Sedimentological analysis

The town of Como (N Italy) was founded in 59 BC on the shores of the homonymous lake. Its present-day environmental setting derives from the interactions between lacustrine, alluvial and human dynamics. The lake coastline moved through time because of alluvial progradation, town expansion and land reclamation. Since 1700 AD, more than 200 m of land reclamation towards the North are observed from historical maps of the study area. The harbor is a strategic infrastructure for a coastal town and its localization is a critical issue. Archaeological evidence found in the Como urban area points to a different position of the harbor during the Roman period and the Middle Ages; presently, those areas are buried below several meters of sediments due to land subsidence and the artificial filling of coastal areas. The results of a geoarchaeological study aimed at understanding the evolution of the coastal area are presented here. Adopted methodolo-gies include the collection of available archa...

This study examines the grain size distribution and sediment properties of sediments collected from Bayelsa State's Clough Creek in Nigeria's lower Niger Delta.Sediment cores were taken using a percussion drilling rig at intervals of 0.75 meters from 0 to 30 meters. Dry sieve methods was used in accordance with ASTM D422 guidelines, and only samples with a sizable sand content were chosen for grain size examination. A total of 12 sand-rich samples were analyzed from BH1 (4.5m, 12m, 21m), BH2 (4.5m, 12m), BH3 (12m, 21, 24 m), and BH4 (4.5m, 12m, 21m, 24m).The findings indicate that the sediments are primarily very coarse to coarse sand, with mean grain sizes ranging from 0.13 to 0.50 φ. This suggests that the sediments were deposited in moderate to high-energy settings, such as active tidal channels.The sediments were classified as very well sorted to well sorted based on the sorting values (σi), which varied from 0.14 to 0.38 φ. This suggests that the sediment supply and transport energy were consistent over the majority of the sampling depths. Most samples were fine-skewed, with skewness values (Sk) ranging from -0.12 to +0.67, indicating a minor dominance of finer particles and a decrease in flow energy, a coarse-skewed (-0.12) was noticed on a sample from BH4 (4.5 m) which probably indicates a high-energy entry point or closeness to a more erosive zone. Broad grain size distributions and varied depositional energy conditions, characteristic of tidally influenced settings, were indicated by the typically low kurtosis (Kg) values, which ranged from 0.00 to 0.20, placing them in the platykurtic to highly platykurtic categories. Grain size metrics vary both vertically and laterally between boreholes, indicating the interaction of tidal, fluvial, and estuarine processes that shaped Clough Creek's sedimentary structure. The investigation comes to the conclusion that the creek's sediments were deposited in an active and dynamic environment, with texture and grain size distribution being influenced by localized variations in flow regimes. These results provide important information about the movements of sediment in Niger Delta creek systems and set a baseline particle size profile for Clough Creek.

The vast extend of sedimentation deposits making up the Grès Armoricain and its equivalents over the north Gondwana domain is used in this study to test the hypothesis of continuity betwen the Armorica and Gondwana plates during the Early Ordovician. The distribution of continental and marine environments, the large volume of transported clastic material, and the consistent current directions all indicate that the source of sediment supply on the north Gondwanan margin was to the south of the Sahara. Although there were local signs of incipient rifting between the two plates, Armorica was not yet detached from Gondwana by Arenigian time.

Goda Buticha is a cave site near Dire Dawa in southeastern Ethiopia that contains an archaeological sequence sampling the late Pleistocene and Holocene of the region. The sedimentary sequence displays complex cultural, chronological and sedimentological histories that seem incongruent with one another. A first set of radiocarbon ages suggested a long sedimentological gap from the end of Marine Isotopic Stage (MIS) 3 to the mid-Holocene. Macroscopic observations suggest that the main sedimentological change does not coincide with the chronostratigraphic hiatus. The cultural sequence shows technological continuity with a late persistence of artifacts that are usually attributed to the Middle Stone Age into the younger parts of the stratigraphic sequence, yet become increasingly associated with lithic artifacts typically related to the Later Stone Age. While not a unique case, this combination of features is unusual in the Horn of Africa. In order to evaluate the possible implications ...

