scholarly journals Dataset of macrobenthic species, organic matter content and grain-size distribution in surficial seafloor sediments in outer continental shelf, pockmark fields and Capbreton Canyon tributaries in the southeastern Bay of Biscay

Data in Brief ◽  
2021 ◽  
pp. 107464
Author(s):  
José Germán Rodríguez ◽  
Joxe Mikel Garmendia ◽  
Iñigo Muxika ◽  
Iñaki Quincoces ◽  
Ibon Galparsoro
Keyword(s):  
Grain Size ◽  
Organic Matter ◽  
Continental Shelf ◽  
Size Distribution ◽  
Grain Size Distribution ◽  
Organic Matter Content ◽  
Matter Content ◽  
Bay Of Biscay ◽  
Outer Continental Shelf ◽  
Seafloor Sediments

scholarly journals Characterization of mobilized sediments and organic matter in retrogressive thaw slumps on the Peel Plateau, NWT, Canada

2020 ◽  
Author(s):  
Lisa Bröder ◽  
Kirsi Keskitalo ◽  
Scott Zolkos ◽  
Sarah Shakil ◽  
Suzanne Tank ◽  
...  
Keyword(s):  
Grain Size ◽  
Organic Matter ◽  
Size Distribution ◽  
Grain Size Distribution ◽  
Active Layer ◽  
Organic Matter Content ◽  
Matter Content ◽  
Permafrost Soils ◽  
Extractable Organic Matter ◽  
Peel Plateau

<p>The Peel Plateau in northwestern Canada hosts some of the fastest growing “mega slumps”, retrogressive thaw slumps exceeding 2000 m<sup>2</sup> in area. The region is located at the former margin of the Laurentide ice sheet and its landscape is dominated by ice-rich hummocky moraines. Rapid permafrost thaw resulting from enhanced warming and increases in summer precipitation has been identified as a major driver of sediment mobilization in the area, with some of the largest slumps relocating up to 10<sup>6</sup> m<sup>3</sup> of previously frozen sediments into fluvial networks. The biogeochemical transformation of this thawed substrate within fluvial networks may represent a source of CO<sub>2</sub> to the atmosphere and have a large impact on downstream ecosystems, yet its fate is currently unclear. Concentrations of dissolved organic matter are lowered in slump-impacted streams, while the particle loads increase. Here, we aim to characterize the mobilized material and its sources by analyzing active layer, Holocene and Pleistocene permafrost, debris (recently thawed, still at the headwall) and slump outflow samples from four different slumps on the Peel Plateau. We use sediment properties (mineral surface area, grain size distribution), carbon isotopes (<sup>13</sup>C, <sup>14</sup>C) and molecular markers (solvent-extractable lipids, lignin phenols, cutin acids, non-extractable compound classes analyzed by pyrolysis-GCMS) in order to assess the composition and quality of the mobilized sediment and organic matter and thereby improve our understanding of their fate and downstream effects. Preliminary results show that organic matter content and radiocarbon age in debris and outflow from all four slumps are dominantly derived from Holocene and Pleistocene permafrost soils with a smaller influence of the organic-rich active layer. Degradation proxies based on extractable lipid and lignin biomarkers suggest Holocene and Pleistocene permafrost organic matter to be more matured than the fresh plant material found in the active layer, while debris and outflow samples show a mixed signal. For the non-extractable organic matter, aromatics and phenols make up the largest fraction of all samples. Lignin markers are almost exclusively found in the active layer samples, which also contain a larger proportion of polysaccharides, while N-containing compounds and alkanes make up the remaining 2-25 % with no obvious patterns. Active layer soils also have the highest median grain sizes, whereas Pleistocene permafrost soils consist of much finer mineral grains. Samples collected at the slump outflow are significantly more homogeneous (i.e., showing a narrower grain size distribution) than any of the other samples. We thus infer that both organic matter degradation and hydrodynamic sorting during transport play a role within these slump features; determining their relative magnitudes will be crucial to better assess potential feedbacks of these increasingly abundant “mega slumps” to changing climate.</p>

Evaluating the Integral Suspension Pressure method for measuring the particle size distribution in soils with high organic matter content

2020 ◽  
Author(s):  
Cristina Contreras ◽  
Sara Acevedo ◽  
Sofía Martínez ◽  
Carlos Bonilla
Keyword(s):  
Particle Size ◽  
Organic Matter ◽  
Particle Size Distribution ◽  
Size Distribution ◽  
Soil Analysis ◽  
Organic Matter Content ◽  
Matter Content ◽  
New Methodologies ◽  
Pre Treatment ◽  
Standard Techniques

<p>Typical information in soil databases is the soil texture and particle size distribution. These properties are used for soil description or predicting other soil properties such as bulk density or hydraulic conductivity. Measuring particle size distribution with standards methods such as the pipette or hydrometer is time-consuming because of the sample pre-treatment used to remove organic matter or iron and the sample post-treatment. Nowadays, there are new methodologies for determining soil particle size distribution, such as the Integral Suspension Pressure (ISP) method, which measures the silt content in a semi-automatized process. Thus, the main objective of this study was to evaluate the suitability of the ISP method compared to standard techniques used in soil analysis and evaluate the effect of organic matter content in the ISP measurements. The main results showed that the ISP method is equivalent in accuracy to the pipette, especially for soils rich in silt or sand content. Also, the results demonstrate the convenience of removing the soil organic matter when using the ISP for soils with more than 1.5% organic matter.</p>

