river) belt, a mélange zone was proposed as a potential suture zone of the SCB and IB. However, the provenance and age of the Song Chay mélange is poorly known. In order to better constrain the age and provenance of the elements forming the Song Chay mélange

We investigated mid-infrared reflectance spectra of anorthosite samples from Mt. Briand near the Manicouagan impact structure. Microprobe analyses of the plagioclase minerals reveal that they have a similar chemical composition (labradoritic), which is corroborated by the location of the Christiansen Feature at around 7.96 m (1256 cm−1). However, their respective spectral shapes differ from each other

Seismic data are traditionally acquired based on spatial sampling requirements, noise properties and budgetary constraints. However, designing a survey without taking into account the complexity of the subsurface may result in an image without the expected quality. Also, the subsequent preprocessing and processing steps may exploit or misuse the acquired data. The design should therefore incorporate

A clear concept of the recharge pathways for surface flow in mountain rivers is important for understanding the effects of climate change on streamflow in mountain block hydrology. In a mountain river in Alberta, Canada, three subsurface end-member sources were identified using silica, sulfate, and the isotopic composition of sulfate: interflow (water that has not undergone significant rock-water interaction)

The Sichuan-Yunan-Guizhou triangle region contains numerous economically important carbonate-hosted Zn-Pb deposits that occur in the Late Indosinian thrust and fold system rather than foreland basin. In this paper, we investigate the thrust-controlled Zhugongtang deposit (>30.0 Mt ores @ 6.76 wt.% Zn and 2.27 wt.% Pb) as a case study, using ore deposit geology, in-situ trace elements and isotopes in

The growth and evolvement features of crack are of great significance to study the failure mechanism of rock mass and valuate the stability of the cavity. In this study, in order to obtain the mechanics parameters and external macroscopic crack propagation characteristics of red sandstone, triaxial compression tests were carried out. Based on the experimental results, a numerical model was established

Evaluation of terrestrial shale gas resource potential is a hot issue in unconventional oil and gas exploration. Organic-rich shales are widely developed in the Jurassic strata of Tarim Basin, but their shale gas potential has not been described well. In the study, the Lower-Middle Jurassic fine-grained sedimentary rocks (Kangsu and Yangye Formations) in northern Kashi Sag, northwestern Tarim Basin

This work investigates the individual and combined effects of temperature and volatile organic compound precursor concentrations on the chemical composition of particles formed in the dark ozonolysis of α-pinene. All experiments were conducted in a 5 m3 Teflon chamber at an initial ozone concentration of 100 ppb and initial α-pinene concentrations of 10 and 50 ppb, respectively; at constant temperatures

Arctic low clouds and the water they contain influence the evolution of the Arctic system through their effects on radiative fluxes, boundary layer mixing, stability, turbulence, humidity, and precipitation. Atmospheric models struggle to accurately simulate the occurrence and properties of Arctic low clouds, stemming from errors in both the simulated atmospheric state and the dependence of cloud properties

Fire is an important source of ozone (O3) precursors. The formation of surface O3 can cause damage to vegetation and reduce stomatal conductance. Such processes can feed back to inhibit dry deposition and indirectly enhance surface O3. Here, we apply a fully coupled chemistry–vegetation model to estimate the indirect contributions of global fires to surface O3 through O3–vegetation feedback during

Abstract. With the rising food demands from the future world population, more intense agricultural activities are expected to cause substantial perturbations to the global nitrogen cycle, aggravating surface air pollution and imposing stress on terrestrial ecosystems. Much less studied, however, is how the terrestrial ecosystem changes induced by agricultural nitrogen deposition may modify biosphere-atmosphere

Abstract. Eighteen free amino acids (FAAs) were quantified in cloud water sampled at the puy de Dôme station (PUY – France) during 13 cloud events. This quantification has been performed without concentration neither derivatization, using LC-MS and the standard addition method to avoid matrix effects. Total concentrations of FAAs (TCAAs) vary from 1.2 µM to 7.7 µM, Ser (Serine) being the most abundant

Abstract. The ice phase in mixed-phase clouds has a pivotal role in global precipitation formation as well as for Earth's radiative budget. Above 235 K, sparse particles with the special ability to initiate ice formation, ice nucleating particles (INPs), are responsible for primary ice formation within these clouds. However, the abundance and distribution of INPs remain largely unknown. Mineral dust

