Source Of Gypsum Research Articles

Evaluation of active carbon under sodic soil after gypsum and bio- compost application

An experiment was conducted to evaluate the active carbon under sodic soil after the improvement through natural sources of gypsum and bio-compost. This experiment was carried out at the Indian Agricultural Research Institute, Sub Regional Station, Pusa (Samastipur), Bihar during the Kharif session of 2018 and 2019. The experimental site was laidout in split plot design with four treatments of gypsum and bio-compost application in main plots and ten rice genotypes sowed into subplots and replicated in thrice times. After the experiment results observed that the improved soil pH, ESP, and EC significantly. The active carbon was observed to the significantly higher in more application doses of bio-compost than gypsum and also observed that some rice genotypes helps in improving active carbon under-treated with bio-compost and gypsum plots i.e. CSR-36, CSR-27, CR-3884-244-8-5-6- 1-1, and CSR-30.

Role of Sulphur Nutrition in Oilseed Crops: A Review

India is a significant importer of edible oils and an important producer of oilseed. India stands as fourth leading oilseeds producing countries after USA, China and Brazil. Oilseed has become one of the most valuable agricultural commodities. Sulphur (S) plays an important role in determining the quality of oil seed from these crops. It is referred to as the fourth major nutrient after N, P and K because crops need sulphur slightly less than they require P. It is required for the formation of proteins, vitamins and chlorophyll. It is an integral part of amino acid such as cystine, cysteine and methionine which are essential components of protein. Plant can absorb sulphur in the form of sulphate (SO4 2-) which is decomposes into sulphur. It is a factor for the determination of higher yield seed and quality of seed that content oil in oilseed crops. Since, sulphur is immobile in plants, it must be continuously supplied from crop emergence till maturity. So, reduced yield can come sulphur shortage at any stage of growth. It can be overcome by supplying sulphur containing fertilizers to plant by soil application and foliar application. Among the source of sulphur, elemental sulphur and gypsum are widely utilized in sulphur deficiency.

Comparison of the effectiveness of mined and by-product South African gypsums and other calcium sources for soil sodicity remediation

Studies evaluating the effectiveness of South African gypsum sources are scarce or outdated because of newly introduced products, such as granulated and liquid gypsums. The efficacy of calcium (Ca) nitrate and micro-fine (MF) calcitic limes in comparison to gypsums has also never been evaluated. The aim of this study was to compare the effectiveness of mined and by-product gypsums and other Ca sources in terms of soil sodicity remediation and saturated hydraulic conductivity (Ksat) improvement. In a controlled laboratory study, 12 mined and by-product gypsums sources, MF calcitic limes and calcium nitrate were surface-applied to a sodic, sandy loam soil to achieve an exchangeable sodium percentage (ESP) of 5%. The soils received 300 mm simulated rainfall, and then soil chemical properties and Ksat were determined. Finer by-product gypsum sources (particularly liquid and flue gas desulphurisation (FGD) gypsums) exhibited faster dissolution rates and superior performance in lowering soil ESP to 4.2–4.7% and pH by 0.5–0.7 units compared to Class A mined gypsums (ESP 9.0–11.1% and 0.2 pH units). Only the liquid, phospho-, FGD gypsums and calcium nitrate significantly increased soil hydraulic conductivity (123–130%) compared to the control. The MF calcitic limes had no effect on the sodic soil properties.

Effect of Sources and Levels of Sulphur on Quality, Nutrient Content and Uptake of Summer Cowpea (Vigna unguiculata L. Walp.) under South Gujarat Condition in India

A field experiment was conducted during 2021 to study the effect of sources and levels of sulphur on summer cowpea (vigna unguiculata L. walp.) under south Gujarat condition. The results revealed that application of sulphur with gypsum source showed significantly higher seed yield (1392 kg ha-1), stover yield (2502 kg ha-1), crude protein yield (295.18 kg ha-1), nutrients content and uptake (N, P, K and S) by seed and stover and maximum net realization of Rs. 56100.38 ha-1 with BCR of 1.74. The application of 30 kg S ha-1 gave significantly higher crude protein yield (302.03 kg ha-1), seed yield (1393 kg ha-1), stover yield (2508 kg ha-1), nutrients content and uptake by seed and stover and maximum net realization of Rs. 55861.08 ha-1 with maximum BCR 1.71.

