Sediment Type Research Articles

The Ellrott grab: A small, lightweight sediment sampler for collecting undisturbed sandy sediments

AbstractSampling sandy surface sediments is an important first step in understanding biogeochemical processes in these dynamic environments. However, sampling such sediments poses several challenges, especially when undisturbed samples with porewater are required. Several grab samplers are commercially available, but they are either prone to sample loss, too heavy or bulky for use in small vessels, or those with spring‐loaded mechanisms present safety issues. Here, we present the Ellrott grab, a lightweight sediment sampler designed for collecting undisturbed surface sediments including porewater and overlying bottom seawater. The sampler consists of a frame and a rotating bowl that can collect 370 cm2 of surface sediments up to 10 cm deep (2.5 liters total volume). The instrument is 40 × 60 cm in size, has a basic weight of 10 kg, with up to 20 kg additional weights for stability in sandy sediments. Two persons can operate the grab and it can be used on small boats with a crane and winch system or a hand winch. The grab is now in routine use in the Wadden Sea and in Isfjorden, Svalbard. The samples obtained from the grab were suitable for various geochemical and microbial analyses. Using microelectrodes, we found that in situ oxygen profiles were similar to ex situ profiles in cores subsampled from the grab, confirming that the grab causes minimal disturbance to the sample. Although the grab was designed for collecting sandy sediments, it could also be applied to silty sediments, allowing straightforward and efficient sampling of various sediment types.

Assessment of sediment accumulation inside the harbour basin in the development plan due to longshore sediment transport (LST) rate. A case study of Genaveh port

ABSTRACT In this paper, the hydrographic data, empirical formulas and numerical modelling were used to investigate the longshore sediment transport (LST) rate in the Genaveh port to calculate the sediment accumulation in the harbour basin under the development plan. The Genaveh port is located on the northern coast of the Persian Gulf. Based on the field sediment collection, the type of sediment in this area is fine sand and silty sand. The empirical formulas, LITPACK, and MIKE21-FM were utilised to calculate the LST rate in the region, bathymetric changes in front of the port, and the sediment accumulation in the harbour basin, respectively. The results indicated that the main direction of non-cohesive sediment is from the northwest to the southeast in the region. Moreover, due to the existence of Dareh Gap River, the location of the harbour basin’s mouth is important in reducing sediment accumulation in the harbour basin.

Architectural Characteristics and Distribution Patterns of Gravity Flow Channels in Faulted Lake Basins: A Case Study of the Shahejie Formation in the Banqiao Oilfield, China

Internal depositional architecture and sand body distribution are the main challenges faced in the development of gravity flow channel deposits in China. Despite significant progress in the exploration and development of gravity flow deposits in recent years, our understanding of the internal architecture of composite sand bodies within gravity flow channels is still limited. Gravity flow channels represent a widely developed sedimentary type in the Shahejie Formation of the Banqiao Oilfield, Huanghua Depression. The lack of understanding of the spatial stacking relationship of gravity flow channel sand bodies hinders further development and remaining oil recovery within the oilfield. Through this study, we aimed to dissect the composite channels (5th architectural units) and single channels (4th architectural units) at the study area, using a combination of well logs and seismic data. We explored the identification criteria and spatial distribution characteristics of internal architectural elements within gravity flow channel reservoirs, based on abundant drilling data, well density grids, and 3D seismic data. By identifying and delineating single channels, we were able to summarize six identification criteria for single channels, including relative elevation differences, curve shapes, and the number of interbeds. We obtained the sand body scale and aspect ratio of single channels and established three depositional architectural patterns, i.e., isolated, lateral migration, and vertical accretion, thus revealing the differences in the spatial stacking relationships of sand bodies in different structural locations (blocks). This work provides new insights into the depositional architectural patterns of gravity flow channel deposits in the Banqiao Oilfield, Huanghua Depression.

