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ABSTRACT Fluvial facies models based on river planform are flawed and not fully fit for purpose. An alternative approach to classifying fluvial deposits is based on river discharge characteristics. A recent paper showed that the co‐efficient of variance of annual peak discharge (CVQp) correlates well with the characteristics of preserved alluvium for a suite of modern rivers. Here, the database of rivers is expanded and augmented, and the utility of this statistic confirmed. For modern rivers, plotting the running‐value of CVQp for a set interval (for example, 30 years) over a longer discharge record shows that the statistic varies both spatially and temporally. The CVQp can rise abruptly at a given location in response to a single flow event if that event is significantly larger than is common in that river. Such abrupt changes in CVQp are superimposed on longer‐term patterns of more gradual change stimulated by environmental factors or anthropogenic effects such as dam construction. If the period of calculation for CVQp is relatively short, ‘anomalous’ events appear more frequently. Sequential studies of modern rivers indicate that such anomalous events have a high probability of being preserved in the alluvial record of the river, and suggest that, over the timeframes of channel filling and abandonment, they may constitute the dominant (characteristic) portion of the record in high CVQp systems. Since flow events with strongly peaked hydrographs (flashy discharges) are more common in high CVQp systems and leave a record dominated by upper flow regime stratification styles, it follows that the alluvial record of high CVQp rivers will be dominated by upper flow regime stratification. In contrast, in lower CVQp systems the occurrence of an event that changes the running CVQp value significantly may form a distinct event deposit, and the temporarily changed CVQp is unrepresentative for the duration of the channel's life. The dominance of upper flow regime stratification, together with decreased preservation of identifiable macroform structure, increased lateral lithological heterogeneity, and in many cases increased preservation of in situ tree fossils in channel deposits of higher CVQp rivers, forms the basis for a series of new facies models for low, moderate, high and very high/ultra‐high CVQp alluvial systems and deposits. The new models can be applied to ancient successions either in combination with traditional, planform‐based models, or not. These models provide information about ancient palaeoenvironmental conditions, and changes in such conditions over time at various scales via stratigraphic investigations. [ABSTRACT FROM AUTHOR]

This study discusses the potential of archaeological organic objects in anthropogenic sediments in terms of research into human impact on the medieval landscape and environment. In the Bohemian‐Moravian Highlands, at a mid‐altitudinal stream valley site (ca. 510 m asl), remains of a cut medieval forest stand with anthropogenic wooden structures and buried by technogenic sediments (e.g., ore, gangue and tailings) were archaeologically excavated. The site was analysed using an interdisciplinary approach, applying methods from archaeology, archaeobotany, sedimentology, pedology and geochemistry as well as dendrochronology and radiometric dating. The vegetation can be reconstructed as forest with a dominance of fir and an admixture of spruce and alder. The surrounding slopes were covered by broadleaf trees. Remains of wooden technical structures, stamped, ground and washed ores and gangue, together with fragments of grinding stones, allow the interpretation of the site as an ore and stamp mill linked to ore washing equipment. This record of a buried medieval fir forest can be likewise used as a historical testimony and analogue for present‐day issues on ecology and forestry, aiming at ecological revitalisation and adaptation of forests to ongoing climate change in Central Europe. [ABSTRACT FROM AUTHOR]

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The recognition of meandering rivers in Earth's prevegetation stratigraphic record is hindered by an absence of depositional models specifically tailored to unvegetated single‐channel rivers. As a result, their abundance on the early Earth is currently unknown. Here, sedimentological studies of two modern meandering river reaches with unvegetated banks were conducted. Both reaches are located in arid basins of Nevada, USA. Stratigraphy was analysed in conjunction with satellite imagery and high‐resolution topographic data to understand how channels and floodplains record past flow conditions. Analyses of point‐bar and channel‐fill deposits showed that lateral accretion sets are not heterolithic but, rather, composed of mixed sand and sand‐sized mud aggregates (clumps of clay and silt) interpreted to have formed through flocculation. Levées are present but subdued. Notably, downstream‐migrating outer‐bank‐attached bars are prominent architectural features that may be common in unvegetated meandering rivers in arid landscapes elsewhere. The identification of such depositional elements in the stratigraphic record may enhance recognition of ancient unvegetated meandering rivers and improve reconstructions of palaeohydrology on early Earth and Mars. [ABSTRACT FROM AUTHOR]

The Modder River basin has been the focus of extensive surveys followed by targeted excauations of specific erosional gullies (known Locally as dongas), where Middle and Later Stone Age artefacts mid fossils are abundant. At Damulei, a donga located on the left bank of the Modder, lithic artefacts and fossils were observed iii the 19906. Here, we present the results of two seasons of fieldwork (2019/21) at this locality, as well as unpublislied surface fautial remains collected iii 1995/96. Damulei formed as a result of overbank deposition of tlie Modder River, as indicated by micromorphological analysis. Tlie accumulation of tlie sedimentary sequence beneath the artefact-bearing levels started at 27 +. 3 ka at the earliest, based on optically stimulated luminescence dating. Artefacts, fatinal reninins, and phytoliths show that the site is characterised by Holocene Later Stone Age technology in mi open-grassland elivironment typical of the terminal Florisian Land Mammal Age. Damplei expands our knowledge of the Later Stoile Age iii the westent Free State, and hightights the need for more extensive dating programmes nimed at framing human occupation iii the central interior of South Africa. [ABSTRACT FROM AUTHOR]

This study aims to determine the characterization of alluvial soil as a place to grow Chinese betel (peperomia pellucida L.) in Ambon city. Parameters studied included morphological characterization of alluvial soil and description of Chinese betel nut (Peperomia pellucid a L.). The results of observations in the field and analysis of soil samples in the laboratory that have been collected are used as material to identify soil morphological characterization. Meanwhile Chinese betel nut (Peperomia pellucid a L.) collected from alluvial soil was selectively explored by exploring the research area using the Cruise Method. Furthermore, a phytochemical test was carried out to determine its phytochemical content. The results showed that the color of the soil and the rusty color of the alluvial soil in Ambon City was generally brown. The alluvial soil structure at the study site has an O horizon with a soil layer thickness of 17 cm, an A horizon with a thickness of 45 cm soil lumpy structure and a Bw horizon with a soil thickness of 30 cm and the C horizon with a thickness of 65 cm is classified as having a globular lumpy soil structure, It has a high clay and silt content. The lower the soil solum, the lower the C-organic content. The soil in Ambon city has moderate fertility. Low base saturation is associated with low C-organic content in the soil. Chinese sirih that grows on alluvial soil types in Ambon City contains several classes of compounds that are beneficial to health like flavonoids, alkaloids, tripenoids, phenolics, tannins and saponins so that they have ethnomedicin effects such as anticancer, antimicrobial, antidiabetic, antihypertensive and antioxidant activities. [ABSTRACT FROM AUTHOR]

