Characterization Of Sediments Research Articles

Elemental and mineralogical characterization of marine sediments and their relationship to sedimentary and oceanographic processes in Central Bransfield Basin.

This work consists of the sedimentological, mineralogical, and geochemical characterization of eight marine sediment cores collected in the Central Bransfield Basin, along a transect between the South Shetland Islands to the Antarctic Peninsula and its correlation to the sedimentary and oceanographic processes of the area. A chemical characterization based on X-ray fluorescence dispersive spectrometry was implemented to obtain geochemical data of the marine sediment while the minerals were identified by X-ray diffraction. The study allowed to classify the cores into three groups according to their sediment source and chemical and mineralogical characteristics. The joint assessment of the geochemical and mineralogical signature of the sediment has confirmed that the elemental ratios Ti/Ca and Fe/Ca can be applied as proxies in the reconstitution of the terrigenous contribution to the Central Bransfield Basin if we consider the sedimentary contribution of the volcanic edifices present in the region. The Fe/K ratio associated with the Chemical Index of Alteration reinforced an increase in the degree of weathering near South Shetland Island, which is also pointed out by other authors in studies on climate change mainly in the subantarctic islands. The trend of temperature increase implies the importance of monitoring the region.

Impact of historic sediment characterisation on predicting polychaete distributions: a case study of so-called muddy habitat shovelhead worms (Annelida: Magelonidae)

Impact of historic sediment characterisation on predicting polychaete distributions: a case study of so-called muddy habitat shovelhead worms (Annelida: Magelonidae)

Sediments and bedforms of the Harle tidal inlet (Wadden Sea, Germany)

ABSTRACT The paper presents a map of sediment surface distribution and bedforms in the Harle tidal inlet, German Wadden Sea. Data collection, processing, and map editing were realized within the sublittoral mapping program of Lower Saxony national waters carried out by the NLWKN – Coastal Research Station. The map is the result of the combined use of multibeam echosounder, sub-bottom profiler, and ground-truth data. The sediment characterization is achieved by an unsupervised approach using an Object-Based Image Analysis (OBIA) on a normalized backscatter mosaic, verified by nineteen sediment samples. Morphometrical parameters and sub-bottom data provided important information to identify hard substrates and bedforms.

Mineralogical and Sedimentological Characterization of the Clay-Rich Sediments from Ases Cave (Cova Dets Ases, Mallorca, Spain): Origin and Classification

The Mallorca coastal caves present large amounts of speleothems that have been studied for decades. However, the sedimentary deposits also present in these cases have not been given the same attention. This work is the first study entirely focused on these deposits, specifically the ones found in the Ases cave. These deposits are formed by clay minerals (illitic phases, kaolinite, smectite, and chlorite), calcite and quartz, and minor proportions of dolomite, albite, orthoclase, hematite, and goethite. The grain size and the electron microscopy studies suggested the presence of different sedimentation processes (bedrock degradation, creep or saltation, and suspension) and different origins (authigenic and detrital origins) for the different sediments. Based on these differences, two types of deposits were characterized: autochthonous and allochthonous deposits. The first ones are located on the floor of chambers and corridors in subaqueous zones, indicating the stability of the mixing zone (and therefore the sea level) over time. The second ones appear filling voids on the walls and the ceiling in the terrestrial zone, evidencing the filling of the cavity in the presence of water (during a wet period). These results are very important to complete the understanding of the caves and their evolution and support the relevance of these materials in paleoenvironmental studies.

Archaeometric Surveys of the Artifacts from the Archaeological Site of Baro Zavelea, Comacchio (Ferrara, Italy)

This work is part of a project of the Superintendence of Archaeology, Fine Arts, and Landscape for the enhancement of the widespread archaeological heritage of the Po delta area. Excavation activities, carried out in 2015, allowed the sampling of the stratigraphic elements and artifacts of the archaeological site of the lighthouse tower of Baro Zavelea, municipality of Comacchio (Ferrara, northeast Italy). In this work, the geochemical characterization of sediments and building materials was conducted using granulometric analyses, X-ray fluorescence analysis, and calcimetry on different types of samples, including sands, clays, mortars, and bricks, with the scope to better characterize all of the different types of sediments collected. This multidisciplinary approach allowed the diagnostic and evaluation of the state of conservation of Baro Zavalea. Granulometric analyses highlighted the fact that depositional environments were of very different natures: fluvial environments and paleo–alveo environments. In addition, XRF analysis allowed the discrimination of different clay samples, some from basins poor in carbonates, while, for the construction of the bricks of the second wall structure, clays rich in carbonate were chosen to add lightness to the structure.

