Carbon mineralization

The Charge Distribution MUltiSite Ion Complexation or CD-MUSIC modeling approach is used to describe the chemical structure of carbonate mineralaqueous solution interfaces. The new model extends existing surface complexation models of carbonate minerals, by including atomic scale information on the surface lattice and the adsorbed water layer. In principle, the model can account for variable proportions of face, edge and kink sites exposed at the mineral surface, and for the formation of inner-and outer-sphere surface complexes. The model is used to simulate the development of surface charges and surface potentials on divalent carbonate minerals as a function of the aqueous solution composition. A comparison of experimental data and model output indicates that the large variability in the observed pH trends of the surface potential for calcite may in part reflect variable degrees of thermodynamic disequilibrium between mineral, solution and, when present, gas phase during the experiments. Sample preparation and non-stoichiometric surfaces may introduce further artifacts that complicate the interpretation of electrokinetic and surface titration measurements carried out with carbonate mineral suspensions. The experimental artifacts, together with the high sensitivity of the model toward parameters describing hydrogen bridging and bond lengths at the mineralwater interface, currently limit the predictive application of the proposed CD-MUSIC model. The results of this study emphasize the need for internally consistent experimental data sets obtained with well-characterized mineral surfaces and in situ aqueous solution compositions (that is, determined during the charge or potential measurements), as well as for further molecular dynamic simulations of the carbonate mineral-water interface to better constrain the bond lengths and the number plus valence contribution of hydrogen bridges associated with different structural surface sites.

The first occurrence of chrysoberyl in the Borborema Pegmatite Province (BPP) in northeastern Brazil is reported from up to 0.5 m large boulders in the dumps covering the Roncadeira pegmatite, worked in the 1940's for Sn-and Ta-ore concentrate. The chrysoberyl occurs in tabular, transparent light yellow crystals, up to two centimeters across. It is associated with quartz and fibrolitic sillimanite along centimeter-thick sigmoidal shear zones crosscutting banded sodic aplite facies of the pegmatite. Along the crystal borders, the chrysoberyl (Cbl) contains commonly small rounded inclusions of quartz and microscopic fibrous radial aggregates of sillimanite. A metamorphic-metasomatic origin of the chrysoberyl by the reaction Beryl + albite + muscovite + H + = chrysoberyl + quartz + sillimanite + Na + K + H 2 O, seems to be the most plausible to explain the observed textural relations. Chrysoberyl contains 1.25 to 1.81 wt. % FeO tot . Contents of SiO 2 and other, potentially chromophore oxides of Cr, V, and Ti are mostly below limits of detection. A few exceptions for Si and V are below 0.01 wt. % oxide. The average formula along an electron-microprobe scan from core to rim of a selected Cbl crystal is: Be 0.931 ± 0.017 (Al 2.028 ± 0.011 ,Fe 0.026 ± 0.002 ) Σ2.054 ± 0.013 O 4 (± 1σ, n = 92). The origin of sillimanite + chrysoberyl + quartz under amphibolite-grade metamorphic conditions (~600 °C, 3.5 to 5 kbar) implies either an existence of a new generation of syn-metamorphic REL-pegmatites in the BPP or a late-tectonic recurrent increase in P-T conditions in the area. Another, less probable, alternative is a metastable formation of chrysoberyl and sillimanite at lower, retrometamorphic P-T conditions. The interaction of similar pegmatites known to occur south and north of Roncadeira with metabasic rock intercalations in the Seridó Formation opens the perspective for the finding of the gem-variety alexandrite in the BPP.

The capture and geological CO 2 storage (CCGS) in deep aqui fers, depleted oil and gas fields and coal seams appears to be one of the main solutions to reduce greenhouse gases release to the atmosphere (IPCC, 2005). The geochemical reactivity between the mixed fluids (supercritical CO 2 and brine) and the clayey caprock formations under physicochemical conditions of geological storage remain largely under-investigated. The caprock is characterized by inherent properties notably supported by a high clayey content such as low reactivity, low permeability and high elasticity/plasticity. This study presents experimental and modeling results regarding the geochemical reactivity of two caprock samples under CO 2 storage conditions: a rock sample from the Chinle formation in Moab (Utah -USA) and a sample from the Comblanchie n formation in Charmotte (Paris Basin -France). Experiments were conducted in pressurized cells where fluids (CO 2 and brine) are maintained at constant temperature (80 to 150°C) and pressure (1 to 150 bar). The duration of the experiments rang ed from 30 t o 360 days. The brine was synthesized as a representative solution of a saline aquifer. In the experiments, carbonate minerals (dolomite, calcite) dissolve partially or totally in the short term. In the long -term experiments, a new form of complex carbonat e precipitates. To evaluate clay minerals reactivity, the same series of experiments were performed with a purified mixed -layer illite/smectite mineral (I/S), illite and smectite. The I/S reveals a clear stability towards CO 2 whereas illite and smectite tend to be destabilized in the long -term. Kaolinite is the most reactive clay mineral as it dissolves totally in the long -term experiments. To predict and compare the geochemical reaction pathways, reactive transport modeling was performed focusing on the be havior of the cap -rock at the timescale of the experiments (30 to 365 days). Calculations were also extended to duration up to 10,000 years which is the relevant timescale for the long term safety assessment of CO 2 storage.

Here, we present detailed electron microprobe analyses and age data of high-medieval lead-silver smelting slags. The mineral composition data provide a database of all silicate and oxide phases in the slag. Bulk chemistry as well as mineral composition is used to reconstruct liquidus, solidus, and viscosity of the slag melt. By calculating the mass balance of the smelting process, a mass ratio of the various compounds used in the smelting process is determined. Through this we were able to discriminate qualitatively between non-ferrous metal smelting slags and bloomery slags. We also report a new type and process of silver production in which argentiferous galmei (zinc carbonate) was used as a main silver ore together with galena. The results indicate a sophisticated high-medieval smelting technology, in which a slag with a low liquidus and a low viscosity was created.

Mineralization of Billurik dere is located in and on the contact zone of granitic and dioritic magmatics of the Yüksekova complex. The mineralization which occur in the magmatic, emplaced along E-W striking tension fractures and of vein type in nature. The mineral assemblages of these veins are pyrite, chalcopyrite, sphalerite, galena, magnetite, specularite and some of these minerals are dominant ore minerals in some veins. The mineralizations which occur on the contact zones are contact type in nature and they bear additional minerals such as Cu-sulphosalts, Bi-sulphosalts and Ag-fahlore. The mineralizations are associated with serialization, kaolinization, silicification, tourmalinization and epidote formation. The mineralizations developed possibly during thrusting of the Keban metamorphics on the Yüksekova complex in a time span from Upper Cretaceous to Paleocene and related with the tectonic evolution of the area.