The town of Como (N Italy) was founded in 59 BC on the shores of the homonymous lake. Its present-day environmental setting derives from the interactions between lacustrine, alluvial and human dynamics. The lake coastline moved through time because of alluvial progradation, town expansion and land reclamation. Since 1700 AD, more than 200 m of land reclamation towards the North are observed from historical maps of the study area. The harbor is a strategic infrastructure for a coastal town and its localization is a critical issue. Archaeological evidence found in the Como urban area points to a different position of the harbor during the Roman period and the Middle Ages; presently, those areas are buried below several meters of sediments due to land subsidence and the artificial filling of coastal areas. The results of a geoarchaeological study aimed at understanding the evolution of the coastal area are presented here. Adopted methodolo-gies include the collection of available archa...

Present study is aimed at assessment of Bholari river sand for its geotechnical characterization and suitability as fine aggregate which is being quarried in Jamshoro district, Sindh, Pakistan. For this purpose, sand samples (n=11) were collected from quarry sites and main river channel. Physical properties reveal that Bholari sand is mainly coarse to fine in size (0.2 mm-5 mm). Average values of fineness modulus, specific gravity, bulk density and void content of collected samples are 2.58, 2.56, 1659.90 kg/m 3 and 35.12% respectively which varied within the corresponding permissible ranges of ACI (American Concrete Institute). Carbonate content of about 57.59% is also in agreement with corresponding range for fine aggregate. Petrographic examination revealed that Bholari River sand mainly comprises of quartz and rock fragments with subordinate limestone fragments. As per classification of Dott (1964), Bholari sand is lithic arenite where quartz (50%) occurs as main mineral followed by rock fragments (30%), feldspars (15%) and other opaque minerals (5%). Texturally, the sediments are angular (77%) to sub-round (33%). All these physical properties lie within the range set by National Highway Authority (NHA) and American Standard of Testing Material (ASTM). It is concluded that Bholari River sand is suitable for use in concrete mixed with cement and asphalt.

International audienceAfter Soltanian a major erosive stage shaped the morphology of the lower valley of the Tamri wadi (Atlantic diet wadi halfway between Agadir and Essaouira-South Western Morocco) eroding much of soltaniens deposits. During the Holocene, the lower valley of the Tamri wadi was invaded again by alluvial and colluvial materials from the watershed and Realignment soltaniens sediments. The Holocene wadi bottom Tamri is in the form of stepped alluvial terraces or nested below the main terrace Soltanian Pylon. From the village of Tamri, Tamri wadi is bordered by a system of Holocene terraces more or less well developed. One tributary alluvial terrace in the Ighzer Ougadir. According to their morphological device in the lower valley, the Holocene terraces morphosedimentary have 3 levels: a J. Mater. Environ. Sci. 7 (10) (2016) 3699-3710 RQM8_Nador_2015 El Ouahidi et al. ISSN : 2028-2508 CODEN: JMESCN 3698 terrace is the top level (the main terrace of the village of Tamri...

This research addresses paleoclimatic variations using sedimentological, geochemical, and planktic foraminifera. The study was carried out in a survey core (ANP 1011) collected on the continental slope of the Icaraí Sub-basin (Ceará Basin), on the coast of the Municipality of Itapipoca, CE, Brazil. Particle size analysis, CaCO3 content, Ti/Ca and Fe/Ca ratios, and the analysis of foraminifera associations for biostratigraphic purposes were performed. Based on the relative abundance of planktic foraminifera, with indicators of warm and cold water throughout the studied cores, two biozones (Y: Upper Pleistocene and Z: Holocene), and two subzones (Z2 and Z1) were recognized. The data of sedimentological markers obtained confirmed the occurrence of more wet phases in northeastern Brazil during the early stages of the Holocene. The Ti/Ca and Fe/Ca ratios, as well as the geochemical and micropaleontological proxies, indicated a farther north displacement of the Intertropical Convergence Z...

