Concentrations Of Alkaline Earth Elements Research Articles

Association between selected alkaline earth elements concentrations in umbilical cord and risk for cleft lip with or without cleft palate

The relationship between alkaline earth elements in utero exposure and the risk of cleft lip with or without cleft palate (CL ± P) remains unclear. We aimed to investigate the associations between the concentration of alkaline earth elements in umbilical cord and risk for CL ± P. A case-control study was carried out in this study, including 78 cases and 142 controls. Association between each metals and the risk of CL ± P were evaluated with conventional logistic regression, bayesian kernel machine regression and weighted quantile sum regression models. Logistic regression model indicated that in utero exposure to higher levels of Barium was associated with increasing risk for CL ± P (odds ratio = 2.79, 95% confidence interval, 1.22–6.38) and for cleft lip with cleft palate (odds ratio = 3.94, 95% confidence interval, 1.45–10.72). Bayesian kernel machine regression model showed the statistical association between the metals mixture and risk difference of CL ± P, and barium was associated with CL ± P risk when all other metals were held fixed at the 25th percentiles (risk difference = 1.07, 95% confidence interval, 1.01–1.14). In weighted quantile sum model, barium accounted for most of the weight index in the combined effect of the metals mixture. The weighted quantile sum index showed that a quartile increase in the index resulted in an increase odds of 1.69 (95% confidence interval, 1.16–2.46) for CL ± P and of 2.11 (95% confidence interval, 1.34–3.35) for CLP. No associations were found in the three statistical models between Calcium, Magnesium and Strontium and the risks of CL ± P. In conclusion, in utero exposure to mixtures of alkaline earth elements was associated with an increased risk for CL ± P, of which barium was likely to be important factors in the development.

The Influence of Karst Aquifer Mineralogy and Geochemistry on Groundwater Characteristics: West Bank, Palestine

This work reports, for the first time, the mineralogical and geochemical characteristics of karst aquifers in the Central West Bank (CWB) catchment in Palestine. It provides an integrated study approach by correlating the geochemistry of the lithology and hydrochemical data of groundwater samples. Mineralogical analysis showed that all of the samples were dominantly composed of either calcite CaCO3 (5–100 wt. %) or dolomite CaMg(CO3)2 (4–100 wt. %), with minor amounts of quartz and feldspar, which is supported by the inorganic carbon content (9–13 wt. %) and hydrochemical composition of the spring water samples. The whole-rock geochemical data indicated that the samples have low contents of trace elements and transition metals. In contrast, the concentrations of alkaline earth elements (Mg, Ca, Sr, Ba) and Mn were high in the rock and groundwater samples. Generally, the trace elements of rock samples with concentrations >10 ppm included Sr (17–330 ppm), Mn (17–367 ppm), Ba (2–32 ppm), W (5–37 ppm), Cr (3–23 ppm), Zn (1.7–28 ppm), V (4–23 ppm), and Zr (1–22 ppm), while the concentrations of all the other trace elements was below 10 ppm. Ionic ratios and hierarchical cluster analysis (HCA) suggested that the chemical evolution of groundwater was mainly related to the geogenic (rock–water) interaction in the study area. This is clear in the alkaline earth elements (Mg, Ca, Sr, Ba) ratios, especially regarding the Sr values. The calcite rock samples had higher Sr (mean 160 ppm, n = 11) than those of the dolomite rocks (mean 76 ppm, n = 9).

Are concentrations of alkaline earth elements in maternal hair associated with risk of neural tube defects?

The relationship between maternal intake of alkaline earth elements (AEEs) during the period of neural tube closure and the risk of neural tube defects (NTDs) is still unclear. We propose that AEE deficiency during the early period of pregnancy is associated with an elevated risk of NTDs in the offspring. In this study, we recruited 191 women with NTD-affected pregnancies (cases) and 261 women who delivered healthy infants (controls). The concentrations of four AEEs (Ca, Mg, Sr, Ba) in maternal hair sections that grew during early pregnancy were analyzed. Information on the dietary habits of the mothers was also collected by questionnaire. Higher concentrations of the four AEEs in hair had protective effects against the risk of total NTDs, with odds ratios with 95% confidence interval (comparing groups separated by each median level) of 0.44 (0.28–0.68) for Mg, 0.56 (0.36–0.87) for Ca, 0.45 (0.28–0.70) for Sr, and 0.41 (0.26–0.65) for Ba. Significant negative dose-response trends were identified for the relationships between the four AEE concentrations in maternal hair and the risks of anencephaly and spina bifida, but not for encephalocele. The frequencies of maternal consumption of fresh green vegetables, fresh fruit, and meat or fish were positively correlated with the concentrations of AEEs in hair. We concluded that the maternal intake of AEEs may play an important role in preventing NTD formation in offspring, and that this intake is related to maternal dietary habits of consuming fresh green vegetables, fresh fruit, and fish or meat.