Elevated nitrogen (N) inputs into terrestrial ecosystems are causing major changes to the composition and functioning of ecosystems. Understanding these changes is challenging because there are complex interactions between ÔdirectÕ effects of N on plant physiology and soil biogeochemistry, and ÔindirectÕ effects caused by changes in plant species composition. By planting high N and low N plant community compositions into high and low N deposition model terrestrial ecosystems we experimentally decoupled direct and indirect effects and quantified their contribution to changes in carbon, N and water cycling. Our results show that direct effects on plant growth dominate ecosystem response to N deposition, although long-term carbon storage is reduced under high N plant-species composition. These findings suggest that direct effects of N deposition on ecosystem function could be relatively strong in comparison with the indirect effects of plant community change.

Significant fracture and porosity sealing characterizes the sedimentary cover-basement interface in the northwestern margin of the Aquitaine Basin (France). Dolomite and calcite (and sometimes fluorite, barite and quartz) constitute most of the fracture fillings. They contain primary inclusions of brines having chlorinities in the range of 3.3 to 5.5 mol Cl/kg solution, with total homogenization temperatures in between 65 and 130 jC for quartz and slightly lower for dolomite, barite, fluorite and calcite. Crush-leach analyses indicate that brines are characterized by Na/K ratios of 5 to 40, Na/Li ratios of 20 to 530, and Cl/Br ratios of 200 to 1000, which are rather typical of deep basinal brines. The fluid y 18 O signature is estimated to be c 6.6 F 1.8x SMOW for a crystallization temperature of 100 F 20 jC and the yD value is À 30 F 10xSMOW. The fluid source for the fracture filling mineral is interpreted as a deep sedimentary brine expelled during a period of maximum subsidence in the Aquitaine Basin, which migrated along the sediment cover/basement, a zone characterized interface which is characterized by high permeabilities below the Toarcian shales. The sealing is likely to be linked to the mixing of the brines with dilute, ascending hot waters. These dilute waters infiltrated from emerged zones, convected and heated at depth, reaching temperatures of 100 jC (up to 150 jC on the basis of cation geothermometry). Extensional activity, of probable Cretaceous age, related to the Gascogne Gulf rifting could be considered as the most likely cause of a significant fluid migration event at the basement/cover interface all along the margins of the French Massif Central. These processes are large scale as shown by the similarities of mineral sequences, fluid types and general features of most of the F -Ba -Pb -Zn deposits located at the basement -sedimentary cover interface.

Carbonation of formation minerals converts low viscosity supercritical CO 2 injected into deep saline reservoirs for geologic sequestration into an immobile form. Until recently the scientific focus of mineralization reactions with reservoir rocks has been those that follow an aqueous-mediated dissolution/precipitation mechanism, driven by the sharp reduction in pH that occurs with CO 2 partitioning into the aqueous phase. For sedimentary basin formations the kinetics of aqueous-mediated dissolution/precipitation reactions are sufficiently slow to make the role of mineralization trapping insignificant over a century period. For basaltic saline formations aqueous-phase mineralization progresses at a substantially higher rate, making the role of mineralization trapping significant, if not dominant, over a century period. The overlooked mineralization reactions for both sedimentary and basaltic saline formations, however, are those that occur in liquid or supercritical CO 2 phase; where, dissolved water appears to play a catalyst role in the formation of carbonate minerals. A model is proposed in this paper that describes mineral carbonation over sequestration reservoir conditions ranging from dissolved CO 2 in aqueous brine to dissolved water in supercritical CO 2 . The model theory is based on a review of recent experiments directed at understanding the role of water in mineral carbonation reactions of interest in geologic sequestration systems occurring under low water contents.

A model is presented describing the factors and processes which determine the measured 14C ages of soil calcium carbonate. Pedogenic carbonate forms in isotopic equilium with soil CO 2. Carbon dioxide in soils is a mixture of CO 2 derived from two biological sources: respiration by living plant roots and respiration of microorganisms decomposing soil humus. The relative proportion of these two CO z sources can greatly affect the initial 14C content of pedogenic carbonate: the greater the contribution of humus-derived CO 2, the greater the initial 14C age of the • • • 1"4 carbonate mineral. For any gwen mixture of CO 2 sources, the steady-state CO 2 distribution vs. soil depth can be described by a production/diffusion model. As a soil ages, the 14C age of soil humus increases, as does the steady-state 14C age of soil CO 2 and the initial 14C age of any pedogenic carbonate which forms. The mean 14C age of a complete pedogenic carbonate coating or nodule will underestimate the true age of the soil carbonate. This discrepancy increases the older a soil becomes. Partial removal of outer (and younger) carbonate coatings greatly improves the relationship between measured 14C age and true age. Although the production/diffusion model qualitatively explains the 14C age of pedogenic carbonate vs. soil depth in many soils, other factors, such as climate change, may contribute to the observed trends, particularily in soils older than the Holocene.

In this study we investigated the quantitative and qualitative aspects of soil organic matter (SOM) in an calcareous subsoil under agricultural use. The aim of this research was to evaluate the carbon stocks as well as the potential of SOM to be degraded by the soil microbial biomass. Soil samples were collected in the basin of "Kamech" in Tunisia from four soil profiles at five depths (0-30 cm, 30-50 cm, 50-70 cm, 70-110 cm and 110-140 cm). Samples were incubated at 28°C during 90 days and CO2 evolution was monitored throughout the incubation using NaOH (1N) traps. The soils sampled had a high clay content of more than 50 %. They were classified as Vertisols (WRB-FAO classification). The SOM content decreased from topsoils to subsoils. The carbon mineralization from top-and subsoils after 70 days ranged between 530 and 572 mg C-CO2 kg soil-1. The difference is not significant after 70 days of incubation with no significant differences between both. We conclude that The incubation indicated that there were metabolically active microbes in the subsoil which can degrade the organic matter. The significance of these phenomena with regards to the carbon stocks throughout the profile will be discussed.

Chemical weathering is a fundamental geochemical process regulating the atmosphere-land-ocean fluxes and earth's climate. It is under natural conditions driven primarily by weak carbonic acid that originates from atmosphere CO2 or soil respiration. Chemical weathering is therefore assumed as positively coupled with its CO2 consumption in contemporary geochemistry. Strong acids (i.e. sulfuric- and nitric acid) from anthropogenic sources have been found to influence the weathering rate and CO2 consumption, but their integrated effects remain absent in the world largest river basins. By interpreting the water chemistry and overall proton budget in the Yangtze Basin, we found that anthropogenic acidification had enhanced the chemical weathering by 40% during the past three decades, leading to an increase of 30% in solute discharged to the ocean. Moreover, substitution of carbonic acid by strong acids increased inorganic carbon evasion, offsetting 30% of the CO2 consumption by carbon...

