0000000000846104
AUTHOR
Pierpaolo Zuddas
Zirconium–hafnium and rare earth element signatures discriminating the effect of atmospheric fallout from hydrothermal input in volcanic lake water
The geochemical behaviour of Rare Earth Elements, Zr and Hf was investigated in the thermal waters of Nevado del Ruiz volcano system. A wide range of pH, between 1.0 and 8.8, characterizes these fluids. The acidicwaters are sulphate dominatedwith different Cl/SO4 ratios. The important role of the pH and the ionic complexes for the distribution of REE, Zr a nd Hf in the aqueous phase was evidenced. The pH rules the precipitation of authigenic Fe and Al oxyhydroxides producing changes in REE, Zr, Hf amounts and strong anomalies of Cerium. The precipitation of alunite and jarosite removes LREE from the solution, changing the REE distribution in acidic waters. Y-Ho and Zr-Hf (twin pairs) have a…
The distribution of Rare Earth Elements discriminates the growth substrate of Vitis vinifera L.
Sustainable agricultural, food-related strategies and geographic traceability require understanding of the plant physiological response to stress potentially generated by contaminated soils. Here, we have investigated the effect of contaminated substrate on growth of Vitis vinifera L. plants analysing the distribution of full Rare Earth Elements (REE) spectra in different parts of the plant. Experiments were carried out using pristine plants growing in a handmade substrate (blank experiment) and in REE artificially-enriched soil (spiked experiment). Our results show that both plant mass and REE amount in leaves are not influenced by the substrate enrichment while roots are by one-order of m…
Rare earths behaviour during the deposition of volcanic sublimates
Abstract In this study, the REE distribution between volcanic fluids and related solids in fumaroles with temperatures ranging from approximately 100 to 421 °C was investigated in different geological scenarios. The treatment of geochemical REE data was carried out by calculating the REE enrichment factors (EF REE ) relative to the volcanic host rocks in studied sites under the assumption that the REE transport takes place as silicate aerosol in volcanic fluids. Shale-normalised REE concentrations in these fluids have been assessed to investigate whether the REE transport as aqueous complexes in water-saturated volcanic gas is reasonable. The REE behaviour in alkaline condensates according …
Zr- Hf Fractionation During Water-Rock Interaction
International audience; Zr and Hf are two elements having same ionic charge and similar ionic size at a given coordination number. Despite the Zr/Hf ratio is considered to be quite constant in meteorites and lithospheric rocks, seawaters collected from the surface down to varying depths of several Pacific Ocean stations reveal that the Zr/Hf ratio increases by one order of magnitude. Very recent studies have shown that, in both ground waters and lake waters, the Zr/Hf ratio is either higher or lower compared to the interacting minerals displaying a large variability in the distribution of these twin elements. In this communication the possible processes responsible for such a large fraction…
Behavior of rare earth elements in an aquifer perturbed by CO2 injection: Environmental implications
International audience; Three cubic-meters of CO2-saturated water was injected into a subsurface fractured aquifer in a post-mined area, using a push-pull test protocol. Groundwater samples were collected before and after CO2-injection to quantify geochemical changes. CO2-injection initially reduced the pH of water from 7.3 to 5.7, led to the enrichment of major ions (Ca2+, Mg2+, and alkalinity), and dissolved trace metals (including Fe, Mn, As, and Zn) in the groundwater. Rare earth elements (REE) and yttrium concentrations were also measured in these samples before and after CO2 perturbation, to evaluate their behavior. An enrichment of total Y plus REE (REY) occurred. REY fractionation w…
Relationship between lanthanide contents in aquatic turtles and environmental exposures
International audience; Trace elements released in the environment during agricultural practices can be incorporated and accumulated in biological fluids and tissues of living organisms. The assessment of these exposures were carried out investigating lanthanide distributions in blood and exoskeleton samples collected from Emys trinacris turtle specimens coming from sites with anthropogenic discharge in western and south Sicily, along migration paths of many bird species from Africa to Europe. The data show a significant (Rxy = 0.72; Rxy > 0.67; α = 0.025) linear relationship between the size of turtle specimens and the lanthanide contents in blood lower than 0.4 μg L−1 whereas this relatio…
Influence of pH and temperature on the early stage of mica alteration
