Loose Sediments Research Articles

State of the Marine Ecosystem Near the Mouth of the Agoy River (Black Sea)

Aim.To study the state of the marine ecosystem of the recreational‐tourist zone of the Caucasian sector of the Black Sea through the example of a beach near the mouth of the Agoy River.Material and Methods. Phytoplankton, heterotrophic bacterioplankton, infusoria, holoplankton, meroplankton, ichthyoplankton, zoobenthos of loose bottom sediments and hydrochemistry samples of the water and bottom sediments were collected in June 2012 on three sections from the mouth of the Agoy River to the coastal runoff zone (depths 2.5–7.5 m). The identification of species of plankton and of the zoobenthos and of the chemical parameters of water and sediments was carried out according to standard methods. Results.It was revealed that most of the beach area, where psammophilic biocenoses of Lucinella divaricate and Chamelea gallina (Bivalvia) were located, was in satisfactory condition. An increase in the density of Lucinella divaricate, a rare species in the late 1990s, was noted. In the runoff zone, there was observed the appearance of cyanobacteria and the suppression of zoobenthos, expressed through the replacement of mollusc biocenoses by the biocenosis of the polychaete, Capitella capitate, with a biomass two orders of magnitude lower than the average for the area. High numbers of heterotrophic bacterioplankton (4.5 million cell/ml) and infusoria (64 million ind./m3) could indicate bacterial contamination of this zone. The negative impact of waste water on plankton is manifested in a decrease in the population of netted zooplankton, their abnormal development, and the increasing role of microheterotrophs.Conclusions.The results obtained give an image of the state of marine coastal ecosystems of recreational‐tourist and cordoned areas of the Caucasus and can be useful for the further monitoring of this region.

Reconstructing climate and soil formation processes in the Atxoste rock-shelter (Upper Ebro Valley, Northern Spain): A preliminary geoarchaeological view of human communities during the Pleistocene-Holocene transition in the Ebro Valley and Cantabrian Spain

Natural, anthropic and post-depositional formation processes can affect the formation of sediments in rock shelters. Geoarchaeological analyses were carried out on a series of samples of compact and loose sediments provenient from the 1995 to 2005 excavation campaigns at the Atxoste shelter. This work focuses on climate reconstruction of the Upper Ebro Valley, comparing it with results of previous studies of the area and its surroundings, as well as the Cantabrian region. We also point out the problem of sediment conservation when analyzing sites containing Pleistocene/Holocene and/or Mesolithic/Neolithic transition stratigraphies. Thanks to the geoarchaeological study we have differentiated three climatic events: - The end of the Pleistocene as a period characterized by cold, humid conditions and with probable seasonal droughts. - The Pleistocene-Holocene transition that corresponds to a climatic moment in which the indicators of cold climate have practically disappeared. - The beginning of the Holocene, when a significant and rapid climatic improvement takes place, with an increase in temperatures, a decrease in rainfall but maintaining the humidity. The identification of the different post-depositional processes has been key to identifying the state of the recovered archaeological material. Therefore, this study is based on the geoarchaeological analysis, approaching the period central to this paper (Pleistocene-Holocene transition). This is crucial in order to obtain a better understanding of the paleoecology and archaeological aspects.

Architectural effects on fossil preservation. The case of macaroni coralline algae

Coralline red algae with protuberances in their thalli are common and instructive examples of fabricational effects on fossil preservation. The body (thallus) of non-geniculate coralline algae is a coherent mass of cell filaments. All vegetative cells, except the epithallial ones at the tip of each filament are enclosed by a high-Mg calcite wall. Many extant and extinct species of coralline algae have protuberances in their thalli. Protuberances appear both on the dorsal surface of algae that grow attached to a rigid substrate and in unattached specimens living on loose sediment. In either case, protuberances develop due to a higher growth rate of fi laments in their centre. In each growth step, the cells formed at the protuberance apex are longer than coeval cells at the protuberance sides. The cell length decreases radially outwards from the protuberance tip. Consequently, central cells in protuberances are generally longer than lateral ones. Calcite walls of central, longer cells are thinner, less dense, and richer in Mg2+ than those of lateral cells. Accordingly, the former are more susceptible to dissolution during fossilization. As a result, dead and fossil coralline algae with protuberance centres partially or totally dissolved are relatively common. In these cases, protuberances occur as structures with an empty or vuggy central part and well-preserved sides. This macaroni-like preservation of corallines is particularly common in Cenozoic marl deposits, formed mainly by concentrations of unattached branching coralline thalli.

