High Strontium Content Research Articles

Strontium isotopes as an indicator for groundwater salinity sources in the Kirkuk region, Iraq

The Kirkuk region in northern Iraq hosts some of the largest oil fields in the Middle East. Several anticline structures enabled vertical migration and entrapment of the oil. Frequently, complex fracture systems and faults cut across the Eocene and middle Oligocene reservoirs and the cap rock, the Fatha Formation of Miocene age. Seepage of crude oil and oil field brines are therefore a common observation in the anticline axes and contamination of shallow groundwater resources is a major concern. In this study, 65 water samples were collected in the Kirkuk region to analyze and distinguish mixing processes between shallow groundwater resources, uprising oil field brines, and dissolution of gypsum and halite from the Fatha Formation. Hydrochemical analyses of the water samples included general hydrochemistry, stable water isotopes, as well as strontium concentrations and for 22 of the samples strontium isotopes (87Sr/86Sr). Strontium concentrations increased close to the anticline axes with highest concentrations in the oil field brines (300mg/l). Strontium isotopes proved to be a valuable tool to distinguish mixing processes as isotope signatures of the oil field brines and of waters from the Fatha Formation are significantly different. It could be shown, that mixing of shallow groundwater with oil field brines is occurring close to the major fault zones in the anticlines but high concentrations of strontium in the water samples are mainly due to dissolution from the Fatha Formation.

Endocrine disrupting activities of surface water associated with a West Virginia oil and gas industry wastewater disposal site

Currently, >95% of end disposal of hydraulic fracturing wastewater from unconventional oil and gas operations in the US occurs via injection wells. Key data gaps exist in understanding the potential impact of underground injection on surface water quality and environmental health. The goal of this study was to assess endocrine disrupting activity in surface water at a West Virginia injection well disposal site. Water samples were collected from a background site in the area and upstream, on, and downstream of the disposal facility. Samples were solid-phase extracted, and extracts assessed for agonist and antagonist hormonal activities for five hormone receptors in mammalian and yeast reporter gene assays. Compared to reference water extracts upstream and distal to the disposal well, samples collected adjacent and downstream exhibited considerably higher antagonist activity for the estrogen, androgen, progesterone, glucocorticoid and thyroid hormone receptors. In contrast, low levels of agonist activity were measured in upstream/distal sites, and were inhibited or absent at downstream sites with significant antagonism. Concurrent analyses by partner laboratories (published separately) describe the analytical and geochemical profiling of the water; elevated conductivity as well as high sodium, chloride, strontium, and barium concentrations indicate impacts due to handling of unconventional oil and gas wastewater. Notably, antagonist activities in downstream samples were at equivalent authentic standard concentrations known to disrupt reproduction and/or development in aquatic animals. Given the widespread use of injection wells for end-disposal of hydraulic fracturing wastewater, these data raise concerns for human and animal health nearby.

Origins of elements building travertine and tufa: New perspectives provided by isotopic and geochemical tracers

Fluid/rock interaction represents a major process in the formation of calcitic or aragonitic travertine and tufa (CATT). In most cases, CATT is associated to limestone dissolution somewhere along the hydrogeological pathway. However, a wide array of other substratum (basalts, rhyolites, carbonatites, ultramafics, granites, dolomites, evaporites) can act as potential source of elements involved in the formation of CATT. This study reports on the evaluation of potential geochemical tracers linking CATT to their substratum, and unravelling the origin of elements. A large database was established from available literature data as well as new data acquired in the frame of this study for a set of Modern to Recent CATT (Ligurian ophiolites, Italy; the Chaine des Puys, Limagne graben and Paris Basin, France; Reunion Island, Indian Ocean; Jebel Oust, Tunisia). Four most reliable tracing methods are identified (1) δ13C and δ18O cross-plot allows distinguishing epigean (minδ13C=−27.2‰, maxδ13C=0.9‰, meanδ13C=−12.3‰ for N=314) from hypogean systems (minδ13C=−4‰, maxδ13C=11.7‰, meanδ13C=−2.87‰ for N=198). Very low δ13C values (<−12‰) and δ18O>−4‰ associated to negative δ13C values are specifically indicative of an ultramafic source rock. (2) Barium and strontium cross-plot helps to discriminate different groups of source rocks amongst the hypogean CATT: (i) source rocks composed of mixed limestones, evaporites, and dolomites are characterised by low barium (<100ppm) and high strontium (>400ppm) contents, (ii) mafic and granitic source rocks are undifferentiated and display similar barium (from 15 to 930ppm) and high strontium (>200ppm) contents, (iii) the carbonatite group is characterised by its exceptional high barium and strontium values. In epigean CATT, a pure limestone source rock usually relates to very low barium and strontium contents (<50ppm and <70ppm respectively), whereas mixed limestone, evaporite and dolomite source rocks generally display low strontium content (<580ppm) with higher barium content (>50ppm). (3) Relatively high beryllium content (>30ppm) in CATT seems to indicate a pure granitoid source. (4) High chromium concentrations (>20ppm) are systematically documented in Modern CATT located on an ultramafic substratum. The definition of diagnostic compositional fields for actively forming or recently formed CATT is influenced by many factors including water composition, water temperature, dissolved gas composition and concentration, biological activity, position in the sedimentary body and early diagenesis, in addition to substratum lithology. However, the results of this study illustrate that, despite these many factors, the combined use of Ba, Sr, Be, Cr, δ13C, and δ18O may be valuable to discriminate the rock lithology prevailing in the hydrogeological or palaeo-hydrogeological reservoir of CATT.