A variety of stream power‐based approaches for predicting catchment‐scale alluvial channel adjustment have been developed. There is an international interest in applying these to inform river catchment management. However, there is some uncertainty regarding their ability to make consistently accurate predictions. This study evaluates the performance of a range of stream power indices for predicting observed channel adjustment. Remotely sensed data were used to generate 33 different stream power indices every 50 m across the networks of five test catchments. The performances of the indices were evaluated by comparing them against observations of erosion and deposition‐dominated channels extracted from the UK's River Habitat Survey (RHS) database. A selection of metrics for evaluating the performance of the indices were calculated. The key finding from this study is that the stream power indices were poorly associated with the observations of alluvial channel adjustment. It is not clear whether this poor association is due to limitations with stream power indices or the suitability of the RHS observations. However, this is not the first study to find a weak association between stream power and observed adjustment. Therefore, caution is recommended to anyone hoping to take advantage of the practicability of stream power indices until further testing is applied using alternative observation datasets. An additional finding from this study is the inconsistency of outcomes between different measures of model performance. It is recommended that future studies also employ multiple model performance measures rather than relying on accuracy alone. [ABSTRACT FROM AUTHOR]

Abstrak. Penelitian ini bertujuan untuk menganalisis lapisan yang terindikasi terhadap kontaminasi air asin pada akuifer di bawah permukaan berdasarkan data Vertical Electrical Sounding (VES). Nilai resistivitas yang rendah berbanding terbalik dengan nilai konduktivitas yang tinggi sehingga nilai resistivitas yang rendah menunjukkan tingkat kontaminasi air asin yang tinggi. Berdasarkan geologi regional, litologi pada daerah penelitian berupa endapan aluvium yang terdiri dari endapan kerikil, pasir dan lumpur yang berasal dari aliran sungai serta pengaruh pasang surut air laut. Penelitian ini menggunakan 3 (tiga) data Vertical Electrical Sounding (VES) yang dianalisis untuk menentukan lapisan terkontaminasi air asin sampai dengan kedalaman 152 meter. Hasil penelitian berdasarkan pengukuran Vertical Electrical Sounding (VES) menunjukkan sebaran litologi secara umum didominasi pasir hingga pasir kerikil. Kedalaman tingkat kontaminasi air asin yang tinggi sangat bervariasi. Pada lokasi pengukuran VES P11, tingkat kontaminasi air asin yang tinggi dengan nilai resistivitas 0,19 – 1,5 ohm.m pada kedalaman 12,4 – 67,7 meter. Pada lokasi pengukuran VES P22, tingkat kontaminasi air asin yang tinggi dengan nilai resistivitas 1,64 – 2 ohm.m pada kedalaman 3,59 – 10 meter dan 46,6 – 57,2 meter. Pada lokasi pengukuran VES P04 terindikasi tingkat kontaminasi air asin sangai rendah. Kontaminasi air asin pada akuifer air tawar pada lokasi pengukuran VES P11 dan VES P22 bisa disebabkan oleh menurunnya muka air tanah pada musim kemarau sehingga terjadinya intrusi air laut kedalam akuifer air tawar. Selanjutnya penyebab lain karena daerah pengukuran terletak pada endapan aluvium yang dipengaruhi pasang surut air laut pada masa lalu. Abstract. This study aims to analyze layers indicated for saltwater contamination in subsurface aquifers based on Vertical Electrical Sounding (VES) data. A low resistivity value is inversely proportional to a high conductivity value, so a low resistivity value indicates a high level of saltwater contamination. Based on regional geology, the lithology in the study area is alluvial deposits consisting of gravel, sand, and mud deposits originating from river flows and the influence of tides. This study uses 3 (three) Vertical Electrical Sounding (VES) data which are analyzed to determine the layer contaminated with salt water up to a depth of 152 meters. The results of the study based on Vertical Electrical Sounding (VES) measurements show that the lithology distribution is generally dominated by sand-to-gravel sand. The depth of high levels of saltwater contamination varies greatly. At the VES P11 measurement location, the level of saltwater contamination is high with a resistivity value of 0.19 – 1.5 ohm.m at a depth of 12.4 – 67.7 meters. At the VES P22 measurement location, the level of saltwater contamination is high with a resistivity value of 1.64 – 2 ohm.m at a depth of 3.59 – 10 meters and 46.6 – 57.2 meters. At the VES P04 measurement location, it is indicated that the level of saltwater contamination is very low. Saltwater contamination in freshwater aquifers at the VES P11 and VES P22 measurement locations could be caused by the lowering of groundwater levels during the dry season, resulting in seawater intrusion into freshwater aquifers. Furthermore, another cause is that the measurement area is located in alluvium deposits which were influenced by tides in the past.

Delta-plain strata of the Cenomanian Dunvegan Formation, in north-east British Columbia, represent anastomosed rivers that were flanked by vegetated crevasse splays, wetlands and shallow lakes. These rocks preserve a rich record of ankylosaur and ornithopod walking and wading tracks, as well as crocodylian swim traces and tracks. Analysis of depositional, erosional, and trace-making events reveals alternating phases of flooding and emergence that controlled both animal activity (walking, wading, swimming) and mud substrate consistency (firm vs. soupy), and hence fidelity of track preservation. Some tracks resemble those produced by both ankylosaurs and crocodylians, and confident attribution is difficult. The absence of tail drag marks suggests an ankylosaur trackmaker, whereas prominent claw marks might favour a crocodylian origin. Unusually large crocodylian swim traces suggest animals about 9 m, and possibly up to 12 m in length. These large traces may represent a precursor to the giant crocodylian Deinosuchus. Ankylosaur tracks are well-preserved in lake and channel-margin deposits, whereas crocodylian traces are most commonly preserved in firm muddy lake sediments that had experienced previous subaerial exposure and dewatering. Close integration of trace fossils with sedimentary and stratigraphic features makes it possible to reveal a detailed chronology of biotic and sedimentary events on palaeo-surfaces. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Plant Production is the property of Egyptian National Agricultural Library (ENAL) and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

