Inputs of the major element potassium into the ocean from rivers and on-axis high temperature hydrothermal systems have likely varied on geological timescales. Variable uptake of potassium into lavas altered in low-temperature, off-axis, hydrothermal systems could keep the potassium concentration in seawater within the narrow range (~9.5 to 11 mmol L-1) observed in the Phanerozoic. To test this hypothesis a better understanding of the timing of alteration, and of the role of changing environmental conditions on seawater/basalt reactions is required. The age of 69 samples of the secondary, potassium-rich, phyllosilicate mineral celadonite from lavas in the Troodos ophiolite were determined using Rb-Sr radiometric dating to test whether potassium uptake occurs within a specific time interval. Measurements used tandem quadrupole ICP-MS/MS. Combined with published radiometric ages the dataset revealed regional differences in the duration of celadonite formation in the Troodos ophiolite lavas. In one area, where significant hydrothermal sediments were deposited on the lavas, celadonite formed as much as ~40 Myr after the crust accreted, whereas in an area with rare hydrothermal sediments celadonite formation was largely limited to the first ~20 Myr after crustal accretion. These differences in duration of celadonite formation in the upper oceanic crust are interpreted as reflecting differences in distribution of hydrothermal sediments that act as a source of labile Fe that is needed for celadonite formation. To test if there are significant variations of duration and timing of celadonite formation on various scales in the upper oceanic crust I measured the first in-situ Rb-Sr ages of celadonite in lavas from DSDP and ODP drill cores. These ages show that ~80% of celadonite formed from pervasive fluid flow within the first ~20 Myr after the oceanic crust accreted. All celadonite ages roughly correlate with the cumulative heat flow removed from the oceanic lithosphere in the same time interval. In combination the >100 new celadonite ages presented here provide strong evidence that most celadonite forms in the first ~20 Myr after crustal accretion and environmental conditions could be significant in controlling potassium uptake. To determine whether the potassium sink from seawater into altered seafloor lavas varied over time I compile a dataset of the potassium content of lavas from DSDP and ODP drill cores (0 to 180 Myr age range). Estimates of the average potassium content of individual holes reveal that this varies with age. However, holes of similar age show a similar magnitude of variability to that which occurs over this time. To investigate the source of the variability of potassium in altered lavas I modelled the effects of bottom seawater temperature and pH using PHREEQC. The models indicate that if the fluid is in equilibrium with K-feldspar, Na-beidellite and calcite, an increase in bottom seawater temperature and/or decrease in pH would lead to the potassium concentration in the off-axis fluid to increase significantly. This emphasizes the need for future studies to investigate feedback mechanisms between low-temperature hydrothermal alteration in response to changing environmental conditions. / Graduate / 2022-07-12

The inductively coupled plasma mass spectrometer (ICP-MS) is the instrument of choice for trace and ultra-trace elemental analysis. However, the ICP-MS suffers from matrix effects. Matrix effects occur when instrument response varies as the composition of the sample matrix is changed. Matrix effects, or non-spectroscopic interferences, limit the accuracy of routine analysis. Identification of the sources of matrix effects provide a basis for reducing or eliminating them. As inaccuracies in the ICP-MS are more severe than those in the ICP atomic emission spectrometer, the problem may be due, at least in part, to the vacuum interface used to couple the plasma source and mass spectrometer. The research herein is a study of matrix effect sources in the first stage of the vacuum interface. This study utilized laser-induced fluorescence of atomic species to identify factors affecting analyte transport through the sampling orifice of the vacuum interface. Several non-idealities in the performance of the interface were found. (1) Operating conditions and sample compositions can negatively affect the efficiency with which ions are extracted through the vacuum interface coupling the plasma source to the mass spectrometer. (2) The sampling cone itself was found to suppress and narrow ion distributions in the plasma. (3) Changes in the degree of ionization were identified in the first vacuum stage. The evidence of recombination and state-changing collisions was observed in the first vacuum stage at lower power settings. Matrix effects occur in the first vacuum stage, the first step of the ion extraction process. This work shows that changes in ion transport through the first vacuum stage of the vacuum interface of an ICP-MS affect the overall performance of the instrument.