Twenty-two rainwater samples from Guiyang city, southwestern China, have been analyzed for their chemical compositions and 87 Sr / 86 Sr ratios, with a main purpose to get a better understanding of the general features of rainwater in Guiyang city and their correspondences to human activities. The rainwaters studied are almost acidic (pH = 4.53) and show big changes in major ion composition. Ca 2+ and Mg 2+ are the principal cations in the rainwaters and their mean values are 56.6 Amol/L (12.5-163.8 Amol/L) and 12.8 Amol/L (4.5-47.3 Amol/L ), respectively. The sum of Ca 2+ and Mg 2+ accounts for 78%-96% of the total cations in the studied rainwaters. Na + was the least abundant of the major cations with a mean content of 4 Amol/L (0.9-7.8 Amol/L). SO 4 2À is the predominant anion, with a mean content of 94 Amol/L (33.5-279.4 Amol/L), coming next is NO 3 À with a mean content of 48 Amol/L (2.1-251.8 Amol/L). SO 4 2À and NO 3 À together account for 77%-99% of the total anions. Ca 2+ and Mg 2+ in the rainwater are most likely from dissolution of carbonate minerals in dust or aerosol, unlike K + that shows more contribution of anthropogenic sources to the rainwater. Na + does not vary in concentration with Cl À . Significant enrichment of Cl À relative to Na + as compared with sea water indicates negligible contribution of marine source, which is supported by the evidence that the total rainwater samples show lower 87 Sr / 86 Sr ratios (ranging from 0.707934 to 0.709080) than sea water. The rainwater samples are characterized by high contents of NO 3 À , SO 4 2À , and Cl À relative to Na + , as compared to the rainwater from other areas in the world, suggesting that the anions (NO 3 À , SO 4 2À , and Cl À ) have mainly of anthropogenic sources. Sr isotope shows potential to trace sources of contaminants when combined with other chemical factors: covariation of 87 Sr / 86 Sr ratio with Cl À / Na + in the rainwater suggest presence of at least two anthropogenic sources for the rainwater samples studied. The coal-combustion industries are probably the major atmospheric contaminant sources in Guiyang city.

Early stage amorphous precursors provide a low energy pathway for carbonate mineralization. Many natural deposits of carbonate minerals and biogenic calcium carbonate (both amorphous and crystalline) include significant amounts of Mg. To understand the role of magnesium-containing amorphous precursors in carbonate mineralization, we investigated the energetics and structure of synthetic amorphous Ca-Mg carbonates with composition Ca 1Àx Mg x CO 3 ÁnH 2 O (0 6 x 6 1) using isothermal acid solution calorimetry and synchrotron X-ray scattering experiments with pair distribution function (PDF) analysis. Amorphous magnesium carbonate (AMC with x = 1) is energetically more metastable than amorphous calcium carbonate (ACC with x = 0), but it is more persistent (crystallizing in months rather than days under ambient conditions), probably due to the slow kinetics of Mg 2+ dehydration. The Ca 1Àx Mg x CO 3 ÁnH 2 O (0 6 x 6 1) system forms a continuous X-ray amorphous series upon precipitation and all intermediate compositions are energetically more stable than a mixture of ACC and AMC, but metastable with respect to crystalline carbonates. The amorphous system can be divided into two distinct regions. For x = 0.00-0.47, thermal analysis is consistent with a homogeneous amorphous phase. The less metastable compositions of this series, with x = 0.0-0.2, are frequently found in biogenic carbonates. If not coincidental, this may suggest that organisms take advantage of this single phase low energy amorphous precursor pathway to crystalline biogenic carbonates. For x P 0.47, energetic metastability increases and thermal analysis hints at nanoscale heterogeneity, perhaps of a material near x = 0.5 coexisting with another phase near pure AMC (x = 1). The most hydrated amorphous phases, which occur near x = 0.5, are the least metastable, and may be precursors for dolomite formation.

An investigation of the impact of injected CO 2 on reservoir mineralogy was completed as part of the geochemical monitoring and modelling of the Pembina Cardium CO 2 Monitoring Project southwest of Drayton Valley, Alberta, Canada. Oil production at the pilot is primarily from the upper two of three stacked sandstone units of the Cardium Formation in the Pembina field. Core analyzed included samples from each of the three sandstone units, and encompassed three distinct time periods: pre-water flood (1955), pre-CO 2 flood ( ), and post-CO 2 flood (2007). The results of whole rock analysis (XRF, ICP, and XRD), and microscopy (polarizing and electron microprobe) suggest the three separate sandstone units are both texturally and compositionally similar regardless of when the core was recovered. Framework grains are predominately sub-angular to sub-rounded quartz/chert (up to 90.0 wt%), and include smaller amounts of lithic fragments (shale), feldspar (k-feldspar, and albite), mica (muscovite and chlorite), and fluor-apatite. Authigenic pyrite is found as finely disseminated rhombs throughout the formation. Clay minerals present are predominantly kaolinite and illite. Kaolinite appears as fine discrete pore filling books, and is considered to be authigenic. Illite occurs as a major constituent of shale fragments, as well as fine pore bridging strands. The sandstone's irregular pores are cemented to varying degrees by silica and/or carbonate minerals (calcite and siderite). Dissolution features associated with formation diagenesis, including the degradation of detrital grains (quartz and feldspar), the partial and/or complete removal of carbonate cements, and the presence of residual clays, are found in core from each of the three time periods. Attributing dissolution features in post-CO 2 flood core to the interaction of minerals and carbonic acid is difficult due to the geologic history of the formation.

Forests ecosystem plays a significant role in supplying multiple services given the unique properties of forest soils, in which the elements of C, N, and P are essential to support soil fertility and site productivity. However, soil properties at different soil depths between plantation forests (PF) and natural forests (NF) have not been well quantified. Therefore, the current study was carried out in the Qilian Mountains of northwest China to determine the difference between PF and NF in the soil properties, both physical (e.g., bulk density, BD) and chemical (e.g., pH value, the contents, stocks, and stoichiometry of soil organic carbon (SOC), total N (TN), and total P (TP)). Research analyzed soil samples at different depths (0-20, 20-40, 40-60, 60-80, and 80-100 cm). The results showed that the soils' pH values and BD were significantly higher (p ≤ 0.05) in PF than in NF and increased with soil depth. The contents of SOC, TN, and TP decreased considerably with soil depth and then stabilized at the soil depth of 80-100 cm. The NF showed significantly higher (p ≤ 0.05) SOC, TN, and TP contents than PF, confirming that the soil quality of PF had not fully recovered yet. The stocks of SOC and TN quickly decreased with soil depth up to 40-60 cm and stabilized gradually. Additionally, the soil stoichiometry of C:P and N:P decreased significantly with rising soil depth, while the C:N ratio remained unchanged. The N:P and C:P ratios were lower in PF than in NF, while the C:N ratio was higher in PF than in NF. In conclusion, the results show that the soils of NF present significantly higher stocks of SOC and TN but lower (or nearly equal) TP stocks than PF (under the same age group and tree species composition). These results imply that maintaining NF and avoiding their replacement by PF can help keep higher soil quality and related ecosystem services.