This study was conducted to determine the effect of pedological variation on the physical and chemical characteristics and environmental factors of alluvial and desert soils in Al-Muthanna (Badia Al-Samawaa). Six pedons were taken, three pedons from the alluvial plain, at Al-Rumaitha, Al-Suwayr and Al-Khidhur, and three Pedons in desert soils distributed over the Samawah desert at Fadhah Umm Shih, Al-Batah and Al-Rehab. Pedons have been described morphologically in the field. Samples were taken from each horizon of all study pedons to perform the required laboratory analyzes. The results indicated that there was a variation between the desert alluvial soils properties, especially in the ratio of calcium carbonate and electrical conductivity (EC). The alluvial soils were characterized by a high percentage of salinity and a decrease in calcium carbonate, as well as variations in the color of the soil, as for the bulk density, it was revealed that there is a deaf layer in the desert soils at a depth of 30 cm. The electrical conductivity of desert soils was between 1.1-4.5 dSm m-1, the conductivity of alluvial soils was between 10.5-20.12 dSm m-1, the cation exchange capacity (CEC) of desert soils was between 10.4-11.0 cmol.kg-1, the alluvial soils were between 11.0-20.14 cmol.kg-1, as for the proportion of calcium carbonate (CaCO3), its value in desert soils reached between 200-450 mg kg-1, its value in alluvial soils was between 210-340 mg kg-1, the value of gypsum for desert soils was between 0.4-9.0 ml g kg-1 and for alluvial soils it was between 1.0-5.5 g kg-1. [ABSTRACT FROM AUTHOR]

Abstract This study evaluates variations in petrophysical properties within a mixed alluvial to lacustrine carbonate system (Miocene, Madrid Basin, Central Spain). The transition from alluvial environments to lake margins settings displays a shift from alluvial, siliciclastic red sandstones and mudstones to palustrine–lacustrine mudstones to packstones. Fluctuations in lake‐water level enabled land plants to occupy the lake margins during periods of low lake levels. The palustrine carbonates include features like pseudo‐microkarst, nodular and mottled limestones; the lacustrine deposits include enlarged root cavities, desiccation cracks and channel bodies. Scarce fresh water biota comprises charophytes, gastropods and ostracods. The sediments possess high natural, irregular varying, gamma‐ray values at the alluvial–lacustrine transition, and low, but constant values at full lacustrine sites. Acoustic properties agree with lithological variations within individual facies. Porosity is the most important parameter influencing P‐wave and S‐wave velocities. The scatter in the velocity–porosity relationship links to the porosity type; macro‐porosity or microporosity. The wide range of pore types and pore sizes results in a weak porosity to permeability relationship for the carbonate‐dominated rocks with low permeability for microporous and high permeability for macro‐porous carbonates. The sandstones (probably only inhibiting interparticle porosity), and to a lesser extent the sandy wackestones to packstones, show quite a strong relationship between porosity and permeability. Elastic properties of mixed alluvial–lacustrine deposits (this study) and marine deposits (literature data) overlap as variations in pore structures and porosity values are similar. Only 16% of the marine and lacustrine carbonate sediments display Equivalent Pore Aspect Ratio values above 0.2. In travertine deposits, 83% of the samples exceed Equivalent Pore Aspect Ratio values above 0.2, which highlights that travertine deposits are dominated by larger Equivalent Pore Aspect Ratios compared to lacustrine and marine carbonate deposits. Travertines display other rock frameworks with different pore types, pore distribution and amount of porosity.

Ancient Šuruppak, today Fara, was one of the major Sumerian cities in Mesopotamia. It was situated along one of the ancient watercourses of the Euphrates River. Findings date it back to the Jemdet Nasr period around 3000 bc with a continuous occupation until the end of the Ur III period around 2000 bc. Fara was first explored and excavated by the Deutsche Orient‐Gesellschaft in the years 1902 and 1903 under the direction of Walter Andrae. Multiple excavation trenches with lengths up to 900 m transect the 1 km2 wide mound and are still visible today which enables us to georeference the excavation maps. Today, the 2.2 km2 wide archaeological area is dry and without any vegetation. Thousands of deep looting pits are covering the majority of mound which not only destroyed its upper metres but also challenge the application of geophysical prospection methods and their interpretation. The magnetometer prospecting of selected areas on and around the mound was carried out with three devices, two total field magnetometers and one gradiometer. The individual survey areas were combined in post‐processing by applying a high‐pass filter on the total field data sets and multiplying the vertical gradiometer data sets by a factor of two. This approach provides visually uniform magnetograms, despite being obtained by different devices, which simplifies subsequent visual interpretation. These magnetograms enable us to review, and to extend the results of the old excavations. The comparison show a good correlation in accuracy to the old drawings and positive identification of the already excavated features with magnetometry. Highlights of the survey are the discovery of the city wall confirming its existence, the layout of a unique building complex in the centre of the mound, likely a temple, traces of canals inside the city and an evaluation of magnetometer prospection over a looted area. [ABSTRACT FROM AUTHOR]

The Segura mining field, the easternmost segment of the Góis–Panasqueira–Segura tin–tungsten metallogenic belt (north–central Portugal), includes Sn-W quartz veins and Li-Sn aplite-pegmatites, which are believed to be genetically related to Variscan Granites. Sediment geochemistry indicates granite-related Ti-enrichments, locally disturbed by mineralization, suggesting magmatic and metamorphic/metasomatic titaniferous phases. Therefore, Segura alluvial samples and the geochemistry of their TiO2 polymorphs (rutile, anatase, and brookite) were investigated, and their potential as exploration tools for Sn and W deposits was evaluated. The heavy-mineral assemblages proved to be good proxies for bedrock geology, and TiO2 polymorph abundances were found to be suitable indicators of magmatic and/or metasomatic hydrothermal processes. The trace element geochemistry of Segura's alluvial rutile, anatase, and brookite is highly variable, implying multiple sources and a diversity of mineral-forming processes. The main compositional differences between TiO2 polymorphs are related to intrinsic (structural) factors, and to the P-T-X extrinsic parameters of their forming environments. Anomalous enrichments, up to 9% Nb, 6% Sn and W, 3% Fe, 2% Ta, and 1% V in rutile, and up to 1.8% Fe, 1.7% Ta, 1.2% Nb, 1.1% W 0.5% Sn and V in anatase, were registered. Brookite usually has low trace element content (<0.5%), except for Fe (~1%). HFSE-rich and granitophile-rich rutile is most likely magmatic, forming in extremely differentiated melts, with Sn and W contents enabling the discrimination between Sn-dominant and W-dominant systems. Trace element geochemical distribution maps show pronounced negative Sn (rutile+anatase) and W (rutile) anomalies linked to hydrothermal cassiterite precipitation, as opposed to their hydrothermal alteration halos and to W-dominant cassiterite-free mineralized areas, where primary hydrothermal rutile shows enrichments similar to magmatic rutile. This contribution recognizes that trace element geochemistry of alluvial TiO2 polymorphs can be a robust, cost- and time-effective, exploration tool for Sn(W) and W(Sn) ore deposit systems. [ABSTRACT FROM AUTHOR]