The orogenic effects on forebulge evolution: A case study from Cenozoic deposits in the Salento Peninsula, Italy

The Salento Peninsula is a part of the larger Apulia Carbonate Platform, one of the carbonate platforms that have developed along the southern margin of the Tethys Ocean since the Triassic, above the Adria microplate. This peninsula represents the culmination of a lithospheric anticline formed due to the subduction of the Adria Plate beneath two mountain belts migrating in opposite directions: the Dinarides-Albanides-Hellenides (DAH) chain, moving from NE to SW, and the southern Apennines (SA) chain, moving from SW to NE. Consequently, the Salento Peninsula represents the foreland sector of these two mountain belts, whose different migration rates, deeply influenced the carbonate sedimentation and paleogeographic evolution of this area over the last 60 Myr. In our study field analysis, a database of 350 wells, and 90 seismic lines calibrated with 3 exploration wells were employed to characterize the physical stratigraphy and depositional setting of the Salento Peninsula and define its paleogeographic evolution during the Paleogene and Neogene. Our results suggest that temporal variations in sedimentation rates and types as well as the reduced thickness (maximum 200 m) of the Cenozoic stratigraphic succession in the internal sectors and both along the Adriatic and Ionian margins of the Salento Peninsula are directly or indirectly linked to the migration rates of the DAH and SA chains. These migration rates played a role in determining changes in subsidence rates, the occurrence of soft-sediment deformation, and the influx of Plio-Pleistocene fine-grained terrigenous sediments, especially along the Ionian margin. Although the investigated succession exhibits a reduced thickness, it comprises several lithostratigraphic units bounded by unconformity surfaces. Within these units, a stack of complete and incomplete simple and composite high- and low-rank depositional sequences has been recognized. Our data suggest that these units are the result of a multifold cyclicity, reflecting the close interaction between eustatic sea-level changes and the tectonic setting of the area.

Relating Geotechnical Sediment Properties and Low Frequency CHIRP Sonar Measurements

Low frequency acoustic methods are a common tool for seabed stratigraphy mapping. Due to the efficiency in seabed mapping compared to geotechnical methods, estimating geotechnical sediment properties from acoustic surveying is attractive for many applications. In this study, co-located geotechnical and geoacoustic measurements of different seabed sediment types in shallow water environments (<5 m of water depth) are analyzed. Acoustic impedance estimated from sediment properties based on laboratory testing of physical samples is compared to acoustic impedance deduced from CHIRP sonar measurements using an inversion approach. Portable free fall penetrometer measurements provided in situ sediment strength. The results show that acoustic impedance values deduced from acoustic data through inversion fall within a range of ±25% of acoustic impedance estimated from porosity and bulk density. The acoustic measurements reflect variations in shallow sediment properties such as porosity and bulk density (~10 cm below seabed surface), even for very soft sediments (su < 3 kPa) and loose sands (~20% relative density). This is a step towards validating the ability of acoustic methods to capture geotechnical properties in the topmost seabed layers.

Underwater Acoustic Propagation using Monterey-Miami Parabolic Equation in Shallow Water Kayeli Bay Buru Distric

Indonesia's geographical position is an advantage compared to other countries, both in terms of geoeconomics, geopolitics and geostrategy. For this reason, it is necessary to develop and use acoustic methods to describe underwater features, carry out underwater communications or to measure oceanographic variables at sea. This research was intended to provide an analytical and visual graphical description with the aim that it can be used for various purposes both in the research, military and other marine fields, as well as to analyze the influence of sediment and different frequencies on acoustic propagation patterns in shallow waters of Kayeli Bay. This research was conducted using CTD data from Kayeli Bay, which is a body of water in Buru Regency, Maluku Province and is located between 3° 15' 55'' – 3° 22' 50" S and 127° 01'35" – 127° 01' 35 "E, using the Monterey-Miami parabolic equation method using 4 types of sediment and 3 different frequencies as model input. From the results of this research it can be concluded that the propagation of sound waves in shallow seas is greatly influenced by the type of sediment and frequenty used. Changes in acoustic impedance at the bottom of the water and within the water column can significantly influence the behavior of acoustic waves in shallow water environments, and accurate acoustic impedance data are critical for effective ray tracing modelling.