Goda Buticha is a cave site near Dire Dawa in southeastern Ethiopia that contains an archaeological sequence sampling the late Pleistocene and Holocene of the region. The sedimentary sequence displays complex cultural, chronological and sedimentological histories that seem incongruent with one another. A first set of radiocarbon ages suggested a long sedimentological gap from the end of Marine Isotopic Stage (MIS) 3 to the mid-Holocene. Macroscopic observations suggest that the main sedimentological change does not coincide with the chronostratigraphic hiatus. The cultural sequence shows technological continuity with a late persistence of artifacts that are usually attributed to the Middle Stone Age into the younger parts of the stratigraphic sequence, yet become increasingly associated with lithic artifacts typically related to the Later Stone Age. While not a unique case, this combination of features is unusual in the Horn of Africa. In order to evaluate the possible implications ...

The sedimentology and geochemistry of the major oxides and trace elements of DF-2 well, Onshore, Niger Delta, are presented in this study. The study is aimed at describing the sedimentological characteristics as well as using the major oxides and trace elements to investigate the provenance, tectonic history and palaeo-depositional conditions of the well. Selected samples were investigated with fused bead X-Ray Fluorescence (XRF) spectrometry to determine their major oxides and fused bead laser ablation inductively couple plasma mass spectroscopy (LA-ICP-MS) for their trace elements. Sedimentological analysis from the well shows that the lithology ranged from shaly sand, sandy shale, sandstone and shale. The results show the dominance of silicon oxide (SiO 2) contents which ranges from 81.1 to 91.4 wt. % (average of 87.1 wt. %). The low average concentration of Cr<150 ppm and Ni <100 ppm, the ratios of Th/Sc, Th/Co, Th/Cr, Cr/Th, La/Sc, as well as the plots of Th/Co versus La/Sc and TiO 2 versus Zr, all infer a felsic source rock. The discrimination plots of ratioK 2 O/Na 2 O against SiO 2 and Log K 2 O/Na 2 O against Log SiO 2 /Al 2 O 3 indicated passive continental margin. Various chemical classifications of the sediments show that the sandstone facies plotted mainly in quartzarenite, sublitharenite and Fe-rich sand domains. The samples were deposited under oxic environment based on the average values of U/Th (0.26 ppm), Ni/Co (2.79 ppm) and Cu/Zn (1.81ppm) and bivariate plot of Ni/Co versus V/Cr. However, the bivariate plot of Ni/Co versus V/ (V+Ni) specifies oxic to anoxic conditions and V/Vi + Ni ratios indicate oxic, suboxic to euxinicpalaeode positional environments for the sediments. Geochemical characterization illustrates mixed marine and terrigenous source input, deposited mainly in semi humid/humid climate. The positive values attained from ratios of Al 2 O 3 /(CaO+MgO+Na 2 O+K 2 O) infers mineralogical maturity based on stable mobile oxides content in the studied samples.

In this research, we try to study the sedimentary characteristics and the trend of textural changes in the sediments of the Jajrood River from upstream to downstream at the point of junction to Latiyan dam. Based on the textural changes of sediments along the path from the upstream in the Garmabdar area to the downstream to the Latiyan Dam, the Jajrood River is divided into four A, B, C and D basins. Twenty sediment samples were collected and all sieved by dry and wet method also the specimens were morphoscopically studied. Data from field and laboratory phases were combined and interpreted using reliable scientific sources and finally a detailed summary was obtained regarding sedimentology of the study area. Mineralogically, the sediment type of the river is a clastic carbonate sedimentary type with fragments ranging from 30 to 58 percent and rock fragments between 25 to 50 percent abundance. Other minerals, such as feldspar minerals, account for about 1 to 4 percent, quartz 5 to 10 percent, and opauqe minerals from 1 to 5 percent. Examination of the average particle size in the A to D basins shows that decreasing trend of sediment size from the A to C basin occurs and reverses in the D basin. In the first three basins, the sorting grade of the river sediments is very bad and in the last basin it has become extremely bad. The amount of kurtosis of the particle distribution curve from upstream to downstream of the river is generally increasing trend. Textural changes along the river do not follow natural conditions due to the influence of various natural factors such as the entry of distributary into the main River, and phenomena such as landslide and rock collapses and debris flows, especially during floods along the riverbank.

