Paleoclimatic reconstructions based on the study of structures of large kurgans of the Bronze Age and soils buried under different structures for the steppe zone of Russia

2021 ◽  
Author(s):  
Alena Sverchkova ◽  
Olga Khokhlova
Keyword(s):  
Magnetic Susceptibility ◽  
Organic Carbon ◽  
Physicochemical Properties ◽  
Steppe Zone ◽  
Organic Carbon Content ◽  
Buried Soils ◽  
Study Region ◽  
The Third ◽  
Earthen Structures ◽  
Wide Range

<p>Geoarchaeological studies of soils buried under burial mounds (kurgans) and materials of kurgan structures make it possible to solve a wide range of scientific problems. In the steppe zone of Russia, such studies are carried out in order to determine and compare the composition of buried soils and materials of kurgan structures, as well as to study the structure of earth monuments and to obtain data on the technology used by ancient people for their building.</p><p>We carried out geoarchaeological studies in two key areas: in Krasnodar (kurgan Beisuzhek 9) and Stavropol (kurgan Essentuksky 1) regions. For each object, the particle-size distribution and physicochemical properties of the earthen materials of the kurgans and buried soils were investigated.</p><p>Kurgan Essentuksky 1 was built in the second quarter of the 4th millennium BC (Maykop culture) according to a single plan in a short time (several decades). The kurgan with a height of 5.5-6.0 m and a diameter of 60 m consisted of four earthen and three stone structures. The earthen structures consisted of alternating layers of dark, slightly compacted humified and light dense carbonate-rich material that were taken from buried soils, i.e. dark material from the Ahkb and AhBkb horizons, and light material from the B1kb horizon. This is confirmed by similar changes in the physicochemical properties of paleosols and overlying kurgan structures. A decrease in the organic carbon content and an increase in the content of calcium carbonate, values of pH<sub>H2O</sub> and magnetic susceptibility from the first to the fourth paleosols predetermined similar changes in the materials from the first to the fourth earthen structures (from the center to the periphery of the kurgan).</p><p>In the Beysuzhek 9 kurgan, three earthen structures of different ages were identified: the first and the second - the middle of the 2nd millennium BC (Novotitorovsk culture), the third construction - the beginning of the 2nd millennium BC (Catacomb culture). Each of the subsequent structures overlapped and went beyond the boundaries of the previous one: the second overlapped the first and also untouched soil next to the first; and the third overlapped the second completely and also overlapped previously uncovered soil next to the second structure. The height of the kurgan was more than 4 m, the diameter - about 100 m. The material of each structure was a soil mass from the middle horizons of the buried soils, most likely the Bkb horizon. Samples from the kurgan structures were taken from one column in the middle of the central baulk. Physicochemical analysis of paleosols and earthen structures overlying them showed a decrease in the content of organic carbon and magnetic susceptibility, an increase in the content of carbonate carbon and pH<sub>H2O</sub> from the center to the periphery of the kurgan.</p><p>According to the results of the physicochemical properties of paleosols and materials of both key areas in the second half of the 4th millennium BC there was a climate change in the study region - the average annual temperatures increased and the amount of precipitation decreased.</p>

Trace element concentrations in road deposited sediments of Athens, Greece: A comparison with baseline soil data

2020 ◽  
Author(s):  
Paraskevi-Maria Kourgia ◽  
Ariadne Argyraki
Keyword(s):  
Magnetic Susceptibility ◽  
Organic Carbon ◽  
Urban Areas ◽  
Surface Soil ◽  
Anthropogenic Activities ◽  
Natural Environments ◽  
Organic Carbon Content ◽  
Geochemical Background ◽  
Aqua Regia ◽  
Wide Range

