Mineralogical Composition Of Soils Research Articles

Influence of stress history on thermal conductivity of saturated fine-grained soils

This research investigated variations in thermal conductivity <i>k</i> for normally consolidated (NC) and overconsolidated (OC) saturated fine-grained soils at different levels of vertical effective stress. A series of undrained heating tests were performed using a specially designed consolidometer with central radial heating arrangement and temperature measurements within a soil specimen. For different soils investigated in this research, <i>k</i> correlated well with soil consolidation characteristics (compression index <i>λ</i> and swelling index <i>κ</i>) and vertical effective stress <i>σ</i><sub>v</sub>ʹ at both NC and OC states. However, the rates of increment of steady- and transient-state values of <i>k</i> (<i>k</i><sub>st</sub> and <i>k</i><sub>tr</sub>, respectively) with <i>σ</i><sub>v</sub>ʹ differed from one soil to another. For OC clays, both <i>k</i><sub>tr</sub> and <i>k</i><sub>st</sub> increased with preconsolidation stress <i>σ</i><sub>c</sub>ʹ. A set of equations were proposed to estimate both <i>k</i><sub>st</sub> and <i>k</i><sub>tr</sub> for saturated fine-grained soils as functions of <i>σ</i><sub>v</sub>ʹ, <i>λ</i>, <i>κ</i>, and stress history. At a particular value of <i>σ</i><sub>v</sub>ʹ, the dependence of <i>k</i> on overconsolidation ratio (OCR) and <i>σ</i><sub>c</sub>ʹ marked the importance of considering stress history in the determination of <i>k</i>. The influence of soil mineral composition on <i>k</i> was also explored. Quantification of soil mineralogical composition and available data on mineral thermal conductivity enabled prediction of <i>k</i><sub>tr</sub> with reasonable accuracy.

Zinc speciation in highly weathered tropical soils affected by large scale vegetable production

Agriculture in highly weathered tropical soils often requires considerable application of lime and fertilizers to ensure satisfactory plant nutrient levels. The consequences of these continue long-term applications is not well understood may induce changes in soil chemical properties, the abundance, and speciation of potentially toxic trace element and as well as of micronutrients in agriculture soils. In this study, we evaluated the adsorption (at pH 5) and speciation of Zn in tropical soils (both agricultural and native vegetation) as a function of fertilization and contact time using chemical fractionation analyses and X-ray absorption spectroscopy. The soils overall had high Zn adsorption capacities (∼ 700 mg kg-1), but the agricultural soil was approximately 30 % higher than of the soil under native vegetation, and the proportion of Zn in the mobile fraction was 35 % in native vegetation and 21 % in agricultural soils. Zn speciation via linear combination analysis showed a strong relationship with soil mineralogical composition and reveled that Zn associated with organic matter decreased while Zn associated with P increased after the conversion of soils from native vegetation to highly fertilized soil. Aluminosilicate soil minerals were identified as major sinks of soil Zn, accounting for 34 % of total Zn retention regardless of soil origin and land use. Association of Zn with phosphate (i.e., hopeite) was observed in the agricultural soil samples, which might be an unexpected Zn-bearing mineral in highly weathered tropical soils and could have impacts on Zn plant nutrition.

Topography and canopy cover influence soil organic carbon composition and distribution across a forested hillslope in the discontinuous permafrost zone