Fluoride contamination in groundwater resources of Alleppey, southern India

Alleppey is one of the thickly populated coastal towns of the Kerala state in southern India. Groundwater is the main source of drinking water for the 240,991 people living in this region. The groundwater is being extracted from a multi-layer aquifer system of unconsolidated to semi-consolidated sedimentary formations, which range in age from Recent to Tertiary. The public water distribution system uses dug and tube wells. Though there were reports on fluoride contamination, this study reports for the first time excess fluoride and excess salinity in the drinking water of the region. The quality parameters, like Electrical Conductivity (EC) ranges from 266 to 3900 μs/cm, the fluoride content ranges from 0.68 to 2.88 mg/L, and the chloride ranges between the 5.7 to 1253 mg/L. The main water types are Na-HCO3, Na-CO3 and Na-Cl. The aqueous concentrations of F− and CO32− show positive correlation whereas F− and Ca2+ show negative correlation. The source of fluoride in the groundwater could be from dissolution of fluorapatite, which is a common mineral in the Tertiary sediments of the area. Long residence time, sediment–groundwater interaction and facies changes (Ca-HCO3 to Na-HCO3) during groundwater flow regime are the major factors responsible for the high fluoride content in the groundwater of the area. High strontium content and high EC in some of the wells indicate saline water intrusion that could be due to the excess pumping from the deeper aquifers of the area. The water quality index computation has revealed that 62% of groundwater belongs to poor quality and is not suitable for domestic purposes as per BIS and WHO standards. Since the groundwater is the only source of drinking water in the area, proper treatment strategies and regulating the groundwater extraction are required as the quality deterioration poses serious threat to human health.

The preparation of strontium-substituted hydroxyapatite bone phantoms with high strontium concentrations

The current in vivo x-ray fluorescence spectrometry (IVXRF)-based method of bone strontium quantification is dependent on calibration against plaster of Paris (poP; ) calibrators/phantoms. Issues with the dissimilarity of the poP in comparison to bone mineral and the known issue with high levels of strontium contamination in commercial poP materials has led to the development of a strontium-free hydroxyapatite bone mineral phantom material. The analyte is introduced into this material by doping of a high concentration setting solution. This phantom material is not particularly well suited for the preparation of strontium containing bone phantoms which are high in strontium concentration (in the mol % concentration range) and thus when the (Ca + Sr)/P mole ratio is to be kept at 1.67: that of hydroxyapatite. This work thus evaluates the feasibility of preparing high concentration strontium-substituted hydroxyapatite phantoms using a CaHPO4 · 2H2O/Ca(OH)2/Sr(OH)2 · 8H2O cement mixture. It was found that a strontium-substituted HAp phantom material can be prepared by mixing suitable quantities of CaHPO4 · 2H2O, Ca(OH)2 and Sr(OH)2 · 8H2O to a (Ca + Sr)/P mole ratio of 1.67. Setting of the phantom using a 1 M setting solution (to increase phosphate concentration) produced a phantom composed of ()5(PO4)3OH of known strontium concentration. The final phantom material was found to be a strontium-substituted product (through x-ray diffraction and Raman spectroscopy measurements) to the degree of substitution expected. This work thus describes the preparation of a bone phantom material which can be used for the calibration of IVXRF systems of bone strontium quantification, as well as for other modalities (i.e. dual energy x-ray absorptiometry and quantitative ultrasound) in the case that bone strontium concentrations are expected to be high such as in the case of individuals taking strontium salts for the treatment/prevention of osteoporosis.