In the world, the hazards of intense rainfall are recurrent and increasing. In addition, they are one of the natural hazards that cause the most severe damage to infrastructure and even cause deaths every year. Flow-type landslides are capable of develop in areas with different geomorphological, geological and climatic characteristics. In hyper-arid zones such as the Atacama Desert, these hazards are capable of develop in a timely manner, causing catastrophes. This study analyzes the flow-type landslide in a hyper-arid mountainous area in La Chimba basin of Antofagasta city (Chile). For this, a hydrometeorological analysis is carried out through a pluviometric analysis, statistical analysis of frequencies through the Gumbel probabilistic method of extreme values and determination of maximum flows by obtaining IDF (intensity-duration-frequency) curves and design rainfall intensity as a function of concentration time. To obtain the maximum flows of liquid runoff and debris, for different return periods, the rational method was used with the method proposed by O'Brien. For the determination in the impact zone, the modeling software HEC-RAS (Hydrologic Engineering Center's River Analysis System) and RAMMS (Rapid Mass Movements). Hydrographs are used for a return period of about 200 years, considered the most unfavorable scenario with the Voellmy–Salm model. To validate the modeling, a morphometric, sedimentological and comparative analysis is carried out between real impact zones of 1991 event and those generated in this study. It is concluded that the sedimentological and morphometric characteristics indicate that the type of flow that it can originate would have a rapid response to rainfall events of great intensity or duration. The modeling provided by HEC-RAS represents a fluvial-type flow, while the RAMMS modeling is closer to the consistency of a flow-type landslide, which is estimated to be closer to reality. The results show that despite being in a hyper-arid zone, the rainfall factor is capable of landslides triggering in mountainous areas. [ABSTRACT FROM AUTHOR]

This research was conducted on clay soils, especially for vegetable plantations, aimed to determine the ability of the soil layer to distribute nutrients and restore soil health and fertility due to the use of chemical fertilizers and pesticides. Through microbial activity that is controlled by spreading through a horizontal biohole, this study observes in real time through a micro controller the changes in soil acidity, infiltration rate, electrolyte conductivity levels and porosity levels through soil infiltration rates. Through simulations with the variable microbial population, it can be seen the level of EC and other parameters against the time of observation in real time. From the observations of graphs and EC standards, it can be seen that the ability of the soil to because until day 45 the soil fertility level has not reached = 1500 uS / cm with a microbial population = 103/cfu. support the planting schedule both during the vegetative growth period and during the generative growth period, so that we will know when is the right time to do: soil recovery, initial planting and when the tubers / flowers / fruit begin to be conditioned. until cooked based on nutrient values observed through sensors that convert analog parameters by the micro controller into digital information transmitted by wifi in real time. The initial condition before simulating the soil fertility value with the Electrolyte Conductivity (EC) parameter is 744 uS / cm, the simulation results are: Simulation 1: nutrient content for generative growth was achieved on day 27 with fertility level = 1525 uS / cm with Microbial Population 108/cfu. Simulation 2: nutrient content for generative growth was achieved on day 42 at the fertility level = 1500 uS / cm with microbial population = 105/cfu. Simulation 3: nutrient content for generative growth cannot be observed. [ABSTRACT FROM AUTHOR]

Sandy alluvial soils contaminated with crude oil were investigated with a view to understanding the effects of crude oil contamination on their engineering properties. Bulk samples of alluvial soils compacted in layers were admixed thoroughly with 10% by volume of the contaminant and were cured for 63 days under room temperature in the laboratory and outside in the open to simulate field conditions. Mineralogical and chemical compositions of soils were obtained using X-ray diffraction and X-ray fluorescence analyses, and specific gravity, hydraulic conductivity, and compaction tests were conducted on the soils before and after contamination. Results show that the soil is silica-rich with SiO2 content of 96.24g/g. This is corroborated by the high quartz content (96.62%) observed from the mineralogical composition with minor amounts of kaolinite (6.04%), and trace amounts of haematite (0.02%). The addition of crude oil resulted in an increase in maximum dry density (MDD) with a corresponding decrease in hydraulic conductivity, optimum moisture content (OMC), and specific gravity for both laboratory and outside cured samples. Hence, crude oil contamination can be said to modify the engineering properties of sandy soils, and the environment of samples’ emplacement also contributed to the alteration pattern observed.

A study was conducted in lower Shiwaliks of Punjab, India to study the soil organic carbon (SOC) stock variation in hill, piedmont plain and alluvial plain regions of Punjab, and further to investigate the SOC variability down the slope in the lower Shiwaliks region of Punjab. The SOC fractions viz. very labile carbon, labile carbon, less labile carbon and recalcitrant were determined using standard methodologies. The total SOC stock in 0–60 cm soil depth was highest in plain region (31.81 Mg ha−1), followed by piedmont (23.43 Mg ha−1) and lowest in hill region (22.86 Mg ha−1). Whereas, the SOC concentration in surface layer was highest in foot slope (5.76 g kg−1) followed by mid slope (4.14 g kg−1) and lowest in up slope (2.32 g kg−1). Among the SOC fractions the average labile carbon content in soil samples was found in the order, hills (0.81 g kg−1) > piedmonts (0.73 g kg−1) > plains (0.50 g kg−1). The soil bulk density (Db) was higher in the plain than that of piedmont and hills. Moreover, a similar trend is observed in case of water holding capacity. Regression analysis has revealed significant relationship between Db and SOC stock at p

• During sea-level rise, an alluvial-deltaic system has a critical spatial dimension. • The over-expanded system is subjected to non-deltaic transgression with shrinkage. • Shrinkage can be normalized by autostratigraphic length and time scales. • During shrinkage, the alluvial channels change their intrinsic behavior. • The shrinkage concept can account for some alluvial features on Earth and Mars. The dynamics of downstream alluvial systems undergoing relative sea level (RSL) rise exhibit significant variations depending on spatial size. According to autostratigraphy theory, such systems cannot sustain deltaic sedimentation under a steady RSL rise (rate R slr), and are prone to non-deltaic transgression once their plain area A exceeds the critical limit A crt. During this transgression, A decreases asymptotically toward A crt , while the overall alluvial aggradation rate R agg_overall increases toward R slr. In this study, we investigated the behavior and morphodynamics of an overexpanded system through physical modeling, with a focus on the inherent area scale of the depositional system. In the early stages of non-deltaic transgression (A >> A crt , R agg_overall << R slr), the alluvial channels experience minimal aggradation rate R agg_channel (< R slr), leading to stabilization and inundation. As the transgression progresses, the channels aggrade more rapidly, increasing the likelihood of lateral migration and avulsion. Eventually, a state of morphodynamic equilibrium is reached, characterized by A ∼ A crt , R agg_overall ∼ R slr , and R agg_channel ∼ constant > R slr despite sustained non-deltaic transgression. During this equilibrium stage, the channels undergo rapid aggradation, resulting in complete destabilization with continuous lateral migration and frequent avulsion, forming system-wide subaqueous steps. The implications of overexpansion and autogenic shrinkage in response to RSL rise extend to stratigraphic convergence during RSL cycles and provide insights into Holocene non-deltaic transgression. Moreover, when combined with decelerating RSL rise, this process could have facilitated marine delta development. However, projected accelerated RSL may lead many modern marine deltas to transition into non-deltaic transgressive systems. Additionally, natural alluvial channels may exhibit varying behavior depending on the spatial size of the non-deltaic transgressive system. Furthermore, the autogenic shrinkage model may offer an explanation for the stepped surfaces observed on alluvial fans and deltas on Mars. [ABSTRACT FROM AUTHOR]