Tracking reduction of water lead levels in two homes during the Flint Federal Emergency

A Federal Emergency was declared in Flint, MI, on January 16, 2016, 18-months after a switch to Flint River source water without phosphate corrosion control. Remedial actions to resolve the corresponding lead in water crisis included reconnection to the original Lake Huron source water with orthophosphate, implementing enhanced corrosion control by dosing extra orthophosphate, a “Flush for Flint” program to help clean out loose leaded sediment from service lines and premise plumbing, and eventually lead service line replacement. Independent sampling over a period of 37 months (January 2016–February 2019) was conducted by the United States Environmental Protection Agency and Virginia Tech to evaluate possible human exposure via normal flow (∼2–3 L/min) sampling at the cold kitchen tap, and to examine the status of loose deposits from the service line and the premise plumbing via high-velocity flushing (∼12–13 L/min) from the hose bib. The sampling results indicated that high lead in water persisted for more than a year in two Flint homes due to a large reservoir of lead deposits. The effects of a large reservoir of loose lead deposits persisted until the lead service line was completely removed in these two anomalous homes. As water conservation efforts are implemented in many areas of the country, problems with mobile lead reservoirs in service lines are likely to pose a human health risk.

Delineating of groundwater potential zones based on remote sensing, GIS and analytical hierarchical process: a case of Waddai, eastern Chad

The delineation of favourable areas of water potentials and their management must be based on rigorous scientific studies. Thus, geographic information system (GIS) and remote sensing (RS) techniques are extremely important in predicting and mapping favourable groundwater zones. This paper aims to map potential areas of groundwater in Waddai region, eastern Chad. A region which has experienced successive droughts over the last two decades, causing the drying of most of the rivers in the area. This study focuses on combining GIS, RS, and analytical hierarchy process; in addition to the factors controlling the movement and retention of groundwater. Six factors (rainfall, slope, land use/land cover, drainage density, lineament density, and lithology) were used to integrate the spatial analysis of areas likely to hold groundwater. The results indicate that potential groundwater areas are unevenly distributed throughout the study area. For instance, the northwestern part is characterized by a low groundwater potential. This low potential in this part of the study area as well as a small portion of the eastern area is explained by a low density of lineaments and drainage, the presence of moderate precipitations, and a semi-permeable lithology (alternating hard rocks and loose sediments). While every low and moderate area occupy most of the middle of the region, good ground water reservoirs occupy a large part of the region. This distribution is explained by good fracturing, permeability, lineament density, high drainage, gentle slope, and precipitation. Therefore, areas of the northwestern part are highly suitable for groundwater exploration and exploitation. Hence; these results would be a guide for future explorations and will maximizes the economic efficiency of the ground water exploitation processes. Furthermore, this map will be useful as a guide in decision-making and on water policy planning.

