A technique for diagnostics of micro-inclusions in the objects of soil and geological origin: validation and practical application

A method for diagnosing microinclusions in the objects of soil and geological origin is developed on the basis of the Atlas of microinclusions in soils (hereinafter referred to as the Atlas). The validation procedure and an example of the practical application of the developed technique are considered. A review of the content and structure of the Atlas, which contains 37 types of microinclusions is presented. Diagnosis of microinclusions is carried out using the Atlas key which is a sequence of identifying diagnostic features (transparency, shape, color, gloss, fracture, structure, as well as density, magnetic properties, hardness, brittleness) for different types of microinclusions. A scheme for determining the nature of a microinclusion (red brick) using the Atlas key is given as an example. The validation procedure of this method consists in experimental verification of the reliability of testing and evaluation of the reproducibility of test results under different conditions: when examining samples of various complexity by several performers at different times using different stereo microscopes. We used 17 soil samples that were previously (2 – 8 years ago) tested and stored as control samples in a laboratory collection of site-collected samples. One part of the samples was examined in usual forensic soil examinations, the other was studied in the framework of participation in the procedure of interlaboratory proficiency testing under the ENFSI (European Network of Forensic Science Institutions). Two experts performed independent studies of control samples at different times. It is shown that the composition of the complex of microinclusions (by type and number) in each of the studied samples coincides with the composition of the corresponding control sample. The experts performed 108 tests, and there were no erroneous results which indicates the reproducibility of the test results and the competence of the experts. An example of the practical application of the developed technique is given.

Geological influence in the index properties variability and shear strength probability density functions.

Soil properties variability in geotechnical engineering is one of the most important tasks in reliability-based designs (RBDs). However, these analyses have been carried without taking into account the influence of the geological origin in the different aspects that alter the soil properties variability. Therefore, two types of geological formations are analysed: residual soils (stationary origin) and mudflows (dynamic origin). First, the index properties variability was evaluated for each geology, where mudflows are less variable in comparison with the residual soils. It was confirmed that the correlations of the effective friction angle should not be used for high plasticity and fine-grained soils; however, the shape characteristics of the Probability Density Functions (PDF) of both effective and total parameters depends on the geological origin. The undrained compressive strength (qu) analyses show that geology influences the shape characteristics of the PDF and is directly proportional to the (N1)60 PDF. From the results, mudflows present a qu PDF with a lognormal tendency, which is inferred to be due to the possible presence of rock fragments and randomness related to the soil's formation. However, the residual soils, under the same state of weathering tend to have a normal qu PDF, possibly due to the stationary origin of these soils.Supplementary material:https://doi.org/10.6084/m9.figshare.c.5420240

Quantitative Expression of the Burial Phenomenon of Deep Seafloor Manganese Nodules

Manganese (polymetallic) nodules on the deep seafloor in the open ocean have attracted great interest because of their economic potential. Visual data on nodules found on the deep seafloor such as photographs and videos have increased exponentially with the recent progress of related technologies. These data are expected to reflect useful information for estimating these mineral resources, as well as understanding their geological origin. Although the size, number, and coverage of manganese nodules have been measured in seafloor images, the burial of such nodules has not been sufficiently examined. This paper focuses on mathematical expression of the burial of the manganese nodules and attempts to quantitatively elucidate relations among burial degree and nodule geological parameters. The results, that is, a dataset obtained by calculations of relations among parameters, are also utilized for considerations of quantitative expression of burial. These considerations are expected to contribute to a better understanding of the geological origin of manganese nodules.

Different Waters for Different Performances: Can We Imagine Sport-Related Natural Mineral Spring Waters?

Preserving the hydration status means to balance daily fluids and salt losses with gains, where the losses depend on several physiological and environmental factors. Especially for athletes, these losses could be relevant and negatively influence the performance: therefore, their hydro-saline status must be preserved with personalized pre- and rehydration plans all along the performance period. Scientific literature in this field is mainly dedicated to artificial sport drinks. Different territories in most world areas are rich in drinking natural mineral spring waters with saline compositions that reflect their geological origin and that are used for human health (often under medical prescription). However, scarce scientific attention has been dedicated to the use of these waters for athletes. We therefore reviewed the existing literature from the innovative viewpoint of matching spring water mineral compositions with different athletic performances and their hydro-saline requirements.

