Mesoscale geomorphic change on barrier estuarine regime at the tropical coast of Chandipur, India: Evidence from assessment of grain-size distribution

It is crucial for policy makers and environmental managers to determine the future dynamics of coastal wetlands, especially the existence of their response, disruption, and recovery regimes. Reconstruction of meso-scale evolution in coastal ecosystems can help to adapt coastal resource management techniques to the natural scales of system activity, thereby encouraging true biodiversity. This research provides an overview of decadal (mesoscale) geomorphic transition by high-resolution grain size analysis of a sediment deposit from a barrier estuary regime on the Chandipur coast, India. Coastal marshland’s grain size distribution (GSD) has generally been analyzed using End Member Mixing Models (EMMA) and Probability Density Function (PDF) methods (e.g. log-normal, log skew-Laplace). Although these techniques do not consider the compositional nature of the records, which can undermine the outcomes of the interpretation of sedimentary deposits. The approach to reliable granulometric analysis of lithostratigraphic sequences aims at establishing direct links between fluid dynamics and subsequent shifts in the texture of sediments. In this study, GSD analysis of marsh sediment is represented by compositional data analysis (CoDa) and a multivariate statistical framework. Barrier estuary evolution, presented by time lapses of satellite maps coupled with grain size and carbon content of marsh sediment, primarily reflects the evolving hydrodynamics of the back barrier area. These findings will provide a statistically robust analysis of the depositional system in coastal marshland. Multiannual environmental variations in the back barrier configuration illustrate the importance of this applied approach with respect to bridging the basis of estuarine evolution and process information.

Assessment of Clay Deposits Quality from East of Erbil, Kurdistan Region, Iraq for some Ceramic Industries

For the assessment of clay deposits for brick manufacturing, seven clay samples from different locations were collected by channel sampling method from Injana, Mukdadiyah, Bai Hassan formations and Quaternary deposits in Bestana village, the study area is located east of Erbil city (NE Iraq). For ceramic manufacturing, the quality of clay should be measured according to some physical properties. The mineralogical and geochemical study revealed by using X-ray diffraction and chemical characteristics, which represented that all clay samples containing; kaolinite, smectite, illite, and chlorite with some mixed clay and non-clay mineral quartz, calcite, dolomite, and feldspar. The physical properties of clay samples including grain size analysis and Atterberg limits showed that the raw materials contain clay in high proportion, silt in medium proportion, and sand in minor proportion. Plasticity index of the studied samples showed that they are moderately plastic to plastic range. The geochemical analysis of the studied samples showed that the clay raw materials are composed mainly of silica and alumina, which act as refractory material in the ceramic industry. In addition to that, there are different proportions of calcium, iron oxides, magnesium, potassium, and sodium, which are flux oxides.

Grain size variation in sand column along Chhatrapur coast, Ganjam district, Odisha – A clue to the depositional environment

The concentration of heavy mineral placer deposits along the coastal tracts are function of various favourable factors i.e. hinterland geological formations, prevalence of favourable climatic condition, their transportation through intricate drainage systems and various coastal processes, which operated during the geological past. Textural analysis of the available unconsolidated sediments from the present deposits is of vital importance to decode the prevailing depositional environment while grain size analysis is the major parameter used. Present study highlights the grain size analysis of the identified sand column from Chhatrapur Mineral Sand Deposit along the coastal tract of Odisha to infer the environment of deposition of heavy mineral bearing sand and their heavy mineral content variation. Standard procedure of sampling, data analysis and interpretation techniques were adopted. Result shows that, sands from frontal and rear dune are characterized by distinct bi-modal distribution, medium to fine, moderately to well sorted with good positive skewness, whereas, sand from Inter-dunal region shows dominant unimodal, medium to coarse grain, moderately poorly sorted nature and slightly positive skewness. The better heavy mineral concentration (10 to 25 % grade) in frontal and rear dunes is attributed to prevalence of aeolian dune deposition accompanied by good sorting. In contrast, the low concentration of heavy mineral (3 to 6 %) in inter dune region is due to occasional fluvial regime and poor sorting of sediments. Thus, grain size analysis can be an effective tool to decipher local prevailing depositional environment, which has a bearing on heavy mineral concentration as well.