Identification of potential artificial groundwater recharge sites in an alluvial setting: A coupled electrical resistivity tomography and sediment characterization study

Alluvial aquifers are one of the most exploited and easily accessible aquifer networks across the world, as they coincide with regions of intensive human settlements. Over the years, improper management and overexploitation of groundwater has severely stressed the natural replenishing capacity of these aquifer systems. Identification of potential artificial recharge networks and their monitoring are urgently needed for long-term sustainable groundwater management. In this study, an efficient and cost-effective strategy to locate prospective groundwater recharge zones is devised by integrating electrical resistivity tomography (ERT), sediment characterization, and temporal monitoring techniques. The efficacy of the above strategy is evaluated in the central part of Indo-Gangetic basin (IGB). Correlation of 2-D ERT models with borehole lithology and depth-wise variation of hydraulic parameters deciphered the existence of prospective regions composed of highly permeable strata within ∼6–48 m depth. In addition, the behavior of the delineated prospective regions was monitored by applying time-lapse ERT study. The comparison of time-lapse 2-D ERT models highlighted a significant reduction in post-monsoon resistivity profiles, suggesting an increase in saturation levels due to infiltration of rainwater. This study provides an integrated cost-effective approach for identification of prospective artificial recharge sites and monitoring their efficacy in replenishing shallow aquifers, thereby enabling sustainable groundwater management.

Characteristic regional differences in trace element pattern of 2014 German North Sea surface Wadden sediments - A judge and assessment.

The European Marine Strategy Framework Directive (MSFD) requires good ecological status of the marine environment. This also includes the Wadden Sea located in the southeastern part of the North Sea and its chemical status of sediments. Based on results from campaigns conducted in the 1980s, 32 surface sediment samples were taken in 2014 to check whether the sampling strategy required for characterizing the trace element content in sediments is representative and to determine the degree of pollution and potential changes over the last decades. For this purpose the elemental mass fractions of 42 elements were assessed in the ≤20μm grain size fraction of the surface sediments. Based on cluster analysis a clear correlation between the element distribution and the geographical location of the sampling locations of the German Wadden Sea could be found. As a result of the principal component analysis, three sub-catchments were significantly separated from each other by the characteristic element distributions in the sediments (Norderney and Weser, Elbe and offshore areas, and North Friesland). With the help of discriminant analysis, the classification was confirmed unambiguously. Small anomalies, such as potentially contaminated sites from WWII, could be identified. This proved that the sampling strategy for sediment characterization with reference to trace elements in the Wadden Sea of the German Bight is representative. The impact of regulation and changes on the overall sediment quality is most evident when looking at the environmentally critical elements such as As, Cd, Hg, and Cr. For these elements the mean mass fractions show a significant reduction over the last three decades. Current sediments feature only slightly elevated mass fractions of Ag, Cd, Ce, Cs, Nd, Pb and Se at some sampling locations.

Sediment characterization of bottom propagating reversing buoyancy particle-bearing jets

Lofting characteristics and sedimentation patterns in reversing buoyancy particle-bearing jets are investigated experimentally and theoretically. The presence of particles and buoyancy show notable differences in the jet dynamics and shape of the sediment deposit. The suction force significantly influences the lofting location of the jet. The sedimentation dynamics are affected by the bottom drag and entrainment of the ambient fluid.