Material characteristics of historic scagliola interiors in Vienna: A view through the microscope.

Composition and microstructure of four Viennese scagliola samples, originating from the early 18th to early 20th centuries, were analysed by different methods of microscopy. Results indicate a similar composition in all samples; only minor differences could be observed in the porosity and grain-size-distribution. While, the calcium sulphate raw material was fired at low temperatures (<200°C), the presumable presence of anhydrite II in two samples may indicate hot spots (200-300°C) during the calcination. To achieve 'marble-like' patterns mineral pigments were used to dye the ground mass. The first results show that scagliola surfaces of this study were produced by using the same or very similar technology between the 18th and early 20th centuries. The present study focuses on scagliola interiors in Vienna, Austria from different stylistic periods between the early 18th and early 20th centuries. Scagliola, also called stucco marble, imitates natural stone. It is produced by a mixture of gypsum (CaSO4 ·2H2 O), different pigments, animal glue and water. In the history of interior design, the material played an important role in the 18th and 19th centuries in Central Europe. The aim of the research was a detailed investigation of four selected samples in order to identify the raw materials and manufacturing technology of the stucco marbles used over time in Vienna. As a first step thin sections (i.e. polished, transparent samples with a thickness of 0.03 mm) were prepared from the samples and analysed by different microscopic techniques. All samples showed similarities in their bulk properties, but detailed investigations revealed also some differences in their mineralogical composition. The gypsum binders contained typical air voids and so-called secondary pores which were formed by dissolving larger binder-related particles during the preparation of the mixture. The macroporosity (i.e. the amount of the pores in the samples which are larger than 0.01 mm) measured on microscopic images varied in a narrow range between 14.1% and 19.3%. The raw materials of all samples were fired at relatively low temperatures (i.e. below 200°C), but in two samples we could also determine a few anhydrite (CaSO4 ) crystals that normally form at higher temperatures in the kiln. This indicates that the distribution of temperature in the kiln was heterogeneous during the firing process. The amount and appearance of some minor mineral constituents such as dolomite (CaMg[CO3 ]2 ) and celestine (SrSO4 ) suggest that they were naturally occurred in the raw material and not deliberately added to the binder as a filling material. To achieve different colour hues and imitate natural stone surfaces, fine-grained mineral pigments and charcoal powder were used. Although we have no distinct information about the gypsum sources of these stucco marbles, several small historical gypsum quarries existed southwest of Vienna. Some of them were already in operation in the 16th century, thus a local gypsum occurrence used as a raw material is very probable. Due to the fact that the main features of the analysed samples were very similar, we assume that the scagliola surfaces of this study were produced by using the same or very similar technology between the 18th and early 20th centuries.

Mining Exploration, Raw Materials and Production Technologies of Mortars in the Different Civilization Periods in Menorca Island (Spain)