Hydrochemistry deducing basaltic trap thickness for groundwater resource mapping along the Deccan Volcanic Province (DVP) margin in India

It is hypothesized that hydrochemical parameters can be employed to deduce the basaltic trap thickness and that there exist diverse hydrochemical processes within the existing host rocks along the Deccan Volcanic Province (DVP) margin. Chemical imprints of aquifers, in various flows of flood basalt and fissured zones of granites, had been appraised using major ion chemistry of groundwater in a test site of 623 km2 at the southern margin of the DVP in India. The wide ranging hydrochemical processes, obtained from empirical data, describe the predominance of carbonate, dolomite, calcite and anorthite weathering in basalts, and alkali feldspar (albite and orthoclase) in granites. Results showed that the elevated concentrations of alkaline earth elements in basaltic aquifers and alkali rich elements in granitic aquifers were useful in tracing the sources of host rock for dissolved mineral reactants. Further, a digital elevation model using Shuttle Radar Topography Mission (90 m) elevation satellite data aided in deciphering trap thickness, vertical transition zone of trap and granitic basement comprising the well depths and hydrochemistry. The mapping of trap thickness is useful to explore the groundwater resources at the vertical transition zone between the basaltic trap and granitic base. The estimated thickness of the basaltic trap is varied from 4 to 98 m at the DVP southern margin, which is further verified with the help of exploratory well lithologs matched closely.

Increasing shallow groundwater CO 2 and limestone weathering, Konza Prairie, USA

In a mid-continental North American grassland, solute concentrations in shallow, limestone-hosted groundwater and adjacent surface water cycle annually and have increased steadily over the 15-year study period, 1991–2005, inclusive. Modeled groundwater CO 2, verified by measurements of recent samples, increased from 10 −2.05 atm to 10 −1.94 atm, about a 20% increase, from 1991 to 2005. The measured groundwater alkalinity and alkaline-earth element concentrations also increased over that time period. We propose that carbonate minerals dissolve in response to lowered pH that occurs during an annual carbonate-mineral saturation cycle. The cycle starts with low saturation during late summer and autumn when dissolved CO 2 is high. As dissolved CO 2 decreases in the spring and early summer, carbonates become oversaturated, but oversaturation does not exceed the threshold for precipitation. We propose that groundwater is a CO 2 sink through weathering of limestone: soil-generated CO 2 is transformed to alkalinity through dissolution of calcite or dolomite. The annual cycle and long-term increase in shallow groundwater CO 2 is similar to, but greater than, atmospheric CO 2.

Progressive dolomitization of Florida limestone recorded by alkaline earth element concentrations in saline, geothermal, submarine springs

Studies in the late 1970s revealed that the effluents of saline, geothermal, submarine springs on the West Florida Shelf have compositions nearly identical to seawater, except for distinct Ca enrichments and Mg depletions, probably resulting from dolomitization. During annual visits between 1996 and 2003 we collected high‐purity effluents from four submarine springs and from Warm Mineral Springs (WMS), which is located on land. Filtered effluents were analyzed for major ions and for Sr and Ba. These analyses confirm the seawater‐like composition of the effluents as well as the Ca enrichment and Mg depletion. The alkaline earth elements Sr and Ba, like Ca and Ra, are significantly enriched in the effluents compared to ambient seawater, by average factors of 1.6 and 3.8, respectively (about 9 and 12 for WMS). The Mg depletion, and the Sr and Ba enrichments, while invariant over the 7‐year sampling period, increase gradually from south to north, consistent with progressive dolomitization of limestone along the purported convective flow path of the warm seawater. The Ca enrichment shows no obvious trend because, besides dolomitization, gypsum dissolution is an independent source of Ca. A simple mass balance indicates that the Ca excess is fully accounted for by these two processes in all four submarine springs. This is not the case for WMS, where a residual Ca excess points to a third source of Ca, presumably limestone dissolution that occurs upon mixing of the modified seawater with fresh groundwater from the Floridan Aquifer System.