Characterizing Gas Hydrate-Bearing Marine Sediments Using Elastic Properties—Part 2: Seismic Inversion Based on a Pore-Filling–Solid Matrix Decoupling Scheme

Characterizing gas hydrate-bearing marine sediments using seismic methods is essential for locating potential hydrate resources. However, most existing pre-stack seismic inversion methods estimate the properties of sediments containing gas hydrates without considering specific characteristics associated with gas hydrate occurrences. In the present study, a pore-filling–solid matrix decoupling amplitude variation with offset (AVO) formula is proposed to represent seismic reflectivity in terms of properties associated with gas hydrates. Based on the rock physics relationships of solid substitution, the parameters introduced into the decoupling AVO equation estimate the concentration of gas hydrates with different occurrences, including pore fillings mixed with water and solid components forming part of the dry sediment frame. A theoretical model test indicates that seismic attributes obtained with the decoupling AVO inversion are superior to the conventional wave velocities-related properties in predicting gas hydrate saturations. A realistic model test further validates the applicability of the proposed method in characterizing a gas hydrate system with varying concentrations and layer thickness. By adjusting the tuning parameters, the configurations and concentrations of the gas hydrate system can be identified using the obtained attributes. Therefore, the presented method provides a useful tool for the characterization of gas hydrate-bearing sediments.

An integrated approach for sediment characterization of Dead Sea, Israel: Implications to marine environment.

The Dead Sea (DS) sediment samples from two different sites on the west coast were analyzed. The objective is to document sediment characterization in order to study the interrelation existing among ingredients. The analyses show that Fe, Mg and Zn are the most significant trace elements found in the Sediment. Anthropogenic activities such as Industries, untreated sewage, agricultural wastes are some of the pollution sources that are considered to be lethal to the marine ecosystem. The DS is slowly disappearing at an alarming rate of 1m/year. Hence a constant and precise mitigation, monitoring and management is mandatory. The present work is part of such goal in order to understand the health of the DS ecosystem. A cumulative and consistent effort of the Governments, stakeholders, tourists and the public will help in order to preserve and protect the health of the rare DS marine ecosystem for future generations.

Broadband acoustic quantification of mixed biological aggregations at the New England shelf break.

At the New England shelf break, cold, less saline shelf water collides with warmer saltier slope water to form a distinct oceanographic front. During the Office of Naval Research Sediment Characterization Experiment in 2017, the front was mapped by narrowband (18 and 38 kHz) and broadband (70-280 kHz) shipboard echo sounders. The acoustically determined cross-shelf velocity of the front ranged in amplitude from 0.02 to 0.33 m/s. Acoustic surveys revealed aggregations of scatterers near the foot of the front. Acoustic backscatter in conjunction with Northeast Fisheries Science Center bottom trawl surveys identified longfin squid (Doryteuthis pealeii) and mackerel (Scomber scombrus) as the most likely scatterers in the aggregations. A mixed species scattering model was developed and further refined by the use of a matching method used for distribution of the lengths of each species. The mean length of squid and mackerel, respectively, using the matching method was 4.45 ± 1.00 and 20.25 ± 1.25 cm compared with 6.17 ± 2.58 and 22.76 ± 1.50 cm from the trawl data. The estimated total biomass of the aggregation was a factor of 1.64 times larger when using the matching method estimated length distribution compared to the trawl length distribution.

Wetland Restoration through Excavation: Sediment Removal Results in Dramatic Water Quality Improvement

We evaluated whether sediment excavation improved water quality in a former (pre-European settlement) wetland complex that was a farm in the early 1900s and then later in the 1990s/early 2000s was allowed to naturally refill with water and became nutrient-rich ponds plagued by legacy phosphorus issues. Two ponds were recently restored via dewatering, excavation of the surface sediment, and hydrologic reconnection to an adjacent creek to re-establish a flow-through marsh. The removal of ~103,000 m3 of phosphorus-laden sediment and reconnection to the adjacent stream resulted in improved water quality, with a reduction in total phosphorus concentration from ~1000 μg/L to ~20 μg/L and a 40% reduction in specific conductivity in both former ponds. Soluble reactive phosphorus concentrations declined substantially in one pond, from ~720 μg/L to 3 μg/L, but not in another pond, which was partially dredged by the landowner prior to restoration. Additionally, phosphorus concentration in the downstream receiving water body also declined but to a much more modest degree. Sediment excavation was an effective restoration tool in this former agricultural system, but given the expense and potential impact on pre-existing biota, a full-system diagnosis, including cost, sediment characterization, and control of external nutrient loading, is recommended before its implementation elsewhere.