Ten samples from Odi River bed were collected by divers at different locations and sent to the laboratory for granulometric analysis. Samples were dried to remove moisture content and poured into a set of BSS standard sieves and mechanically vibrated for at least fifteen minutes to enable the grains to separate into their different sizes. Textural and statistical parameters were then calculated from the results of the particle size distribution. The result shows that the grain size ranges from -2 φ – -1 φ (granules) to 3 φ – 4 φ (very fine sand). The average mean of the population is 0.89 φ, with a modal class in the 1 φ – 2 φ size grade. The average sorting value is 1.26 σ which indicates a poorly sorted population. Skewness varies through the population, but, the average skewness is -0.16 (Negatively skewed). 60% of the sediments range from leptokurtic to extremely leptokurtic, 10% are very platykurtic, 10% are platykurtic and 20% are mesokurtic. Traction and saltation transport m...

The town of Como (N Italy) was founded in 59 BC on the shores of the homonymous lake. Its present-day environmental setting derives from the interactions between lacustrine, alluvial and human dynamics. The lake coastline moved through time because of alluvial progradation, town expansion and land reclamation. Since 1700 AD, more than 200 m of land reclamation towards the North are observed from historical maps of the study area. The harbor is a strategic infrastructure for a coastal town and its localization is a critical issue. Archaeological evidence found in the Como urban area points to a different position of the harbor during the Roman period and the Middle Ages; presently, those areas are buried below several meters of sediments due to land subsidence and the artificial filling of coastal areas. The results of a geoarchaeological study aimed at understanding the evolution of the coastal area are presented here. Adopted methodolo-gies include the collection of available archa...

This study determines the geochemical and depositional environment analysis of the sediments of the Sohnari Member of the Laki Formation, Northern Kirthar Fold Belt of Pakistan. The Energy-Dispersive-X-Ray Spectroscopy (EDS) technique is used for the detection of major elements and the effects of shifting depositional climatic conditions of six representative samples which were acquired from the Sohnari Member of the Laki Formation at Lakhra area, Sindh, Pakistan. The sedimentological studies clarify that the sediments the Sonahri Member are relatively immature and most migrated in clastic mode. The availability of Silica shows that the Member was formed due to biochemical precipitation and detrital mode and was deposited at a fast rate of sediment deposition under the fluvio-deltaic depositional system. This is also deduced that the rapid rate of sediment deposition might be created a reducing atmosphere and allowing for the mineralization of sulphur.

This study determines the geochemical and depositional environment analysis of the sediments of the Sohnari Member of the Laki Formation, Northern Kirthar Fold Belt of Pakistan. The Energy-Dispersive-X-Ray Spectroscopy (EDS) technique is used for the detection of major elements and the effects of shifting depositional climatic conditions of six representative samples which were acquired from the Sohnari Member of the Laki Formation at Lakhra area, Sindh, Pakistan. The sedimentological studies clarify that the sediments the Sonahri Member are relatively immature and most migrated in clastic mode. The availability of Silica shows that the Member was formed due to biochemical precipitation and detrital mode and was deposited at a fast rate of sediment deposition under the fluvio-deltaic depositional system. This is also deduced that the rapid rate of sediment deposition might be created a reducing atmosphere and allowing for the mineralization of sulphur.