H 2O speciation in float glass and soda lime silica glass

The speciation of H 2O in float glass (FG) and soda lime silica glass (SLS) was investigated using IR and NMR spectroscopy. Molar absorption coefficients for the near-infrared (NIR) combination bands at 4500 and 5200 cm − 1 , assigned to OH groups and H 2O molecules, respectively, were determined using hydrated glasses containing 0.5–7.4 wt.% of dissolved H 2O. Water contents of the samples used in the calibration were determined by Karl–Fischer titration or mid-infrared spectroscopy. Different combinations of baseline corrections and intensity measures were applied to evaluate the NIR spectra with tangent baselines and measurement of peak heights giving the best reproducibility. Deviations up to 30% relative were observed between water species concentrations determined by NIR spectroscopy using an internally consistent calibration based on bulk water content and those determined by low temperature static 1H NMR spectroscopy. This implies that the assumption of constant NIR absorption coefficients may be not valid for glasses in which dissolved water is strongly hydrogen-bonded. Based on the NMR data the NIR absorption coefficients were re-calibrated, demonstrating that in particular the absorption coefficient for the band at 4500 cm − 1 ( ε 4500) varies with water content. For float glass ε 4500 grows by 35% when the water content increases from 0.5 to 4.0 wt.%. An opposite trend was found for soda lime glass with an approximately linear decrease of ε 4500 by 27% relative between 0.5 and 7.5 wt.% H 2O. For the 5200 cm − 1 band we could not resolve a dependence of the absorption coefficient ( ε 5200) on water content (values of 0.89 ± 0.06 and 0.95 ± 0.06 L mol − 1 cm − 1 were determined for FG and SLS glass, respectively). However, this may be a consequence of the low precision in determining of ε 5200 at water contents below 2 wt.%. Based on the improved NIR calibrations, the OH concentrations at given water content are typically lower in FG than in SLS glasses with apparent saturation values of 1.4 wt.% (FG) and 2.2 wt.% (SLS) of water dissolved as OH groups. The difference in OH contents could be related to the different chemical compositions of these two glasses, in particular the concentration of alkaline-earth elements and the ratio of Mg / Ca, which are larger in FG glass than in SLS glass. Using the new water speciation data, we have re-evaluated the molar absorption coefficient for the H 2O bending vibration band at 1630 cm − 1.

Multi-element geochemistry of sediments from the Pearl River system, China

Sediment samples were taken along the West, North, and East rivers of the Pearl River system at 28 locations in 1998, and a total of 49 elements were determined by ICP–AES, ICP–MS and INAA. The probability features of the datasets were studied, and the average concentrations of these elements in sediments of the three rivers were calculated. Significant differences in element concentrations among the three rivers were observed and the results were confirmed by statistical tests including analysis of variance (ANOVA), Kruskal–Wallis test, and t-test. Spatial distribution maps of element concentrations were produced using a geographical information system (GIS). The immobile trace elements (such as Sc, Ti, V, Cr, Mn, Fe, Co, and Ni) are enriched in the West River where limestone dominates the rock types in the watershed. Because of the strong weathering, immobile trace elements are enriched and reside in secondary minerals of the weathering products. All three rivers have high concentrations of rare earth elements (REEs) because of strong weathering, but relatively higher concentrations of REEs are observed in sediments of the East River where granite dominates the rock type. Granite contains high concentrations of REEs and the sediments have inherited this feature from their bedrock. Alkaline element (Li, Na, K, Rb, and Cs) concentrations are elevated in sediments of the East River, these may reside in granitic primary minerals. Relatively high concentrations of alkaline earth elements (Mg, Ca, Sr, and Ba) are observed in the West River, inherited from the limestone bedrock. High Pb and Bi concentrations are found in the North River and are caused by Pb mineralization and the discharge of a smelter in the upper reaches of the river. However, statistical tests did not indicate a significant difference between Pb concentrations in the North River and the other two rivers, which suggests that statistical results should be carefully used and explained.