<p>Urban areas are typical examples of disturbed natural environments where human development has significantly altered the geochemical background of trace elements in surface soil and sediment. Road dusts and gully sediments are reflective of a wide range of anthropogenic activities in cities and are a useful resource for evaluating the level and distribution of trace metal contaminants in the surface environment. The evaluation of contamination in these sinks provides useful information of how the drainage system of the cities contributes to urban pollution.</p><p>A total of 26 urban road deposited sediment samples were collected from different altitudes within the Athens basin based on the hydrographic network of the area. The samples were analyzed for 33 elements following an aqua regia dissolution. Sample organic carbon content, pH and grain size distribution have been determined and magnetic susceptibility measurements and mineralogical analysis by powder X-ray diffraction were also performed in order to identify possible factors explaining the variability of elemental concentrations. Also, sixteen samples were analyzed for polycyclic aromatic hydrocarbons (PAHs) in order to detect their sources in the Athens urban environment.</p><p>Aqua regia concentrations in the analyzed sediments reached maximum values of 18 mg/kg for As, 2 mg/kg for Cd, 14 mg/kg Co, 193 mg/kg Cr, 640 mg/kg Cu, 25600 mg/kg Fe, 112 mg/kg Ni, 3092 mg/kg Pb and 1469 mg/kg Zn. The median values of the studied elements were estimated to be 13 mg/kg for As, 1 mg/kg for Cd, 8 mg/kg Co, 98 mg/kg Cr, 215 mg/kg Cu, 17154 mg/kg Fe, 70 mg/kg Ni, 267 mg/kg Pb and 598 mg/kg Zn, respectively. With the exception of Co and As, both maximum and median values were found to be much higher than those in Athens soils from a previous study. Cluster analysis on the results identified two major groups of elements based on an over 43.59% criterion of similarity. The first cluster contains elements of geogenic origin including Co, Fe, Mn and Ni. The parameters of % organic carbon, magnetic susceptibility, Cu and Cr are grouped together in a second cluster showing a similarity level over 65% while a third cluster groups together Pb, Zn and Cd and is interpreted as anthropogenic.</p><p>In a previous systematic baseline study of Athens, it was found that the major factor controlling variability of the chemical composition of surface soil was the bedrock chemistry, resulting in a significant enrichment in concentrations of Ni, Cr, Co and possibly As. Anthropogenic influences were also significant in soil, controlling a spectrum of elements that are typical of human activities, i.e. Pb, Zn, Cu, Cd, Sb, and Sn. The clustering of elements in the present study indicates that although the geogenic origin of some elements is retained in road sediments, a greater number of elements indicate anthropogenic influence in their distribution. Briefly, it was documented that road deposited sediments reflect the characteristics of the anthropogenic activities taking place, and that traffic- related activities are the primary sources of contaminants.</p>

scholarly journals Mineralization of soil organic nitrogen under waterlogged conditions in relation to other properties of tropical rice soils

Soil Research ◽  
1983 ◽  
Vol 21 (2) ◽  
pp. 133 ◽  
Author(s):  
KL Sahrawat
Keyword(s):  
Organic Matter ◽  
Organic Carbon ◽  
Soil Properties ◽  
Total Nitrogen ◽  
Organic Nitrogen ◽  
Wetland Rice ◽  
Organic Carbon Content ◽  
Rice Soils ◽  
Wide Range ◽  
Mineralizable Nitrogen

The mineralizable nitrogen pool in wetland rice soils plays a dominant role in the nitrogen nutrition of rice even in fertilized paddies. There is a lack of information on how different soil properties affect ammonification of organic nitrogen in wetland rice soils. Surface samples of 39 diverse Philippine soils representing a wide range of pH, organic matter and texture were studied to determine the relationships between ammonification of organic nitrogen and soil properties. Simple correlation analysis showed that ammonium production was correlated highly significantly with total nitrogen (r = 0.94**), organic carbon (r = 0.91**) and C/N ratio (r = -0.46**), but it was not significantly correlated with cation exchange capacity, clay or pH. Multiple regression analayses showed that organic matter (organic carbon and total nitrogen) accounted for most of the variation in mineralizable nitrogen. These results suggest that organic carbon content is a good index of mineralizable nitrogen in tropical wetland rice soils.

scholarly journals The color of refractory organic carbon

2018 ◽  
Vol 189 (2) ◽  
pp. 9 ◽  
Author(s):  
Maxime Debret ◽  
Yoann Copard ◽  
Antonin Van Exem ◽  
Geneviève Bessereau ◽  
Frank Haeseler ◽  
...  
Keyword(s):  
Organic Matter ◽  
Organic Carbon ◽  
Carbon Content ◽  
Anthropogenic Activities ◽  
Organic Matter Content ◽  
Matter Content ◽  
Mineral Matter ◽  
Organic Carbon Content ◽  
Fast Method ◽  
Wide Range