Inverse modeling of saturated-unsaturated flow in site-scale fractured rocks using the continuum approach: A case study at Baihetan dam site, Southwest China

Modeling saturated-unsaturated flow in fractured rock formations remains a challenging issue due to the difficulties in properly calibrating the unsaturated flow properties for fractured rocks. On the basis of the continuum approach, this study uses inverse modeling to determine the unsaturated hydraulic parameters of fractured rocks, loose sediments, and geologic structures in a large-scale slope under difficult hydrogeologic conditions at the Baihetan dam site, Southwest China. The saturated hydraulic conductivities were determined a priori by packer tests. Field data, including time-series of groundwater level observations and available discharge measurements, is used. A combined procedure of orthogonal design, finite element forward analysis, artificial neural network, and genetic algorithm is adopted for the inverse analysis with high computational efficiency. The numerical results well reproduce the typical features of multiple water tables and wedge-shaped unsaturated zones controlled by gently-sloping tuff zones of low vertical permeability, showing 46–65% of groundwater flowing subhorizontally along each tuff zone and the remaining 35–54% infiltrating vertically and recharging deeper layers. The drastic drawdown of groundwater level after 10-year site characterization is also reproduced. The calculated discharge and water tables agree reasonably well with field observations, indicating that the estimated parameters are representative of the unsaturated hydraulic properties at the site. This work provides an efficient and effective methodology for seeking an optimal solution in large-scale inverse modeling of saturated-unsaturated flow, and further manifests the feasibility of the continuum approach in predicting unsaturated flow in site-scale fractured rock formations.

The Cyclops Mountains Massif (New Guinea, Indonesia) as the provenance area for metal-bearing shelf sediments from the Carolinian Sea

In 2009, on the initiative of PT Halmahera Perkasa the “Jayapura” exploration project was carried out in Indonesia. As part of this project, exploration of the sea bottom in the northern coast of New Guinea was carried out over a distance of ~45 km. The suction dredge collected 59 samples of loose sediments from the shelf bottom surface of the Carolinian Sea (to a depth of 60 m below the sea-floor). The extracted samples are usually poorly and moderately sorted sands (5 samples), medium-grained sands (21 samples), and fine-grained sands (33 samples). The sand composition shows, among others, a wide spectrum of heavy minerals of ultra-mafic (Cr-garnet, chromium spinel, Mg-olivine) and metamorphic (epidote, clinochlore, amphibole, titanite) origin. The content of heavy minerals in the sediments is up to 54.77 wt.%. It was found that the source of heavy fraction in the eastern and western parts of the coast is the rock of the ophiolite series building the Cyclops Mountains Massif. The mineral composition of sediments from the central coastal zone corresponds to the types of rocks building the metamorphic core of the Cyclops Mountains (amphibolite, gneisses, andesite). Three mineral-geochemical subprovinces were determined on the basis of analyses of heavy mineral decomposition and chemical analyses of sediments. Shelf sediment from the eastern part of the coast is characterized by an increased content of strategic metals (Ni up to 3560, W up to 3130 and Co up to 142 ppm). In the central zone, the V content increases up to 244 ppm and the Ag content up to 5 ppm. In the shelf sediments there is a strong depletion in the REE.

Diagnosing the landslide areas of Angren open pit marginal mass according to the data of seismo- and electrical prospecting

