The shape of the Upper Carboniferous non-marine bivalve Anthraconaia in relation to the organic carbon content of the host sediment

1987 ◽  
Vol 78 (3) ◽  
pp. 177-195 ◽  
Author(s):  
R. M. C. Eagar
Keyword(s):  
Organic Carbon ◽  
Regional Distribution ◽  
Maximum Growth ◽  
Shell Shape ◽  
Marine Bivalve ◽  
Organic Carbon Content ◽  
Maximum Width ◽  
Upper Carboniferous ◽  
The Relationship ◽  
Host Sediment

ABSTRACTAnthraconaia lived on clay grade sediments. In highly variable life assemblages of the A.prolifera group of the E German Wettin Shales (Stephanian C) organic carbon percentage of the host sediment correlates with wu/m and A/L ratios of the shell (where wu is the maximum width ventral to the line of maximum growth, m, L the maximum length measured parallel to the line of the hinge, and A the length anterior to the umbo). Decrease in the organic carbon of the sediment is associated with decrease in umbonal development, elongation of the shell along the m axis, and straightening and reflection of the ventral margin; the latter becomes subparallel to the dorsum or to the m axis with a concomitant decrease in size. These results confirm and amplify earlier work on Anthraconaia in the Appalachian coalfields. The same morphological trends in relation to organic carbon characterise the Anthraconaia modiolaris group of Britain, both within a single succession in upper Westphalian A sediments in Yorkshire, and also in three shell bands of Lower Westphalian B age in S Wales, Yorkshire and central Scotland. In the last named, above the Musselband Coal, statistical formulae (of Leitch 1940) for the species A.salteri are shown to define neither the type assemblage nor its stratigraphical position. The shell-shape/organic carbon relationship has been broadly confirmed on other horizons of lower Westphalian B age in the Scottish and Pennine coalfields. Far from embarrassing the stratigrapher, the relationship, which reflects ultimately trophic level of deltaic palaeoenvironments, contributes to our understanding of non-marine bivalve faunas, especially of the apparent regional distribution of ‘species’ of Anthraconaia.

scholarly journals VIS-NIR spectral reflectance for discretization of soils with high sand content

2019 ◽  
Vol 40 (1) ◽  
pp. 99
Author(s):  
Gustavo Eduardo Pereira ◽  
Letícia Sequinatto ◽  
Jaime Antonio de Almeida ◽  
Alexandre Ten Caten ◽  
Josie Moraes Mota
Keyword(s):  
Organic Carbon ◽  
Carbon Content ◽  
Diffuse Reflectance ◽  
Diffuse Reflectance Spectroscopy ◽  
Soil Depth ◽  
Spectral Response ◽  
Sodium Dithionite ◽  
Organic Carbon Content ◽  
Spectral Curves ◽  
The Relationship

The aim of this study is to evaluate the spatial distribution and relationships between the physicochemical attributes and radiometry of soils with high sand contents. One hundred surface horizon samples were collected for physicochemical and spectral analyses of the soil. The samples were selected spatially by the conditioned Latin hypercube method. The physicochemical analyses consisted of granulometry, organic carbon content, and iron oxides content, extracted using sodium dithionite-citrate-bicarbonate (DCB). The spectral response of the soils was analyzed in the 400 to 1000 nm range. The spectral curves were obtained from the samples of the surface horizons, which were categorized according to the attribute in question. The relationship between the soil physicochemical attributes and soil radiometry was evaluated through a Pearson's correlation. There was a tendency for the organic carbon content to decrease with an increase in soil depth, associated with the presence of soils with higher sand contents. For soils with iron contents lower than 80 g kg-1, there was an increase in the reflectance along the spectrum, whereas for soils with contents between 80 and 160 g kg-1, the reflectance decreased after 600 nm, with greater variation along the spectrum for soils with iron contents higher than 120 g kg-1. The diffuse reflectance spectroscopy could potentially allow for granulometric distinction between the soils evaluated.

SELENIUM DISTRIBUTION IN CANADIAN SOIL PROFILES

1974 ◽  
Vol 54 (1) ◽  
pp. 63-68 ◽  
Author(s):  
M. LÉVESQUE
Keyword(s):  
Organic Carbon ◽  
Soil Profiles ◽  
Organic Carbon Content ◽  
Surface Layers ◽  
Parent Materials ◽  
Podzolic Soils ◽  
Marked Accumulation ◽  
Relationship Of ◽  
The Relationship ◽  
Combined Data

The distribution of selenium (Se) in 54 Canadian soil profiles was examined according to horizon in the profile, and to soil properties. Apart from the organic surface layers, the Podzolic B horizons had the highest Se values (0.52 ppm), and so displayed a marked accumulation. The Luvisolic and Gleysolic B horizons also showed some accumulation. The Se content of parent materials was generally low (0.10 ppm). Simple correlation analyses of the combined data (irrespective of horizon) indicated that Se distribution was closely associated with both organic carbon and NH4-oxalate extractable Fe and Al. When the data were arranged according to genetic groupings, this association remained true only for Podzolic B horizons. Multiple regression analyses revealed that the predominant factors involved in the Se distribution were the Se content of parent materials, and the organic carbon content of the upper horizons, in that order, except for Podzolic soils. Clay had little or no influence on the Se distribution. In spite of the relationship of Se to parent materials, the contribution by atmospheric contaminants to the Se enrichment of soils could remain important.