Mineral dissolution and precipitation reactions actively participate in controlling fluid chemistry during water–rock interaction. In this study, the changes in the biotite and muscovite basal surface nano-morphology were evaluated during interaction with fluids of different pH (pH = 1.1, 3.3 and 5.7) at different temperatures (T =2 5, 120, and 200 C). Results show that at the nanometre scale resolution of the atomic force microscope (AFM), dissolution generates etch pits with a stair-shaped pattern over the (0 0 1) surface. The flux of dissolved elements decreases when pH increases. However, at pH 5.7, a change was found in the flux after 42 h of reaction when abundant gibbsite and kaolini…
Trace element fractionation through halite crystallisation: Geochemical mechanisms and environmental implications
Halite is an important mineral for industry, agriculture and food production. It crystallises after water evaporation, while the progressive growth of dissolved metal ions in brines is occurring. Then, halite exploitation may provide the delivery of metal ions in the environment and the mechanism of this trace element accumulation should be studied. In this work we investigate the distribution of lanthanides and Y (hereafter named Rare Earth Elements, REE), Zr and Hf between crystallising halite and brines in the Dead Sea as geochemical tools for recognising the mechanism of metal ion removal from brines and accumulation in halite. Halite forms cubic crystals where octahedral planes sometim…
Zirconium and hafnium fractionation and distribution of Rare Earth Elements in neutral–alkaline waters: Case study of Lake Van hydrothermal system, Turkey
International audience; We investigated the distribution of Zr, Hf, and rare earth elements (REE) as the sum of lanthanides plus Y in the hydrothermal system in the Lake Van area of south-eastern Turkey. This system is characterised by water with variable pH in alkaline conditions resulting from hydrothermal CO2 upraise and neoformation of calcite minerals in near equilibrium with the interacting waters. Zr, Hf, and REE determinations were carried out for aqueous phases and suspended solids in lake water and surrounding thermal springs. We found that dissolved Hf is partitioned relative to Zr during calcite formation and that such fractionation is a function of the Ca2+ activity in warm wat…
Discrimination between effects induced by microbial activity and water-rock interactions under hydrothermal conditions according to REE behaviour
AbstractRare earth elements (REE) were investigated in siliceous stromatolites forming in the Specchio di Venere Lake on Pantelleria Island. Chondrite-normalised patterns show significant La enrichments and Eu depletions suggesting that fluids involved in stromatolite growth experienced strong rock-water interactions under hydrothermal conditions. At the same time, enrichments in heavy REE (HREE) with respect to intermediate REE (MREE) suggest that hydrothermal fluids interacted with microbial mats during deposition of the stromatolites. The above-mentioned features suggest that rock-water interactions and bacterial activity were simultaneously recorded in the REE patterns of stromatolites,…
The behaviour of zirconium and hafnium during water-rock interaction
Abstract Zr and Hf are two elements with same ionic charge and similar ionic size at a given coordination number. Despite the Zr/Hf ratio is quite constant in meteorites and lithospheric rocks, in natural waters can be either higher or lower compared to values of interacting minerals and rocks. Here, we reanalyze very recent published and present new data on continental and brine waters indicating that the Zr and Hf behavior is dependent on the properties of the authigenic phases formed during the water-rock interaction process. Our results show that water pH in the range between 1 and 9 and water ionic strength in the range between 0.001 and 4 mol kg−1 are responsible for the change of the…
The behaviour of zirconium, hafnium and rare earth elements during the crystallisation of halite and other salt minerals
Abstract Halite crystals from Messinian and Tortonian evaporites from Sicily and Spain and current precipitated halite crystals and the relative parent brines (active evaporation systems) were investigated in order to evaluate the Zr, Hf and Rare Earth Element (REE) behaviour. Halite crystallisation from evaporating brines fractionates Zr, Hf and REE through a two-step process. During the first step, dissolved complexes of studied elements are scavenged onto the surfaces of crystallising halite. During the second step, elements are co-precipitated into the crystal lattice as it grows. The first step mechanism is determined by the dissolved REE speciation. In saltworks where carbonate-REE co…
Rapid migration of CO2-rich micro-fluids in calcite matrices