The Great Artesian Basin (GAB) is a water source for more than 200,000 residents in central Australia. This study investigates the relationship of bromine and chlorine stable isotopes to groundwater chemistry in a confined aquifer in the southwestern GAB to better understand its flow regime and solute sources. δ 81 Br values range from +0.66‰ near the recharge area to +1.04‰, 150km down gradient, while δ 37 Cl ranges from 0‰ to -2.5‰. While δ 37 Cl decreases with distance from the recharge area, δ 81 Br increases slightly. Bromide in the recharge area is possibly enriched from selective atmospheric processes causing fractionation in marine aerosols during transport. When confined and isolated from the atmosphere, increases in bromide and to a lesser extent strontium concentrations may contribute through water-rock interaction to changes in isotopic signatures along the flow system. 87 Sr/ 86 Sr values range from ~0.717 near the recharge zone to a depleted 0.708 160km down gradient.

Groundwater is a critical resource in Khanyounis city as it is the main source of water. The aquifer has deteriorated to a high degree, during the last two to three decades, in quality and quantity. More than 90% of the population get their drinking water from brackish water desalination plants. Fifteen domestic wells were sampled in 2002 to probe the hydrogeochemical components that influence the water quality. Na, K, Ca, Mg, Cl, SO 4 , NO 3 , and HCO 3 were analyzed. The data were statistically treated and plotted on the Piper diagram. A hydrogeochemical numerical model for carbonate minerals was constructed using the PHREEQ package. The results show that the groundwater is polluted with Cl, from seawater, and NO 3 , sourced from fertilizers and sewage. The regression analysis shows that there are three groups of elements that are significantly and positively correlated. Na-Cl signature and plot show that seawater intrusion is advancing into the aquifer. The main hydrochemical facies of the aquifer (Na+K-Cl+SO 4 ), represents 60% of the total wells. Whereas 32.3% of the wells are located in the no pair up and no pair down fields on the Piper diagram. Calcite, dolomite, and aragonite solubility were assessed in terms of the saturation index where they show positive values indicating supersaturation. The hydrogeochemical behavior is rather complicated and is affected by anthropogenic and natural parameters.

Groundwater with high geogenic arsenic (As) is extensively present in the Holocene alluvial aquifers of Ghazipur District in the middle Gangetic Plain, India. A shift in the climatic conditions, weathering of carbonate and silicate minerals, surface water interactions, ion exchange, redox processes, and anthropogenic activities are responsible for high concentrations of cations, anions and As in the groundwater. The spatial and temporal variations for As concentrations were greater in the pre-monsoon (6.4-259.5 μg/L) when compared to the post-monsoon period (5.1-205.5 µg/L). The As enrichment was encountered in the sampling sites that were close to the Ganges River (i.e. south and southeast part of Ghazipur district). The depth profile of As revealed that low concentrations of NO 3 -are associated with high concentration of As and that As depleted with increasing depth. The poor relationship between As and Fe indicates the As release into the groundwater, depends on several processes such as mineral weathering, O 2 consumption, and NO 3 -reduction and is decoupled from Fe cycling. Correlation matrix and factor analysis were used to identify various factors influencing the gradual As enrichment in the middle Gangetic Plain. Groundwater is generally supersaturated with respect to calcite and dolomite in post-monsoon period, but not in pre-monsoon period. Saturation in both periods is reached for crystalline Fe phases such as goethite, but not with respect to poorly crystalline Fe phases and any As-bearing phase. The results indicate release of arsenic in redox processes in dry period and dilution of arsenic concentration by recharge during monsoon. Increased concentrations of bicarbonate after monsoon are caused by intense flushing of unsaturated zone, where CO 2 is formed by decomposition of organic matter and reactions with carbonate minerals in solid phase. The present study is vital considering the fact that groundwater is an exclusive source of drinking water in the region which not only makes situation alarming but also calls for the immediate attention.

Increased carbon dioxide levels in the atmosphere and its influence on climate change is a growing concern in the scientific, political, and social communities. Methods of mitigation are being tested to explore carbon capture and storage through the biosynthesis of stable carbon-containing compounds using different strains of calcifying cyanobacteria. By utilizing marine genera, the cyanobacteria could potentially be grown in brine waste waters, conserving valuable fresh water resources. In this experiment, two strains of Synechococcus were cultured in flasks with varying levels of CO 2 : air, 5% CO 2 , and 15% CO 2 . Growth of each culture was monitored by measuring optical density and pH level. Morphological characteristics of each culture were analyzed through light microscopy and scanning electron microscopy. Preliminary results have shown inconsistent morphology and growth. Cultures started from previous experiments lacked duplication of observed filamentous morphology, but exhibited better growth in high CO 2 levels. The incubation of cultures in media with varying levels of calcium chloride will be used to analyze and compare the sequestration of carbon through calcium carbonate production. Analysis of the chemical composition of precipitates in the media and the exopolysaccharide sheath (ESP) and surface layer (S-layer) of cells will verify the presence of calcium carbonate. Methods include the use of Scanning electron microscopy-energy-dispersive X-ray spectroscopy (SEM-EDX) and polarized light microscopy. If experimental outcomes verify efficient production of calcium carbonate from sources of high CO 2 , these cyanobacteria may be viable systems for capturing carbon from coal fired power plants.

Increased carbon dioxide levels in the atmosphere and its influence on climate change is a growing concern in the scientific, political, and social communities. Methods of mitigation are being tested to explore carbon capture and storage through the biosynthesis of stable carbon-containing compounds using different strains of calcifying cyanobacteria. By utilizing marine genera, the cyanobacteria could potentially be grown in brine waste waters, conserving valuable fresh water resources. In this experiment, two strains of Synechococcus were cultured in flasks with varying levels of CO2: air, 5% CO2, and 15% CO2. Growth of each culture was monitored by measuring optical density and pH level, as calcification requires an alkaline environment. Morphological characteristics of each culture were analyzed through light microscopy and scanning electron microscopy to compare differences in cell surface and association. Preliminary results have shown inconsistent morphology and growth. Cultu...

Groundwater is a critical resource for drinking and irrigation, yet its quality in rural areas such as Motipur block, Muzaffarpur (Bihar), remains poorly characterized. This study evaluated groundwater suitability by analyzing 40 samples from hand pumps and tube wells for key parameters, including pH, electrical conductivity (EC), bicarbonate (HCO₃⁻), chloride (Cl⁻), and total dissolved solids (TDS). Results revealed slightly alkaline conditions (pH 7.50-8.34, avg. 7.95), within WHO/BIS permissible limits. However, EC exceeded the BIS threshold (500 µS/cm), and 23 samples surpassed WHO bicarbonate standards (350 mg/L). Although most TDS values (300-1150 mg/L) complied with BIS limits (500 mg/L), chloride concentrations (355-1136 mg/L) consistently exceeded safe thresholds (250 mg/L). These findings underscore localized contamination risks, emphasizing the need for targeted interventions to ensure sustainable groundwater management in the region.