Organic matter studies find an echo within different topics such as biogeochemical cycles, processes occurring in continental surfaces, anthropogenic activities, climate science, earth and planetary sciences, etc. Today’s challenges include finding and developing the most appropriate method(s) supporting the differentiation and characterisation of various types of recalcitrant organic matter in modern environments. In this study, we focus on combustion residues and coals as these two types of organic matter contain a significant amount of so-called recalcitrant organic carbon (black carbon and fossil organic carbon). Both these materials are ubiquitous, broadly stem from the same living organisms and have similar polyaromatic structures. In this respect, we tested a spectrophotometry method, classically used for sedimentology, as a very fast method for preliminary investigations. Analyses were performed with a wide range of standards and referenced samples. The results discriminate three different spectral signatures related to the degree of transformation of organic matter related to the degree of aromaticity (i.e. carbonisation). Using calibration curves, total organic carbon content can be estimated in experimental mixes with mineral matter and in a real context using subsurface sample (Gironville 101 borehole, Paris Basin, France). This method has particularly high sensitivity to very low organic matter content and is shown to be promising for a rapid evaluation of the organic carbon content.

scholarly journals Effects of Epichloë endophyte and repeated cutting on nutrition compositions of Festuca sinensis

2020 ◽  
Vol 66 (No. 10) ◽  
pp. 526-532
Author(s):  
Weihu Lin ◽  
Jianjun Wang ◽  
Chong Xu ◽  
Dongdong Duan ◽  
Wenbo Xu ◽  
...  
Keyword(s):  
Organic Carbon ◽  
Plant Growth ◽  
Crude Protein ◽  
Dry Matter ◽  
Western China ◽  
Organic Carbon Content ◽  
The Third ◽  
Cutting Frequency ◽  
Promote Plant Growth ◽  
Epichloë Endophyte

The presence of Epichloë endophyte can promote plant growth and increase the accumulation of host plant nutrients. We determined the dry matter (DM) and important nutritional indicators of E+ (infected by endophyte) and E– (not infected by endophyte) Festuca sinensis under the three-time repeated cutting. The results indicated that the total nitrogen, total phosphorus, crude protein (CP), crude fat (CF), crude ash (CA) contents, and DM of F. sinensis decreased with the repeated cutting increase and reached the minimum after the third time cut. The total organic carbon content of F. sinensis peaked at the second time cut. In addition, the DM of F. sinensis was significant (P < 0.05) positively correlated with its quality CP, CF, and CA contents, and the appropriate repeated cutting times of F. sinensis was 1–2 times. We concluded that the presence of endophyte and proper cutting frequency can increase the quality and biomass of F. sinensis in Western China.  

scholarly journals On-farm study reveals positive relationship between gas transport capacity and organic carbon content in arable soil

SOIL ◽  
2019 ◽  
Vol 5 (1) ◽  
pp. 91-105 ◽  
Author(s):  
Tino Colombi ◽  
Florian Walder ◽  
Lucie Büchi ◽  
Marlies Sommer ◽  
Kexing Liu ◽  
...  
Keyword(s):  
Carbon Sequestration ◽  
Organic Carbon ◽  
Soil Organic Carbon ◽  
Root Growth ◽  
Carbon Content ◽  
Gas Transport ◽  
Organic Carbon Content ◽  
Soil Aeration ◽  
Soil Organic Carbon Content ◽  
Wide Range

Abstract. Arable soils may act as a sink in the global carbon cycle, but the prediction of their potential for carbon sequestration remains challenging. Amongst other factors, soil aeration is known to influence root growth and microbial activity and thus inputs and decomposition of soil organic carbon. However, the influence of soil aeration on soil organic carbon content has been explored only little, especially at the farm level. Here, we investigated relationships between gas transport properties and organic carbon content in the topsoil and subsoil of 30 fields of individual farms, covering a wide range of textural composition. The fields were managed either conventionally, organically, or according to no-till practice. Despite considerable overlap between the management systems, we found that tillage increased soil gas transport capability in the topsoil, while organic farming resulted in higher soil organic carbon content. Remarkably, higher gas transport capability was associated with higher soil organic carbon content, both in the topsoil and subsoil (0.53 < R2 < 0.71). Exogenous organic carbon inputs in the form of crop residues and organic amendments, in contrast, were not related to soil organic carbon content. Based on this, we conjecture that higher gas transport capability resulted in improved conditions for root growth, which eventually led to increased input of soil organic carbon. Our findings show the importance of soil aeration for carbon storage in soil and highlight the need to consider aeration in the evaluation of carbon sequestration strategies in cropping systems.