This study evaluates variations in petrophysical properties within a mixed alluvial to lacustrine carbonate system (Miocene, Madrid Basin, Central Spain). The transition from alluvial environments to lake margins settings displays a shift from alluvial, siliciclastic red sandstones and mudstones to palustrine–lacustrine mudstones to packstones. Fluctuations in lake‐water level enabled land plants to occupy the lake margins during periods of low lake levels. The palustrine carbonates include features like pseudo‐microkarst, nodular and mottled limestones; the lacustrine deposits include enlarged root cavities, desiccation cracks and channel bodies. Scarce fresh water biota comprises charophytes, gastropods and ostracods. The sediments possess high natural, irregular varying, gamma‐ray values at the alluvial–lacustrine transition, and low, but constant values at full lacustrine sites. Acoustic properties agree with lithological variations within individual facies. Porosity is the most important parameter influencing P‐wave and S‐wave velocities. The scatter in the velocity–porosity relationship links to the porosity type; macro‐porosity or microporosity. The wide range of pore types and pore sizes results in a weak porosity to permeability relationship for the carbonate‐dominated rocks with low permeability for microporous and high permeability for macro‐porous carbonates. The sandstones (probably only inhibiting interparticle porosity), and to a lesser extent the sandy wackestones to packstones, show quite a strong relationship between porosity and permeability. Elastic properties of mixed alluvial–lacustrine deposits (this study) and marine deposits (literature data) overlap as variations in pore structures and porosity values are similar. Only 16% of the marine and lacustrine carbonate sediments display Equivalent Pore Aspect Ratio values above 0.2. In travertine deposits, 83% of the samples exceed Equivalent Pore Aspect Ratio values above 0.2, which highlights that travertine deposits are dominated by larger Equivalent Pore Aspect Ratios compared to lacustrine and marine carbonate deposits. Travertines display other rock frameworks with different pore types, pore distribution and amount of porosity. [ABSTRACT FROM AUTHOR]

Abstract: Banda Aceh can be categorized as an earthquake-prone city because of the existence of two active segments namely Seulimeum and Aceh. Both segments are considered to provide great potential damage in the future. In this article, we conduct a microtremor survey in the Peukan Bada, sub-part of Banda Aceh city, to learn the vulnerability level and support disaster mitigation plan. A total of 20 sites were measured with a seismometer to record the seismic waveform. The waveform was recorded in 45 minutes with a sampling rate of 100 sps and has analyzed using the horizontal-vertical spectrum ratio (HVSR). The results obtained are the dominant parameters, such as the period with a range of 0 – 0.5s, frequency with a range of 0 – 6 Hz, seismicity vulnerability index with a range of 0.1 – 0.5. The result was relevant to the geological conditions of Peukan Bada that dominated by alluvial rocks and mud sediments. The level of vulnerability (Kg > 1.0) obtained is quite high and proportional to the soil type that can amplify the seismic waveform. The results obtained are expected to be a supporting study of disaster mitigation and understand the geological conditions of Banda Aceh in terms of seismic vulnerability. Abstrak: Banda Aceh dapat dikategorikan sebagai kota rawan gempa karena adanya dua segmen aktif yaitu Seulimeum dan Aceh. Kedua segmen tersebut bisa memberikan potensi kerusakan yang besar di masa mendatang. Pada tulisan ini, kami melakukan survei mikrotremor di Kecamatan Peukan Bada, salah satu sub-wilayah kota Banda Aceh, untuk mempelajari tingkat kerentanan dan mendukung rencana mitigasi bencana. Sebanyak 20 lokasi diukur dengan seismometer untuk merekam bentuk gelombang seismik. Gelombang direkam selama 45 menit dengan jumlah sampel 100 sps dan dianalisis menggunakan horizontal-vertical spectrum ratio (HVSR). Hasil yang diperoleh adalah parameter yang dominan yaitu periode dengan rentang 0 – 0,5s, frekuensi dengan range 0 - 6 Hz, indeks kerentanan kegempaan dengan rentang 0,1 – 0,5. Hasil tersebut relevan dengan kondisi geologi Peukan Bada yang didominasi oleh batuan aluvial dan endapan lumpur. Tingkat kerentanan (Kg > 1,0) yang diperoleh cukup tinggi dan sebanding dengan jenis tanah yang dapat memperbesar gelombang seismik. Hasil yang diperoleh diharapkan dapat menjadi pendukung kajian mitigasi bencana dan memahami kondisi geologi Banda Aceh dari segi kerentanan seismik.

In the present study, we used stable water isotopes (δ18O and δD) of source waters (rain, snow, and glacier melt) and groundwater to identify and estimate the sources of recharge in alluvial aquifer(s). The stable water isotopic composition of source waters showed a significant correlation with altitude (R2 = 0.75). Unlike source waters, the groundwater did not show significant spatio-temporal variation. The attenuation in the isotopic signal of groundwater may be due to lag and mixing of different waters recharging from different altitudes. The results revealed that snowmelt (44 ± 0.9% to 68 ± 2.7%) predominantly recharges the groundwater. The glacier melt contribution to groundwater recharge (2 ± 0.1% to 14 ± 0.9%) in Upper Jhelum Basin (UJB), although limited to some summer and autumn months, has tremendous significance in sustaining the groundwater recharge. The early and rapid melting of winter-accumulated snow due to climatic variability may disturb the seasonal water balance and decrease the annual groundwater recharge. [ABSTRACT FROM AUTHOR]

Diffuse Reflectance Spectroscopy (DRS) is a rapid, relatively new method in Quaternary research to analyse sediments and paleosols. This method takes into account clay mineral content, amount of Fe-bearing minerals and grain size composition of samples, simultaneously. Different Quaternary sediment samples were chosen forcharacterization and comparison their reflectance curves to detect the essential spectral properties of differentpaleosols and parent materials. Samples of different sediment types and paleosol variants were investigatedfrom a loess-paleosol sequence from Malá nad Hronom (Slovakia) and from a fluvial-aeolian sediment complex from Pilismarót (Hungary). Five investigated curve sections were separated as the best indicators of reflectance properties of DRS curves. Spectral properties of samples were compared by using the length of investigated curve sections. This investigation showed quantifiable differences between the units of Pleistocene sediment successions, based on the reflectance properties. The influence of pedogenic processes was properly detectable. Significant discrepancies were observed between reflectance curves of well-developed paleosols and parent material samples in the visible and near-infrared range. Differences between the weak developed paleosol layers and their parent materials were only observed in the visible range. Fine sand, sandy silt and loess materials could be separated from each other based on the intensity of entire reflectance curves.