Invertebrate diversity associated with a shallow rhodolith bed in the Mediterranean Sea (Mar Piccolo of Taranto, south‐east Italy)

Abstract Rhodoliths, formed by free‐living coralline algae, are distributed worldwide, and the rhodolith beds (RBs) that they form are recognized as structurally complex habitats. In the Mediterranean, they are generally distributed in the mesophotic zone, at depths of 30–100 m; so far, only a few shallow RBs (<2 m) have been reported (e.g. Îles Kuriat, Tunisia, and Stagnone Marsala, Italy). Here a shallow‐water RB located in the Mar Piccolo of Taranto (south‐eastern Italy, Mediterranean Sea) is described. The diversity of associated invertebrates, the rhodolith‐forming algal species, the type of sediments, and the bed extent are characterized. The RB investigated extends over 5 ha at depths of 0.5–1.5 m. The rhodoliths vary in shape and size, from pralines to large spherical structures, and are formed by a single species, Neogoniolithon brassica‐florida, growing around nuclei of both natural and anthropogenic origin. The associated fauna consisted of 158 taxa, 79 (50%) of which were new basin records. The associated diversity was approximately twice that of the underlying and nearby sediments. The structural complexity of the RBs promotes biodiversity and provides shelter, food, and a breeding ground for numerous species, including seahorses, which are a conservation priority in this basin.

Microplastic in Beach Sediment of Nasi Island, Aceh Besar Regency, Indonesia

Microplastic might be a small size of plastic that is directly released into the environment or the result of larger in size of plastic degradations. The presence and effect of microplastic have been reported globally. However, the existence of microplastic trapped in beach sediment of Nasi Island is limited. This research was conducted to analyse the type of sediment, abundance and type of microplastic polymer found in beach sediments in Nasi Island, Aceh Besar Regency, Aceh Province, Indonesia. Sampling was carried out in April 2022 at Nipah Beach and Alue Riyeung Beach in Nasi Island, Aceh Besar Regency. Sediment type was analysed by dry sieve method, using a stratified sieve shaker while the observation of microplastic and its polymer were identified by microscope and Fourier Transform Infrared Spectroscopy (FTIR), respectively. The results showed that the types of sediment at both beaches belonged to the sand type. There were three types of microplastics found, namely fragments, films, and fibres. The highest abundance of microplastics was found in a 0.063mm filter at Nipah Beach with an amount of 2651 Particles/Kg while the lowest was found in a 0.125mm filter with an amount of 8 Particles/Kg at Alue Riyeung Beach. As the polymer types, it is found that fragment type microplastics are likely to have PETE (Polyethylene Terephthalate) polymers, film type microplastics are likely to have PS (Polystyrene) polymer types and Fibre microplastics are likely to have LDPE (Low-Density Polyethylene) polymers.

Dense Neural Network for Classification of Seafloor Sediment using Backscatter Mosaic Feature

Water transportation plays a vital role in global economic activities, facilitating more than 85% of international trade and serving as a cost-effective and essential means to fulfill the demand for goods and services. Similarly, the Benoa Port, situated in the southern part of Denpasar City, operates in the same manner. By utilizing Multibeam Echo Sounder (MBES) backscatter data, backscatter mosaics can be generated to identify various seafloor sediment types, which consist of rock fragments, minerals, and organic materials. The characteristics of these sediments, such as grain size, density, composition, and others, can be observed. To improve the classification of sediments, the integration of backscatter data and backscatter features, such as ASM (Angular Second Moment), Energy, Contrast, and Correlation, can be employed. Supervised classification models like Dense Neural Network (DNN) can be utilized to accurately determine the types of seafloor sediments. The application of DNN modeling resulted in a training accuracy rate of 88% and a testing accuracy rate of 100%. The accuracy results delineated six distinct sediment types. Notably, sandy silt exhibited the highest distribution, accounting for 49.30%, whereas soft clayey silt registered the lowest distribution at 0.53%, as determined by their respective spatial prevalence.

Fluvioglacial deposits in large lakes and inland seas of the eastern periphery of the Baltic Shield: formation peculiarities, lithological features and place in the palaeogeography of the Late Pleistocene-Holocene in the Northwest European part of Russia

In the report, on the basis of studies of the Quaternary cover of the Ladoga and Onega lakes and the White Sea carried out in the last decade, the question of the peculiarities of the formation of the first glacial lakes on the eastern periphery of the Baltic crystalline shield, the time of their deposition, and the peculiarities of sedimentogenesis is discussed. It is concluded that sediments of a specific type of sedimentation, which are formed everywhere in inland basins (seas and lakes) can be identified as a glacial-water formation specific to the glacial regions of the Earth.

Limno-glacial deposits: Sources of sediments and processes of sedimentation

The article presents the theoretical postulates of limno-glacial type of sedimentation and examines its features on the example of the Onego Ice Lake.