Reconciling the geogenic and non-crustal origins of elements in an Indo-Bangla transboundary river, Atrai: Pollution status, sediment quality, and preliminary risk assessment

This study has been conducted on an anthropogenically less influenced transboundary river (Atrai: Indo-Bangladesh) to comprehend the inherent geochemistry and identify potential elemental sources. In doing so, across the Bangladeshi portion, 30 river-bed samples were culled and studied by neutron activation analysis to quantify the abundances of 15 geochemically and toxicologically significant elementals (Na, Al, K, Ti, Cr, Mn, Co, Zn, As, Rb, Sb, Cs, Ba, Th, and U). The results revealed that the mean concentrations (μg/g) of Rb (154.6), Cs (7.53), Th (20.90), and U (4.88) were 1.5–2.0 times higher than crustal values. Besides, geo-environmental indices revealed ‘uncontaminated to moderately contaminated’ pollution status with minor enrichment or contamination for Rb, Th, Sb, U, and Cs, relatively concentrated in the mid-to-downstream zone possessed geogenic and non-crustal origins. The positive matrix factorization and other statistical approaches revealed predominant geogenic enrichment of Na, K, Al, Ti, Zn, Cs, Rb, As, Th, and U from differential mineralogical compositions via weathering, elemental fractionations, and biogeochemical mobilization. Contrariwise, several anthropogenic sources (for Cr, Sb, Co, Mn, Th) were also ascertained in the vicinity of Atari River. However, sediment characterization based on SQG threshold values manifested that Cr and Mn possess rare biological effects on local aquatic organisms. Nevertheless, SQGs-based and ecological risk indices invoked minor to no potential ecotoxicological intimidations for the considered metal(oid)s (Cr, Mn, Co, Zn, As, and Sb). Hence, this study manifested the usefulness of a less anthropogenically affected river to reckon geogenic and non-crustal elemental origins in the compounded riverine sediment.

Characterization of the gassy sediment layer in shallow water using an acoustical method: Lake Kinneret as a case study

AbstractRemote characterization and parameterization of gassy sediments have significant environmental importance for quantifying the global methane budget and assessing its impact on climate change. Acoustic techniques that have been developed hold advantages over direct sediment sampling (e.g., using pressurized and frozen cores), as they permit comparatively quick and cost‐effective assessments over the large bottom areas. This paper proposes a non‐invasive acoustic method that allows simultaneous assessments of the free gas content () and the thickness () of a gassy layer in the aquatic surface sediments. The method is based on amplitude measurements and frequency analysis of the bottom reflection coefficient in the wide frequency band (300–3500 Hz). The spatial variability of and in freshwater Lake Kinneret (Israel) is studied, where the upper sedimentary layer is characterized by a high organic matter content, high methane production rates, and a large . The assessed values of and varied from 0.1% to 0.6%, and from 20 to 40 cm, respectively, depending on the location of measurements. These results are in reasonable agreement with gas void fractions measured directly in frozen sediment cores, where the depth‐averaged varied from to . The suggested methodology should have considerable practical implementation for remote spatiotemporal monitoring of shallow gassy sediments in aquatic ecosystems.

Reservoir sediment characterisation by diffuse reflectance spectroscopy in a semiarid region to support sediment reuse for soil fertilization

PurposeSoil erosion by water yields sediment to surface reservoirs, reducing their storage capacities, changing their geometry, and degrading water quality. Sediment reuse, i.e., fertilization of agricultural soils with the nutrient-enriched sediment from reservoirs, has been proposed as a recovery strategy. However, the sediment needs to meet certain criteria. In this study, we characterize sediments from the densely dammed semiarid Northeast Brazil by VNIR-SWIR spectroscopy and assess the effect of spectral resolution and spatial scale on the accuracy of N, P, K, C, electrical conductivity, and clay prediction models.MethodsSediment was collected in 10 empty reservoirs, and physical and chemical laboratory analyses as well as spectral measurements were performed. The spectra, initially measured at 1 nm spectral resolution, were resampled to 5 and 10 nm, and samples were analysed for both high and low spectral resolution at three spatial scales, namely (1) reservoir, (2) catchment, and (3) regional scale.ResultsPartial least square regressions performed from good to very good in the prediction of clay and electrical conductivity from reservoir (< 40 km2) to regional (82,500 km2) scales. Models for C and N performed satisfactorily at the reservoir scale, but degraded to unsatisfactory at the other scales. Models for P and K were more unstable and performed from unsatisfactorily to satisfactorily at all scales. Coarsening spectral resolution by up to 10 nm only slightly degrades the models’ performance, indicating the potential of characterizing sediment from spectral data captured at lower resolutions, such as by hyperspectral satellite sensors.ConclusionBy reducing the costly and time-consuming laboratory analyses, the method helps to promote the sediment reuse as a practice of soil and water conservation.