Organic matter content of sediments in continental shelf area of southeast coast of India

2012 ◽  
Vol 184 (12) ◽  
pp. 7247-7256 ◽  
Author(s):  
Syed Ajmal Khan ◽  
K. G. Mohamed Thameemul Ansari ◽  
P. Somasundharanair Lyla
Keyword(s):  
Organic Matter ◽  
Continental Shelf ◽  
Organic Matter Content ◽  
Matter Content ◽  
Shelf Area ◽  
Southeast Coast Of India ◽  
Southeast Coast ◽  
Continental Shelf Area

WITHIN-PEDON VARIABILITY IN SOIL PROPERTIES

1982 ◽  
Vol 62 (4) ◽  
pp. 631-639 ◽  
Author(s):  
G. T. PATTERSON ◽  
G. J. WALL
Keyword(s):  
Particle Size ◽  
Organic Matter ◽  
Calcium Carbonate ◽  
Particle Size Distribution ◽  
Soil Properties ◽  
Size Distribution ◽  
Organic Matter Content ◽  
Matter Content ◽  
Soil Drainage ◽  
Soil Material

Replicate soil samples (2–20) from the A, B and C horizons of 41 pedons were collected to measure within-pedon variability of particle size distribution, organic matter content, calcium carbonate equivalent and pH. Variability in soil properties was examined in relation to the mode of origin of the soil material, soil horizonation and soil drainage. Variance in particle size distribution was significantly influenced by mode of deposition as well as by soil horizons, while soil drainage had no significant influence on the variation in particle size distribution. Variance in calcium carbonate equivalent and organic matter content was not influenced by soil drainage or mode of deposition. The number of replicate samples required for statistically reliable evaluation of a pedon at given confidence limits was determined for the soil properties studied. The results of these calculations indicate the need for up to five replicate samples to achieve satisfactory levels of accuracy at the 95% confidence level for some of the soil properties studied.

scholarly journals Superficial sediments and their relation to polyehaete families in a subtropieal embayment, Mexico

2015 ◽  
pp. 237-238
Author(s):  
Nuria Méndez ◽  
María Green Ruiz
Keyword(s):  
Grain Size ◽  
Organic Matter ◽  
Organic Matter Content ◽  
Fine Sand ◽  
Matter Content ◽  
Pearson’S Correlation ◽  
Pearson's Correlation ◽  
Superficial Sediments ◽  
Soft Bottoms

The soft bottoms in front of Mazatlan Bay and "Isla de la Piedra" Peninsula were studied to produce maps (depth, grain size and organic matter content in sediments). Sixty samples were óbtained with a 30 x 30 van Veen grab (4-21 m depth) and polychaetes were extracted from 21 subsamples. Grain size ranged from -1.05 phi (gravel) to 3 .81 phi (very fine sand), with fme sand predominl\ting. Organic matter content in sediment was 0.91-3.06 % (most values = 1-2 %). Thirty polychaete families (905 individuals/m2 in mean) were found, and Cirratulidae, Spionidae, Onuphidae, and Pilargiidae were domiuant. Pearson's correlation of grain size.

scholarly journals Variability of macrofauna distribution along a dissipative log-spiral sandy beach in Rio de Janeiro, Southeastern Brazil

2017 ◽  
Vol 81 (1) ◽  
pp. 111 ◽  
Author(s):  
Carlos A.M. Barboza ◽  
Tatiana Cabrini ◽  
Gustavo Mattos ◽  
Viviane Skinner ◽  
Ricardo Cardoso
Keyword(s):  
Grain Size ◽  
Organic Matter ◽  
Community Structure ◽  
Organic Matter Content ◽  
Principal Component ◽  
Matter Content ◽  
Southeastern Brazil ◽  
Individual Species ◽  
Beach Slope ◽  
Sediment Sorting

Log-spiral beaches display defined physical gradients alongshore. However, the majority of studies focus on the variability of a single population of macrofauna species. We aimed to investigate the variation in species distribution and in community structure along ten transects on a log-spiral beach. Principal component analysis indicated a clear physical gradient alongshore. Redundancy analysis showed that the sheltered end was related to smaller particle sizes, higher organic matter content and high densities of polychaetes. The exposed end was characterized by coarser sand, lower organic matter content and a high presence of crustaceans. Model selection indicated that the “best fit” to explain the variability in the number of individuals included grain size and beach slope. Variability of the polychaete Scolelepis squamata was best explained by grain size, slope and sediment sorting. The best model for the cirolanid Excirolana armata only included sediment sorting. The physical gradient in sediment texture and the beach slope explained more than one-third of the variability in community structure. The physical variables were also correlated with the distribution of the individual species. We showed that the physical gradient on log-spiral coasts may be an important driver of macrofauna variability, even at mesoscales and in dissipative conditions.

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