This study deals with the mortars and subordinately rocks collected from the archaeological site of Cap de Forma, that is a “Bien de Interés Cultural” located on a cape along the southeastern coast of Menorca (Balearic Islands, Spain). Cap de Forma consists of different structures belonging to different periods and civilization phases: a fortified settlement of Talaiotic age, built in cyclopean technique and including three rooms and a rainwater cistern; a nearby necropolis of tombs (cuevas) excavated into the cliff; a more recent site occupancy testified by plastering of the cistern; a house-fort (pecheña casa-quartel), a lookout point of the 17th–18th century. Compositional features and mineralogy of mortars and rocks were investigated by optical microscopy and X-ray diffraction. Physical properties (density, porosity, water saturation and water saturation coefficients and mechanical strength) were also determined. This work is aimed at characterizing these archaeologic remains to understand the building technique, the choice of raw materials and possibly their provenance, taking into account the age and civilization they belong to. Results indicate that cocciopesto-rich mortars were used in the cistern watertight and other ancient structures linking from a Roman age. The cocciopesto seems to derive from local pottery even if some evidence would suggest the contrary, whereas the source of the binder is definitely the local Mg-rich limestone. The house-fort was plastered with gypsum-based mortars in the 17th–18th century. The most likely source of raw gypsum was the island of Mallorca where some quarries were opened in the same period. Mechanical and physical tests reveal a strong state of decay that requires conservation actions. This work sheds light on a poorly studied monument, better constraining the different phases of its occupation. Some interesting questions, such as the cocciopesto provenance, are still open.

Geochemical And Mineralogical Assessment Of Secondary Gypsum In Al-Najaf, Iraq And Employment As Raw Material For Cement Industry

The Portland cement industry is one of the strategic industries in any country. The basis of an industry success is the availability of raw materials and, the low extraction in addition to transportation costs. The Bahr Al-Najaf region is abundant with limestone rocks but lacks primary gypsum. An investigation had been carried out to identify the source of secondary gypsum as an alternative to primary gypsum. Twelve boreholes were drilled for a depth of 2 m, as the thickness of suitable secondary gypsum layer ranges from 1 to 1.5 m. The mineralogical study revealed the predominance of gypsum followed by quartz and calcite, with an average of 62.9%, 19.6% and 14.35%, respectively. The geochemical analysis revealed that the content of SO3 is appropriate and ranging from 41.92% to 32.89% with an average of 37.73%. The SO3 content is within an acceptable range. The mean abundance of the major oxides of the study area may be arranged as SO3 &gt; CaO&gt; SiO2&gt; MgO&gt; Al2O&gt; Fe2O3. The insoluble residue was at an acceptable rate. The laboratory experiments for milling secondary gypsum with clinker has successfully proven the production of Portland cement that matches the limits of the Iraqi Quality Standard (IQS) No. 5 of 1984. Great care must be taken when using secondary gypsum; secondary gypsum must be mixed well to maintain the chemical properties before blending with clinker and utilizing in the cement mill in the cement plant.

Gypsum Amendment Induced Rapid Pyritization in Fe-Rich Mine Tailings from Doce River Estuary after the Fundão Dam Collapse

Mine tailings containing trace metals arrived at the Doce River estuary, after the world’s largest mine tailings disaster (the Mariana disaster) dumped approximately 50 million m3 of Fe-rich tailings into the Doce River Basin. The metals in the tailings are of concern because they present a bioavailability risk in the estuary as well as chronic exposure hazards. Trace metal immobilization into sulfidic minerals, such as, pyrite, plays a key role in estuarine soils; however, this process is limited in the Doce River estuarine soil due to low sulfate inputs. Thus, to assess the use of gypsum amendment to induce pyritization in deposited tailings, a mesocosm experiment was performed for 35 days, with vinasse added as carbon source and doses of gypsum (as a sulfate source). Chemical and morphological evidence of Fe sulfide mineral precipitation was observed. For instance, the addition of 439 mg of S led to the formation of gray and black spots, an Fe2+ increase and decrease in sulfides in the solution, an increase in pyritic Fe, and a greater Pb immobilization by pyrite at the end of the experiment. The results show that induced pyritization may be a strategy for remediating metal contamination at the Doce River estuary.