Introduction: On Mars, the search for life has been a principal goal for centuries, and it remains so today. In pursuit of this objective, we present the results of Strategic Initiative 6, developed at the NAI Workshop in Tempe AZ. Background: 19th century visual impressions of surface albedo markings (Schiaparelli, Lowell) and their temporal changes were mis-interpreted as "canals" and "seasonal vegetation", fueling the fantasies of many laymen and some writers (e.g., Burroughs, Welles), Such views persisted in some quarters until the mid-20th century, ending only with the advent of Mars exploration from space. In 1965, Mariner 4 returned images of a heavily cratered Mars that ended the perception of a widely vegetated planet. In 1969, Mariner 7 opened an era of searches for other biosignatures with the announced discovery of methane and ammonia; however, a retraction was issued almost immediately when the detected spectral signatures were assigned instead to CO 2 . The Mars-orbiting Mariner 9 characterized the atmosphere in detail (composition, temperature) over several annual cycles, and showed discouraging upper limits of potential biomarker gases, including methane. Mariner 9 and later searches through 2000 (KPNO, ISO, CFHT) were averaged over the dayside hemisphere, and sometimes over all seasons, and they provided a parade of increasingly sensitive searches but no clear detections. Beginning in 1976, the Viking 1 & 2 orbiters imaged large areas of Mars at high spatial resolution, revealing many landforms that suggested the presence of flowing water on early Mars (>3.5 Ga). The orbiters also explored the global distributions and annual cycles of CO 2 and water, while landed payloads searched for microbial life and extant organics in nearsurface soil samples without success. The search for life then shifted to identification and mapping of geomorphology and mineral signatures characteristic of long exposure to water ("Follow the Water"). In 2001, Mars Global Surveyor identified hematite (a mineral that forms in standing water) in Sinus Meridiani, which then was chosen as the landing site for the Opportunity rover. Opportunity confirmed long-standing water but found no evidence of extant biogenic minerals (e.g., carbonates) in near-surface samples. Mars Express (Omega) and Mars Orbiter (CRISM) identified and

Rock-Water interactions and hydrogeochemical processes are critical for understanding groundwater chemistry and the environmental impacts of various geological formations. These interactions involve several chemical processes that significantly influence the composition and groundwater quality. The present study aims to investigate the rock-water interactions and hydrogeochemical processes through the water samples collected from Mandya district. The study involved Piper's diagram, Gibb's diagram and Scatter plots of various parameters in revealing chemical processes that influence hydro geochemistry. The concentrations of these ions varied spatially and temporally in different taluks of Mandya district, depending on the lithological formations of those locations. Ions were dominated by Na>Ca>Mg>K = HCO >Cl>SO >CO. Ca-Mg-Cl, Ca-Na-HCO , and Ca-HCO types were the dominant hydro chemical facies noticed in the 3 4 3 3 3 study area. Hydrogeochemical processes provide valuable insights into the complex systems of rock-water interaction and to aid in effective groundwater management and pollution mitigations.

Research involving management of carbon dioxide has increased markedly over the last decade as it relates to concerns over climate change. Capturing and storing carbon dioxide (CO 2 ) in geological formations is one of many proposed methods to manage, and likely reduce, CO 2 emissions from burning fossil fuels in the electricity sector. Saline formations represent a vast storage resource, and the waters they contain could be managed for beneficial use. To address this issue, a methodology was developed to test the feasibility of linking coal-fired power plants, deep saline formations for CO 2 storage, and extracting and treating saline waters for use as power plant cooling water. An illustrative hypothetical case study examines a representative power plant and saline formation in the south-western United States. A regional assessment methodology includes analysis of injectioninduced changes in subsurface groundwater chemistry and fate and transport of supercritical CO 2 . Initial water-CO 2 -formation reactions include dissolution of carbonate minerals as expected, and suggest that very little CO 2 will be stored in mineral form within the first few centuries. Reservoir simulations provide direct input into a systems-level economic model, and demonstrate how water extraction can help manage injection-induced overpressure. Options for treatment of extracted water vary depending upon site specific chemistry. A high efficiency reverse osmosis system (HERO TM ) shows promise for economical desalination at the volumes of recovered water under consideration. Results indicate a coupled use CO 2 storage and water extraction and treatment system may be feasible for tens to hundreds of years.

Research involving management of carbon dioxide has increased markedly over the last decade as it relates to concerns over climate change. Capturing and storing carbon dioxide (CO 2 ) in geological formations is one of many proposed methods to manage, and likely reduce, CO 2 emissions from burning fossil fuels in the electricity sector. Saline formations represent a vast storage resource, and the waters they contain could be managed for beneficial use. To address this issue, a methodology was developed to test the feasibility of linking coal-fired power plants, deep saline formations for CO 2 storage, and extracting and treating saline waters for use as power plant cooling water. An illustrative hypothetical case study examines a representative power plant and saline formation in the south-western United States. A regional assessment methodology includes analysis of injectioninduced changes in subsurface groundwater chemistry and fate and transport of supercritical CO 2 . Initial water-CO 2 -formation reactions include dissolution of carbonate minerals as expected, and suggest that very little CO 2 will be stored in mineral form within the first few centuries. Reservoir simulations provide direct input into a systems-level economic model, and demonstrate how water extraction can help manage injection-induced overpressure. Options for treatment of extracted water vary depending upon site specific chemistry. A high efficiency reverse osmosis system (HERO TM ) shows promise for economical desalination at the volumes of recovered water under consideration. Results indicate a coupled use CO 2 storage and water extraction and treatment system may be feasible for tens to hundreds of years.

Here, we present detailed electron microprobe analyses and age data of high-medieval lead-silver smelting slags. The mineral composition data provide a database of all silicate and oxide phases in the slag. Bulk chemistry as well as mineral composition is used to reconstruct liquidus, solidus, and viscosity of the slag melt. By calculating the mass balance of the smelting process, a mass ratio of the various compounds used in the smelting process is determined. Through this we were able to discriminate qualitatively between non-ferrous metal smelting slags and bloomery slags. We also report a new type and process of silver production in which argentiferous galmei (zinc carbonate) was used as a main silver ore together with galena. The results indicate a sophisticated high-medieval smelting technology, in which a slag with a low liquidus and a low viscosity was created.

Here, we present detailed electron microprobe analyses and age data of high-medieval lead-silver smelting slags. The mineral composition data provide a database of all silicate and oxide phases in the slag. Bulk chemistry as well as mineral composition is used to reconstruct liquidus, solidus, and viscosity of the slag melt. By calculating the mass balance of the smelting process, a mass ratio of the various compounds used in the smelting process is determined. Through this we were able to discriminate qualitatively between non-ferrous metal smelting slags and bloomery slags. We also report a new type and process of silver production in which argentiferous galmei (zinc carbonate) was used as a main silver ore together with galena. The results indicate a sophisticated high-medieval smelting technology, in which a slag with a low liquidus and a low viscosity was created.