The Barsele area is located in the "Gold Line", southwest of the volcanogenic massive sulphide (VMS) Skellefte district which hosts more than 85 known VMS-deposits where some are gold-bearing. The Barsele area consists of the Central, Avan and Skiråsen intrusion hosted gold deposits, the Norra gold-bearing VMS-deposit and the Risberget zone. This study includes a geochronological study of two coherent volcanic rocks from the Norra zone using Laser Ablation-Inductively Coupled Plasma-Mass Spectrometry and Scanning Electron Microscope images of zircons and also includes petrographic microscopy of thin sections and lithogeochemical data used in classification diagrams.  This study presents two new LA-ICP-MS zircon U-Pb ages for VMS-hosting volcanic rocks from the Barsele area: o   1956.8 ± 6.47 Ma (n: 17, MSWD: 0.99), sample A from a hydrothermally altered volcanic rock  o   1952.2 ± 14.5 Ma (n: 6, MSWD: 1.1), sample B from a rhyolite-dacite  The new U-Pb age constraints presented in this study indicate that the volcanic rocks of the Norra zone are older than the volcanic rocks in the Skellefte Group. The results presented in this report together with the earlier dated c. 1.96 Ga metadacite suggests that the volcanic rocks of the Barsele area are located at a lower chronostratigraphic level than the Skellefte Group, i.e., at the chronostratigraphically lower Bothnian Supergroup. Additionally, the results presented here conclude that two VMS-events can be delineated by geochronological data which further opens up for the question if the Barsele area belong to an older arc system (e.g., the Knaften arc) or were part of an arc system evolving continuously between 1.95-1.88 Ga (e.g., the Knaften-Skellefte arc). / Barsele, Västerbottens län, norra Sverige, ligger i ett område som kallas för Guld linjen och är beläget sydväst om Skelleftefältet där mer än 85 kända förekomster av massiva sulfidmalmer (VMS), vissa guldförande, förekommer. Barseleområdet är uppdelat i Central, Avan och Skiråsen zonen, Norra zonen och Risberget zonen där Norra zonen är en guldförande VMS-fyndighet. Denna studie inkluderar en geokronologisk studie av zirkoner från två vulkaniter från Norra zonen som har analyserats med Laser Ablation Inductively Coupled Plasma Mass Spectrometry och avbildats med svepelektronmikroskop samt petrografisk studie av två tunnslip och klassificeringsdiagram baserade på litogeokemisk data. Denna studie presenterar två nya LA-ICP-MS zirkon U-Pb åldrar för VMS-förande vulkaniter i  Barseleområdet:  o   1956.8 ± 6.47 Ma (n: 17, MSWD: 0.99), prov A från en hydrotermalt omvandlad vulkanisk bergart o   1952.2 ± 14.5 Ma (n: 6, MSWD: 1.1), prov B från en ryolit-dacit De två nya  U-Pb zirkon åldersbestämningarna som presenteras i denna studie indikerar att de vulkaniska bergarterna i Norra zonen är äldre än de vulkaniska bergarterna som tillhör Skelleftegruppen. Vidare antyder de presenterade åldrarna i denna studie tillsammans med den tidigare genomförda dateringen av en metadacit (cirka 1.96 Ga) på att de vulkaniska bergarterna i Barseleområdet kan tillhöra suprakrustala bergarter tillhörande Bottniska bassängen. Barseleområdet föreslås därför förekomma vid en lägre kronostratigrafisk nivå jämfört med Skelleftegruppen, det vill säga vid samma kronostratigrafisk nivå som Bottniska Supergruppen. Utifrån de resultat som presenteras här kan slutsatsen att två VMS-områden kan avgränsas av geokronologiska data som ytterligare öppnar för frågan om Barsele-området tillhör ett äldre bågsystem (t.ex. Knaften-bågen) eller var en del av ett bågsystem som utvecklades mellan 1.95-1.88 Ga (t.ex. Knaften-Skelleftebågen).

Tooth enamel is among the most durable substances in the human body and as such has high recoverability in forensic anthropology cases. Its crystalline hydroxyapatite matrix has a slightly variable chemical composition which incorporates biologically available trace elements. The trace elements are derived from an individual's diet and the water he or she consumes during the period of enamel formation. As a result, trace element profiles of enamel can reflect the geology, pollution, and certain cultural dietary factors of the area in which the individual resided during this period. This research examines a sample of teeth with known demographic information from the Antioquia Modern Skeletal Reference Collection in Medellin, Colombia. A sample set of 75 teeth from 61 individuals born in areas throughout northwestern Colombia were analyzed using laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS), a minimally destructive, semi-quantitative technique. Analysis was performed at the Center for Archaeology, Materials, and Applied Spectroscopy (CAMAS) at Idaho State University. 33 elements were analyzed in the sample. Nonparametric methods were used to assess the relationship between elemental profiles and region of origin. Sr, Mo, Ag, Ba, Eu, and Tm concentration profiles were found to vary among regional groups. Al, Ni, Cr, Mn, Co, Sr, Cd, Sb, Sm, Eu, and U were found to predict region of origin. Differences in municipality were classified with 72% accuracy, variation across the department of Antioquia was classified with 67% accuracy, and the age of the geologic substrate was classified with 67% accuracy. The results suggest that trace element analysis of permanent tooth enamel may be of some use in estimating an individual's region of origin in forensic anthropological contexts. Further research with both larger sample sizes and more geographic variation is necessary.