Development of a Unified Geotechnical Database and Data Processing on the Example of Nur-Sultan City

Development of a geotechnical database for the young capital of Kazakhstan, Nur-Sultan city, became a paramount concern of both the scientific community and industry. The creation of the Kazakhstan model of the geotechnical database was based on a fixed dataset which included a city map with determined X, Y, and H coordinates and the user generated data obtained from the materials of engineering and geological surveys from more than 2000 boreholes. Based on the assessment of the built-up area of the city, six main engineering-geological elements (EGE) were identified. The territory of the city was regrouped into eight zones instead of the previous six based on the geological origin and stratigraphy interposition of the EGE. Engineering properties of the soils were considered for physical and mechanical characteristics, where the plasticity limits demonstrated an accurate correlation to the elasticity modulus E and distribution boundaries between the alluvial and eluvial types of the soil on the graph. So, the increased liquid and plastic limits are replicated by higher values of elasticity modulus E, and hence better strength characteristics of a particular soil layer and vice versa, while the moisture content and soil density did not show any obvious pattern and requires additional verification on the construction site. Finally, a geotechnical map was built for the driven piles and the optimal variations in the pile length for each zone were determined.

Uranium Vertical and Lateral Distribution in a German Forested Catchment

The natural measurements of uranium (U) are important for establishing natural baseline levels of U in soil. The relations between U and other elements are important to determine the extent of geological origin of soil U. The present study was aimed at providing a three-dimensional view of soil U distribution in a forested catchment (ca. 38.5 ha) in western Germany. The evaluated data, containing 155 sampled points, each with four major soil horizons (L/Of, Oh, A, and B), were collected from two existing datasets. The vertical U distribution, the lateral pattern of U in the catchment, and the occurrence of correlations between U and three groups of elements (nutrient elements, heavy metals, and rare earth elements) were examined. The results showed the median U concentration increased sevenfold from the top horizon L/Of (0.14 mg kg−1) to the B horizon (1.01 mg kg−1), suggesting a geogenic origin of soil U. Overall, soil U concentration was found to be negatively correlated with some plant macronutrients (C, N, K, S, Ca) but positively with others (P, Mg, Cu, Zn, Fe, Mn, Mo). The negative correlations between U and some macronutrients indicated a limited accumulation of plant-derived U in soil, possibly due to low phytoavailability of U. Positive correlations were also found between U concentration and heavy metals (Cr, Co, Ni, Ga, As, Cd, Hg, Pb) or rare earth elements, which further pointed to a geogenic origin of soil U in this forested catchment.

Variations in mineralogy of dust in an ice core obtained from northwestern Greenland over the past 100 years

Our study is the first to demonstrate a high-temporal-resolution record of mineral composition in a Greenland ice core over the past 100 years. To reconstruct the past variations in the sources and transportation processes of mineral dust in northwestern Greenland, we analyzed the morphology and mineralogical composition of dust in an ice core from 1915 to 2013 using Scanning Electron Microscopy (SEM) and Energy-Dispersive X-ray Spectroscopy (EDS). Analysis of the SEM-EDS reveals that the ice core dust mainly consisted of silicate minerals and the composition varied substantially on multi-decadal and inter-decadal scales, suggesting that the geological origin of the ice core minerals changed periodically during the past 100 years. The multi-decadal variation trend differed among mineral types: kaolinite generally formed in low- or middle-latitude areas were abundant in the colder periods (1950 to 2000), whereas mica, chlorite, feldspars, mafic minerals, and quartzes formed in arid, high-latitude, and local areas were abundant in the warmer periods (1915 to 1949 and 2005 to 2013). This indicates that the multi-decadal variation of the relative abundance of the minerals can be attributed to the local temperature changes in Greenland. The trajectory analysis shows that the minerals were mainly transported from the western coast of Greenland in the two warming periods, which was likely due to an increase of dust sourced from local ice-free areas. On the other hand, the abundant kaolinite was likely derived from old sediments at higher latitudes in North America, rather than from low and middle latitudes.