An unexpected concentration of calcicole mosses and lichens has been discovered at and near a small spring seep on the granite headwall of the North Basin of Mt. Katahdin, Piscataquis County, Maine. Water samples from the spring were circumneutral and high in calcium ion content, whereas other springs, ponds, and streams on the mountain tested acidic and low in calcium. Because the Katahdin granite contains no primary carbonate minerals, it is suggested that the source of calcium enrichment in the North Basin spring water is secondary calcium carbonate (calcite) precipitated in cavities and fractures near the base of the upper Katahdin granite and its subsequent dissolution and mobilization by percolating groundwater. Plagioclase, epidote, and other calcic minerals in the granite supply the primary calcium ions. The moss calcicoles grew in small discontinuous patches on wet humified peaty soil over alpine bedrock ledges in communities having floristics and water chemistry similar to lowland rich fens. Present in or near the seep were mosses previously unrecorded for New England or Maine [Loeskypnum wickesiae (Grout) Tuom., Neckera oligocarpa Bruch in Hartm., Pseudoleskea radicosa (Mitt.) Mac. & Kindb., Tortella tortuosa var. fragilifolia (Jur.) Limpr., Warnstorfia sarmentosa (Wahlenb.) Hedena ¨s], one lichen [Hymenelia cyanocarpa (Anzi) Lutzoni], reported here for the first time from North America, and another lichen (Thelidium minutulum Ko ¨rb.) for the first time from the contiguous United States. An area adjacent to the seep, but unaffected by calcareous seep-water, was remarkable for a concentration of rare lichen species of acidic rocks, including Catillaria contristans (Nyl.) Zahlbr. and Lecanora caesiosora Poelt, that have not previously been reported from North America. The bryophyte and lichen flora of the seep area is an example of a Holocene alpine microrefugium. Refugia such as these can serve as a source of propagules that allow new populations to establish elsewhere in mountainous terrain, or beyond, during climatic and other environmental change. Therefore, extant, cryptic microrefugia are important biogeographically and especially worthy of preservation efforts.

Some nutrient elements, trace metals and some chemical indices of mineralization which include total nitrogen, total organic carbon, phosphorus, lignin and tannin have been determined in the leaf prunings of Gmelina arborea, Vitellaria paradoxa, Tectona grandis, Entada africana, Prosopis africana, Parkia biglobosa, Leucaena leucocephala and Gliricidia sepium.

The Harzandat plain is part of the East Azarbaijan province, which lies between Marand and Jolfa cities, northwestern of Iran, and its groundwater resources are developed for water supply and irrigation purposes. For hydrogeological consideration and optimum management of groundwater resources a mathematical model as an efficient and economical tool was prepared. In order to evaluate the quality of groundwater in study area, 36 groundwater samples were collected and analyzed for various parameters. Chemical indexes like sodium adsorption ratio, percentage of sodium, residual sodium carbonated, permeability index (PI) and chloroalkaline indexes were calculated. Based on the analytical results, groundwater in the area is generally very hard, brackish, high to very high saline and alkaline in nature. The abundance of the major ions is as follows: Cl> HCO 3 > SO 4 and Na>Ca>Mg>K. The dominant hydrochemical facieses of groundwater is Na-Cl type and alkalis (Na, K) and strong acids (Cl, SO 4 ) are slightly dominating over alkali earths (Ca, Mg) and weak acids(HCO 3 ,CO 3 ). The chemical quality of groundwater is related to the lithology of the area and the residence time of the groundwater in contact with rock materials. The results of calculation saturation index by computer program PHREEQC shows that the nearly all of the water samples were supersaturated with respect to carbonate minerals and undersaturated with respect to sulfate minerals. Assessment of water samples from various methods indicated that groundwater in study area is chemically unsuitable for drinking and agricultural uses.

The composition of surficial salts formed near dry and drying saline lakes are partly the product of processes active in the unsaturated zone between the ground surface and the water table. These processes were investigated by determining the abundance of water-extractable solutes in sediment from the ground surface to the water table (~2.8 m) beneath Franklin Lake playa, California. Accumulation

Peatlands represent large carbon (C) reservoirs that can act as a source or sink for greenhouse gases. The response of peatland gaseous C fluxes to global climate change and atmospheric sulfate deposition, however, remains uncertain. Methanogenesis is thought to be one of the most important anaerobic C mineralization pathways in peatlands, especially in regions where input of sulfate from acid deposition is low. However, sulfate reduction has been quantified rarely in freshwater wetlands. Here we report greater anaerobic C flow through sulfate reduction than through methanogenesis at all sites situated along a global atmospheric sulfur deposition gradient. Stoichiometric mass balance suggests that fermentation is a dominant anaerobic C mineralization pathway in unpolluted peatlands, while methanogenesis contributed minimally to total anaerobic carbon mineralization in these sites. Furthermore, global increases of atmospheric sulfur deposition minimize the impacts of climatic warming by simultaneously decreasing rates of methanogenesis while causing little change in rates of total anaerobic C mineralization in Sphagnum-dominated peatlands.

Alkaline earth metals, such as calcium and magnesium oxides, readily react with carbon dioxide (CO 2 ) to produce stable carbonate minerals. Carbon sequestration through the formation of carbonate minerals is a potential means to reduce CO 2 emissions. Calcium-rich, industrial solid wastes and residues provide a potential source of highly reactive oxides, without the need for pre-processing. This paper presents the first study examining the feasibility of carbon sequestration in cement kiln dust (CKD), a byproduct generated during the manufacturing of cement. A series of column experiments were conducted on segments of intact core taken from landfilled CKD. Based on stoichiometry and measured consumption of CO 2 during the experiments, degrees of carbonation greater than 70% of the material's potential theoretical extent were achieved under ambient temperature and pressure conditions. The overall extent of carbonation/sequestration was greater in columns with lower water contents. The major sequestration product appears to be calcite; however, more detailed material characterization is need on pre-and post-carbonated samples to better elucidate carbonation pathways and products.