Experimental study of As elimination from the pit water in locality Zlatá Idka-Rieka, Slovakia and characterization of sediment in this locality

The study presents introductory laboratory and in-situ experiments focused on elimination of As from the pit water in locality Zlatá Idka-Rieka, Slovakia, as well as on characterization of the sediment parameters in this locality from the viewpoint of their eventual toxicity. The mobility of As from the sediment is dependent on the chemical bonds with non-stable Fe oxides/hydroxides, creating surface coatings on the grains of minerals and soil, present in the lake of pit water. Leachates after the Simply Bioavailability Extraction Test contained high concentrations of Fe (223 mg.l–1), Mn (165 mg.l–1), as well as As (11.1 mg.l–1), which are potential toxic for people in case of contamination of the soil attached to vegetables, or from coarse dust that can be inhaled and then swallowed. The batch adsorption experiments were performed in the laboratory and next in in-situ conditions. As adsorbents natural zeolite, terra rossa and their mixture were used. In laboratory the As adsorption was fast, reached equilibrium almost after 4 hours. The adsorption capacity of zeolite and terra rossa was 18.3 and 25,3 μg.g–1, respectively. Effect of in-situ As removal was the highest for terra rossa (almost 85 %) and the concentration of As in leachate after the experiment was slightly higher than required limited value. The promising results for future in-situ applications brought laboratory column experiments, where after 4 cycles of adsorption the effectivity of columns was still 95 % independently on the columns filling (layers or mixture of studied adsorbents).

Ecological risk assessment of metal and hydrocarbon pollution in sediments from an urban tropical estuary: Tijuca lagoon (Rio de Janeiro, Brazil).

Urban tropical lagoons are often impacted by eutrophication, metal, and polycyclic aromatic hydrocarbon (PAH) contamination, but the toxicity of their bottom sediments is still poorly investigated in South America. Aiming to contribute to filling this gap, a sediment quality assessment was conducted in the Tijuca Lagoon (Rio de Janeiro, Brazil) using different lines of evidence (LOEs) including sediment characterization, determination of metals and PAHs, and acute toxicity testing with burrowing amphipods (Tiburonella viscana). Mud and organic matter contents played a crucial role in contaminant distribution along the lagoon. The concentrations of PAH were generally low (mean ΣPAH = 795.42 ± 1146.2ng/g; n = 23), but a contamination hotspot of light PAH compounds was identified. Such PAHs were mainly pyrolytic, probably related to the deposition of atmospheric pollution, although petrogenic compounds also occur in the lagoon. The data indicated the occurrence of geochemical anomalies of Zn, Cu, Pb, and Hg (mean values = 176.9 ± 91.6, 45.1 ± 21.3, 35.2 ± 15.0, 0.1442 ± 0.0893mg/kg, respectively; n = 23), probably associated with industrial wastes, garbage deposition, urban runoff, and domestic sewage contributions. The mortality of T. viscana was significant for more than 85% of the samples (mean mortality = 70.3 ± 26.0%; n = 23), but it was not significantly correlated with PAH and metal concentrations. On the other side, domestic sewage contributions and eutrophication seem to play a relevant role in sediment toxicity. Actually, the toxicity observed in the tests seems to be due to the simultaneous influence of multiple toxicants and their combined effects on the organisms. Such stressors may include not only metals, PAH, and eutrophication but also chemicals not evaluated in this study, such as hormones, pharmaceuticals and personal care compounds, perfluorocompounds, detergents, and others.

Characterization and Interpolation of Sediment Polychlorinated Biphenylsand Polybrominated Diphenyl Ethersin Resident Killer Whale Habitat along the Coast of British Columbia, Canada.