Potential of Lacto-Gypsum as an Amendment to Build Soil Quality

Strategies for the use of amendments on agricultural soils are needed to help build resilience against potential soil threats. Gypsum is commonly applied to improve soil quality and nutrient supply. However, the sustainability and environmental safety of some gypsum sources is uncertain. This study aims to i. characterize a new by-product, lacto-gypsum, derived from a dairy whey side stream over a 1 year pilot production cycle and ii. assess the temporal variability of the raw form of lacto-gypsum and the stability of its physico-chemical and compositional properties when stored under three potential storage regimes. Results showed that lacto-gypsum compares favorably with conventional equivalents in terms of nutrient and trace element concentrations and represents an environmentally safe material free of contaminants. Storage form did not affect its main physico-chemical characteristics over time and the raw lacto-gypsum remained stable up to 20 days when stored at 4°C. In contrast to conventional gypsum, the lacto-gypsum had very low pH. In general this new lacto-gypsum shows potential as a suitable product for use as a soil amendment or as an acidification agent for animal slurry to reduce ammonia gas emissions during storage. However, further evaluation of this by-product in real life scenarios is required.

Edaphological and water quality conditions that limit agricultural development in semi-arid zones of Northeastern Mexico.

Salinity is one of the main causes of soil degradation, which reduces the capacity for biomass production. Naturally, saline soil is related to climatic, hydrogeological, and edaphic processes. Evaporite rocks are a potential source of gypsum and anhydrite in climates where annual rainfall does not exceed 400 mm. Like any salt, anhydrite contributes to salinity processes that reduce osmotic potential in plants, giving rise to water stress that reduces turgor in plants. In the Zona Media of San Luis Potosí, soil salinity is not homogeneous but rather varies spatially and is associated with soil genesis, agricultural irrigation water quality, and climate. Water sodicity (% Na), toxicity (pH, B3+ y Cl-), and salinity hazards were evaluated by applying agricultural water quality indices. Low sodicity hazard was found at all sample points; chloride and boron did not pose toxicity hazards, but high sulfate concentrations can lead to toxicity and calcium and magnesium deficiency. The salinity hazard was high, identified using OP, EC, TDS, ES, and PS indices. This condition is related to the region's evaporite soils and semi-arid climate.

Sulphur on Groundnut Yield and Quality

Groundnut yield is enhanced by the sulfur supplement which aids in the improvement of chlorophyll synthesis leading to higher partitioning of assimilates resulting in high growth and yield parameters. Sulfur deficiency results in poor flowering, fruiting, cupping of leaves, reddening of stems, petiole and stunted growth. Sulfur is required for the synthesis of protein, oils and vitamins. Methionine (21 % S), cysteine (26 % S), Cystine (27 % S) are important amino-acids that are supplied by sulfur triggers protein synthesis and biochemical reactions that increases oil content and oil quality .Variety of sulfur sources and levels had been tried in experiments by researchers to evaluate the potential level that sustains high growth, yield and productivity of groundnut resulting in higher net returns. Application of sulfur about 40-60 kg ha-1 proved to an optimistic level through gypsum sources for groundnut.

Gypsum efflorescence on clay brick masonry: Analysis of potential efflorescence origins

Gypsum efflorescence on clay brick masonry is a growing problem, leading to a persistent grey-white staining of masonry facades. Gypsum efflorescence has been reported in the United Kingdom, the Netherlands and Belgium, with a specific occurrence on masonry facades erected over the last few decades. This article investigates the origin of this recent occurrence of gypsum efflorescence, with accelerated testing of the gypsum efflorescence sensitivity of separate and combined masonry components. It is demonstrated that both brick and mortar may provide a gypsum source, respectively, via the dissolution of anhydrite and the carbonation of ettringite. Neither does however directly result in gypsum efflorescence, as the released gypsum commonly subfloresces below the brick surface. The efflorescence is instead triggered by mortar admixtures, the application of which has indeed risen strongly in recent decades. Avoiding gypsum efflorescence on clay brick masonry hence requires an inert alternative for the mortar admixtures.