t. The Toa Baja Well drilled in northern Puerto Rico to a depth of 2705 m (8872 ft.) penetrated over 550 m (1800 ft.) of Tertiary carbonates. The limestone-dominated portion of the well consists mostly of shallow-water backreef carbonates. Metastable carbonates have been either calcitized, dolomitized or dissolved. The petrographic character of the Tertiary carbonates in the Toa Baja Well, and those reported by Monroe [1980], the cathodoluminescence petrography, and the stable isotopic compositions indicate that these carbonates were rapidly cemented in the marine environment (limiting compaction), that replacement of metastab!e carbonates by calcite and precipitation of sparry calcite took place mostly in meteoric diagenetic environments and dolomitization probably occurred in a meteoric-marine mixing zone. Given the history of numerous drainage systems that dissected the Tertiary carbonates throughout their depositional history [Monroe, 1980] and the repeated Cenozoic sea level oscillations [Monroe, !980; Seiglie and Moussa, 1984], it is likely that alteration of metastable carbonates took place during lowstands. Interstratified fluvial deposits suggest the continued influence of meteoric fluids in local highlands [Monroe, !980]. introduction The Toa Baja #1 well was drilled to evaluate the depositional history of the northem Puerto Rico sedimentary sequence and to assess postdepositional changes in these •ents. Major questions posed for the shallow carbonate dominated sediments of the Toa Baja #1 well (Figure 1) are: what type of diagenetic modifications are involved, when these occurred (early vs. late), whether diagenetic modifications involved hot (burial) fluids, and the fate of organic matter and possible hydrocarbon generation or involvement. In an attempt to clarify the nature of diagenetic modification of the Middle Tertiary carbonates present in the Toa Baja #1 well petrographic and stable isotope studies have been undertaken. The limestone-dominated portion of the Toa Baja Well ranges from 25 m (80 ft.) down to 570 meters (1875 ft.) in depth. The carbonates consist mostly of shallow-water backreef carbonates of Tertiary age [Montgomery et al., 199!]. Detrital influx is prominent in various portions of the stratigraphic sequence in the well (Figure 1). Most of these detrital sediments are fluvial in origin, and record the evolution 0fpaleodrainage systems that were periodically active throughout the Tertiary [Monroe, 1980]. The penetrated carbonates outcrop throughout the north coast of Puerto Rico and are described by Monroe [1980]. From the known

Organic carbon degradation experiments were carried out using flow-through reactors with sediments collected from an intertidal freshwater marsh of an eutrophic estuary (The Scheldt, Belgium). Concentrations of nitrate, nitrite, dissolved inorganic carbon (DIC), dissolved organic carbon, methane, dissolved cations (Ca 2? , Mg 2? , Na ? and K ? ), total dissolved Fe, phosphate and alkalinity were measured in the outflow solutions from reactors that were supplied with or without the terminal electron acceptor nitrate. Organic carbon mineralization rates were computed from the release rates of DIC after correcting for the contribution of carbonate mineral dissolution. The experiments ran for several months until nitrate reducing activity could no longer be detected. In the reactors supplied with nitrate, 10-13% of the bulk sedimentary organic carbon (SOC) was mineralized by the end of the experiments. In reactors receiving no nitrate, only 3-9% of the initial SOC was mineralized. Organic matter utilization by nitrate reducers could be described as the simultaneous degradation of two carbon pools with different maximum oxidation rates and half-saturation constants. Even when nitrate was supplied in non-limiting concentrations about half of the carbon mineralization in the reactors was due to fermentative processes, rather than being coupled to nitrate respiration. Fermentation may thus be responsible for a large fraction of the DIC efflux from organic-rich, nearshore sediments.

The influence of soil aggregation as a means to protect soil organic carbon (SOC) from mineralization is unclear in very sandy soils. The dominant forest cover types in the Lower Coastal Plain of the US where sandy surface soils prevail are loblolly pine (Pinus taeda) and slash pine (Pinus elliottii var elliottii). The purpose of this study was to investigate the role that aggregation plays in C incorporation and sequestration in very sandy soils of the Lower Coastal Plain found under loblolly and slash pine ecosystems. Thirteen forest stands (seven loblolly pine; six slash pine) were used for this investigation. A sonic dismembrator was used to apply dispersive energy in order to destroy aggregates. The use of sonic energy was shown to be a valid tool for studying aggregates in sandy soils. The data showed that aggregates do not protect ASOC from mineralization in these very sandy soils. Loblolly pine surface mineral horizons accumulated 131% more TSOC than slash pine soil horizons. Slash pine soils had a 27% higher specific mineralization rate than loblolly pine soils; and Diffuse Reflectance Fourier Transform spectra (DRIFTS) showed that soils under loblolly pine were more aromatic than those under slash pine -and became more aromatic as mineralization proceeded. Due to their dominance in the Lower Coastal Plain of the US, pine ecosystems play an important role in the conversion of atmospheric CO 2 into the TSOC pool. However, soil aggregation should not be considered a mechanism to protect SOC in these very sandy soils when modeling soil carbon dynamics, even though slash pine systems show a slightly greater capacity to develop aggregates.

Bauxite residue or Red Mud (RM) is a by-product from alumina refineries. It has a high pH of 11-13 and accumulates globally at 200 million tons yearly, totalling about 4.6 billion tons. Being an alkaline anthropogenic geomaterial, its adsorption properties and reactivity with acidic gases make it a potential sink for CO 2 and SO X emissions from the aluminium industry. It offers both research challenges and opportunities for its utilisation at an industrial scale. In particular, carbon capture and mineralisation (CCM) within RM has been demonstrated in situ and waste disposal areas through direct air trapping of atmospheric CO 2. The RM-CO 2 system is also operated in ex-situ conditions in various physical states, such as powder, wet cakes, and slurry, with yields of carbonates as CaCO 3 , Na 2 CO 3 , and FeCO 3. Our contribution as a review illuminates significant advancements made and challenges for enhancing the mineral carbonation potential of RM, thereby delineating areas necessitating further exploration. Although, researchers have primarily focused on accelerating the CCM process in RM through slurry carbonation techniques. Recent advancements in filter press technologies have favoured soda recycling and wet cake disposal of RM, creating artificial mountains of RM stacks. With changing disposal trends for RM, it is vital to understand the mechanisms that govern long-term atmospheric CO 2 trapping in RM disposal areas. Recent investigations of techniques, hydrothermal treatment and dual-stage calcification-carbonation methods have expanded the domain of CCM in RM. Given the global need to reduce CO 2 emissions, CCM using RM does offer promising insights on account of its unique physicochemical and mineralogical properties. We, although presume that RM alone will not fully offset the CO 2 emissions of the aluminium industry. Enhanced weathering and mineral carbonation could reduce over 50% of refinery emissions. Uncertainties persist regarding methods of CO 2 sequestration potential and techno-economic feasibility when tested at a field scale. Moreover, contrasting results are revealed, primarily regarding changing disposal trends, variabilities in mineralogy, and limited knowledge of micro-mechanisms of the CCM process in RM. This work elucidates existing knowledge on synthesising CO2 mineralisation, pathways, and mechanisms under various states associated with leveraging RM as a significant carbon sink in current and future climate change mitigation efforts.
Red mud
Bauxite residues
Carbon capture
Mineralisation
Sequestration potential
Carbon sink
enhanced weathering

The current BCR procedure for metal fractionation recommended by the Standard Measurement and Testing Programme requires rather time-consuming sample pretreatment. Ultrasonic energy seems to be an attractive alternative for leaching metal from solid samples into a liquid extractant phase. This study aims at optimizing ultrasonic extraction in order to replace the BCR method of leaching using acetic acid and to apply the procedure of assessing element mobility in bottom sediment rich in moderately soluble carbonate minerals. The application of ICP-MS allowed the determination of As, Cd, Cr, Cu, Pb, Ni, Tl and Zn in extracts, in a wide range of concentration without any special treatment. Finally, 40 min extraction in an ultrasonic bath was proposed for evaluation of the mobile fraction of As, Cd, Cr, Cu, Pb and Zn as an assessment of environmental risk. The recovery of the ultrasound-assisted extraction in comparison to the shake-filter method, as applied in the common BCR procedure, was slightly higher than 100% for As, Cr and Pb, reasonably high (about 70%) for Cd, Zn and Cd, but did not exceed 21% for Tl. Also, the mobility and extractability (relative mobility) of the studied elements from sediment collected over one year were compares. According to the results obtained after 40 min of ultrasound-assisted extraction it can be concluded that mobility did not change over one year for Cr, Cu, As, Cd, Ni and Tl, but noticeable differences for Zn and Pb were observed. The total content of all studied elements was almost the same in samples taken in the years 2003 and 2004, respectively.