Implementation on a Preparation and Controlled Compaction Procedure for Waste-Fiber-Reinforced Raw Earth Samples

Earth bricks are a traditional eco-friendly construction material. In this study, harbor-dredged sediments were used along with hemp shiv to develop a brick manufacturing procedure and compaction techniques to produce durable earth bricks for the valorization of waste hemp shiv and dredged sediments. Prismatic specimens of size 4 × 4 × 16 cm3 were manufactured with Dunkirk sediments after analyzing their suitability for earth bricks according to the French standard for flexural strength test to observe the indirect tensile strength and impact of the compaction techniques on the strength of bricks. Crude bricks were manufactured with varying hemp shiv content from 0% to 5% by mass. Compaction techniques such as dynamic compaction, static compaction, and tamping were applied. The effect of hemp shiv content and compaction techniques was evaluated with a flexural strength test and the distribution of fibers in bricks. Grain size analysis of sediments with French and Spanish standards shows that the sediments granulometry is suitable for earth bricks. The flexural strength testing of bricks indicates that bricks with saturated hemp shiv have higher flexural strength. Earth bricks have maximum strength with dynamic compaction with 1% hemp shiv, which satisfies the adobe bricks tensile strength requirements that vary from 0.012 to 0.025 MPa (NZS 4298, 1998; NORMA E.080 (2017).

Structure and Mechanical Properties of the Dueñas Clay Formation (Tertiary Duero Basin, Spain): An Overconsolidated Clay of Lacustrine Origin

The Dueñas Clay Formation is considered an example of a deposit of lacustrine continental origin. It is formed mainly by overconsolidated clays and includes feldspathic arenites, and clayey and silty levels; however, in geotechnical projects it is considered a clay unit and treated as a whole. The structure of each level was assessed in the field, in thin sections, and by SEM in the case of the clayey level. In addition, identification, strength, deformation, and durability tests were undertaken according to the nature of the samples (grain size analysis, Atterberg Limits, point load test, direct shear tests, uniaxial compression tests, swelling pressure, and unidimensional consolidation tests). The durability test was used as a criterion for dividing the levels within the formation according to their behavior as soil or rock. It was observed that the proportion and type of carbonate cementation controls the way in which the material behaves, with sparithic cement increasing the strength. The clay levels are expansive due to the presence of smectite, which also influences their behavior under shear stress. In addition, the massive and laminar structure of the layers caused by the continental conditions, in addition to the processes of post-sedimentation, explain their low compressibility.

The Influence of Basalt Powder on the Physicochemical Properties of Impoverished Oxisoils from Ngaoundéré (Adamawa - Cameroon)

The present study aims at assessing the fertilizing potential of basalts on impoverished oxisoils from Ngaoundéré (Adamawa, Cameroon). This specifically involves the application of finely ground basalts on impoverished oxisoils and monitoring changes in physicochemical properties during six months. An experimental design which consisted in a randomized complete block design is constituted of three series of four treatments each one: the control (ST), the control soil mixed with 100 g of finely ground basalt (T0 + BA_10), the control soil mixed with 200 g of finely ground basalt (T0 + BA_20), the control soil mixed with 300 g of finely ground basalt (T0 + BA_30). Each treatment was replicated ten times in every serie. The control treatment is only soils of Ng, collected at the top soil and without any basalt application. They are clayey, acid and display an average CEC. The basalt is rich in silica (47.52%), Calcium (8.22%), Magnesium (4.03%), sodium (4.01%), potassium (2.42%) and displays average content in alumina (16.54%) and iron (11.1%). The experiment was carried out in pots, and the incubated soil samples were analyzed after 0, 1, 2, 4 and 6 months. The analyzes mainly focused on the physicochemical parameters (Grain size analysis, pH, Cation exchange capacity (CEC), the sum of exchangeable bases (SBE) and the saturation rate (V). Obtained results indicated that the application of basalt greatly improved the chemical properties of oxisoils from Ngaoundéré: the pH changes from acidic (5.5) to weakly acidic (6.5); the saturation rate, as well as the sum of exchangeable bases and the cation exchange capacity increased. Physicochemical properties of the soil are closely accompanied by an increase in fertility. It appears that 10 and 20% treatments are the most efficient treatments. Thus, the basalts from Manwi can be recommended as petrofertilizer to improve the chemical properties of impoverished soils and especially for plants requiring alkalis and alkaline earth.

Monsoon Variability Reconstructed from Sedimentological and Mineral Magnetic Studies from Vaghad Tank Deposits, Nashik District, Maharashtra

An attempt made to reconstruct the monsoon variability using sedimentological, geochemical and mineral magnetic studies from deposits in Vaghad Tank, Nashik district, Maharashtra (India). The ~140 years multi-proxy data of the 3.3 meter thick sedimentary section of the tank exhibits some minor changes in sediment characteristics up to the depth of ~150 cm. The grain-size analysis and mineral magnetic studies of 67 samples of sediment suggests that, the sediment dominated by clay. Overall, sedimentary profile does not exhibit any systematic trend in the sediment properties. Finally, the present study concludes no significant changes in the past monsoon conditions have been occurred during the last century but some minor changes in the hydrodynamic conditions have been noticed during the last few decades.