Recent near-shore ostracod fauna of the Caspian Sea

The work is based on the E.A.Gofman’s collection of recent ostracods. Here we present summarized data on our results of studying 45 near-shore sampling sites and previously published data, which were the first one to investigate the distribution of recent ostracods in the Caspian Sea and to discuss the influence of such factors as bottom sediments type, water temperature and salinity. Overall, distribution of the ostracods in the Caspian Sea shows a remarkable depth control. The near-shore ostracod assemblage of the Caspian Sea indicates shallow water conditions. Predominant species tolerates temperature and salinity seasonal changes. In northern area assemblage is dominated by Cyprideis torosa and contains abundant euryhaline species tolerant to reduced salinity ranges reflecting the river influence, significant temperature changes and unstable hydrological regime. In the Central and Southern Caspian Sea, the assemblage is mostly represented by the Tyrrhenocythere amnicola donetziensis and other stenohaline species. The analysis of the recent near-shore ostracods of the Caspian Sea allows to conclude that salinity, along with water depth, are the leading factors determining the composition of ostracod assemblages.

Bedforms and sediment dynamics under reduced sediment input and estuarine engineering: the case of the Bou Regreg estuary, Morocco

The Bou Regreg riverine estuary constitutes a microtidal environment located within an urban region and characterized by limited sediment inflow from its catch basin hinterlands. The construction of the Sidi Mohamed Ben Abdellah (SMBA) dam has notably diminished sediment supply, especially coarser fractions. In light of these conditions, this study aimed to classify sediment types according to the Folk and Ward classification, stratify morphometric parameters and temporal fluctuations based on dune types, and ultimately evaluate the sediment dynamics driving observed bedform variations. Using an integrated approach, data collection involved various techniques, including CTD profiling, bottom videography, side-scan sonar imaging, sub-bottom profiling, and Van Veen bottom grab sampling. The bed morphology includes segments of smooth bed, erosional and dredged bottom, localized scour features, and submarine dune fields, displaying notable heterogeneity. Acoustic seabed reflections indicated two bedform clusters with maximum lengths of 42.6 m and heights of 1 m. Flow velocities were linked to the presence of 2D and 3D dune forms. Morphological variations encompassed straight, sinuous, and barchan dune configurations, mainly asymmetric with NNW–SSE seaward orientation. Sediment mean size fluctuations spanned from muddy to medium sand deposition. The findings revealed the intricate interplay of dynamics shaping dune field configurations and the heterogeneous dispersion of bedforms throughout the estuary likely due to a sharp decline of sediment discharge caused by the dam upstream and coastal engineering. The study emphasizes the dynamic nature of dunes, highlighting their sensitivity to shifting hydrodynamic conditions and sediment availability, leading to morphological fluctuations over time.

Multitemporal Acoustic Backscatter Data Analysis to Monitor the Dynamics of Seabed Surface Sediments

Backscatter strength is a product of underwater acoustic remote sensing. This study used a multibeam echosounder as an acoustic remote sensing instrument to collect backscatter strength data. These data are then used to classify the surficial sediment distribution. To monitor the difference in seabed sediment distribution, a time-series survey was performed to obtain multitemporal acoustic backscatter data. An EM 304 multibeam system from Kongsberg was mounted on the Research Vessel Baruna Jaya III from the Indonesia National Research and Innovation Agency (BRIN). It was used to collect backscatter data in the waters of Raja Ampat, Indonesia. The data were collected at different times, April and July 2021. Geometric and radiometric corrections were applied to these backscatter data. Based on the angular response curve analysis from acoustic backscatter strength, the research area can be classified into four seabed sediment types: boulder, gravel, sand, and mud. A comparison of both time series backscatter data shows that the boulder and gravel areas increased by 13.6% and 19.0%, respectively. Elsewhere, the area with sediment types of sand and mud diminished by 30.5% and 2.0%. The change in the sediment type area occurred as much as 50.5%, while the remaining 49.5% area remained unchanged. This resulting value is apparently derived from the steep topography that rapidly changes sediment distribution. One such suggestion is that sediment sampling should be performed to confirm the model from angular response curve analysis.