Keterkaitan parameter nilai pH, C-organik, N-Total, C/N dan alofan pada beberapa Andisols di Jawa Barat

SoilREns ◽  
2017 ◽  
Vol 15 (1) ◽  
Author(s):  
Rina Devnita ◽  
Mahfud Arifin ◽  
Ridha Hudaya ◽  
Ade Setiawan ◽  
Apong Sandrawati
Keyword(s):  
Organic Carbon ◽  
Carbon Content ◽  
Total Nitrogen ◽  
Soil Analysis ◽  
Volcanic Eruptions ◽  
Soil Parameters ◽  
Organic Carbon Content ◽  
Ph Values ◽  
Relationship Of ◽  
The Relationship

The correlation of chemical parameters and soil mineralogy one to another in Andisols were interesting to be studied, to increase the understanding of soil reactions, nutrient availability and soil mineral content. Andisols from three locations and derived from three different volcanic eruptions namely G. Tangkuban Parahu, G. Patuha and G. Tilu, with andesite, andesite-basalt and basalt parent materials respectively, were examined the correlation of several soil parameters. The values of pH, organic carbon, total nitrogen, C/N and allophane content were obtained from the soil analysis of every horizon of the soil profiles at each site. Correlation analyses were used to see the relationship of the parameters. The results showed a negative correlation between pH and organic carbon (r = -590 *). The soil pH values were positively correlated with the amount of allophane (r = 0.687 *). The pH values were correlated positively with imogolite content (r = 0.356 *). The pH values were negatively correlated with organic carbon (r = -0.590 *). The organic carbon content was negatively correlated with depth (r = - 0.582 *). The organic carbon content was negatively correlated with allophane (r = 0.707 *). Total nitrogen values were negatively correlated with increasing depth (r = -0.531 *).Keywords: Mt. Tangkuban Parahu, Mt. Patuha, Mt. Tilu, andesit, andesit-basalan, alophane

Space-time monitoring of soil organic carbon content across a semi-arid region of Australia

2021 ◽  
Vol 24 ◽  
pp. e00367
Author(s):  
Patrick Filippi ◽  
Stephen R. Cattle ◽  
Matthew J. Pringle ◽  
Thomas F.A. Bishop
Keyword(s):  
Organic Carbon ◽  
Soil Organic Carbon ◽  
Carbon Content ◽  
Arid Region ◽  
Space Time ◽  
Organic Carbon Content ◽  
Soil Organic Carbon Content ◽  
Semi Arid Region ◽  
Semi Arid

scholarly journals Influence of Slope Gradient and Aspect on Soil Organic Carbon Content in the Region of Niš, Serbia

2021 ◽  
Vol 13 (15) ◽  
pp. 8332
Author(s):  
Snežana Jakšić ◽  
Jordana Ninkov ◽  
Stanko Milić ◽  
Jovica Vasin ◽  
Milorad Živanov ◽  
...  
Keyword(s):  
Land Use ◽  
Spatial Distribution ◽  
Organic Carbon ◽  
Soil Organic Carbon ◽  
Slope Aspect ◽  
Available Phosphorus ◽  
Organic Carbon Content ◽  
Slope Gradient ◽  
Phosphorus And Potassium ◽  
Uncultivated Land

Topography-induced microclimate differences determine the local spatial variation of soil characteristics as topographic factors may play the most essential role in changing the climatic pattern. The aim of this study was to investigate the spatial distribution of soil organic carbon (SOC) with respect to the slope gradient and aspect, and to quantify their influence on SOC within different land use/cover classes. The study area is the Region of Niš in Serbia, which is characterized by complex topography with large variability in the spatial distribution of SOC. Soil samples at 0–30 cm and 30–60 cm were collected from different slope gradients and aspects in each of the three land use/cover classes. The results showed that the slope aspect significantly influenced the spatial distribution of SOC in the forest and vineyard soils, where N- and NW-facing soils had the highest level of organic carbon in the topsoil. There were no similar patterns in the uncultivated land. No significant differences were found in the subsoil. Organic carbon content was higher in the topsoil, regardless of the slope of the terrain. The mean SOC content in forest land decreased with increasing slope, but the difference was not statistically significant. In vineyards and uncultivated land, the SOC content was not predominantly determined by the slope gradient. No significant variations across slope gradients were found for all observed soil properties, except for available phosphorus and potassium. A positive correlation was observed between SOC and total nitrogen, clay, silt, and available phosphorus and potassium, while a negative correlation with coarse sand was detected. The slope aspect in relation to different land use/cover classes could provide an important reference for land management strategies in light of sustainable development.

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