AbstractTopography and canopy cover influence ground temperature in warming permafrost landscapes, yet soil temperature heterogeneity introduced by mesotopographic slope positions, microtopographic differences in vegetation cover, and the subsequent impact of contrasting temperature conditions on soil organic carbon (SOC) dynamics are understudied. Buffering of permafrost‐affected soils against warming air temperatures in boreal forests can reflect surface soil characteristics (e.g., thickness of organic material) as well as the degree and type of canopy cover (e.g., open cover vs. closed cover). Both landscape and soil properties interact to determine meso‐ and microscale heterogeneity of ground warming. We sampled a hillslope catena transect in a discontinuous permafrost zone near Fairbanks, Alaska, to test the small‐scale (1 to 3 m) impacts of slope position and cover type on soil organic matter composition. Mineral active layer samples were collected from backslope, low backslope, and footslope positions at depths spanning 19 to 60 cm. We examined soil mineralogical composition, soil moisture, total carbon and nitrogen content, and organic mat thickness in conjunction with an assessment of SOC composition using Fourier‐transform ion cyclotron resonance mass spectrometry (FT‐ICR‐MS). Soils in the footslope position had a higher relative contribution of lignin‐like compounds, whereas backslope soils had more aliphatic and condensed aromatic compounds as determined using FT‐ICR‐MS. The effect of open versus closed tree canopy cover varied with the slope position. On the backslope, we found higher oxidation of molecules under open cover than closed cover, indicating an effect of warmer soil temperature on decomposition. Little to no effect of the canopy was observed in soils at the footslope position, which we attributed, in part, to the strong impact of soil moisture content in SOC dynamics in the water‐gathering footslope position. The thin organic mat under open cover on the backslope position may have contributed to differences in soil temperature and thus SOC oxidation under open and closed canopies. Here, the thinner organic mat did not appear to buffer the underlying soil against warm season air temperatures and thus increased SOC decomposition as indicated by the higher oxidation of SOC molecules and a lower contribution of simple molecules under open cover than the closed canopy sites. Our findings suggest that the role of canopy cover in SOC dynamics varies as a function of landscape position and soil properties, namely, organic mat thickness and soil moisture. Condition‐specific heterogeneity of SOC composition under open and closed canopy cover highlights the protective effect of canopy cover for soils on backslope positions.

A 200-year snapshot of soil development in pyroclastic deposits derived from the 1815 super explosive eruption of Mount Tambora in Indonesia

Early-stage pedogenic processes and formation rates on completely obliterated volcanic landscapes, such as the super explosive 1815 Mount Tambora eruption, have not previously been robustly explored. The objectives of this study were to determine (i) the mineralogical composition of the sand fraction, selected physical and chemical soil properties and potential nutrient reserves after 200 years of pedogenesis, and (ii) chemical weathering indices, rate of soil formation, and rates of C and N accretion. Soil formation was examined for five soil profiles on stable plain/foot slope positions representing the diversity of soils in these landscape positions, which are important for agricultural production. Results showed that the soil mineralogical composition of the sand fraction was dominated by easily weatherable minerals (e.g., labradorite and augite volcanic glass) indicating high potential nutrient reserves (e.g., Ca2+, Mg2+, K+, P) as confirmed by X-ray fluorescence (XRF) analyses. Allophanic material formation was minimal (<2.3%) owing to the preferential accumulation of Al3+ into Al-humic complexes. The low contents of allophanic materials and metal-humus complexes resulted in low P-retention (17.5–43.4%) within the soil solum, with the highest value in surface horizons (33–43%). Morphological features showed rapid solum (A + B horizons) development of 22 to 107 cm. Shallow soils occurred on shallow eruption deposits (consisting of pyroclastic flow underlain by pumice), whereas the deepest soils were found on thick deposit consisting of either trachyandesite pyroclastic or basaltic andesite materials. The chemical index of alteration (CIA) followed the order of A horizons (48.4 ± 4.6) > B horizons (45.4 ± 2.4) > C horizons (43.8 ± 4.2) ≈ tephra/lava (43.1), indicating accumulation of Al oxides and depletion of base cations in the upper horizons. Similarly, the base depletion index (BDI) showed a trend of A horizons (1.13 ± 0.18) < B horizons (1.25 ± 0.09) < C horizons (1.34 ± 0.20) ≈ tephra/lava (1.35), indicating depletion of base cations (Ca2+, Mg2+, K+, Na+) from the soil surface to C horizons. Based on solum depths (A + B horizons) and 200 years of post-eruption soil development, the solum formation rate ranged from 1.2 to 5.3 mm yr−1. Appreciable stocks of SOC (2.3–12.8 kg C m−2) and SON (0.21–0.77 kg m−2) accumulated over the 200 year period. Eruption materials from the Mt. Tambora eruption with a precisely known timescale contributed new pedological insights documenting rapid soil formation rates from pyroclastic materials leading to a rapid recovery of soil functions to support agricultural production.