New methods for the preparation and dielectric properties of Lа2 − xSrxNiO4 (х = 1/8) ceramic

The perovskite-type oxide La2−xSrxNiO4 (x=1/8) was prepared by a new precursor route. The reaction proceeds in the self-ignition mode. Single-phase powder and gas-tight ceramic samples can be produced by single annealing of decomposition products. It was shown that as a result of thermobaric treatment of La2−xSrxNiO4 (x=1/8) the solid solution La2−xSrxNiO4 with a higher concentration of strontium and the second phase La3Ni2O7 are formed. Short-term (5min) thermobaric treatment (P=2.5GPa) at t°=900°С changes the unit cell parameters, but is not accompanied by structural transitions. At the same time, morphological restructuring of the sample occurs—the agglomerates delaminate into thin plates crystals. It was established that the permittivity of the material exposed to thermobaric treatment is much higher compared to that of the sample annealed at atmospheric pressure and virtually does not depend on frequency in a wide temperature range.

Major storm periods and climate forcing in the Western Mediterranean during the Late Holocene

Big storm events represent a major risk for populations and infrastructures settled on coastal lowlands. In the Western Mediterranean, where human societies colonized and occupied the coastal areas since the Ancient times, the variability of storm activity for the past three millennia was investigated with a multi-proxy sedimentological and geochemical study from a lagoonal sequence. Mappings of the geochemistry and magnetic susceptibility of detrital sources in the watershed of the lagoon and from the coastal barriers were undertaken in order to track the terrestrial or coastal/marine origin of sediments deposited into the lagoon. The multi-proxy analysis shows that coarser material, low magnetic susceptibility, and high strontium content characterize the sedimentological signature of the paleostorm levels identified in the lagoonal sequence. A comparison with North Atlantic and Western Mediterranean paleoclimate proxies shows that the phases of high storm activity occurred during cold periods, suggesting a climatically-controlled mechanism for the occurrence of these storm periods. Besides, an in-phase storm activity pattern is found between the Western Mediterranean and Northern Europe. Spectral analyses performed on the Sr content revealed a new 270-year solar-driven pattern of storm cyclicity. For the last 3000 years, this 270-year cycle defines a succession of ten major storm periods (SP) with a mean duration of 96 ± 54 yr. Periods of higher storm activity are recorded from >680 to 560 cal yr BC (SP10, end of the Iron Age Cold Period), from 140 to 820 cal yr AD (SP7 to SP5) with a climax of storminess between 400 and 800 cal yr AD (Dark Ages Cold Period), and from 1230 to >1800 cal yr AD (SP3 to SP1, Little Ice Age). Periods of low storm activity occurred from 560 cal yr BC to 140 cal yr AD (SP9 and SP8, Roman Warm Period) and from 820 to 1230 cal yr AD (SP4, Medieval Warm Period).

Geochemistry of Ukhrul Limestone of Assam-Arakan Subduction Basin, Manipur, Northeast India

Abstract: Geochemical studies of the carbonate rocks of Ukhrul limestone from Hundung and Payoi area of Ukhrul District of Manipur, India have been carried out through investigation of major oxides and trace elements geochemistry to determine their chemical composition, to establish the distribution pattern and mutual relationship of the elements, for chemical classification of the limestones and also to decipher environmental conditions that existed during the time of deposition of the calcareous sediments. The study indicates that the limestones were deposited in open to protected near shore, marginal neritic environment with argillaceous sediment flux derived from a granitic continental crust. Protected basin existed partly in Paoyi area. Presence of marine gastropods and foraminifera fossils and higher concentration of strontium in the studied carbonate rocks suggest relatively shallow marine environment of deposition during the Eocene sedimentation.