Geochemistry of alkaline earth elements (Mg, Ca, Sr, Ba) in the surface sediments of the Yellow Sea

The concentrations of alkaline earth elements were measured in the surface sediments of the Yellow Sea in an attempt to establish their sources from horizontal distributions. The maximum concentrations of Mg are found in the central Yellow Sea, and its horizontal distribution is mainly controlled by quartz dilution. The concentrations of Ca and Sr increase toward the southeastern Yellow Sea region. The relatively higher enrichment of Ca and Sr in the southeastern Yellow Sea, with Sr/Ca ratios of 0.0053, suggests the presence of carbonates which are comprised of foraminifera and/or coccoliths, like deep-sea carbonates. On the other hand, the concentrations of Ba increase toward the northeastern Yellow Sea. The higher Ba enrichment in the sandy region of the northeastern Yellow Sea is associated with the presence of feldspar as evidenced by excellent correlations among Ba/Mg, Al/Mg, and Sr/Ca ratios. Our results suggest that the transgressive and relict sand occurring in the eastern parts of the Yellow Sea contains Al, Sr, and Ba enriched feldspars which originated from Arprock River, Korea and thus can be distinguished from sand occurring in the western parts of the Yellow Sea which originated from Yellow and Yangtze Rivers.

Isotopic and trace element constraints on mixing and melting models of marginal basin volcanism, Bransfield Strait, Antarctica

Bransfield Strait is a narrow marginal basin separating the South Shetland Islands from the northern end of the Antarctic Peninsula. Quaternary volcanism occurs in the strait as subaerial and submarine volcanoes aligned on the inferred axis of rifting, and as two subaerial, off-axis volcanoes on the northern margin of the strait. The Bransfield Strait lavas are similar to published analyses from other marginal basins, ranging from basalts and basaltic andesites to trachytes. They exhibit moderate enrichments in alkali and alkaline earth elements relative to high-field-strength elements that are typical of many back-arc basin basalts. The seamount basalts have trace element chemistry similar to enriched mid-ocean ridge basalts (E-MORB), but with variously higher alkali and alkaline earth element concentrations and, frequently, lower Nb. Low-pressure fractional crystallization accounts for most of the compositional variation within individual volcanoes, but it does not explain intervolcano differences even though the volcanoes are closely spaced and presently or recently active. Melting of depleted mantle mixed with 0.5–2% crust or sediment explains the isotopic and trace element variations not accounted for by magma chamber processes. The off-axis volcanoes are the products of less partial melting than the on-axis volcanoes. One of the off-axis volcanoes also contains more of an enriched component in its source. Some of the lavas have Rb/Sr too low to account for their 87Sr/ 86Sr, perhaps due the loss of Rb during mantle metasomatism or interaction between slab-derived fluids and the mantle source of the basalts. Strontium, neodymium, and 207Pb/ 204Pb isotopic signatures remained constant during the transition from Tertiary island arc volcanism to Quaternary marginal basin volcanism, but 206Pb/ 204Pb increased. High Ce N/Sm N of basalts from some volcanoes requires residual garnet in the source. Thus the young (15–25 Ma at the trench) subducted slab is either deeper than 60 km beneath the volcanoes, or it has fractured and is no longer a coherent barrier to melts generated below it.

Petrochemistry and tectonic significance of Lower Cretaceous Barros Arana Formation basalts, southernmost Chilean Andes

The Lower Cretaceous Barros Arana Formation (Albian, hornblende KAr age of 104 Ma), in the Magallanes region of Chile, consists of a sequence of spilitized clinopyroxene- and amphibole-bearing mafic dikes and lavas, and volcaniclastic breccias, occurring within the sedimentary infill of the Rocas Verdes marginal basin and its eastward extension onto the Cretaceous continental platform. Although the original alkali and alkaline earth element concentrations of the basaltic lavas and dikes have been altered by spilitization, the presence of relict pargasitic amphibole phenocrysts, the absence of orthopyroxene, and high LREE contents and LREE/HREE ratios imply mildly alkaline affinities for these basalts. Their low TiO 2 and HFSE (Zr, Nb, Ta, and Hf) contents and high LREE/HFSE ratios suggest affinities with convergent plate boundary arc magmas. The Barros Arana basalts are interpreted as mafic members of the mildly alkaline shoshonitic rock suite of subduction-related arcs. They may have formed as subduction geometry began to undergo the changes (flattening) that ultimately led to the initiation of the closure, deformation, and uplift of the Rocas Verdes basin by the late or post-Albian. The low initial 87Sr/ 86Sr (0.7031) and high initial 143Nd/ 144Nd (0.51277) of the basalts indicate that a generally extensional tectonic regime east of the main calc-alkaline arc allowed eruption of these mafic shoshonites without interaction with continental crust (in contrast to the contemporaneous plutons of the Patagonian batholith).