Microstructure Development in Artificially Cemented, Fine-Grained Soils

Fine-grained sedimentary deposits can bear an increased risk for building settlements due to their moderate stiffness and strength properties, as well as high groundwater tables. However, some buildings, e.g., situated on shallow foundations in Alpine basins, show only relatively small settlements because the formation of carbonate cement can create bridging bonds between the detrital soil particles, leading to increased stiffness. These weak bonds can be damaged through dynamic loads and high static loads, causing a weakening of the soil’s microstructure and resulting in large settlements in several cases. However, the environmental controls and mechanistic processes underlying the formation versus damaging of microstructure in fine-grained, postglacial sediments are, to date, poorly understood. In the present study, fine-grained sediments are artificially cemented by calcium carbonates (CaCO3) to investigate (i) the influence of a mild and sustainable cementation process on the stress–strain behavior of silicate- and carbonate-rich soils and (ii) the possibilities and limitations of artificial microstructure development for soil stabilization. Incremental load oedometer testing (IL), bender element testing (BE), X-ray diffraction (XRD), scanning electron microscopy (SEM) and Brunauer–Emmett–Teller (BET) specific surface area (SSA) measurements are used to characterize the development of cementation and to elucidate the improvements in the soil mechanical properties. It is shown that cementation induced by CaCO3 mineralization (by 5–15% replacement) leads to an increased stiffness (factor ≈ 5–7) and shear wave velocity (factor ≈ 1.1), caused by the formation of nanocrystalline, particle-binding CaCO3 cements. The improvement of soil stiffness is dependent on the CaCO3 replacement level, reaction time and primary soil mineralogical composition.

Effect of the nature of clayey soils (Eastern Morocco) on the thermophysical properties of bricks

Local building materials are gradually replacing expensive and energy-intensive manufactured products. The present paper compares the mineralogical and thermophysical properties of two different soils from eastern Morocco (soil A, Ouled Setout, Nador city; soil B, Touissite, Jerada city), which are extensively employed in the brick-making industry at the national level. Firstly, the geotechnical and mineralogical analyses were carried out for soil identification. The influence of the physical and mineralogical composition of soil on the thermal transport properties of clay bricks was examined using the hot disk method. Except for the calcite content, X-ray diffraction and thermal gravimetric analyses showed almost the same mineralogical composition of soils. Furthermore, plasticity testing showed high plasticity for both soils. Thermal results found that soil B has a lower thermal conductivity than soil A, which may be ascribed to the high sand content that provides more porosity responsible for better thermal insulation. In order to analyze the building energy savings, the thermodynamic behaviour of a residential building constructed with unfired and fired clay bricks manufactured from the soil B were simulated using TRNSYS. Numerical results showed that unfired clay bricks are more thermally efficient than fired bricks, resulting in energy savings per constructed square meter of 4% for heating and 1.65% for cooling in buildings located in semi-arid climates.