Twenty four samples of the Bara formation from east and west sections of Lakhra areas have been investigated, to interpret the environments of deposition and to propose a suitable classification for the sandstones present in the studied sediments. Values of different statistical parameters of the studied sediments grain size data, for example mean, median; standard deviation, skewness, and kurtosis were determined for plotting the cumulative curves and histograms to analyse the data. Study of the shapes, roundness and the sphericity of the grains provided valuable information regarding the environment of deposition. The 92 percentage negative and 8 percentage positive values of skewness, respectively, indicated that the studied sediments are composed of coarse grained-fine grained sediments and deposited under the high-low energy conditions of fluviatile and beach environments. The presence of abundant amounts of Quartz and SiO 2 in the bulk-rock samples also suggested fluviatile/beach environments. The inclusive graphic standard deviation diagrams and the size distribution data also indicated that fine-medium grained sediments, were deposited in the study areas. Occurrence of three groups of sediments for example, sediments from lower lagoon; sediments from upper lagoon and river; and the sediments from the deadend marsh channels from the deeper parts of the basin of deposition, have been recognized. The kurtosis values indicated that studied sediments are composed of Platykurtic, Leptokurtic and Mesokurtic groups of sediments. The sandstones, present in the Bara formation of the Lakhra west and the east areas, showed the textural maturity, therefore, have been classified as sub-mature, and sub-mature to mature sandstones, respectively.

PLANKTONIC FORAMINIFERA BIOSTRATIGRAPHIC ANALYSIS OF FOUR CORES FROM THE ALMIRANTE CÂMARA LOBE COMPLEX, CAMPOS BASIN. The Almirante Câmara lobe complex is located in the northeastern Campos Basin, at the southeastern Brazilian continental margin. This complex is an excellent analogue to the Carapebus Formation, where are the major hydrocarbon reserves from the post-salt interval of this basin. The objective of this work is to contribute to the existing knowledge of this lobe complex through micropaleontological analysis based on planktonic foraminifers from four piston cores, aiming to estimate the age of the sand beds deposition and to propose a hypothesis for the difference among the biozones present in each core and their expected thickness. A total of 39 samples were collected from the piston cores, prepared according to the standard methodology for Quaternary calcareous microfossils, and about 300 tests of planktonic foraminifers were taxonomically identified per sample. In the piston cores LAC 18, LAC 22 and LAC 23 were recognized the Biozone Z and the subzones Y1A and Y1B. In the piston core LAC 19 were identified the Biozone Z, the Subzone Y1 and an indication of the presence of the Biozone X at the base of the piston core. The presence of the Biozone X was not expected in the piston core LAC 19, since it is only 1.23 m long and seismic analysis done by previous works indicated that, at the site where it was collected, the thickness of the Biozone Y should be between 10 m and 20 m. Two hypothesis are considered for this difference. The first is erosion caused by the proximity of this piston core with one of the main deposition channels of the lobes. Other possibility is that of erosion caused by high-energy deep water currents, especially during the Last Glacial Maximum.

Ten samples from Odi River bed were collected by divers at different locations and sent to the laboratory for granulometric analysis. Samples were dried to remove moisture content and poured into a set of BSS standard sieves and mechanically vibrated for at least fifteen minutes to enable the grains to separate into their different sizes. Textural and statistical parameters were then calculated from the results of the particle size distribution. The result shows that the grain size ranges from -2 φ – -1 φ (granules) to 3 φ – 4 φ (very fine sand). The average mean of the population is 0.89 φ, with a modal class in the 1 φ – 2 φ size grade. The average sorting value is 1.26 σ which indicates a poorly sorted population. Skewness varies through the population, but, the average skewness is -0.16 (Negatively skewed). 60% of the sediments range from leptokurtic to extremely leptokurtic, 10% are very platykurtic, 10% are platykurtic and 20% are mesokurtic. Traction and saltation transport m...

This research addresses paleoclimatic variations using sedimentological, geochemical, and planktic foraminifera. The study was carried out in a survey core (ANP 1011) collected on the continental slope of the Icaraí Sub-basin (Ceará Basin), on the coast of the Municipality of Itapipoca, CE, Brazil. Particle size analysis, CaCO3 content, Ti/Ca and Fe/Ca ratios, and the analysis of foraminifera associations for biostratigraphic purposes were performed. Based on the relative abundance of planktic foraminifera, with indicators of warm and cold water throughout the studied cores, two biozones (Y: Upper Pleistocene and Z: Holocene), and two subzones (Z2 and Z1) were recognized. The data of sedimentological markers obtained confirmed the occurrence of more wet phases in northeastern Brazil during the early stages of the Holocene. The Ti/Ca and Fe/Ca ratios, as well as the geochemical and micropaleontological proxies, indicated a farther north displacement of the Intertropical Convergence Z...