International audience; The transport of supercritical fluids is a determining factor for several geological processes and fundamental in predicting natural resource accumulation and distribution. Calcite, ubiquitous in most geological environments, may contain supercritical CO2 trapped under the form of fluid inclusions that may move through grain boundaries affecting the rock physical properties. However, despite macroscopic evidence for this process, until recent it was not possible to characterize this process at the nano-scale due to the difficulty of such observations. In this study, we report nanometer-scale observations on calcite crystal surfaces and demonstrate that stress with ab…
Geochemical characterisation of gases along the dead sea rift: Evidences of mantle-co2 degassing
International audience; The Dead Sea Transform (DST) fault system, where a lateral displacement between the African and Arabian plates occurs, is characterised by anomalous heat flux in the Israeli area close to the border with Syria and Jordan. The concentration of He and CO2, and isotopic composition of He and total dissolved inorganic carbon were studied in cold and thermal waters collected along the DST, in order to investigate the source of volatiles and their relationship with the tectonic framework of the DST. The waters with higher temperature (up to 57.2 °C) are characterised by higher amounts of CO2 and helium (up to 55.72 and 1.91 * 10-2 cc l-1, respectively). Helium isotopic dat…
Using the Trace Element Contents in Bronchoalveolar Lavages to Probe the Human Exposure to Inhaled Particulates
Explosive volcanic eruptions eject large volumes of high surface area, metal-rich dust and ash into the atmosphere. In areas near major volcanic eruptions, humans often interact with these materials and may bioaccumulate heavy and toxic metals. To evaluate these interactions, we examine bronchoalveolar lavage samples (BAL) collected from people exposed to the paroxysmal 2001 Etna eruption. BAL samples reveal a strong enrichment of many toxic heavy metals and the capacity for trace elements released from inhaled particles to induce crystallisation of phosphatic microcryst biominerals in intraaveolar spaces. BAL rare earth element (REE) concentration patterns normalised to shale reveal a ‘V-s…
Trace element behaviour in seawater during Etna's pyroclastic activity in 2001: Concurrent effects of nutrients and formation of alteration minerals
volcanic ash ; trace element leaching ; kinetic experiments ; chlorophyll-alpha; International audience; The eruption of Etna in Sicily on 13 July 2001 marked the most intense activity of the volcano in the last 300 years. The eruption occurred while the oceanographic cruise ANSIC 01 was being conducted to the east of Sicily, presenting a unique opportunity for the investigation of the chemical effects on the marine system during a period of significant (similar to 1 g m(-2)) ash deposition. Comparison of trace element data with measured concentrations from the oceanographic cruise JUVENILE 99, carried out two years before, indicates large enrichments of V. Cr, Mn, Fe, Co, Cu and Pb. We att…
Authigenic phase formation and microbial activity control Zr, Hf, and rare earth element distributions in deep-sea brine sediments
Abstract. Sediments collected from hypersaline and anoxic deep-sea basins in the eastern Mediterranean (Thetis, Kryos, Medee, and Tyro) were characterised in terms of their mineralogical composition, the distributions of rare earth elements (REE), Zr, and Hf and their content of microbial DNA. We identified two major mineralogical fractions: one fraction of detritic origin was composed of quartz, gypsum, and low-Mg calcite bioclasts (with 0 < Mg < 0.07%) and another fraction of authigenic origin constituted of halite, dolomite, high-Mg calcite (with a Mg content of up to 22%) and rare bischofite and showed a textural evidence of microbial assemblages. We found that in the Medee and Ty…
Influence of dissolved organic matter on rare earth elements and yttrium distributions in coastal waters
International audience; Data collected during this study indicate that dissolved Y and REE (rare earth element) behaviour can be monitored through shale-normalised ratios. Relationships occurring between these ratios suggest that leaching from lithogenic materials is the main source of REE in the studied area. This process involves riverine detrital matter in the inner area of the Gulf of Palermo. Features of shale-normalised patterns and the relationship recognised between dissolved Fe and Y/Ho suggest that REE are released from Fe-rich coatings of atmospheric dust. Observed similarities between dissolved Fe and chlorophyll- content suggest that leaching of Fe-rich atmospheric particulates…
Yttrium and lanthanides in human lung fluids, probing the exposure to atmospheric fallout.