Introduction. Sloping structures (quarry sides, dumps, banks, cuts, dams, etc) stability forecasting accuracy improvement requires detailed elaboration of physical-mechanical properties of the rock mass under consideration. Traditional methods of well engineering-geological exploration and hydrogeological monitoring are therefore supplemented by geophysical study. Research aim is to diagnose unstable deconsolidated and wetted zones in marginal masses for the purpose of further forecast of quarry sides stability. Methodology. Databases of geophysical studies obtained by the expeditions of the services of the Republic of Uzbekistan at Angren open pit. Results. For the test area represented by 11 seismic stations at the southern side of the quarry, the criterion assessing the state of the site as potentially landslide hazardous according to the results of circular seismic sounding has been experimentally obtained. With the use of this criterion, in the plan of the landslide zone the borders have been established. For the test area represented by 16 geophysical profiles at the northers side, by electrical profiling graphs and geological sections for the corresponding profiles, 58 "Izvestiya vysshikh uchebnykh zavedenii. Gornyi zhurnal". No. 1. 2020 ISSN 0536-1028 the following regularities have been found: at profile areas adjacent to the runs (rivers), local negative anomalies of effective resistivity up to 20–50 Ohm ∙ m are observed connected with soils wetting; between the anomalous areas the alternation of effective resistivity qualitatively coincides with the alternation of the thickness of a layer of loose deposits. By the arrangement of the negative anomalies borders at the graphs pf effective resistivity dependence on the spread of the profile along all profiles (PR1–PR16), the borders of the wetted zones were established in the plan of the test area. Summary. For geomechanical processes monitoring in the landslide zones it is advisable to apply the method of circular seismic sounding determining the value and the anisotropy coefficient according to the extreme values of compressional arrival time. For the conditions of the Angren open pit, the criterion of potential hazard of landslide development is the value of the anisotropy coefficient higher than 1.6. When elaborating the detailes of the physical properties of landslide zones in quarry sides which are weakened by sand-clay Quaternary sediments, by the method of electrical profiling it is advisable to use: the linear dependence on the thickness of Quaternary sediments on the value of the effective resistivity; hyperbolic dependence of soils relative wetness within the water saturation zones on the value of the effective resistivity ascribed to the reference value defined in the site of soil samples collection, and the borders of wetting zones are to be established by the negative anomalies at electrical profiling graphs. In order to construct the solid geologicalgeophysical models of the landslide zones of the sides, in addition to the geological sections data, the following results of geophysical sounding should be used: the boundaries of landslide zones in the plan, detailed contact geometry of loose Quaternary sediments with bedrock; soil properties modified by wetting

Лучевой мониторинг состояния внутренних органов новорожденных, перенесших общую терапевтическую гипотермию

Purpose: Learning the state of the internal organs in newborns with severe perinatal asphyxia after general therapeutic hypothermia.
 Material and methods: 80 newborns with severe perinatal asphyxia born from January 2014 to May 2019 in Kursk were under observation. In the first 6 hours of life, 52 patients were started with general therapeutic hypothermia (1st observation group), 28 newborns did not perform hypothermia (2nd control group). All children underwent a dynamic complex radiological examination, included ultrasound of the brain, abdominal organs and retroperitoneal space, echocardiography with Doppler, chest X-rays.
 Results and discussion: In both groups of observations, radiation symptoms of liver and gallbladder changes were identified: a uniform increase in the echogenicity of the hepatic parenchyma (98.1 % of cases in group 1 and 100 % of cases in group 2, p > 0.05), visual “impoverishment” of the vascular pattern (98.1 % and 100 %, p > 0.05), hepatomegaly (19.2 % and 21.4 %, p > 0.05), thickening of the gallbladder walls, loose sediment or suspension in its lumen (7.7 % and 10.7 %, p > 0.05). All 80 examined patients showed a bilateral increase in echogenicity of the renal parenchyma with visual impoverishment of intraorgan blood flow and impaired corticomedullary differentiation. The described internal organs changes were reversible and due, in our opinion, mainly to the effect of asphyxiation and resuscitation measures.
 According to the results of chest X-ray, we did not reveal the effect of therapeutic hypothermia on the incidence of hospital pneumonia: it was found in 34.6 % newborns from the 1st group and in 42.9 % – from the 2nd one (p > 0.05). However, in the first 14 days of life the respiratory failure caused by edematous and hemorrhagic changes in patient’s lungs was detected more often in patients from observation group then in patients from control group: respectively 76.9 % and 42.8 % of cases (p <0.05). This indicates a negative effect of general therapeutic hypothermia on the respiratory system of newborns with severe perinatal asphyxia.