Preparation and chemical characteristics of Karunguruvai Khadi used in the traditional Siddha formulation of herbo-mineral-based medicine

IntroductionKhadi is an extract that has been used in the preparation of Pooneeru (muppu) in Siddha medicine, but it has not been scientifically evaluated for modern medicinal purposes. The present study examines the preparation and chemical composition of Khadi. Materials and methodsAccording to the method of the palm leaf literature, Karunguruvai and Samba paddy grains were selected for the preparation of Khadi. After removing the husk of the paddies, the cleaned Karunguruvai and Samba rice were processed according to the methods of Swami and Ramasamy Khon. The processed Khadi of Karunguruvai and Samba were analyzed for chemical constituents and were microbiologically assessed. The chemical composition of the paddy grains was also evaluated to compare with the Khadi constituents. ResultsThe major elements of the paddy grains of Karunguruvai and Samba were calcium (CaO) and sodium (Na2O). The predominant trace elements in the Samba rice were nickel and cadmium, whereas Karunguruvai rice contained arsenic, nickel, copper, and cadmium. Samba Khadi contained the trace elements mercury, chromium, lead, copper, and cobalt, whereas Karunguruvai Khadi had a high content of mercury, vanadium, arsenic, nickel, copper, cadmium, barium, and strontium. Karunguruvai Khadi also contained silicon dioxide (SiO2), aluminum oxide (Al2O3), iron oxide (FeO), manganese oxide (MnO), calcium oxide (CaO), and sodium carbonate (Na2O). By contrast, Samba Khadi contained only ferrous oxide (FeO), calcium oxide (CaO), sulfur dioxide (SO2), and carbon dioxide (CO2), which were chemical constituents of the Samba rice. DiscussionThe composition of Karunguruvai rice was compared with Samba rice and it is identified the absence of heavy metals in Samba as well as Karunguruvai rice. Both of rice powders have more or less similar chemical compounds except phosphorous content. Karunguruvai rice possesses more CaO than Samba rice. The bacterial and fungal activities were assessed during the different stages of Khadi preparation—no activities were found in any form of the Khadi. This suggests that Khadi may have a preventive effect against fungal and bacterial infections. ConclusionThe result of the chemical analysis of Khadi extracts showed that Khadi prepared from the Karunguruvai paddy grains (rice) was the best base solvent for ion exchange in the preparation of muppu than Samba Khadi. The analysis of the composition of these two types of Karunguruvai Khadi show that it is a good solvent for the elimination of heavy metals and for the enrichment of elements in Pooneeru powder (muppu), the chuurnam of Siddha drugs. These characteristics enhance the therapeutic potential and safety of the drugs for healing chronic diseases.

Development of a strontium chronic effects benchmark for aquatic life in freshwater.

There are no national water-quality guidelines for strontium for the protection of freshwater aquatic life in North America or elsewhere. Available data on the acute and chronic toxicity of strontium to freshwater aquatic life were compiled and reviewed. Acute toxicity was reported to occur at concentrations ranging from 75 mg/L to 15 000 mg/L. The majority of chronic effects occurred at concentrations above 11 mg/L; however, calculation of a representative benchmark was confounded by results from 4 studies indicating that chronic effects occurred at lower concentrations than all other studies, in 2 cases below background concentrations reported for US and European streams. Two of these studies, including 1 reporting effects below background concentrations, were repeated and found not to be reproducible; chronic effects occurred at considerably higher strontium concentrations than in the original studies. Studies with narrow-mouthed toad and goldfish were not repeated; both studies reported chronic effects below background concentrations, and both studies had been conducted by the authors of 1 of the 2 studies that were repeated and shown to be nonreproducible. Studies by these authors (3 of the 4 confounding studies), conducted over 30 yr ago, lacked detail in reporting of methods and results. It is thus likely that repeating the toad and goldfish studies would also have resulted in a higher strontium effects concentration. A strontium chronic effects benchmark of 10.7 mg/L that incorporates the results of additional testing summarized in the present study is proposed for freshwater environments.

Migratory history of African longfinned eel Anguilla mossambica from Maningory River, Madagascar: discovery of a unique pattern in otolith Sr:Ca ratios