Production of Gypsum from Clamshells and Waste Acid Recovered from End-of-Life Lead Acid Batteries

Gypsum exists in the Dihydrate (CaSO4 2H2O), Hemihydrate (CaSO4. ½H2O) and the Anhydrite (CaSO4) forms. The exploitation of the natural rock form deposit of gypsum is on the increase, necessitating the need to find alternative and efficient sources of gypsum so as to sustain all the industries dependent on gypsum as raw material. This work investigates the production of gypsum from clamshells and waste sulphuric acid from end-of-life car batteries. Clamshells obtained from the Volta Region of Ghana were calcined at a temperature of about 1000 ˚C with a view of producing CaO which was pulverised to particle size of 96 % passing 106 μm. Samples of the Pulverised Clam Shells (PCS) were then reacted with five different concentrations of the Waste Battery Acid (WBA). The reaction was observed to be very exothermic; a temperature of 101 ˚C was obtained for the 6.5 M concentration of WBA. The resulting mixture was filtered and an XRD analysis was performed on the oven dried residue to ascertain its composition. The findings from the work revealed that 100 g of pulverised clam shells produced an average of 58.08 g of calcined product and 134 g of gypsum. Peaks of SiO2 and CaCO3 in the XRD diffractogram of the gypsum indicated that the reaction between PCS and WBA was incomplete. Conclusively, the results from the XRD analysis showed peaks of the three forms of gypsum that was successfully produced. Keywords: Net Present Value; Internal Rate of Return; Sensitivity Analysis; Risk Analysis

Physical weathering of carbonate host-rock by precipitation of soluble salts in caves: A case study in El Orón-Arco Cave (Region of Murcia, SE Spain)

The dissolution of carbonate host-rock by freshwater in phreatic or vadose conditions is the most common mechanism for the formation of caves; however, circulation of saline solutions through carbonate materials and precipitation of soluble salts may also play an important role. We studied the stable isotope composition (δ18O and δ34S of sulfate, δ18O and δD of structurally-bound gypsum hydration water and 87Sr/86Sr) and salinity of fluid inclusions in gypsum speleothems found in El Orón-Arco Cave (Cartagena, SE Spain). We suggest that physical weathering of carbonate host-rock was driven by precipitation of soluble sea-salts (mostly gypsum and halite), and this process controlled the recent geomorphological evolution of the cave. The Triassic carbonate host-rock shows clear evidence for salt weathering, including gypsum/halite infillings in cracks of the bedrock, mechanical spalling of the carbonate, and detachment of rock fragments that lead to the formation cave voids and in-situ accumulations of piles of unsorted rubble. Sulfur and oxygen isotopes of gypsum sulfate (3.0‰ < δ18O < 11.6‰ and 16.7‰ < δ34S < 20.7‰) are generally lower than modern seawater sulfate and suggest contributions from a 34S-depleted source (i.e. oxidation of pyrite). The δ18O and δD of gypsum hydration water are relatively low compared to expected values for the evaporation of pure seawater to gypsum saturation, suggesting that gypsum precipitation involved a secondary calcium-sulfate source or recycling of gypsum from previous stages, along with mixing of seawater and meteoric water seepage to the cave. The 87Sr/86Sr in gypsum shows intermediate values between modern seawater and Triassic carbonate values because of interaction between the solution and the bedrock. The salinities of the speleothem-forming solutions are relatively high (13.2 ± 3.2 wt% eq. NaCl) compared to gypsum formed from evaporated brackish solutions (i.e. ~4–8 wt% eq. NaCl) and indicate dissolution of earlier evaporites before secondary gypsum precipitation. This cave-forming mechanism, which is related to saline water circulation and precipitation of evaporitic minerals, may be common in other coastal caves.