Keban and its surroundings are generally observed at the contacts of granitoids and epimetamorphic rocks, in Nimri formation and in Keban marbles. Lead-zinc mineralizations in this region are previously interpreted as skarn type occurrences associated with granitoids. In this study, predominantly carbonate mineralizations in the carbonate rocks of Nimri formation and sulphide and carbonate ores within the Keban marbles are investigated. As a result of mineralogical, petrographical and geochemical studies, some significant evidences indicate that the mineralizations are not directly related with the skarn type associated with granitoids. According to the limited data collected during this study, the view that the mineralizations, present in Nimri formation and Keban marble, are mobilized with the influence of granitoids becomes significant. Mineralizations taking place earlier than mobilization are discussed by exhalative sedimentary (SEDEX) type and Mississippi Valley Type (MVT) relying on the present data. Some evidence is found for SEDEX type. While primary occurrences are getting their new positions by means of secondary processes, metallic contents of primary occurrences are enriched. Mobilizations related with metamorphism and/or granitoid impact and enrichment processes caused by weathering are out of the study. The main result of this study is the necessity of new other revitalization of discussions about the origin of primary occurrences for contribution to science and economy.

An investigation of the impact of injected CO 2 on reservoir mineralogy was completed as part of the geochemical monitoring and modelling of the Pembina Cardium CO 2 Monitoring Project southwest of Drayton Valley, Alberta, Canada. Oil production at the pilot is primarily from the upper two of three stacked sandstone units of the Cardium Formation in the Pembina field. Core analyzed included samples from each of the three sandstone units, and encompassed three distinct time periods: pre-water flood (1955), pre-CO 2 flood ( ), and post-CO 2 flood (2007). The results of whole rock analysis (XRF, ICP, and XRD), and microscopy (polarizing and electron microprobe) suggest the three separate sandstone units are both texturally and compositionally similar regardless of when the core was recovered. Framework grains are predominately sub-angular to sub-rounded quartz/chert (up to 90.0 wt%), and include smaller amounts of lithic fragments (shale), feldspar (k-feldspar, and albite), mica (muscovite and chlorite), and fluor-apatite. Authigenic pyrite is found as finely disseminated rhombs throughout the formation. Clay minerals present are predominantly kaolinite and illite. Kaolinite appears as fine discrete pore filling books, and is considered to be authigenic. Illite occurs as a major constituent of shale fragments, as well as fine pore bridging strands. The sandstone's irregular pores are cemented to varying degrees by silica and/or carbonate minerals (calcite and siderite). Dissolution features associated with formation diagenesis, including the degradation of detrital grains (quartz and feldspar), the partial and/or complete removal of carbonate cements, and the presence of residual clays, are found in core from each of the three time periods. Attributing dissolution features in post-CO 2 flood core to the interaction of minerals and carbonic acid is difficult due to the geologic history of the formation.

The present study has analysed the Spatial-temporal distribution of groundwater level (GWL) in the Ghazipur district has been calculated using statistical and graphical methods for the period 1998, 2008 and 2018. In the present study, the GWL trend was analysed using the non-parametric Modified Mann-Kendall (MMK) test for the 39 locations of the Ghazipur district of UP, India. The trend analysis has been tested at a 5 % significance level. The mean, minimum and maximum GWL during the pre-monsoon season(PRM) ranged from 3.16 m to 12.71 m. However, in the post-monsoon (PTM) season, it ranges from 1.76 m to 9.09 m. The GWL trends have been estimated using the non-parametric tests, MMK during the period 1998 to 2018 at 39 locations in the Ghazipur district of Uttar Pradesh, India. From the analysis, The GWL trend analysis has revealed negative magnitudes for 8 locations that covered 20 % portion of total area and positive magnitudes for 31 locations spread in 80 % area in the PRM season...

Here, we present detailed electron microprobe analyses and age data of high-medieval lead-silver smelting slags. The mineral composition data provide a database of all silicate and oxide phases in the slag. Bulk chemistry as well as mineral composition is used to reconstruct liquidus, solidus, and viscosity of the slag melt. By calculating the mass balance of the smelting process, a mass ratio of the various compounds used in the smelting process is determined. Through this we were able to discriminate qualitatively between non-ferrous metal smelting slags and bloomery slags. We also report a new type and process of silver production in which argentiferous galmei (zinc carbonate) was used as a main silver ore together with galena. The results indicate a sophisticated high-medieval smelting technology, in which a slag with a low liquidus and a low viscosity was created.

Groundwater with high geogenic arsenic (As) is extensively present in the Holocene alluvial aquifers of Ghazipur District in the middle Gangetic Plain, India. A shift in the climatic conditions, weathering of carbonate and silicate minerals, surface water interactions, ion exchange, redox processes, and anthropogenic activities are responsible for high concentrations of cations, anions and As in the groundwater. The spatial and temporal variations for As concentrations were greater in the pre-monsoon (6.4-259.5 μg/L) when compared to the post-monsoon period (5.1-205.5 µg/L). The As enrichment was encountered in the sampling sites that were close to the Ganges River (i.e. south and southeast part of Ghazipur district). The depth profile of As revealed that low concentrations of NO 3 -are associated with high concentration of As and that As depleted with increasing depth. The poor relationship between As and Fe indicates the As release into the groundwater, depends on several processes such as mineral weathering, O 2 consumption, and NO 3 -reduction and is decoupled from Fe cycling. Correlation matrix and factor analysis were used to identify various factors influencing the gradual As enrichment in the middle Gangetic Plain. Groundwater is generally supersaturated with respect to calcite and dolomite in post-monsoon period, but not in pre-monsoon period. Saturation in both periods is reached for crystalline Fe phases such as goethite, but not with respect to poorly crystalline Fe phases and any As-bearing phase. The results indicate release of arsenic in redox processes in dry period and dilution of arsenic concentration by recharge during monsoon. Increased concentrations of bicarbonate after monsoon are caused by intense flushing of unsaturated zone, where CO 2 is formed by decomposition of organic matter and reactions with carbonate minerals in solid phase. The present study is vital considering the fact that groundwater is an exclusive source of drinking water in the region which not only makes situation alarming but also calls for the immediate attention.