Abstract. Chlorine dioxide (OClO) is a by-product of the ozone depleting halogen chemistry in the stratosphere. Although being rapidly photolysed at low solar zenith angles (SZAs) it plays an important role as an indicator of the chlorine activation in polar regions during polar winter and spring at twilight conditions because of the nearly linear dependence of its formation to chlorine oxide (ClO)

Abstract. Agro-industrial areas are frequently affected by various sources of atmospheric pollutants that negatively impact public health and ecosystems. However, air quality in these areas is infrequently monitored because of their lower population density compared to large cities, especially in developing countries. The Cauca River Valley (CRV) is an agro-industrial region in Southwest Colombia,

Abstract. Compared to 2019, the global growth rate of atmospheric methane rose by about 50 % in 2020, reaching 15 ppb/yr. Models of global atmospheric chemistry show that reductions in nitrogen oxide (NOx) emissions reduce levels of the hydroxyl radical, and lengthen the methane lifetime. Using estimates of NOx emission reductions associated with COVID-19 lockdowns around the world in 2020, together

The paper presents data on garnets from serpentinized peridotite xenoliths in the Nyurba and Botuoba kimberlite pipes of the Nakyn kimberlite field. The major and trace-element compositions of the garnets were analyzed to determine their compositional specifics and genesis. Based on the REE content and chondrite-normalized distribution patterns, the garnets are divided into two types with sinusoidal

Abstract— The paper summarizes authors' earlier and newly obtained experimental data on the formation of phlogopite and chromium-bearing potassium titanates of the crichtonite, magnetoplumbite, and hollandite groups, which are indicator minerals that characterize various stages of modal metasomatism in the upper mantle. Phlogopite-forming reactions were studied in the garnet–orthopyroxene system in

Phase relations in one of the key petrological systems, CaSiO3, have been comprehensively investigated for the first time in the pressure range 0–100 GPa and temperatures 0–2500 K within the density functional theory using the method of lattice dynamics in the quasi-harmonic approximation. The results showed that at atmospheric pressure and 0 K CaSiO3 is stable in the wollastonite structure, which

Abstract— The paper presents data on phase relations in garnet-bearing carbonatite from the Tromsø Nappe, Norway. The carbonatite matrix consists of calcite–dolomite carbonate with three generations of garnet inclusions (up to 15–20%). The relics of the primary garnets (Grt1) are depleted (<10–2 wt %) in the rare earth elements (REE). The garnet of the second and third generations (Grt2–3) is anomalously

Abstract— A review of the data available on the composition and abundance of titanium-bearing phases in the Earth’s mantle is provided in the paper. The main attention is paid to the discussion of natural minerals: the patterns of the mineralogy of mantle titanium-bearing phases (rutile, FeTiO3 ilmenite, garnet, pyroxene, spinel and post-spinel phases, phases with ilmenite- and perovskite-type structures

Abstract— Natural serpentine was experimentally recrystallized in the presence of chromite, corundum, and carbonatite as sources of Cr, Al, and Ca, respectively, at P = 5 GPa and T = 1300°C using a BARS multi-anvil high-pressure apparatus. The experimental products contained synthesized mineral assemblages corresponding to those of natural garnet peridotites. Electron probe microanalysis (EPMA) of

Abstract. In the present study, structure of sedimentary basins in the Eastern Asia Arctic zone is analysed by employing the approach based on decompensative gravity anomalies. Two obtained models, differing in their initial conditions, provide thickness and density of sediments in the study area. They demonstrate essentially new details on the structure, shape and density of the sedimentary basins

Modern carbonate tufa towers in the alkaline (~pH 9.5) Big Soda Lake (BSL), Nevada, exhibit rapid precipitation rates (exceeding 3 cm/year) and host diverse microbial communities. Geochemical indicators reveal that carbonate precipitation is, in part, promoted by the mixing of calcium-rich groundwater and carbonate-rich lake water, such that a microbial role for carbonate precipitation is unknown.

Flow-only and coupled flow-diffusion experiments at 95 °C and 100 bars pCO2 carried out in micro-capillary tubes packed with forsterite mineral grains were used to constrain a coupled classical heterogeneous nucleation and crystal growth reactive transport model describing the formation of secondary magnesite. The study made use of a novel experimental setup in which one capillary tube for flow is