scholarly journals QUANTITATIVE INDEX OF TOC CONTENT OF DIFFERENT AGE THICKNESSES OF TRANSCARPATHIAN DEPRESSION AS OIL GAS GENERATION ESTIMATION CRITERIA

2019 ◽  
Vol 1 (178) ◽  
pp. 41-46
Author(s):  
Andrii LOKTIEV
Keyword(s):  
Organic Carbon ◽  
Total Organic Carbon ◽  
Oil And Gas ◽  
Quantitative Estimation ◽  
Sedimentary Cover ◽  
Core Material ◽  
Organic Carbon Content ◽  
Geological Unit ◽  
Wide Range ◽  
Gas Potential

The Transcarpathian foredeep of Ukraine is a geological unit within the Carpathian folded structure, presented by Neogene molasses, which cover Pre-Neogene folded base. Five deposits of combustible gas were discovered within the foredeep – Russko-Komarivske, Stanivske and Korolevskoye within the Mukachevo depression and Solotvino and Dibrovske fields within the Solotvino depression. Despite the fact that most domestic researchers adhere to the view of gas migration along deep tectonic faults into the sedimentary cover of the Transcarpathian foredeep, it is important to analyze the basin for favourable conditions for the generation of natural gases within the sedimentary cover. Samples of core material, selected from 57 intervals of different age complexes of rocks from Transcarpathian wells for quantitative estimation of total organic carbon in rock, were analyzed in the department of sedimentary strata of IGGCM NASU. The results of the studies indicate the presence of rocks with low as well as good and even very good oil and gas potential for total organic carbon content, which are overwhelmingly related to the deposits of Pre-Neogene folded base. In general, a wide range of TOC content is established by the analysis. Rocks with TOC content of more than 1% are found both in rocks of the Pre-Neogene base (w. № 22-, 23-Solotvino, 1-Bushtinska, 1-Borodivsko-Novosilska), and in the molar thickness of the Neogene (St. No. 1-Velyko-Dobronska, 8-Tyachivska), which indicates sufficient content to generate hydrocarbons. Further research aimed at determining the oil and gas potential will allow to determine the priority directions of oil and gas exploration within the Transcarpathian foredeep.

scholarly journals Organic matter across subsea permafrost thaw horizons on the East Siberian Arctic Shelf

2018 ◽  
Author(s):  
Birgit Wild ◽  
Natalia Shakhova ◽  
Oleg Dudarev ◽  
Alexey Ruban ◽  
Denis Kosmach ◽  
...  
Keyword(s):  
Organic Matter ◽  
Organic Carbon ◽  
Luminescence Dating ◽  
Arctic Shelf ◽  
The Arctic ◽  
Organic Carbon Content ◽  
Study Region ◽  
Permafrost Thaw ◽  
Siberian Arctic ◽  
Subsea Permafrost

Abstract. Thaw of subsea permafrost across the Arctic Ocean shelves might promote the degradation of organic matter to CO2 and CH4, but also create conduits for transfer of deeper CH4 pools to the atmosphere and thereby amplify global warming. In this study, we describe sedimentary characteristics of three subsea permafrost cores of 21–56 m length drilled near the current delta of the Lena River in the Buor–Khaya Bay on the East Siberian Arctic Shelf, including content, origin and degradation state of organic matter around the current thaw front. Grain size distribution and optically stimulated luminescence dating suggest the alternating deposition of aeolian silt and fluvial sand over the past 160 000 years. Organic matter in 3 m sections across the current permafrost table was characterized by low organic carbon contents (average 0.7 ± 0.2 %) as well as enriched δ13C values and low concentrations of the terrestrial plant biomarker lignin compared to other recent and Pleistocene deposits in the study region. The lignin phenol composition further suggests contribution of both tundra and boreal forest vegetation, at least the latter likely deposited by rivers. Our findings indicate high variability in organic matter composition of subsea permafrost even within a small study area, reflecting its development in a heterogeneous and dynamic landscape. Even with this relatively low organic carbon content, the high rates of observed subsea permafrost thaw in this area yield a thaw-out of 1.6 kg OC m−2 year−1, emphasizing the need to constrain the fate of the poorly described and thawing subsea permafrost organic carbon pool.