Reevaluation of Perchlorate in Gale Crater Rocks Suggests Geologically Recent Perchlorate Addition

AbstractPerchlorate (ClO4−) was discovered in Martian soil by the Phoenix lander, with important implications for potential Martian biology, photochemistry, aqueous chemistry, and the chlorine cycle on Mars. Perchlorate was subsequently reported in both loose sediment and bedrock samples analyzed by the Sample Analysis at Mars instrument onboard the Curiosity rover in Gale crater based on a release of O2 at 200–500°C. However, the continually wet paleoenvironment recorded by the sedimentary rocks in Gale crater was not conducive to the deposition of highly soluble salts. Furthermore, the preservation of ancient perchlorate to the modern day is unexpected due to its low thermodynamic stability and radiolytic decomposition associated with its long exposure to radioactivity and cosmic radiation. We therefore investigate alternative sources of O2 in Sample Analysis at Mars analyses including superoxides, sulfates, nitrate, and nanophase iron and manganese oxides. Geochemical evidence and oxygen release patterns observed by Curiosity are inconsistent with each of these alternatives. We conclude that perchlorate is indeed the most likely source of the detected O2 release at 200–500°C, but contend that it is unlikely to be ancient. Rather than being associated with the lacustrine or early diagenetic environment, the most likely origin of perchlorate in the bedrock is late stage addition by downward percolation of water through rock pore space during transient wetting events in the Amazonian. The conclusion that the observed perchlorate in Gale crater is most likely Amazonian suggests the presence of recent liquid water at the modern surface.

Characterization of seabed properties from Scholte waves acquired on floating ice on shallow water

ABSTRACTSeismic surveying of the coastal areas in the Arctic is best facilitated during wintertime when the sea ice is land‐fast. This eases the logistics of the operation and assures that there is no damage made to the vulnerable tundra. Seismic experiments on floating ice on shallow water performed in a fjord in Svalbard in the Norwegian Arctic show prominent Scholte waves. The dispersion relation of Scholte waves can provide the shear wave velocities of the seabed sediments. Scholte wave data can potentially be obtained when the seismic source and geophone receivers are both placed on top of the floating ice. However, the Scholte wave data become more distinct by using an air gun lowered some metres below the ice. A rock physics model based on a two‐step differential effective medium scheme has been tuned to predict seismic properties found for very loose sediments, among these very high P‐wave to S‐wave velocity ratios. The rock physics model enables us to convert seismic velocities obtained from Scholte wave data to quantitative estimates of the sediment composition.

GIS-Based Geomorphological Map of the Calore River Floodplain Near Benevento (Southern Italy) Overflooded by the 15th October 2015 Event

On 15 October 2015, the floodplain of the Calore River underwent a destructive flood, with a stream stage increase up to 10 m. In this paper, we describe the GIS-based, object-oriented geomorphological map of the overflooded sectors of the Calore River floodplain near Benevento. The map graphically represents the field-checked results of a detailed geomorphological study carried out by means of GIS analysis of historical and topographic maps and orthophotos. Particular attention was devoted to the analysis of the channel adjustments experienced by the Calore River since the end of the 19th century, which shaped most of the landforms in the floodplain. The results showed that the investigated floodplain is characterized by abandoned channels, anthropogenic landforms, and five orders of recent river terraces separated by gently-sloping inactive fluvial scarps, less than 2 m high. On the oldest and/or more distal sectors of the floodplain, landforms are badly preserved, probably due to the more prolonged reshaping by natural erosional processes and anthropogenic activities, and to the high erodibility of the loose sediments in which they are shaped. The proposed map could be a key tool for a correct flood hazard assessment in the Benevento area, permitting thematic maps that avoid or reduce the negative effects of events similar to the 15 October 2015 flood.