Mineralogical Analysis of Sand Roses and Sand Dunes Samples from Two Regions of South Algeria

In this work, it is found that the important minerals in sand dunes and sand roses samples from Anqousa in the south-east of Algeria in Ouargla region and from Charouin in the south-west in Adrar area are the quartz and Gypsum phases. The aim of this study is a qualitative and quantitative minerals evaluations of two areas samples using x-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), Scanning electron microscopy (SEM) and energy dispersive x-ray spectroscopy (EDS). Granulometric classification and size distribution were carried out using Laser scattering particle size analyser. Numerous observed diffraction peaks confirm the presence of polycrystalline quartz phase in sand dunes samples as principal mineral. In the case of sand roses samples, the diffraction spectra show that the basic mineral is Gypsum. The sand dunes samples infrared absorption spectrum show the characteristic vibration bond peaks for quartz as 460, 695, 779 and 1082 cm− 1, also these analysis reveal the Gypsum characteristic peaks at 1616 and 1620 cm− 1. FTIR spectra enregistred on sand roses samples showed the absorption peaks at 3552, 3492, 3404, 1685, 1620, 669 and 602 cm− 1 indicate the presence of gypsum. Through combination between the results of DRX, FTIR and EDS, it appears that the concentration of quartz in ouargla sand samples is greater than that in Adrar sand, contrariwise the concentration of Gypsum in Adrar sand dunes is the most important. It was deduced that Adrar sand roses have the higher concentration of Gypsum. The grain size varies between 58.953 and 777.141μm with an average value ≈ 213.386 μm for ouargla sand and between 74.219 and 198.531μm with an average value ≈ 132.684 μm for Adrar sand dunes. The obtained results confirm that the two regions can be important sources of quartz and Gypsum as primary materials for many industry applications.

An empirical rate law for gypsum powder dissolution

The dissolution rates, normalized by surface area, of two different gypsum powders in aqueous solutions were measured by tracking changes in solution composition as a function of time in a continuously stirred batch reactor. The powders were classified into different size ranges to observe the influence of particle coarseness on dissolution kinetics. Changes in solid surface area during the experiment were modeled as a function of mass loss by measuring the specific surface areas of the powders before and after the experiments. Contrary to the implicit assumption in several previous studies, the total powder surface area increases, typically by a factor of two, prior to decreasing with ongoing dissolution. This phenomenon therefore has a significant influence, up to 50%, on the surface area-normalized rate. The initial solution composition was set to one of several prescribed saturation states so that an empirical rate law could be inferred over a wide range of saturations. The rate coefficient for both types of gypsum depended on size, being lower for coarser particles. Other than the difference in rate coefficients, the dissolution rate of both sources of gypsum can be described well by the same mathematical function of solution saturation, at least to within the uncertainty in the measurements. Data from previous studies of gypsum dissolution appear to follow approximately the same dependence on particle size as observed in this study.

Paleohydrogeology of a Paleozoic sandstone aquifer within an intracratonic basin: Geochemical and structural controls

The aqueous geochemistry of the St. Peter Sandstone, a major aquifer in the Illinois Basin, an intracratonic sedimentary basin, is extremely complex. There are multiple sources of water, including in situ remnant brines, leakage from overlying and underlying units, and recharge during both the Pleistocene and Holocene Epochs. In our study region, recharge to the St. Peter Sandstone has come from multiple locations, and structural features, primarily the LaSalle Anticlinal Belt but also possibly the Sandwich Fault Zone, are a major control on recharge and groundwater flow. In the northern part of the study region, Holocene recharge has displaced most of the Pleistocene recharge, but in the rest of the study region considerable amounts of Pleistocene recharge still exist. The ion chemistry in the St. Peter Sandstone cannot be accounted for by simple mixing of Pleistocene recharge and in situ brines, and the most likely mechanism that could account for the aqueous chemistry is leakage of fluids from overlying formations via fractures opened by flexural loading during glacial advances. The water chemistry in the Western Region of our study area is clearly different from the Central and Eastern regions, having a more pronounced signature of Pleistocene water and suggesting different flow paths and sources of recharge. The large concentrations of SO42− and relatively high δ34S values in the Western wells suggest an up-gradient source of anhydrite and/or gypsum, possibly from Mississippian evaporite deposits in Iowa.