Evaluation of some chemical extractants for predicting response of wheat grown in pots to copper in Sub-Himalayan soils

1984 ◽  
Vol 102 (3) ◽  
pp. 659-666 ◽  
Author(s):  
R. Sakal ◽  
A. P. Singh ◽  
B. P. Singh ◽  
R. B. Sinha
Keyword(s):  
Organic Carbon ◽  
Chelating Agents ◽  
Dry Weight ◽  
Organic Carbon Content ◽  
Critical Limit ◽  
The Third ◽  
Chemical Extractants ◽  
Level Of Significance ◽  
Cu Uptake ◽  
Better Than

SummarySeven out of ten chemical extractants were found to be promising for the evaluation of critical limit and response of wheat grown in pots to Cu application in Sub-Himalayan hill and forest soils of recent alluvium origin. The critical limit of available Cu using DTPA-CaCl2(pH 7·3), DTPA-NH4HCO3 (pH 7·6), EDTA-(NH4)2CO3 of pH 8·6, EDTANH4OAc (pH 7·0), n-NH4OAC (pH 7·0), n-NH4OAC (pH 4·8) and n-Mg(NO3)2 of pH 5·9, was 0·66, 1·73, 1·95, 1·38, 0·13, 0·20 and 0·47 mg Cu/kg, respectively. The amount of Cu extracted by these extractants was positively and significantly correlated with ‘Bray's percent yield’. Apart from ‘Bray's per cent yield’, the Cu extracted by most of these extractants was positively and significantly correlated with Cu concentration in the third leaf of wheat, Cu uptake by wheat shoots and organic carbon content of the soils, and negatively correlated with soil pH but the value of this relationship did not approach the 5% level of significance. n-Mg(NO3)2 of pH6·7, N-NH4NO3 and 0·1 n-HCl were found to be ineffective extractants. Among chelating agents, DTPA-CaCl2 was found to be most and EDTA-NH4OAc least promising extractant. N-NH4OAC (pH 4·8) proved to be better than N-NH4OAC (pH 7·0). The critical Cu concentration in the third leaf of wheat was 8·8 mg Cu/kg, below which responses in dry weight to Cu application may be expected.

scholarly journals Effects of Varying Concentrations of Crude Oil on Some Physicochemical Properties of Agricultural Soil

2019 ◽  
pp. 1-13
Author(s):  
Ikuesan Felix Adeleke ◽  
Boboye Bolatito Esther ◽  
Adetuyi Fatusi Clement
Keyword(s):  
Organic Carbon ◽  
Physicochemical Properties ◽  
Crude Oil ◽  
Oil Pollution ◽  
Agricultural Soils ◽  
Organic Matter Content ◽  
Analytical Techniques ◽  
Physicochemical Characteristics ◽  
Matter Content ◽  
Organic Carbon Content

This research investigated the effects of varying concentrations of crude oil on some physicochemical characteristics of crude oil polluted agricultural soils from Igodan- Lisa, Oba-Ile and Ido-Ani areas of Ondo State, Nigeria. The soil samples were exposed to 1-4% (w/w) crude oil and analyzed monthly for six periods using standard physical and chemical analytical techniques. Results indicated that the physicochemical properties were altered. The physicochemical parameters varied with increase in the amount of crude oil spilled and time. The pH and moisture contents (MC) progressively decreased with increase in concentration of crude oil applied to the samples. Polluted soils had lower pH values (4.91- 6.17) and MC (15.24% to 26.83%) relative to control samples. The organic matter content increased with increased amount of crude oil spilled in the range of 6.65-10.93%. The organic carbon contents progressively increased with concentration of crude oil and sampling days. At 4% crude oil pollution, the organic carbon content in the samples were 6.04-8.28%, 5.39-7.82% and 6.05-8.21% for Igodan-Lisa, Oba-Ile and Ido-Ani soils respectively at 0-180 days of experiment. The changes in soil physicochemical suggested that soil integrity and quality is altered by crude oil contamination. The increased acidity with time also suggested the release of acidic metabolites in bioremediation by intrinsic microorganisms.

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