The migratory life histories were investigated for 30 African longfinned eels (Anguilla mossambica) of the yellow eel stage from the Maningory River, East Madagascar using otolith Sr:Ca ratios and parasite composition. The Sr:Ca ratio patterns of nine eels resembled those of A. mossambica in South Africa and of other anguillids and were classified as “typical” Sr:Ca ratio pattern eels. Typical pattern eels were further classified into freshwater residents (five eels) and habitat shifters (four eels) depending on whether they spent their first several years in saltwater. An unique Sr:Ca ratio pattern was found in 21 eels whereby the Sr:Ca ratios in the yellow eel stage increased drastically to extremely high values of 10 to 30 × 10−3 which have not been observed for any Elopomorpha species. These individuals were categorized as “elevated” Sr:Ca ratio pattern eels. The elevated pattern eels were characterized by significantly older ages, lower somatic growth rates, a much higher intensity and abundance of the gastrointestinal parasite Heliconema africanum and a lower abundance of the swim bladder parasite Anguillicoloides papernai. The extremely elevated Sr:Ca ratios of the yellow eel stage result most likely from inhabiting freshwater areas characterized by a high strontium concentration because the ratios far exceeded the known values for Elopomorpha species. Cyclical lows in the otolith Sr:Ca ratios of the elevated type eels corresponded to annuli, revealing either an overwintering movement pattern between habitats with different Sr:Ca ratios, or a seasonal change in the ambient environment.

Co-precipitation of Radium with Barium and Strontium Sulfate and Its Impact on the Fate of Radium during Treatment of Produced Water from Unconventional Gas Extraction

Radium occurs in flowback and produced waters from hydraulic fracturing for unconventional gas extraction along with high concentrations of barium and strontium and elevated salinity. Radium is often removed from this wastewater by co-precipitation with barium or other alkaline earth metals. The distribution equation for Ra in the precipitate is derived from the equilibrium of the lattice replacement reaction (inclusion) between the Ra(2+) ion and the carrier ions (e.g., Ba(2+) and Sr(2+)) in aqueous and solid phases and is often applied to describe the fate of radium in these systems. Although the theoretical distribution coefficient for Ra-SrSO4 (Kd = 237) is much larger than that for Ra-BaSO4 (Kd = 1.54), previous studies have focused on Ra-BaSO4 equilibrium. This study evaluates the equilibria and kinetics of co-precipitation reactions in Ra-Ba-SO4 and Ra-Sr-SO4 binary systems and the Ra-Ba-Sr-SO4 ternary system under varying ionic strength (IS) conditions that are representative of brines generated during unconventional gas extraction. Results show that radium removal generally follows the theoretical distribution law in binary systems and is enhanced in the Ra-Ba-SO4 system and restrained in the Ra-Sr-SO4 system by high IS. However, the experimental distribution coefficient (Kd') varies widely and cannot be accurately described by the distribution equation, which depends on IS, kinetics of carrier precipitation and does not account for radium removal by adsorption. Radium removal in the ternary system is controlled by the co-precipitation of Ra-Ba-SO4, which is attributed to the rapid BaSO4 nucleation rate and closer ionic radii of Ra(2+) with Ba(2+) than with Sr(2+). Carrier (i.e., barite) recycling during water treatment was shown to be effective in enhancing radium removal even after co-precipitation was completed. Calculations based on experimental results show that Ra levels in the precipitate generated in centralized waste treatment facilities far exceed regulatory limits for disposal in municipal sanitary landfills and require careful monitoring of allowed source term loading (ASTL) for technically enhanced naturally occurring materials (TENORM) in these landfills. Several alternatives for sustainable management of TENORM are discussed.

The strontium isotopic evolution of Marcellus Formation produced waters, southwestern Pennsylvania

The production of natural gas and natural gas liquids from unconventional tight shale formations involves hydraulic fracturing and subsequent removal of fluids co-produced with the gas. The chemistry of the returning fluid reflects the original composition of the injection water, mobilized constituents in the shale formation, and co-mingled formation waters liberated by hydraulic fracturing. Produced water from unconventional gas wells tapping the Middle Devonian Marcellus Formation is characterized by high total dissolved solids (TDS), including very high strontium concentrations. In this study, the strontium isotope composition (87Sr/86Sr) was measured in produced waters from four horizontally drilled, hydraulically fractured Marcellus shale gas wells in southwestern Pennsylvania, sampled from the first day after commencement of flowback to as much as 27 months later. The 87Sr/86Sr of the waters tended to change rapidly over the first few days of water return, and then approached (but did not reach) a constant range of values from 0.7113 to 0.7114, which appears to be characteristic of this part of the Marcellus play. In contrast, the concentration of Sr rose more slowly and appeared to hit a steady state value (up to 3000mg/L) by the end of the first year. Taken together with results from earlier work, these data suggest mixing between injected frac fluid and high-TDS formation water, highly enriched in Sr, and isotopically relatively uniform throughout the Marcellus shale gas play. This brine could exist within porous lenses of organic matter in the shale, in pre-existing fractures within the shale, and/or originate from fluids that migrated from adjacent formations at some point during the post-depositional history of the basin.