Multitemporal Acoustic Backscatter Data Analysis to Monitor the Dynamics of Seabed Surface Sediments

Backscatter strength is a product of underwater acoustic remote sensing. This study used a multibeam echosounder as an acoustic remote sensing instrument to collect backscatter strength data. These data are then used to classify the surficial sediment distribution. To monitor the difference in seabed sediment distribution, a time-series survey was performed to obtain multitemporal acoustic backscatter data. An EM 304 multibeam system from Kongsberg was mounted on the Research Vessel Baruna Jaya III from the Indonesia National Research and Innovation Agency (BRIN). It was used to collect backscatter data in the waters of Raja Ampat, Indonesia. The data were collected at different times, April and July 2021. Geometric and radiometric corrections were applied to these backscatter data. Based on the angular response curve analysis from acoustic backscatter strength, the research area can be classified into four seabed sediment types: boulder, gravel, sand, and mud. A comparison of both time series backscatter data shows that the boulder and gravel areas increased by 13.6% and 19.0%, respectively. Elsewhere, the area with sediment types of sand and mud diminished by 30.5% and 2.0%. The change in the sediment type area occurred as much as 50.5%, while the remaining 49.5% area remained unchanged. This resulting value is apparently derived from the steep topography that rapidly changes sediment distribution. One such suggestion is that sediment sampling should be performed to confirm the model from angular response curve analysis.

Study of Mg–Fe content in tourmalines from the dravite–schorl series by Raman spectroscopy

AbstractThanks to their high chemical and mechanical stability, their diffusion in all types of detrital sediments and their complex structural formula (XY3Z6(T6O18)(BO3)3V3W), tourmalines have attracted strong interest in provenance studies since, from their chemical composition, it is possible to reconstruct the source rocks in ancient sediments. Dravite and schorl, belonging to the alkali subgroup 1, are the most abundant tourmaline species, and they have different Y‐site compositions in the unit cell: dravite has more magnesium, while schorl has a higher iron content. For this reason, it is important to measure the Mg–Fe relative content in order to classify the analysed tourmalines in the dravite–schorl series. Raman spectroscopy is a suitable technique as it allows quick and easy measurements that provide chemical and structural information on tourmalines with a high spatial resolution, thus allowing analysis of small grains that could be found in sediments. In this work, we correlated the relative Mg–Fe content (x = Mg/(Mg + Fe)) in different tourmaline samples from the dravite–schorl series ( ) with variations in Raman spectrum parameters in order to find a model for quick tourmaline identification useful for provenance studies. The chemical compositions of the analysed tourmalines are obtained by scanning electron microscope coupled with energy‐dispersive spectroscopy (SEM‐EDS). Raman measurements with a portable spectrometer have also been performed in order to evaluate our results for in situ applications.

Variability in sediment particle size, mineralogy, and Fe mode of occurrence across dust-source inland drainage basins: the case of the lower Drâa Valley, Morocco

Abstract. The effects of desert dust upon climate and ecosystems depend strongly on its particle size and size-resolved mineralogical composition. However, there is very limited quantitative knowledge on the particle size and composition of the parent sediments along with their variability within dust-source regions, particularly in dust emission hotspots. The lower Drâa Valley, an inland drainage basin and dust hotspot region located in the Moroccan Sahara, was chosen for a comprehensive analysis of sediment particle size and mineralogy. Different sediment type samples (n= 42) were collected, including paleo-sediments, paved surfaces, crusts, and dunes, and analysed for particle-size distribution (minimally and fully dispersed samples) and mineralogy. Furthermore, Fe sequential wet extraction was carried out to characterise the modes of occurrence of Fe, including Fe in Fe (oxyhydr)oxides, mainly from goethite and hematite, which are key to dust radiative effects; the poorly crystalline pool of Fe (readily exchangeable ionic Fe and Fe in nano-Fe oxides), relevant to dust impacts upon ocean biogeochemistry; and structural Fe. Results yield a conceptual model where both particle size and mineralogy are segregated by transport and deposition of sediments during runoff of water across the basin and by the precipitation of salts, which causes a sedimentary fractionation. The proportion of coarser particles enriched in quartz is higher in the highlands, while that of finer particles rich in clay, carbonates, and Fe oxides is higher in the lowland dust emission hotspots. There, when water ponds and evaporates, secondary carbonates and salts precipitate, and the clays are enriched in readily exchangeable ionic Fe, due to sorption of dissolved Fe by illite. The results differ from currently available mineralogical atlases and highlight the need for observationally constrained global high-resolution mineralogical data for mineral-speciated dust modelling. The dataset obtained represents an important resource for future evaluation of surface mineralogy retrievals from spaceborne spectroscopy.