The treatment of phosphogypsum with zeolite to use it in binding material

In Lithuania, there are accumulated large amounts of fertilizer by-product – phosphogypsum and there is a lack of sources of natural gypsum. Recycling of by-product is one of the effective solutions of its disposal problem. The paper describes an investigation of the hydration behavior of a phosphogypsum with zeolite (hydrosodalite) addition using ultrasound treatment. Two ultrasound treatment durations: 0.5 min and 2 min were used. It was found that hydrosodalite is an effective adsorption additive for acidic contaminants (solvable P2O5 and F) present in phosphogypsum, which allows regulating the phosphogypsum hydration and setting time. The compressive strength of samples containing 5% hydrosodalite and with 2 min sonication is 35% higher, than the compressive strength of samples without additive and sonication. In this case, the positive effect of sonication and of hydrosodalite additive is combined. Phosphogypsum as a residue from the phosphate fertilizer industry is classified as a Naturally Occurring Radioactive Material (NORM). Therefore, when it is used as an additive component to building materials radioactivity content must be checked. The different amount of the various radionuclides within the natural radioactive decay series, such as that of 226Ra, 228Ra, 228Th, 40K, and 210Pb were measured by high resolution gamma spectrometry. The results showed that activity concentration of natural radionuclides as 226Ra, 228Ra, 228Th, 40K are below the clearance limit and activity concentration indices calculated for all materials used for experiments met the existing criteria allowing to use them for construction purposes.

English

Poor soil fertility, moisture stress, and shortage of early maturing varieties&nbsp;are the major groundnut production constraints in the study area. This study was executed to evaluate the effect of Diammonium phosphate (DAP) and gypsum application, tied ridging and supplementary irrigation on groundnut production. The experiment was laid out in a Randomized Complete Block Design with three replications in two sites. DAP as a source of phosphorous and gypsum as source of calcium were applied at planting and pod setting stages, respectively. While tied ridging and supplementary irrigation were applied at early flowering and during cessation of rainfall, respectively. Phenological, yield, and yield components data were recorded. Analysis of variance indicated that the integrated agronomic management options showed a significant positive effect on plant height, pods per plant, dry biomass weight, dry pod weight, kernel seed yield and 100-seed weight of groundnut at both experimental sites. Between both experimental sites, the highest kernel yield (980 kg/ha) was recorded when supplementary irrigation + tied ridge + fertilizer were practiced while the lowest yield (290 kg/ha) was recorded in the control. &nbsp; Key words: &nbsp;Agronomic practices, yield and yield components, moisture stress, groundnut.

A model of basin evolution in the Qa’ Al-Azraq, Jordan using sulfur isotope analysis to distinguish sources of sulfur and gypsum

The closed basin of the Qa’ Al-Azraq, Jordan records gypsum and sulfur depositions. Analysis of the cored sediments used smear slides, isotope geochemistry of gypsum and sulfur, XRD, and SEM. This study distinguishes the sources of gypsum and sulfur in the basin from four different processes. Algae production was responsible for the presence of laminated sulfur at a depth of 48 m where paleolake levels were at a high stand. Primary gypsum, represented by laminated, thick massive beds, records sulfur isotope values of +15.7‰. This period of the paleolake indicates evaporation processes exceeded precipitation, leading to the deposition of thick, massive bed of gypsum. Other sources of gypsum originate from pyrite oxidation, indicated by the overlapping of sulfur isotope values of gypsum and pyrite at −0.7‰. Bassanite and anhydrite identified in this section resulted from dissolution and recrystallization processes. The application of sulfur isotopic analyses identifies environmental distinct formation processes of sulfate minerals in the Al-Azraq basin. This provides the basis for a model of basin evolution and associated changing climates. Finally, this research considers the effect of sulfate minerals on Al-Azraq basin groundwater.