Abstract The current focus is on the overall pattern of seed storage present in the fragments of the soil of piedmont and alluvial landscapes of the environment. The present study predicted the seed banks of both soils of alluvial and piedmont zones in different ecological conditions and evaluate the potential of seeds in the restoration of both environments. The composition of the seed bank of soil is mainly affected by the alluvial environment and the structure of cleared area shows that more species of germinating annual grasses and growable seeds with the higher total number. Extant vegetation structures have an important role in the diversity of soil seed reservoirs, whose composition corresponded with the openness of the site. When in situ soil seed bank is recruited, it helps to restore only some components of the plant community in an alluvial environment. In our current research, it was confirmed that seed richness was higher in number at lower elevation (alluvial) than that at high elevation (piedmont). Seed richness showed a significant negative correlation with anions, cations, while significantly positive with altitude that suggests the richness pattern of the overall seed bank of the area is influenced by various environmental factors.

Ketersediaan air mempengaruhi faktor pertumbuhan tanaman padi yaitu fisiologi, morfologi, pola pertumbuhan dan hasil padi. Tujuan penelitian ini adalah mengetahui respon beberapa varietas padi sawah dengan tinggi muka air yang berbeda dan mendapatkan varietas padi sawah yang terbaik dan tinggi muka air yang sesuai terhadap hasil tanaman padi sawah. Penelitian lapang ini dilaksanakan di Desa Cipta Karya, Kecamatan Sungai Betung, Kabupaten Bengkayang. Penelitian dilaksanakan selama lima bulan, sejak bulan Februari sampai Juni 2020. Penelitian ini menggunakan metode eksperimen lapangan dengan pola Rancangan Acak Lengkap Faktorial (RALF) yang terdiri dari 2 faktor dan diulang sebanyak 3 kali. Faktor pertama adalah varietas padi (V) sebanyak 4 taraf yaitu varietas Cilosari, Ciherang, Inpari 39 dan Inpago 8 dan faktor kedua adalah tinggi muka air (A) sebanyak 5 taraf yaitu -5 cm, 0 cm, 5 cm, 10 cm dan 15 cm. Pengamatan tanaman meliputi tinggi tanaman, jumlah anakan maksimum, jumlah anakan produktif, umur berbunga, jumlah gabah isi per malai, panjang malai, persentase gabah isi per malai, bobot 1.000 butir dan bobot gabah kering panen per rumpun. Hasil penelitian menunjukkan varietas dan tinggi muka air sangat berpengaruh nyata terhadap komponen pertumbuhan yaitu tinggi tanaman, jumlah anakan maksimum Varietas Cilosari, Inpari 39 dan Inpago 8 memberikan bobot gabah tertinggi yaitu masing-masing sebesar 36,93, 32,40 dan 31,89 g per rumpun. Perlakuan tinggi muka air 5 cm memberikan bobot gabah tertinggi sebesar 37,92 g per rumpun.

The Segura mining field, the easternmost segment of the Góis–Panasqueira–Segura tin–tungsten metallogenic belt (north–central Portugal), includes Sn-W quartz veins and Li-Sn aplite-pegmatites, which are believed to be genetically related to Variscan Granites. Sediment geochemistry indicates granite-related Ti-enrichments, locally disturbed by mineralization, suggesting magmatic and metamorphic/metasomatic titaniferous phases. Therefore, Segura alluvial samples and the geochemistry of their TiO2 polymorphs (rutile, anatase, and brookite) were investigated, and their potential as exploration tools for Sn and W deposits was evaluated. The heavy-mineral assemblages proved to be good proxies for bedrock geology, and TiO2 polymorph abundances were found to be suitable indicators of magmatic and/or metasomatic hydrothermal processes. The trace element geochemistry of Segura’s alluvial rutile, anatase, and brookite is highly variable, implying multiple sources and a diversity of mineral-forming processes. The main compositional differences between TiO2 polymorphs are related to intrinsic (structural) factors, and to the P-T-X extrinsic parameters of their forming environments. Anomalous enrichments, up to 9% Nb, 6% Sn and W, 3% Fe, 2% Ta, and 1% V in rutile, and up to 1.8% Fe, 1.7% Ta, 1.2% Nb, 1.1% W 0.5% Sn and V in anatase, were registered. Brookite usually has low trace element content (2 polymorphs can be a robust, cost- and time-effective, exploration tool for Sn(W) and W(Sn) ore deposit systems.

The application of thin-section petrography, field emission scanning electron microscopy and energy dispersive X-ray analysis (FESEM–EDX), Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), thermo-analysis, and laser Raman spectral analysis methods can be combined to characterize iron-ores and distinguish clay minerals in alluvial soils. The integrated methodology developed for this work provides the basis for a generic mineral characterization toolkit. Five main alluvial soil types have been defined in the upper layer of the lower Kelantan Basin, Malaysia: sand with low clay content, clay sand, sandy clay, mottled clay, and mud-sand. The soils contain significant concentrations of iron oxy-hydroxide, kaolinite, chlorite, and subordinate illite. FTIR spectroscopy showed that goethite in these soils is typical characterized by the presence of the band between 521 and 373 cm−1. Goethite and hematite show ranges of 851–612 cm−1 and 612–392 cm−1, respectively, and goethite twin bands between 3560 and 3738 cm−1. In other samples, the FTIR spectroscopy indicates strong goethite bending vibrations between 3567–3725 cm−1 and 612–832 cm−1, while hematite bands are between 392 and 532 cm−1. Bulk powder XRD analyses indicate goethite is the main iron-bearing mineral, while XRD clay mineral analyses show the presence of chlorite with minor concentrations of illite. Thermal analyses showed the endothermic dehydroxylation peak of goethite occurs between 486 and 502 °C in most of the samples. The difference in the dehydroxylation endothermic peak of goethite can be attributed to the nature of nanocrystalline pedogenic goethite. The presence of exothermic peaks in some samples is ascribed to the goethite-hematite transformation phase. The main iron-bearing mineral phases identified using the Raman laser spectra method are hematite coatings on quartz. In the Si–Onb, Si–Ob–Si, and cations stretching region, Raman bands are observed between ~ 800 and 1150 cm−1, 800 and 600 cm−1, and < 600 cm−1, a frequency which is usually known in the Raman shift for di-octahedral Kaolinite (Al4[Si4O10] (OH)8). Previous studies have been based on assumptions regarding drainage basin mineral composition in the absence of data. This work shows that the sources of transition metals contamination in groundwater can be from local, shallow sources and that collection of data for aquifer media mineral composition is essential for the understanding of the source and fate of soluble metals. [ABSTRACT FROM AUTHOR]