Current issues of search of gold placers in the south of Ukraine

The main gold ore territory of Ukraine is Ukrainian shield, mainly its central and eastern parts. Currently, the potential of Ukrainian shield is estimated at 2.4 thousand tons of gold. Gold ore deposits are insufficiently studied and not brought to development. The same can be said about the development of gold placers. But in the case of shallow deposits its study and development may be economically justified, it does not require large capital investments and allows to recoup costs in a short time. This is especially true given the extremely favorable situation on the world gold market in recent years. Erosion and denudation of native deposits certainly led to the formation of deposits of native placer gold in the sedimentary cover on the territory of the Ukrainian shield and its slopes. Significant amounts of geological information on the widespread distribution of placer gold in loose sediments, in the modern basins of the Dnieper, Southern Bug, Don, Black and Azov Sea shelf, have been accumulated. This corresponds to the location of indigenous sources of gold and the general direction of unloading of river systems. Previous geological studies in this area have revealed numerous manifestations of placer gold of various scales, but no industrial facilities have been recorded. Placer gold in the south of Ukraine is characterized by a high mass fraction of gold of small and thin size classes and significantly aleurite-clay composition of gold-bearing deposits. Such characteristics complicate the geological search and real assessment of gold-bearing objects and, provided that standard sampling and processing methods are used in geological works, lead to underestimation of the real gold content. Studies conducted on the most studied placer sites convincingly show that gold is lost when washing samples, even under careful control. And this is a typical situation for many objects (not only Ukrainian), which were studied using the standard method of extracting free gold by gravity. That is why there are reasonable doubts about the reliability and quality of the current assessment of placer gold deposits. In our opinion, the prospects for the search for loose gold on the Ukrainian shield and its slopes are significantly underestimated. The presence of indigenous sources with great resource potential and at the same time numerous known manifestations of different ages and scales of placer gold clearly indicate the possibility of the formation of placers with industrial characteristics in the sedimentary stratum of southern Ukraine. The use of modern technologies for the gold enrichment and extraction, high-precision analytical research and the favorable state of the world gold market force to urgently review the results of previous geological work. The problem of conducting new comprehensive research aimed at auditing the accumulated data, identifying, and studying of placer deposits namely with gold of small and thin size classes is becoming urgent. The result of such work should be the discovery and industrial development of gold placers, which can be the basis of gold production in Ukraine.

Mineralization of rare metals in the lakes of East Kazakhstan

Purpose. Study on the chemical composition of lake waters, salt brines, brine and bottom sediments to identify the mineralization of rare metals and other types of minerals. Methodology. Mass spectrometric studies (mass spectrometer with inductively coupled plasma ICP-MS 7500cx from AgilentTechnologies) for the purpose of high-precision analytical studies on the chemical composition of salt lake water in order to assess the content of rare elements. The use of unmanned aerial vehicles for linking and geometrizing lakes. Findings. Field surveys on the geometrization and linking of lakes were carried out. From the materials obtained with the help of the drone, orthophotoplans were created (with a measurement accuracy of up to 1 centimeter), as well as a digital terrain model and a digital terrain model. A complex of analytical works was carried out using inductively coupled plasma spectrometry. When analyzing the distribution graphs of the absolute content of micro-components in the waters of the lakes of the Delbegeteysky massif, it was found that all samples were enriched with sodium, phosphorus, iron, magnesium and barium. The results of the analyses revealed the predominance of sulfates and chlorides in the composition of the surface waters of most of the water bodies of the Delbegeteysky massif. At the Burabai site, lake waters are characterized by an alkaline reaction of the environment (on average = 8.71). At the same time, the salinity of water bodies varies from 05 to 9 g/dm3. Originality. Large-scale outcrops of granites of the Kalba complex (P1), with which a rare-metal type of mineralization is genetically associated, are known to be on the selected study sites. Quartz-wire-greisen and quartz-wire tin, tin-tungsten and tungsten formations are also widely developed. Considering the large geochemical migration ability of rare alkaline elements in the thickness of loose sediments as a result of intensive geodynamic processes in the East Kazakhstan region, it is possible to assume the possibility of their migration to the upper horizons and accumulation in salt lakes localized within the area of development of granite intrusions of Permian age and associated deep tectonic faults. Practical value. The results of the research can serve as a revival of the rare metal industry in the region, which will allow developing new high-tech industries and creating new jobs in this area. The obtained results can be used for setting up further exploration and operational work on the selected promising areas.