Validation of Semi-empirical Models for the Prediction of Swelling Stress for Compacted Unsaturated Expansive Soils

Unsaturated swelling soil behaviour is governed by the matric suction, thus the predetermination of swelling stress for expansive unsaturated soil requires rigorous procedures. However, some swelling stress equations assume full saturation of the soil, which leads to the over-design of infrastructure. This study focused on the validation of predictive swelling stress models that correlate suction with other soil properties. Three models were developed, and independent data were used for the validation of the developed models. The predicted swelling stress values were compared to the values predicted by the randomly selected predictive models from the literature. Series of initial studies include the determination of basic soil characterization and swelling stress along with soil mineralogical compositions were conducted to determine their geotechnical properties with their corresponding degree of expansiveness. The replicated expansive soils were also studied for suction, using filter paper techniques to obtain the soil's unsaturated parameters. Based on the obtained experimental results, three models were developed using a mathematical software package (NCSS11). Independent data obtained from a group of final year students working on the swelling stress response of expansive unsaturated soils at the geotechnical engineering Laboratory from the University of Johannesburg were used for the validation. The developed models showed good agreement with the independent data, having a coefficient of determination (R²) of 0.858, 0.931, and 0.890 for Eq. 4, 5, and 6, respectively. Compared to models selected from literature, which recorded R² values of 0.796 and 0.636 with an average variance of 0.097 and 0.257 respectively. The correlation variables showed that the degree of expansion represented by swelling stress demonstrated a proportionality with the moisture capacity along the drying and wetting path of the suction curves. Results suggest that the developed models can reasonably predict the swelling stress of compacted expansive soils at high suction values.

Durability of clayey soil stabilized with Potassium additive

Plastic clayey soils are characterised by large volume changes associated with moisture variation. These soils must be enhanced to ensure their suitability for the construction of engineering infrastructures. Chemical stabilisation with Potassium ions additives from Potash fertiliser (KNO3) was explored in this research with main emphasis on durability of KNO3 treated soil. Many complementary techniques were used in both micro and macro tests: X ray diffraction, mercury intrusion porosimetry test, full scale water retention curve, shear strength test, and California bearing ratio test were conducted. The results show that the optimum amount of KNO3 required is 5% at 48 hours of curing. The addition of KNO3 causes a reduction in the ability of soil to retain water and a variatabletion in the grain and pore size distributions. Also, the addition of KNO3 to the plastic clayey soil played an important role in the transformation of the soil mineralogical compositions from montmorillonite to illite behaviour. The test results obtained during and after water leaching process on the leachate and leached soils show the ability of soil-KNO3 mixture to resist leaching is weak, and the necessity to protect the potassium stabilized soil against long term water penetration process.

Pristine soil property and mineralogy as the strategic rehabilitation basis in post-earthquake-induced liquefaction, tsunami and landslide in Palu, Indonesia

Unprecedented terrible and catastrophic disasters on September 28, 2018 triggered by earthquake-induced liquefaction, tsunami and landslide hit Palu, Central Sulawesi, Indonesia. The objective of the study was to assess and evaluate soil mineralogical compositions, properties, heavy metals, and water quality in the areas of post-earthquake-induced liquefaction, tsunami and landslide to provide the basis for agricultural and ecosystem rehabilitation. The soil samples were collected by digging pits after 12-days of disaster at liquefied soils, tsunami sediments, and soil mass motion/landslide for analyses. Water samples for analysis were collected from soil pits, surface flow and new spring. Results showed that the earthquake-induced liquefaction, tsunami and landslide completely reshape the ecosystem landscape and reset the initial soil formation as revealed by the formation of sand boil microrelief, accumulation of tsunami sediment on initial soil surfaces, and redistribution of soil through mass movement on landscapes. Liquefaction increased the number of weatherable minerals in the sand fraction, varying from 28 to 58% as compared to natural soils (17–42%), indicating the high nutrient reserve of pristine liquefied soils in the long-term. The clay minerals were dominated by smectite followed by illite and kaolinite and were not affected by earthquake impacts. The liquefaction increased soil pH and sand fraction and decreased all soil nutrients, which collectively became severe limiting factors for crop establishment. The tsunami resulted in new material deposits of 5–10 cm thick overlain the natural soils in coastal areas. The deposits did not increase the number of weatherable minerals but resulted in the highest electrical conductivity of soil and water, and high concentrations of Ca, Na, Mg and K ions. The concentration of total and availability of all types of heavy metals is below the threshold limits, indicating no potential heavy metal risks in post-earthquake-induced disaster areas. Information of high weatherable minerals and pristine soil properties, water and heavy metals from this study may provide a strong effective basis for rehabilitation and management of agriculture and the environment in post-disaster areas in the long-term period of time.