A Multi‐Method Database of the Black and White Marbles of Göktepe (Aphrodisias), Including Isotopic, EPR, Trace and Petrographic Data

A database of the ancient marbles of Göktepe near Aphrodisias is reported, and includes 160 white, black and bichrome samples from 13 quarries and two waste deposits. The quarries are grouped into four districts. Districts 1 and 2, to the north, produced exclusively black or dark grey marbles (nero antico). Districts 3 and 4 produced white statuary marble. Nero antico and a black and white stone were also quarried in district 4, where the black marble surfaces again. The samples were characterized using petrography, isotopic analysis, EPR spectroscopy and trace analysis. The Göktepe white exhibits an unparalleled combination of fine grain, low EPR intensity and high strontium concentration that often allows easy identification. The isotopic values are less distinctive and similar to those for Carrara. In most cases, however, they are tightly grouped and also quite indicative. The black marbles exhibit a much weaker metamorphic overprint. With respect to the white marbles, they show analytical similarities but also notable differences. Therefore, establishing their provenance can be more difficult and may require the support of petrographic analysis. The results suggest that the Göktepe marbles were among the most prized and widespread statuary marbles used in Roman times, particularly from the early second century ad onwards.

Hydrothermal activity and its paleoecological implications in the latest Miocene to Middle Pleistocene lacustrine environments of the Baza Basin (Betic Cordillera, SE Spain)

The continental sedimentary record of the Baza Basin (Guadix–Baza Depression, Betic Cordillera, SE Spain) shows six sedimentary units of lacustrine origin deposited from the latest Miocene to the Middle Pleistocene. Depending on the interval considered, the lacustrine deposits are mainly composed of marls, carbonates or gypsiferous evaporites, showing lithological, mineralogical and geochemical features (i.e., magnesium, strontium and sulfur contents, celestine deposits and travertine growths) that are evidence of intense, tectonically-induced hydrothermal activity. According to the high concentrations of strontium and sulfur as well as the abundance of travertines and magnesium clays, the supply of hot waters was greater during the Zanclean, the Gelasian and the Calabrian, as a result of tectonic activity. Hydrothermal activity has continued until the present time and is responsible of the hot springs that are nowadays active in the Guadix–Baza Depression. The paleoenvironmental consequences of these sublacustrine hot springs were that during some intervals the lakes maintained a relatively permanent water table, not subject to periodic desiccations in the dry season, and warmer temperatures throughout the year. This resulted in a high level of organic productivity, especially for the Calabrian, which allowed the development of a rich and well diversified mammalian community, similar to those of modern African savannas with tree patches. In this mild environment, the permanent water sheet favored the presence of drought intolerant megaherbivores such as the giant extinct hippo Hippopotamus antiquus. The high standing crop biomass of ungulates resulted in the availability of abundant carcasses for scavengers such as hyenas and hominins, which explains the very high densities of skeletal remains preserved in the sediments distributed along the lake surroundings.

Geochemical studies on Permian manganese deposits in Guichi, eastern China: Implications for their origin and formative environments

Permian manganese ore deposits are widely distributed in southwestern and eastern China. Guichi Permian manganese district in southern Anhui Province, central eastern China, is currently the most important manganese metal producers in eastern China. Manganese ores (MnO=18.2–45.4wt.%) in Guichi region occur in calcareous, argillaceous and siliceous Mn-bearing sequence of the Permian Gufeng Formation. In contrast to Mn-bearing rocks, the ores have higher Mn, Fe, P, Sr (more than 1500ppm) and Ni contents (>480ppm), higher Mn/Fe (>5) and Lan/Cen (>2) values, and lower Co/Ni (<0.05) ratios. The Guichi manganese deposits also have low Co/Ni (<1) and Co/Zn ratios, low in total REE contents (mostly<100ppm) with negative Eu (0.46–0.75) and Ce (0.42–0.76) anomalies. The mineralogy and geochemistry of manganese deposits in the Guichi region strongly indicate hydrothermal activities, which is supported by high paleotemperatures (49–71°C) of Permian Mn-carbonate ore and Mn-bearing carbonate. The low Ceanom. values (<−0.1) and high strontium contents indicate that the Guichi manganese deposits were formed in high-salinity and oxidative marine sedimentary environment. The Al2O3/TiO2 (9.23–48.2) and Y/Ho (25.9–44.4) ratios, REE patterns, δ13CV-PDB (−10.2‰ to 5.00‰) and δ18OSMOW (20.7–28.0‰) characteristics of Permian manganese deposits reveal a mixed Mn source of volcanic, terrigenous and organic matter.