Resource recovery has become essential to compensate for costly and complex technical requirements to implement zero-liquid discharge (ZLD) policies. Antiscalant removal, especially phosphonate-based antiscalants, is a clear example of resource and potential subsequent valorization. The global market for phosphonate-based antiscalants is expected to grow in the coming years along with increasing membrane desalination projects. It implies the disposal in surface waters of tons of phosphonates and trace elements, present in wastewater and concentrates, every day. Removing the phosphonates and trace elements allows their subsequent recovery and valorization, minimizing squeezing produc-tion/extraction procedures and saving the environment from suffering any im-pact because of them. The first part of this thesis focuses on phosphonate removal with iron and aluminum-based adsorbents. Porous iron and aluminum (oxi)hydroxides can remove phosphonates from concentrates completely. The main limitation of this process is the diffusion of the phosphonates through adsorbent particles. As proved in this thesis, temperature significantly improves the adsorption kinetics of the phosphonates on both adsorbents as a result of the variation of the diffusion coefficient. The presence of calcium also plays an important role, since accelerates the adsorption at the first stages of the process, but limits and saturates the capacity of the adsorbent surface for further adsorption. More research on the role of calcium is needed in this regard to better understand how the adsorption/diffusion of the phosphonates is affected by this common element present in concentrates. Electrocoagulation was studied in the second part of this thesis as a potential approach for phosphonate removal. Using pure iron electrodes, the applied current density can be easily optimized. As a result, dissolved phosphonates are quickly removed from a large concentrate volume at a relatively low cost and minimal sludge production. The benefits of this technique lie in the possibility of producing the substrate (adsorbent) in situ for the phosphonate to be adsorbed. Furthermore, the time required to completely remove the phosphonates is remarkably shorter compared to adsorption, which, as pointed out above, is limited by diffusion phenomena. Alkaline washing was relatively successful at recovering the phosphorus from the sludge, depending on the dissolved phosphonate in the concentrate. Although experimental results may look promising, further research on finding the optimum working conditions has to be addressed. The process is open to improvement in terms of new electrode materials, reactor design, phosphorus recovery, or optimal working temperature. In the third part of the thesis, the adsorption potential of previously tested adsorbents for the removal of elements at trace levels. The iron-based adsorbent, commercialized for phosphate and arsenic removal, turned out to be excellent at removing transition metals (TM) and rare earth elements (REE). The study was carried out in parallel with the exploration of the capabilities of a high-resolution inductively coupled plasma mass spectrometry (HR ICP-MS) instrument. The potential of this analytical procedure allows the detection and quantification of all the isotopes at the ultra-trace level (in the range of a few ng·L-1) and in only one measurement round. Furthermore, interferences from polyatomic species, formed during the ionization in the plasma, are easily resolved due to the high-resolution mode. As a result, the detection of the targeted element is easily discriminated from the potential interferences. This feature makes a remarkable difference regarding ordinary ICP-MS, which requires different analytical procedures to properly resolve overlapping signals. This analytical procedure opens new possibilities to test the adsorbents in new conditions and develop analytical methods for water speciation.

The effects of water and dietary influence, and time duration for discernment, of pectoral fin spine 87Sr/86Sr were evaluated in Atlantic Sturgeon Acipenser oxyrinchus oxyrinchus. Fish were subjected to 87Sr-enriched water (0.1 mg/L) or diet (0.25 migrogram/g or 0.5 microgram/g) for 1, 2, 3, 6, or 12 weeks. Fish were also held at 15 or 25°C to determine if temperature influenced 87Sr/86Sr. Results found fin spine 87Sr/86Sr changed in water after 1 week and diet after 12 weeks suggesting water is the primary influence. In wild Gulf Sturgeon A. o. desotoi, spot ablations closest to the fin spine core separated fish into four 87Sr/86Sr groups (0.7110, 0.7105, 0.7100, and 0.7906) for both the Pascagoula and Pearl Rivers from 2016-2021. In the Pearl River system, 87.5% of fish (pre-first annuli) had stable 87Sr/86Sr indicating minimal movement, whereas decreasing 87Sr/86Sr in the second and third growth zones indicated downriver movement towards estuaries.

No description available.

The study gives a broad background to understand the high demand of lithium batteries in the coming years, especially in Europe. The goal of the study is to use La-ICP-MS to analyse spodumene samples from different lithium deposits in Europe to get a better knowledge of the contents of trace elements in spodumene. Due to unforeseen circumstances linked to the pandemic of COVID-19. the study had to develop an own method to calculate and convert the data acquired with the La-ICP-MS into more quantitative data.  The method developed requires more research and understanding before saying that it can be used for future research, especially for the calculation of major element Li, Al and Si as it showed a value difference to 20% of the “real value”. Source of contamination in the analysed samples (eucryptite) is also being discussed and its implication on the result. Results acquired using this method showed that some trace elements are indeed occurring in spodumene substituting the main elements and are found in all the different geological domains. These elements (Ga, Mn, Se, Fe, V, T) will then also occur in a concentrate of spodumene.

No description available.

No description available.