Improvement of shear strength and compressibility of soft clay stabilized with lime columns

Soft clay improvement using lime columns is an effective and economic method; which used mainly for enhancing the engineering properties of soft soil, reducing settlement and increasing shear strength. Improvements in engineering properties of soft clay can be achieved instantaneously with small additions of lime to soft soils. However, the effectiveness of this improvement depends on the quantity and type of lime as well as the mineralogical composition of soil. In this paper, the behavior of soft clay improved with lime columns has been studied. A series of large scale direct shear box tests were carried out with different number of lime columns, diameter, and different curing periods. Experimental study was carried out on both single and a group of lime columns. The results showed that the group of columns increased the shear resistance of soft clay soil with lesser horizontal deformation. Shear strain decreased by 28% and 47% in case of using 1 and 4 lime columns respectively after 7 days curing. Meanwhile, increasing the lime column diameter was found to increase the shear strength of soft clay and improve its compressibility. Finally, the shear strength was found to be increased by 53% when using a single lime column, while when using a group of 4 lime columns with diameter/length (D/L) ratio equals 0.28, the shear resistance is duplicated compared to the case of soft clay without lime columns.

Identification of minerals in subtropical soils with different textural classes by VIS–NIR–SWIR reflectance spectroscopy

The physical and chemical attributes of soils are strongly influenced by the nature of the minerals they contain and their concentration. Thus, soil texture is directly dependent on the content in clayey minerals, which influences a number of characteristics such as water dynamics. Although the mineralogical composition of soil is usually determined by X-ray diffraction spectroscopy, this technique is expensive and time-consuming, and uses toxic materials, all of which makes it impractical for obtaining large data sets. Also, available methods for acquiring, interpreting and examining visible–near infrared–shortwave infrared (VIS–NIR–SWIR) spectra are largely ineffective with tropical soils. The aim of this work was to ascertain whether VIS–NIR–SWIR reflectance spectroscopy (350–2500 nm) is useful for identifying minerals in subtropical soils as classified by textural class. For this purpose, soil samples were collected at 66 points at three different soil depths (0–20, 20–40 and 40–60 cm) over a study area located in the State of Rio Grande do Sul (Brazil). The soil texture were determined with the pipette method, and soil spectra were recorded on a FieldSpec Pro VIS-NIR-SWIR laboratory spectrophotometer. Soil minerals were identified, and their proportions determined, from the second-derivative of the Kubelka–Munk (KM) function for the spectra. Five main minerals were thus identified from their spectral signatures, namely: hematite, goethite, kaolinite, chlorite and illite. Identification of the minerals was facilitated by classifying the samples according to texture. The higher the clay content was, the higher was the spectral amplitude of the minerals identified. Those textural classes with the highest clay contents exhibited the greatest proportions of iron oxides and of clay minerals such as kaolinite. These relationships allowed more comprehensive analysis of the soils and expeditious characterization of the study area in terms of texture and mineralogy with a view to facilitating decision-making agricultural support policies.