Gyrochorte 'highways' and their environmental significance in shallow-marine sediments

The reworking of a trace by a subsequently following organism represents a so-called sequorichnial behavior and leads to formation of a burrowing highway. Burrowing occur more frequently than assumed in the fossil record. Their ichnological and sedimentological meaning is elucidated by using the trace fossil Gyrochorte . Gyrochorte producers exploiting sandy event beds tend to use burrowing highways in the same direction. Evidently, the Gyrochorte producers are thigmotactically highly sensitive as they can recognize a burrow produced by the same species because of the less densely packed grains, a somewhat increased mud content, and supposedly mucus segregated within the burrow. These changes make the reworking of pre-existing burrows energetically advantageous. However, in shallow-marine settings mucus is degraded rapidly and loose sediment consolidates in a short while. Therefore, the time to recognize a pre-existing burrow appears to be limited and a rather high number of organisms is a prerequisite for reutilization of a previous trace. Burrow highways potentially represent an additional criterion to characterize an opportunistic population strategy.

Ground penetrating radar investigations of the geological structure of loose sediments at solid mineral deposits

For effective commercial development of deposits, an increase in the information content of operational exploration is required. In recent years, the range of methods used to obtain complete and reliable information about the structure and properties of the rock mass of a developed field include remote methods of high-frequency electrical prospecting, in particular, the ground penetrating radar (GPR) method. The paper presents a methodological experience in the interpretation of GPR data of sandy river sediments based on the identification of radar facies. In the considered area, four types of radar facies have been identified that characterize the structure of sandy deposits and the morphology of the river bed. The criteria for identifying radar facies were used to analyze wave patterns of loose sediments in a sand and gravel pit and a placer gold deposit. Experimental GPR investigations are presented by data from a sandy-gravel pit (Warsaw, Poland) and from a placer gold deposit (Yakutia, Russia). As an example, a GPR section along the Paplin quarry and its interpretation, with the identification of GPR facies, is presented. A cross-sectional GPR profile of the dredging landfill is considered for the placer gold deposit. The analysis of the wave pattern was carried out, geological boundaries were highlighted. Based on the interpretation results, the characteristics of the rocks were given. It was noted that according to the GPR data, it is possible to identify zones of uplift of bedrock, which can affect the course of the dredge. As a result of using GPR in a swampy area where drilling was impossible, a deep three-layer section was obtained. The presented results of the successful use of GPR investigations and methodological approaches in the interpretation of data, show the promise of using the GPR method in assessing mining and geological conditions, in particular, placer deposits. At the same time, the efficiency of obtaining data can further contribute to the optimization of technology and increase the efficiency of field development.

Assessment of territorial impact of industrial mercury pollution and proposal for its solution

The mercury electrolysis plant in Usolye Sibirskoye, which was decommissioned in 1998, is a source of mercury pollution, since measures to prevent mercury pollution of the environment were not implemented after its closure. On the territory of the plant, mercury remained in building structures, in sludge, in soils, in loose sediments. All of them are deposited sources of metallic mercury, from where it continues to spread in the air, soils and groundwater. In order to choose the best method to eliminate the source of mercury pollution, it is necessary to conduct an assessment of the impact on all elements of the environment and to identify the places with the highest mercury contamination. In addition, to propose environmental protection measures those are aimed at eliminating the main sources of metallic mercury release to the environment from the decommissioned mercury electrolysis plant. During the environmental impact assessment of the investigated object, the following tasks were performed: an assessment of the existing environmental situation and the state of the natural environment was carried out; alternative scenarios for achieving the planned activity were considered, with a justification for choosing the best one.