A study was conducted in lower Shiwaliks of Punjab, India to study the soil organic carbon (SOC) stock variation in hill, piedmont plain and alluvial plain regions of Punjab, and further to investigate the SOC variability down the slope in the lower Shiwaliks region of Punjab. The SOC fractions viz. very labile carbon, labile carbon, less labile carbon and recalcitrant were determined using standard methodologies. The total SOC stock in 0–60 cm soil depth was highest in plain region (31.81 Mg ha−1), followed by piedmont (23.43 Mg ha−1) and lowest in hill region (22.86 Mg ha−1). Whereas, the SOC concentration in surface layer was highest in foot slope (5.76 g kg−1) followed by mid slope (4.14 g kg−1) and lowest in up slope (2.32 g kg−1). Among the SOC fractions the average labile carbon content in soil samples was found in the order, hills (0.81 g kg−1) > piedmonts (0.73 g kg−1) > plains (0.50 g kg−1). The soil bulk density (Db) was higher in the plain than that of piedmont and hills. Moreover, a similar trend is observed in case of water holding capacity. Regression analysis has revealed significant relationship between Db and SOC stock at p < 0.05. Further, analysis of variance (ANOVA) at p < 0.05 has indicated significant differences among concentration of SOC and stock influenced by land use and soil depths. Thus, an understanding of the effect of physiography on SOC via such studies is important for soil quality management. [ABSTRACT FROM AUTHOR]

Vrgada Island is situated in the central part of the eastern Adriatic coast. Upper Cretaceous limestones crop out on the surface and Pleistocene sediments cover them in some parts of the island. This study focused on a coastal cliff trending N - S on the northern part of the island. Aeolian-alluvial deposits, which are 12.5 m thick were analysed and three different facies in this succession described. The lowermost facies A highlights a strong aeolian influence marked by an increased silt percentage and was deposited during colder climate conditions. Sand and gravel in facies B were deposited by streams of dense, cold water formed by melting snow and ice from the nearby Dinaric mountains. The bioturbated sandy facies C was probably formed during a warmer climate. An unusually high percentage of augite in the lowermost part of facies A can be explained by the input of volcanic dust, most likely from the Roman or Campanian volcanoes in Italy. This, combined with the surface textures on quartz grains detected from SEM photographs indicates a short distance transport for the sediment, no matter which mechanism was dominant. The sediments from Vrgada Island represent a transitional zone between the north Adriatic islands, where aeolian sediments dominate and the South - Eastern Adriatic archipelago, where mixed alluvial and aeolian sediments were observed. [ABSTRACT FROM AUTHOR]

In the world, the hazards of intense rainfall are recurrent and increasing. In addition, they are one of the natural hazards that cause the most severe damage to infrastructure and even cause deaths every year. Flow-type landslides are capable of develop in areas with different geomorphological, geological and climatic characteristics. In hyper-arid zones such as the Atacama Desert, these hazards are capable of develop in a timely manner, causing catastrophes. This study analyzes the flow-type landslide in a hyper-arid mountainous area in La Chimba basin of Antofagasta city (Chile). For this, a hydrometeorological analysis is carried out through a pluviometric analysis, statistical analysis of frequencies through the Gumbel probabilistic method of extreme values and determination of maximum flows by obtaining IDF (intensity-duration-frequency) curves and design rainfall intensity as a function of concentration time. To obtain the maximum flows of liquid runoff and debris, for different return periods, the rational method was used with the method proposed by O’Brien. For the determination in the impact zone, the modeling software HEC-RAS (Hydrologic Engineering Center’s River Analysis System) and RAMMS (Rapid Mass Movements). Hydrographs are used for a return period of about 200 years, considered the most unfavorable scenario with the Voellmy–Salm model. To validate the modeling, a morphometric, sedimentological and comparative analysis is carried out between real impact zones of 1991 event and those generated in this study. It is concluded that the sedimentological and morphometric characteristics indicate that the type of flow that it can originate would have a rapid response to rainfall events of great intensity or duration. The modeling provided by HEC-RAS represents a fluvial-type flow, while the RAMMS modeling is closer to the consistency of a flow-type landslide, which is estimated to be closer to reality. The results show that despite being in a hyper-arid zone, the rainfall factor is capable of landslides triggering in mountainous areas.

The weathering of platinum-group element (PGE) deposits presents unusual problems, especially in the very active environment of lateritic weathering under tropical conditions. There is clear evidence of the destruction of platinum-group minerals (PGM) to form PGE oxides, or fine intergrowths between relict PGM and iron oxides or hydroxides, as an intermediate stage during weathering. The PGE released by weathering are transported in solution with the more soluble Pd species remaining in solution and travelling further than the less soluble Pt species. The presence of PGM in the laterite differing in mineralogy, mineral assemblage and size from those in the primary rock is difficult to explain, especially when they show secondary textures. Differing interpretations have created controversy. Are alluvial PGM derived unaltered from the primary rock where they are rare and, therefore, not encountered by standard petrographic examination? Is it possible that they could have developed in the laterite by some process that we do not yet fully understand? Some favourable genetic conditions have been outlined and debated. For more than 100 years authors have reported secondary ore textures and recently proposed a biogenic origin. Frank Reith and his co-workers provided evidence of a process involving metallophillic bacteria which, for the first time, demonstrates PGM growth in the laboratory under supergene conditions. Their work shows that a mechanism for supergene growth ('neoformation') can occur, which offers a new field of study of the appropriate Eh, pH, $f_{{\rm O}_ 2}$ conditions and organic and bacterial reactions that could permit supergene growth. [ABSTRACT FROM AUTHOR]