Partitioning of heavy metals in different particle-size fractions of soils from former mining and smelting locations in Austria

Austrian soils from mainly historical mining and smelting sites were separated into four particle size fractions (coarse sand, fine sand, silt and clay) to distinguish the possible origins and pathways of heavy metals. Each fraction was extracted with aqua regia to determine the pseudo-total content and with CaCl2 to determine the available content of metals. The soil mineralogical composition of the < 2000 µm fraction was determined by X-ray diffraction (XRD). In general, the concentration of heavy metals and metalloids increased as soil particle size decreased. Based on the correlations of concentrations vs. the log of the mean particle size, obtained from each fraction the presence of unweathered allochthonous minerals were especially present in samples from locations at Rabenstein for most trace elements, at Arzwaldgraben for Cd, Co, Mn and Pb, at Johnsbach for Cd, Co, Mn, Pb and Zn and at Pilgersdorf for Cr. The opposite trend was found for the samples of the industrial area of Arnoldstein, Zeltweg and Hinterlobming suggesting that their metal load was derived from the discharge of effluents or from weathered phases.

Variability of soil mineralogical composition in Sentra Bareh Solok paddy field as affected by eruption material from Mt. Talang

Mt. Talang is one of the active volcanoes in West Sumatra with the last eruption occurred in 2017. The Sentra Bareh Solok paddy field distributed from volcanic middle slope to Singkarak Lacustrine Plain. The composition of sand mineral fraction of nine representative of soil profiles has been analysed using polarization microscope with line counting method. Results show that mineralogical composition are the same, but the amount are different. At the volcanic middle slope, opaque is dominant. It is probably due to thermal formation associated with the melting of existing iron oxides attributed by lava flow. Labradorite and hypersthene are dominant in Alluvial Plain and it could indicate rather slow weathering processes. While, the soils at Lacustrine Plain were dominated by volcanic glass and labradorite and it could be due to silica saturation; more cations and higher pH of soil solution hindering dissolution of minerals. The K-bearing minerals were absent in all soils, indicating K would be the problem as revealed by low K content and its trend decreased from middle slope to the lacustrine. The implication is soils in the Lacustrine Plain and Alluvial Plain would need more K fertilizers than soils in the middle slope.

Ground heave movement evaluation in shallow foundations for expansive soils in Tunja, Colombia

A current challenge in unsaturated soil mechanics is the need to estimate ground heave and associated shallow foundation movements in expansive soils due to water content changes. Such estimation should be simple for geotechnical engineering practitioners and provide reliable foundation designs through quantifying the risk associated with the ground heave. The difficulties in generalizing a method are related to several variables influencing the expansive behavior, including the initial and final stress state condition, soil mineralogical composition, ground wetting depth, soil wetting degree, and geotechnical profile comprising soil strata thickness and groundwater condition. In this research, the evaluation of heave movements for the expansive soils located in the north-east of Tunja (Colombia) is performed through surrogate path (SPM), water content, and consolidation theory-based methods. Initial and final suction profiles were defined to quantify the wetting strains developed at each scenario of partial wetting. The sensitivity of the SPM to the estimated or measured value of constant volume swelling pressure was corroborated. The higher deformations that the soil profile would be able to develop when subjected to a progressive wetting were obtained along with the remaining heave capacity of the soil profile. Finally, concluding remarks and recommendations associated with the practicality and applicability of the methods are presented.

Heavy metal contents in soils and native flora inventory at mining environmental liabilities in the Peruvian Andes

Inadequate waste management in Mining Environmental Liabilities (MEL) represents a risk for the environment and human health and generates social problems. The aim of this article is twofold: i) to evaluate the environmental quality of soils from a geo-ecological perspective; and ii) to inventory native flora around two MEL in the Hualgayoc district in the Peruvian Andes. Soil samples collected for topsoil (upper 30 cm; i.e., soil arable layer) and subsoil (30–60 cm) were classified as Gleyic Cambisols and showed extremely acid pH (3.50–4.19 in site #1 and 2.74–4.02 in site #2). The mineralogical composition of soils is dominated by illite, kaolinite, quartz, and jarosite. The concentrations of six potentially toxic elements (Pb, Zn, As, Cu, Ag, and Cd) were determined. High concentrations of Pb (4683 mg kg−1), Zn (724.2 mg kg−1), Cu (511.6 mg kg−1), Ag (33.4 mg kg−1), and As (3611 mg kg−1) exceeded the maximum permissible limits for agricultural soils according to Peruvian and Canadian regulations. Applied geochemical indexes classified some of the soils as extremely polluted and therefore the studied MEL represent a very high ecological risk. Twenty-two species of native flora belonging to 12 family species were inventoried in such contaminated sites thus having the potential to be used for phytoremediation purposes.