Image based Particle Shape Analysis Toolbox (IPSAT)

Shape analysis can provide vital information regarding the origin, transport and deposition history of grains. Particle shape measurement has been an active area of research for sedimentologists since the 20th century. With advancement in the field of computation and image analysis, shape analysis can be done in a faster and much more accurate way compared to manual measurements. The results obtained are reproducible as compared to visual qualitative analysis. However, there is a lack of image analysis software tools aimed at the field of sedimentology where the fine details of a particle boundaries are required. Image based Particle Shape Analysis Toolbox (IPSAT) developed in the Mathematica environment for the quantitative characterisation of sedimentary grains in 2-dimensions is presented here. This image analysis toolbox can be used to analyse consolidated as well as loose sediment samples. A total of 12 parameters are available for shape measurement comprising conventional shape parameters (roundness, angularity, circularity and irregularity), mathematically complex shape parameters (fractal dimension and Fourier descriptors) and common geometrical shape parameters (aspect ratio, convexity, solidity, mod ratio, rectangularity and compactness). Additionally, IPSAT offers to compute 6 particle size measurement parameters. Furthermore, 2-D particle size distribution can be transformed to a 3-D size distribution for thin section analysis. Example analyses have been carried out on a sandstone and a loose sediment sample. The toolbox presented here aims to establish a textural analysis methodology to be used by geologists and sedimentologists in particular. It will allow users to quantitatively characterise a large set of grains with a fast, cheap and robust methodology.

Induced biological soil crust controls on wind erodibility and dust (PM10) emissions

ABSTRACTInducing biological soil crust (biocrust) development is an appealing approach for dust mitigation in drylands due to the resistance biocrusts can provide against erosion. Using a portable device, we evaluated dust emissions from surfaces either inoculated with biocrust, amended with a plant‐based soil stabilizer, or both at varying wind friction velocities. Four months after application, emissions from all treatments were either indistinguishable from or greater than controls, despite evidence of biocrust establishment. All treatments had greater surface roughness and showed more evidence of entrapment of windblown sediment than controls, factors which may have been partially responsible for elevated emissions. There was a synergistic effect of inoculation and stabilizer addition, resulting in a nearly two‐fold reduction in estimated emissions compared to either treatment alone. Stepwise regression analysis indicated that variables associated with surface crust strength (aggregate stability, penetration resistance) were negatively associated with emissions and variables associated with sediment supply (sand content, loose sediment cover) were positively associated with emissions. With more time to develop, the soil‐trapping activity and surface integrity of biocrust inoculum and soil stabilizer mixtures is expected to increase with the accumulation of surface biomass and enhancement of roughness through freeze–thaw cycles. © 2019 John Wiley & Sons, Ltd.

End-member modeling of the grain size record of loess in the Mu Us Desert and implications for dust sources

The arid and semiarid northern region of China is the most important loess region in the world. In this region, loess records from the Chinese Loess Plateau (CLP) have been studied extensively, but they are often underrepresented in sedimentological-palaeoenvironmental studies dealing with sites in the Mu Us Desert. Thus, the dust sources and sedimentary characteristics of loess in the Mu Us Desert are poorly understood. To address this, 9 loess sections and 44 modern surface samples with different sediment types in the Mu Us Desert are analyzed to determine their grain size distributions. The grain size dataset is subdivided into three end-members (EMs) using EM modeling, and the EM modeling results of loess and surface sediments are compared. Through the above work, we obtain the following information. (1) The modes of EM1, EM2 and EM3 are 16 μm, 70 μm and 234 μm, respectively, thus representing different transport processes from different dust sources. Among them, EM1 represents long-term suspension from distant sources, EM2 represents short-term suspension and saltation driven by dust storms from local sources, and EM3 represents saltation with shorter transport distance than EM2. (2) From northwest to southeast, the content of loess in EM1, EM2 and EM3 shows a gradual decreasing trend, a gradual increasing trend, and a gradual increasing or irregular trend, respectively. This spatial distribution indicates that although the winter monsoon is the main driving force for loess materials, it is not the main controlling factor of the loess grain size. The loess grain size of the Mu Us Desert is greatly affected by the dust sources. (3) The dust sources of loess in the Mu Us Desert are complex. In addition to the common dust sources with the CLP loess, there are also the contributions of local loose sediments, such as alluvial-lacustrine sediments, floodplain sediments and dune sands from the Mu Us Desert.