The northeastern Pacific northern and southern resident killer whale (Orcinus orca) populations are listed as threatened and endangered in Canada, respectively, with persistent, bioaccumulative contaminants, such as polychlorinated biphenyls (PCBs) and polybrominated diphenyl ethers (PBDEs), posing threats to their recovery. Concentrations of PCBs and PBDEs in subtidal surface sediments collected from 97 sites along the British Columbia (BC) coast were used to identify their distribution and profiles, and to assess killer whale habitat quality. Victoria Harbour (VH3(site ID: 1) ) sediments exhibited the highest PCB and PBDE concentrations. For PCBs, PCB-138 was found at the highest concentration, followed by PCB-153, PCB-110, PCB-149, PCB-101, and PCB-118. For PBDEs, individual congeners were ranked as follows: BDE-209 > BDE-207 > BDE-206 > BDE-208 > BDE-47 > BDE-99. Principal component analyses (PCA) illustrated the variations in contaminant profiles, with PC1 for PCBs and PBDEs correlated with the octanol-water partition coefficient (log KOW , p < 0.003). Based on the PCA, sediment particle size, total organic carbon (TOC), and water depth at collection were other factors associated with the distribution of PBDEs, while PCB profiles were associated with TOC. Total PCB and PBDE concentrations at 100% and 34% of the sites, respectively, exceeded the recently adopted British Columbia's Ministry of Environment and Climate Change Strategy Working Sediment Quality Guidelines (PCBs 3.7 pg/g dry wt and PBDEs 1000 pg/g dry wt), considered protective of killer whales. Our findings suggest that the legacy of banned PCBs and PBDEs has the potential to constrain the recovery of killer whales as a result of their mobilization from sediments and consequent uptake by marine food webs. Environ Toxicol Chem 2022;41:2139-2151. © 2022 SETAC.

MORPHOSCOPIC EVALUATION OF SANTO ANTÔNIO RIVER SEDIMENTS IN SERRA DA CANASTRA NATIONAL PARK - MG AND SURROUNDINGS

The sedimentary morphoscopy studies is an important tool to characterize grains of a given channel with studies of sphericity, roundness and parental material, from their results, which can influence the relief sculpture. The purpose of this research is to understand the distribution and characterization of sediments collected in the Santo Antônio River Basin, located in the Serra da Canastra National Park – MG and surroundings, in order to evaluate the dynamics of sediment transport that occur in this space. Through textural analysis and the study of the genetics of the samples collected in the river channels, they are the result of dynamic processes that collaborate for the sculpting of the regional relief. These channels carry sediments, which were collected in a total of 51 points and, for each sampling point, 50 discontinuous grains with three different diameters were evaluated: 0.600mm; 0.850mm; 1.70mm. In all, approximately 7,650 grains were evaluated. Enabling the quali-quantification of the grains on their sphericity, roundness and the lithological aspect of the material. From the analyzes carried out with the granulometry method by sieving and observation by a precision portable digital type magnifier, monocular, 1000x magnification with a 2.0 megapixel camera. The results point to a greater number of sediments with low sphericity, roundness of the very angular to angular type, with predominance of material of geological aspect such as quartz, laterite and mica.

Fine-Grained Sediment Characterization and Process Monitoring Using Nuclear Magnetic Resonance (NMR)

Abstract The intrinsic magnetic moment of hydrogen nuclei allows them to interact with externally imposed magnetic fields; then, nuclear magnetic resonance (NMR) can be used to probe the pore space of wet soils using the water molecules in pores. Surface relaxivity at pore walls combines with molecular diffusion to produce a relaxation rate that is inversely proportional to the pore size in saturated specimens or the mean distance to a pore wall in unsaturated soils. We used NMR to nondestructively characterize pore size distribution, monitor changes in pore space during sedimentation, and track the evolution of water conditions during drying and infiltration. Results show that the evolution of relaxation time distribution reflects pore size contraction, water film thickness reduction, and pore water redistribution. In all cases, the mean relaxation time and water content exhibit a unique relationship for both saturated and unsaturated soils; we propose a parallel plate model to interpret this relationship that only depends on surface relaxivity and specific surface area. Finally, we impose a magnetic field gradient to obtain spatially resolved relaxation spectra; this technique shows the evolution of moisture profile with depth and changes in moisture transport mechanisms during 1D drying. The carefully designed experiments demonstrate the potential of NMR spectroscopy as an effective tool to monitor water conditions and characterize the pore space in fine-grained sediments.