A Conversion for Average Grain Size Based on Gamma Ray Well Log: Application in the Second Member of Xujiahe Formation of Anyue Area, Sichuan Basin

The grain sizes of clastic rock sediments serve as important depositional indicators that are significant in sedimentology and petroleum geology studies. Generally, gamma ray, spontaneous-potential and resistivity well logs are utilized to qualitatively characterize variations in sediment grain size and determine the lithology in clastic reservoirs. However, grain size analysis of modern sedimentary samples collected from active rivers and deltas indicates that the percentage of fine depositional component has a logarithmic relationship with the average grain size in delta and river systems. Using the linear relationship to process the lithology interpretation, siltstones or mudstone is likely to be interpreted as sandstone. Therefore, a logarithmic conversion formula was built up between the gamma ray logs and measured grain size for the second member of the Xujiahe Formation of Anyue Area in the Sichuan Basin. Using the formula, the average grain size and lithology of the exploration wells were determined for the interest intervals. Furthermore, the calculated grain size gives a better understanding of the controlling factors of hydrocarbon-bearing reservoirs in the study area.

Identification of suspected paleotsunami deposits study from Karapyak Beach, Pangandaran area, West Jawa, Indonesia

Identifying and constraining palaeotsunami deposits can be a vital tool for establishing the periodicity of earthquakes and their associated tsunami events beyond the historical records. However, the deposits can be difficult to establish and date. In this study we used the characteristics of the 2006 Pangandaran tsunami deposit as a reference for identification of paleotsunami deposits in Karapyak Beach, Pangandaran area, West Java, Indonesia. Similar to the 2006 Pangandaran tsunami deposit, the Karapyak Beach paleotsunami deposit is characterized by light brown loose sand materials overlying a dark brown paleosoil layer with erosional contact. A thin layer that varies in thickness is locally found right above the erosional contact, with non-laminated coarser grain in the lower part that gradually change into medium to fine sand-sized in upper part. The base of the lower part is rich with broken mollusc shells and corals, and the mid-top of the lower part may contain several intact molusc shells and corals, rock fragments and anthropogenic products (rooftile). Those types of fragments are absent in the upper part of the thin layer. Grain size analysis shows a mixture of fine and coarse grains in the lower part of 2006 tsunami deposits as well as in the suspected paleotsunami deposits, suggesting uprush high energy flow during sedimentation. Fining upward sequence above mixed grain layers reflects waning flow or pre-backwash deposition. Foraminifera analysis also shows a mixture of shallow and deep marine foraminifera in the two deposits. Based on the characteristics of the 2006 tsunami deposits, there are at least four identified paleotsunami deposits at Karapyak Beach, Pangandaran area.

Deglacial Land-Ocean Linkages at the Alaskan Continental Margin in the Bering Sea

A marine sediment record from the central Bering Sea, spanning the last 20 thousand years (ka), was studied to unravel the depositional history with regard to terrigenous sediment supply and biogenic sedimentation. Methodic approaches comprised the inference of accumulation rates of siliciclastic and biogenic components, grain-size analysis, and (clay) mineralogy, as well as paleoclimatic modelling. Changes in the depositional history provides insight into land-ocean linkages of paleoenvironmental changes. During the finale of the Last Glacial Maximum, the depositional environment was characterized by hemipelagic background sedimentation. A marked change in the terrigenous sediment provenance during the late Heinrich 1 Stadial (15.7–14.5 ka), indicated by increases in kaolinite and a high glaciofluvial influx of clay, gives evidence of the deglaciation of the Brooks Range in the hinterland of Alaska. This meltwater pulse also stimulated the postglacial onset of biological productivity. Glacial melt implies regional climate warming during a time of widespread cooling on the northern hemisphere. Our simulation experiment with a coupled climate model suggests atmospheric teleconnections to the North Atlantic, with impacts on the dynamics of the Aleutian Low system that gave rise to warmer winters and an early onset of spring during that time. The late deglacial period between 14.5 and 11.0 ka was characterized by enhanced fluvial runoff and biological productivity in the course of climate amelioration, sea-level rise, seasonal sea-ice retreat, and permafrost thaw in the hinterland. The latter processes temporarily stalled during the Younger Dryas stadial (12.9-11.7 ka) and commenced again during the Preboreal (earliest Holocene), after 11.7 ka. High river runoff might have fertilized the Bering Sea and contributed to enhanced upper ocean stratification. Since 11.0 ka, advanced transgression has shifted the coast line and fluvial influence of the Yukon River away from the study site. The opening of the Bering Strait strengthened contour currents along the continental slope, leaving behind winnowed sand-rich sediments through the early to mid-Holocene, with non-deposition occurring since about 6.0 ka.