Morphological Features of Mosquito Larvicidal Bacillus Thuringiensis Isolated From Soil Samples of Nepal

Anopheles, Culex, and Aedes spp are the main vectors for transmitting malaria, Japanese encephalitis, lymphatics filariasis, dengue, zika, chikungunya, etc. Mosquito-borne diseases are increasing especially dengue in Nepal. Additional tools are required to decrease the disease rate. Biological control tools like Gambusia fish, Cyclopods, Bacillus thuringiensis, etc., have not been adopted and are unavailable in Nepal. The research aims to isolate mosquitocidal Bacillus thuringiensis a biological control tool from the soil samples of Nepal. Bacillus thuringiensis (Bt) was isolated from the soil samples of Nepal by the acetate selection method. The larvicidal bioassay of Bt was studied against the field-collected mosquito larvae. The isolate showing larvicidal activity was coded as Bacillus thuringiensis -14P2A (Bt-14P2A). The growth pattern of the positive control strain Bacillus thuringiensis var israelensis (Bti-IPS-82) and the test strain were studied in different types of culture media. The microscopic morphology was studied by using different staining techniques. Bt-14P2A and Bti -IPS-82 caused 100% mortality of field-collected larvae. Both the strains showed the same type of colony morphology in a standard culture media and uniform turbidity with sedimentation type of growth pattern in broth media. The strains were Gram-positive single rod-shaped of size 1.2X4.8µm in both negatively stained slides and Gram-stained slides. A slight difference in the endospore location was terminal in Bti-IPS-82 and subterminal in Bt-14P2A. The newly isolated Bt-14P2A differs from Bti-IPS-82 in arrangement and endospore location but harbors the same morphological characteristic and larvicidal activity as the positive control strain.

Assessment of Sediment Grain Size and Its Correlation with Microplastic Accumulation and Characteristics in the Kahayan River, Indonesia

The purpose of our research was to investigate the relationship between sediment grain size and the accumulation and characteristics of microplastics in the Kahayan River, Indonesia. The average abundance of microplastic in sediment was 7.3 ± 4.3 n/kg dry weight. The result showed a significant difference between predominant sediment grain size and microplastic occurrence in sediment. Moreover, sediment types of very coarse sand (1–2 mm), coarse sand (0.5–1 mm), and fine sand (0.1–0.2 mm) showed a significant and strong correlation with microplastic abundance. Predominant sediment grain size and microplastic shape (fragment, fiber) or size of >1000 µm also have a significant and strong correlation.

Reduction of the toxin microcystin-LR with different types of sediments

Microcystis aeruginosa blooms in water bodies, evidencing a high risk of exposure to human health due to the release of toxins, which affects water quality. Implementing physical, chemical, and microbial control methods requires an integrated understanding of cyanotoxin dynamics, especially their relationship with sediments. Consequently, sediment obtained from three stations of the Riogrande II reservoir (Antioquia, Colombia) was analyzed to determine the adsorption and removal capacity of the microcystin-LR (MC-LR). For this purpose, the sediment was subjected to different treatments to select the one with the highest MC-LR removal capacity. Furthermore, the effectiveness and stability of adsorption removal process were evaluated by analyzing mechanical processes such as aeration, sonication, and agitation. The dried sediment showed the highest reduction in toxin concentration (93%) after 24 h, followed by washed sediment (91%) and sterilized sediment (81%).On the other hand, the sediment was fractionated into silts and clays; the latter was the least effective. Finally, the fine and half silts were better adsorbents of the toxin, acting similarly over time. Initially, the utilization of sediment that has been dried by sunlight could be a complementary alternative to reinforce MC-LR control methodologies in water bodies.On the one hand, MC-LR desorption assays showed that aeration of the sediment for 30 min caused a release of up to 96% of the adsorbed compound. At the same time, the effect of sonication and agitation was less intense. However, the absorption process must be fast to avoid efficiency losses due to desorption since a high percentage of the toxin was spontaneously desorbed from the sediment in two days.