The Effect of Glucose on &lt;i&gt;Saccharomyces cerevisiae&lt;/i&gt; Cell Biosorption of Strontium under Simulation Culture Conditions

The effect of glucose on Saccharomyces cerevisiae cell biosorption of strontium under simulation culture conditions was studied in this research. The results showed that the glucose adding did not abviously increase the biosorption efficiency in 30-150 min and after 8 h. The glucose adding might stimulate the S.cerevisiae cell biosorption of strontium ions in 4-8 h for high initial strontium concentration. The results indicated that the glucose adding only stimulated S.cerevisiae cell biosorption of strontium at certain biosorption time and the biosorption process first was a physical adsorption followed bioaccumulation according to interface process and cell growth cycle under simulation culture conditions.

Microchemical investigation of bone derived from mice treated with strontium in different chemical forms using scanning electron microscopy and micro-Raman spectroscopy

We used SEM/EDX and micro-Raman spectroscopy to investigate the chemical changes (both on the level of elementary and molecular composition) of mice bones when strontium is incorporated in their microstructure after being administered in the form of two salts: chloride and ranelate. Strontium accumulated mainly in vicinity of bone edges, both cortical and close to bone marrow. The distribution of other elements comprising bone samples (Ca, P, Mg, K etc.) was also determined by energy-dispersive X-ray analysis (EDX). The area adjacent to a cortical bone edge with accumulated strontium has presented modified Raman spectral profiles. Besides most of the Raman bands typical for both mineral (hydroxyapatite with carbonate substitution type B) and organic phases of a bone, we observed a Raman band at 811cm−1. It was detected regularly in the sample with high strontium concentration.

APHRODISIAN MARBLE FROM THE GÖKTEPE QUARRIES: THE LITTLE BARBARIANS, ROMAN COPIES FROM THE ATTALID DEDICATION IN ATHENS

The marble of seven under-lifesize sculptures of barbarians, now in the archaeological museums of Naples, Venice and the Vatican, commonly considered to be Roman copies of the Pergamene Lesser Dedication in Athens, comes from the Göktepe marble quarries near Aphrodisias, as is shown by isotopic, electron paramagnetic resonance, trace analyses, and of petrographic data. Since this marble was used mostly by Aphrodisian artists, this finding confirms, on the basis of scientific data, previous hypotheses on the origin of the sculptors who manufactured the statues. Reliable discrimination from similar fine-grained Asiatic marbles, such asDocimium, is possible primarily on the basis of the composition of the Göktepe marbles, which have unusually low concentrations of manganese and high concentrations of strontium. Present knowledge of the history of the quarries and the distribution of their marbles seems to rule out the possibility that the sculptures date from the late Republican period and supports the opinion, previously proposed on stylistic grounds, that they were manufactured in Rome by Aphrodisian sculptors probably during the first half of the second centuryad.

Formation of nanosized strontium substituted hydroxyapatites

Incorporation of specific elements into calcium phosphates offers the combination of a bioactive material and a therapeutic effect. This is important for improving the integration of implants as well as treating medical conditions. Strontium is a suitable candidate and displays the ability to stimulate bone growth and reducing bone resorption. This study investigated the formation of strontium carbonated hydroxyapatite nanoparticles from an amorphous phase. Crystallization of carbonated hydroxyapatite occurred at 585 °C, but samples with an intended 25% and 75% replacement of calcium with strontium crystallized at 624 °C. Heat treatment at the crystallization temperature revealed that strontium free apatite does not crystallize in 5 minutes, but an increasing strontium concentration leads to a higher rate of crystallization. X-ray diffraction patterns suggest that it may be difficult to include strontium, but higher strontium concentrations are possibly included with ease in the lattice. This work has produced a nanosized apatite accompanied by an amorphous phase after a short heat-treatment time. This offers a range of features that collectively show great promise for significantly enhancing the release of strontium for improved bone therapeutic effects.