Combination of soil texture with Nix color sensor can improve soil organic carbon prediction

The optimum ecosystem functioning is reliant on soil organic carbon (SOC) content which is traditionally measured in the laboratory via a cumbersome wet-chemistry method. This preliminary research tested whether a combination of Nix color sensor and portable X-ray fluorescence (PXRF) spectrometer data with soil texture data can improve soil SOC prediction accuracy relative to using them independently. A total of 371 samples representing diverse soil texture and SOC content were collected from three different ecoregions of eastern India: coastal saline zone, red and lateritic zone, and Gangetic alluvial zone. All dried, ground, and sieved samples were scanned via Nix and PXRF and random forest (RF) regression was used to predict soil SOC with different combinations of data. Soils were grouped into nine textural classes while soil SOC content exhibited substantial variability (0.08–2.26%). Comparing soil SOC with texture (sand + silt + clay), satisfactory prediction accuracy was observed (validation R2 = 0.70). Combining Nix extracted color parameters with texture substantially improved the model performance, producing the validation determination coefficient of 0.81. In contrast, PXRF-Rb, as a proxy of soil clay content was unable to achieve satisfactory prediction performance (R2 = 0.24), indicating the heterogeneity in soil mineralogical composition. The RF variable importance plot using Nix alone identified redness (a*) and yellowness to blueness (b*) as influential predictors, manifesting the impact of red color from Fe and Al-oxides and their significant negative correlation with soil SOC (r = −0.62 and −0.57 for a* and b*, respectively). These color parameters were again identified by the RF variable importance plot of (Texture + Nix)-model, implying that the SOC prediction improvement may be linked with the Nix sensor’s capability of extracting useful information in the visible range. Summarily, a combination of Nix color variables and texture data was adept at predicting soil SOC in lieu of traditional laboratory analysis. The robustness of the (Texture + Nix)-based SOC prediction model can be augmented by incorporating more soil samples representing all 12 soil textural classes and variable SOC content, showing all possible soil colors in the pedogenic environment.

Soils and sediments of Prošće Lake catchment as a possible terrigenous input in the lakes system

The Plitvice Lakes National Park is in the northwestern part of the Dinaric Karst in central Croatia. An important role of the soil in the karst is to purify the waters before they reach the phreatic zone. The soil is also a zone of accumulation, transformation, retardation and dilution of a potential pollutant. Knowing soil mineralogical composition is an important factor in understanding fate and transport of contaminants throughout lakes system. Samples of soil, peat and stream sediment were collected in the Prošće lake catchment and partly in the assumed zone of influence, X-ray diffraction (XRD) and Fourier Transform Infrared spectroscopy (FTIR) analysis of samples was performed to determine dominant mineral species in samples. XRD analysis showed predominance of lowquartz, which was found in all samples, most often as dominant phase. Dolomite was found in half of the samples, almost always as a significant phase while calcite was dominant phase in one of the samples. In most of the samples, members of the feldspars and chlorites groups, as well as muscovite, were present as minor phases. The absorption bands in the range of 2800-3000 cm-1 due to the organic matter are visible in spectra of all samples. These minerals can enter lakes system by surface waters, primarily streams and overland flow during snow thawing and rain, and also in cases of shore erosion. Terrigenic input in lakes is small but cannot be neglected due to the longlasting preservation efforts of the Prošće Lake recharge area, and the Plitvice Lakes National Park in general, terrigenous intake still does not pose a threat to water quality and tufa production. Considering the analyzed samples and characteristics of detected soil constituents, soils and sediments in the Prošće Lake catchment have the ability to retain and purify water on its way to the lakes. On the other hand, in case of the possible contamination in the recharge area of the lakes system, the pollutants can enter the system adsorbed on the soil particles. Learning more about the soils surrounding lakes gives valuable insight into their possible influence on lakes water chemistry and adds one piece of the puzzle into understanding this kind of a natural phenomenon.