Informal small-scale mining is spread in many countries and provides livelihood to numerous families in rural areas yet often with devastating social and environmental impacts. The alluvial gold mining process in Colombia, also known as placer mining, involves excavations using heavy machinery and creates large footprints of bare soil and mining ponds. The very dynamic nature of this extractive activity and its spread in rural and remote areas make its mapping and monitoring very challenging. The use of freely available satellite data of the Copernicus programme provides great new possibilities to study these activities and provides stakeholders integrated data to better understand the spatial and temporal extent of the activities and mitigate affected areas. The objective of this work is to assess the potential of Sentinel-2 data to identify mining areas and to understand the dynamics in landcover change over a study area located at the border of the municipalities of El Bagre and Zaragoza in Bajo Cauca, Colombia. The study utilizes a classification approach followed by post-processing using field knowledge on a set of images from 2016 to 2019. Sequential pattern mining of classified images shows the likelihood of certain annual and seasonal changes in mining-impacted landcover and in the natural vegetation. The results show a slight reduction in the detected mining areas from 2016 to 2019. On the other hand, there are more mining activities in the dry season than in the wet season. Excavated areas of bare soil have a 50% chance to remain in excavation over the considered period or they transition to non-vegetated areas or mining ponds. Vegetation loss due to the extractive activities corresponds to about 35% while recovered vegetated areas are 7% of the total excavated areas in June 2019. An analysis of abandoned sites using NDVI shows that it takes a much longer period than the one considered in this paper for potential natural recovery of vegetation. Finally, the work was disseminated among stakeholders and the public on MapX (https://mapx.org), an online open platform for mapping and visualizing geospatial data on natural resources. It is a pilot study the will be the basis of the analysis of more regions in the department of Antioquia.

The soil quality index is a quantitative assessment concept and it is used in the evaluation of ecosystem components. Because of the high potential for agriculture and biodiversity, deltas are the most valuable parts of the ecosystem. This study aimed to determine the soil quality index (SQI) in the Batumi Delta, Georgia. For this purpose, the study area was divided into five plots due to their morphological positions (L1, L2, L3, L4, and L5). A total of 125 soil samples were taken for analysis including clay content (CC), silt content (SC), sand content (SaC), mean weight diameter (MWD), aggregate stability (AS), amount of water retained under -33 kPa (FC) and -1500 kPa (WP) pressures and organic matter content (OM). These properties were used as the main criteria, and the Analytic Hierarchy Process (AHP) and Factor Analysis were used for weighting them. Sub-criteria were scored using expert opinion and the linear score functions, such as "more is better" and "optimum value". For determining SQI, the additive method (SQIA), the weighted method with AHP (SQIAHP), and the weighted method with factor analysis (SQIFA) were used. The resulting SQI scores of the three methods were ordered as SQIAHP>SQIA>SQIFA, but these differences were not significant. However, the SQI scores of the plots (p£0.01) showed statistically significant differences and were ordered as L5>L4>L3>L2>L1. [ABSTRACT FROM AUTHOR]

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The shallow alluvial aquifers on the floodplain are the major sources of water supply for the dry season farming activities. The research is aimed to estimate the aquifer transmissivity of the alluvial formations on the floodplain using Dar Zarrouk Parameters derived from geoelectric soundings. Ten profiles of vertical electric soundings (VES) using schlumberger array method with the aid of a sensitive ABEM Signal Averaging System (SAS) was in the investigation. The results revealed five geoelectric layers on the alluvial formation of the floodplain. There were three, four, five, six and seven layers beneath the alluvial formation. The results were compared with the alluvial floodplain lithologies at each sounding points with resistivity values ranging between 0.98 Ωm to 4,113 Ωm and depths varying from 0.01 to 146 m. The geoelectric sequence of the alluvial formations of the flood plain reveals semi aquifer system. The aquifer hydraulic characteristics indicated that the transverse resistance R ranged between 436.8 Ωm2 to 77,324.40 Ωm2 with a mean value of 11,963.71 Ωm2. The longitudinal conductance S ranged between 0.0026 to 1.792 with an average value of 0.26348. The hydraulic conductivity value across the floodplain ranged between 0.16 m/day to 29.79 m/day with a mean value of 5.597 m/day. The transmissivity values obtained for the various layers range between 1.6 m2/day to 834.1 m2/day with an average value of 128.86 m2/day. The results of the hydraulic head reveal that the floodplain recharges the River. High groundwater potential zone occurs in the southern part of the study area

Diffuse Reflectance Spectroscopy (DRS) is a rapid, relatively new method in Quaternary research to analyse sediments and paleosols. This method takes into account clay mineral content, amount of Fe-bearing minerals and grain size composition of samples, simultaneously. Different Quaternary sediment samples were chosen for characterization and comparison their reflectance curves to detect the essential spectral properties of different paleosols and parent materials. Samples of different sediment types and paleosol variants were investigated from a loess-paleosol sequence from Malá nad Hronom (Slovakia) and from a fluvial-aeolian sediment complex from Pilismarót (Hungary). Five investigated curve sections were separated as the best indicators of reflectance properties of DRS curves. Spectral properties of samples were compared by using the length of investigated curve sections. This investigation showed quantifiable differences between the units of Pleistocene sediment successions, based on the reflectance properties. The influence of pedogenic processes was properly detectable. Significant discrepancies were observed between reflectance curves of well-developed paleosols and parent material samples in the visible and near-infrared range. Differences between the weak developed paleosol layers and their parent materials were only observed in the visible range. Fine sand, sandy silt and loess materials could be separated from each other based on the intensity of entire reflectance curves. [ABSTRACT FROM AUTHOR]

A review of the geologic literature regarding sedimentation in the San Francisco Bay estuarine system shows that the main part of the bay occupies a structural tectonic depression that developed in Pleistocene time. Eastern parts, including San Pablo Bay and Suisun Bay, have had sedimentation throughout late Mesozoic and Tertiary. Carquinez Strait and the Golden Gate may represent antecedent stream erosion. Sedimentation has included estuarine, alluvial, and eolian deposition. The ages of estuarine deposition includes the modern high sea level stand and earlier Pleistocene interglacial periods. Sediment sources can be generally divided into the Coast Ranges, particularly the Franciscan Complex, and “Sierran.” Much of the estuarine system is floored by very fine sediment, with local areas of sand floor. Near the Golden Gate, sediment size decreases in both directions away from the deep channel. Bedforms include sand waves (submarine dunes), flat beds, and rock and boulders. These are interpreted in terms of dominant transport directions. Near the Golden Gate is an ebb-tidal delta on the outside (including San Francisco bar) and a flood-tidal delta on the inside (parts of Central Bay). The large tidal prism causes strong tidal currents, which in the upper part of the estuary are normally much stronger than river currents, except during large floods. Cultural influences have altered conditions, including hydraulic mining debris, blasting of rocks, dredging of navigation channels, filling of the bay, and commercial sand mining. Many of these have served to decrease the tidal prism, correspondingly decreasing the strength of tidal currents.