Detailed studies of lithologic successions of upper sands of Lower Goru Formation in the subsurface of X Field of Sindh monocline were investigated by Zoom Stereo Binocular examination and thin section study of well cuttings in conjunction with the wireline log and core analysis to understand the depositional environment. The sedimentological studies of the well cuttings samples of each of the main bodies resolved into various lithofacies based on their textural signatures (Grain size, shape, and sorting) wireline log and core analysis. Within A, B and C-sand distinct coarsening and fining upward sequences have been identified which reflect frequent sea level fluctuations. Textural investigations, particularly of those samples composed predominantly of sand size fractions, show that the mean grain size in studied field is fine to medium grained and range between 1.8φ and 2.5φ. The samples are moderate to well sorted and well rounded to sub-angular in shape. Mineralogically, the samp...

This research addresses paleoclimatic variations using sedimentological, geochemical, and planktic foraminifera. The study was carried out in a survey core (ANP 1011) collected on the continental slope of the Icaraí Sub-basin (Ceará Basin), on the coast of the Municipality of Itapipoca, CE, Brazil. Particle size analysis, CaCO 3 content, Ti/Ca and Fe/Ca ratios, and the analysis of foraminifera associations for biostratigraphic purposes were performed. Based on the relative abundance of planktic foraminifera, with indicators of warm and cold water throughout the studied cores, two biozones (Y: Upper Pleistocene and Z: Holocene), and two subzones (Z2 and Z1) were recognized. The data of sedimentological markers obtained confirmed the occurrence of more wet phases in northeastern Brazil during the early stages of the Holocene. The Ti/Ca and Fe/Ca ratios, as well as the geochemical and micropaleontological proxies, indicated a farther north displacement of the Intertropical Convergence Zone (ITCZ) in the Pleistocene-Holocene transition. This may have caused greater precipitation in the Northeastern region of Brazil, effectuating the entry of a high volume of terrestrial sediments directly into the ocean basin.

The paper presents the sedimentological analysis of the menilites suite of the Miocene Starchiojd Formation of the Tarcău Unit from Mlăjet (Buzău Valley). There are described the petrographic types of the silicolithic rhythmites of this organic-rich rock (menilite) widespread throughout the Carpathian region and they are genetically interpreted from the point of view of the cyclicity of the various environmental conditions.

The paper revealed a sedimentological analysis of Eocene Podu Secu formation from Eastern Carpathians Tarcau Unit in the Siriu dam zone on the Buzau River. Based on stratonomic and petrographic characteristics are separated distinct facies and sequences whose integrated interpretation could be important in basin evolution reconstitution.

This article presents a suite of numerical methods contained within a Matlab toolbox for constructing complete particle-size distributions from diverse particle-size data. These centre around the application of a constrained cubic-spline interpolation to logit-transformed cumulative percentage frequency data. This approach allows for the robust prediction of frequency values for a set of common particle-size categories. The scheme also calculates realistic, smoothly tapering tails for open-ended distributions using a non-linear extrapolation algorithm. An inversion of established graphic measures to calculate graphic cumulative percentiles is also presented. The robustness of the interpolation-extrapolation model is assessed using particle-size data from 4885 sediment samples from The Netherlands. The influence of the number, size and position of particle-size categories on the accuracy of modeled particle-size distributions was investigated by running a series of simulations using the empirical data set. Goodness-of-fit statistics between modeled distributions and input data are calculated by measuring the Euclidean distance between log-ratio transformed particle-size distributions. Technique accuracy, estimated as the mean goodness-of-fit between repeat sample measurements, was used to identify optimum model parameters. Simulations demonstrate that the data can be accurately characterized by 22 equal-width particle-size categories and 63 equiprobable particle-size categories. Optimal interpolation parameters are highly dependent on the density and position of particle-size categories in the original data set and on the overall level of technique accuracy.