Estimation of soil saturation with organic carbon

New definitions of “soil carbon sequestration” and “soil carbon deposition” on a quantitative basis taking into account the period of the complete turnover of accumulated organic matter and its distribution over the soil profile are formulated. The carbon protection capacity of soils in the European part of Russia was determined according to Hassink (1997) and Six et al. (2002) based on data of the fine fractions content and the mineralogical composition of soils. The carbon saturation degree of soils and their carbon sequestration potential were calculated according to Meyer et al. (2017) and Wiesmeier et al. (2014) . Gray forest and chestnut soils were classified as poorly saturated with organic carbon, meadow slitized and floodplain meadow soils were moderately saturated, and chernozems was saturated. It has been shown that the carbon sequestration potential of gray forest soil is about 30 t C ha -1 , chestnut soil does not exceed 25 t C ha -1 , meadow soil is 15 – 20 t C ha -1 , and chernozem is less than 5 t C ha -1 . Critical remarks to the 4 ppm initiative were given.

Utilization of marine clay as a bottom liner material in engineered landfills

Abstract A typical Malaysian marine clay was evaluated for its suitability as a bottom liner material to minimize leachate migration in engineered landfills. Grading, plasticity characteristics, unconfined compressive strength, volumetric shrinkage strain, permeability, geochemistry, mineralogical, and microstructural tests were conducted to characterize the clay as well as to evaluate it’s potential as an effective bottom liner material. The work findings reveal that the clay possesses minimal shrinkage potential and adequate strength to support the overburden pressure imposes by the waste. The permeability of the clay increased upon permeation with leachate but still met the Malaysian regulatory requirement of ≤ 10−8 m/s specified by the regulatory authority. X-ray diffraction analysis shows that the soil mineralogical composition was unaltered after permeation with leachate. Nonetheless, the appearances of two new low-intensity hercynite peaks were observed for the leachate permeated sample. These new peaks, however, did not adversely affect the hydro-mechanical properties of the clay. The results demonstrate that the studied marine clay can be employed as a bottom liner material in engineered landfills, hence providing a value-added application of the construction waste material.

On agro-industrial assessment of territorial lands of Tartar region (on the example of Borsunlu village)

Annotation: Due to the climatic features of Azerbaijan, its soil is subject to severe erosion. Thus, eroded (washed, loosened, loosened, etc.) soils are often found in the country. This is explained by the fact that, as is clear from the morphological description of the section in the study area, the color of the soil here is brown in the upper layer, light brown in the middle layer, and straw in the last layer. The structure is heavy clayey in the upper layer, medium clayey in the middle layer and in the last layer. Roots and rhizomes, insect tracts, rust spots are found in new derivatives and fruits. These soils are boiled under the influence of 10% hydrochloric acid (HCl). Hygroscopic moisture is less moisture throughout the profile. The transitions in the genetic layers are clear and gradual.It should be noted that in general, erosion processes lead to erosion and destruction of the topsoil. According to the results of laboratory analysis of soil samples on different soil types from different experimental areas, the actual soil fertility determined for the suitability of different types of agricultural crops, a number of types of agricultural culture. grapes and clover-cheese.This article presents the results of a comparative analysis of the degree of erosion of the land cover formed in the territory of the Tartar region of the Republic of Azerbaijan using aerospace images and studied.Key words: Soil-forming rocks, soil granulometric composition, physicochemical properties, soil mineralogical composition, soil profile, genetic layers, parent rock, erosion process.&#x0D;