International audience; Inhalation of airborne particles can produce crystallization of phosphatic microcrysts in intraaveolar areas of lungs, sometimes degenerating into pulmonary fibrosis. Results of this study indicate that these pathologies are induced by interactions between lung fluids and inhaled atmospheric dust in people exposed to volcanic dust ejected from Mount Etna in 2001. Here, the lung solid-liquid interaction is evaluated by the distribution of yttrium and lanthanides (YLn) in fluid bronchoalveolar lavages on selected individuals according the classical geochemical approaches. We found that shale-normalised patterns of yttrium and lanthanides have a 'V shaped' feature corre…
Zr/Hf ratio and REE behaviour: A coupled indication of lithogenic input in marginal basins and deep-sea brines
Abstract The distribution of dissolved Zr, Hf and Rare Earth Elements (yttrium and lanthanides, hereafter referred to as REE) in the Eastern Mediterranean seawater column was measured in the Kryos basin to evaluate the lithogenic contribution from both Nile River and Sahara and Arabian desert dust. We found dissolved Zr/Hf ratios below the signature of crustal rocks and chondrites; a phenomenon likely driven by the dissolution of the Mn-rich coating of atmospheric dust particles delivered from the desert. In deeper waters, Zr/Hf ratios are clustered close to the signature of crustal rocks and chondrites according to the different Zr and Hf dissolved speciation. The Zr/Hf ratio observed in t…
The behavior of Rare-Earth Elements, Zr and Hf during biologically-mediated deposition of silica-stromatolites and carbonate-rich microbial mats
Abstract Venere Lake, in the Pantelleria Island thermal system (Central Mediterranean Sea) consists of a mix of seawater and hydrothermal volcanic fluids containing high levels of dissolved SiO 2 . Close to the lake's thermal springs, siliceous stromatolites are deposed under high bacterial activity conditions whereas roughly interlaminated Ca-carbonates and microbial mats are widely scattered in the lake. The dissolved REE speciation in lake waters is dominated by [REE(CO 3 ) 2 ] − , [REE(CO 3 )] + and [REE(H 3 SiO 4 )] 2 + complexes. On the contrary the most abundant Zr and Hf species are hydroxyl- and fluoride-complexes. The behavior of REE Zr and Hf in the Venere lake waters is controll…
Zr, Hf and REE distribution in river water under different ionic strength conditions
International audience; The Platani River flowing in south-central Sicily, interacting with evaporite rocks, generates a wide range of ionic strength in the water catchment from 0.1 to 5.0 mol kg−1. We sampled 38 river sites and analysed the composition for the dissolved fraction filtered through 0.45 μm, the truly dissolved fraction obtained through ultrafiltration (10 kDa) and the relative included colloidal fraction.This study was focused on the recognition of Zr, Hf and REE behaviour under changing ionic strength conditions, since this is one of parameters responsible for colloid stability in natural waters. In turn, this phenomenon leads to REE release from the colloidal fraction and t…
Recognition of water masses according to geochemical signatures in the Central Mediterranean sea: Y/Ho ratio and rare earth element behaviour
This study reports the results of geochemical investigations carried out in the Strait of Sicily (Central Mediterranean Sea) during the oceanographic cruise BANSIC 2000, focusing on the area around the Pantelleria Island. We evaluate the interface processes between dissolved phase and suspended particulate matter in the water columns on the basis of Y/Ho ratio and rare earth elements and yttrium distributions that are suitable to trace the occurrence of different water layers in Central Mediterranean Area. The main source of trace elements to the sea water system was recognized in the atmospheric fallout, while different scavenging mechanisms among Y and rare earth elements occur. Cation ex…
Escape of Supercritical-CO2 Fluids Trapped in Calcite Nano-metric Pores
Flow of supercritical CO2-bearing fluids through a rock is a fundamental phenomenon which acts upon a great many geological processes ranging from seismic activity to formation of ore deposits. Atomic Force Microscopy scanning experiments allowed us to infer movement of supercritical CO2-bearing fluids through calcite crystals and relate it to natural decrepitation of nanoscale fluid inclusions. Calculated velocities exceed the rate of diffusion predicated via current vacancy models by several orders of magnitude implying that CO2-rich fluid movement through micro and nano-pore space may presently be greatly underestimated.
Geochemistry of REE, Zr and HF in a wide range of pH and water composition: The Nevado del Ruiz volcano hydrothermal system (Colombia)
International audience; The geochemical behaviour of Rare Earth Elements, Zr and Hf was investigated in the thermal waters of Nevado del Ruiz volcano system. A wide range of pH, between 1.0 and 8.8, characterizes these fluids. The acidic waters are sulphate dominated with different Cl/SO4 ratios. The important role of the pH and the ionic complexes for the distribution of REE, Zr and Hf in the aqueous phase was evidenced. The pH rules the precipitation of authigenic Fe and Al oxyhydroxides producing changes in REE, Zr, Hf amounts and strong anomalies of Cerium. The precipitation of alunite and jarosite removes LREE from the solution, changing the REE distribution in acidic waters.Y–Ho and Z…
Effects of Dissolved Complexation on REE Fate During Interactions between Volcanic Ash and Coexisting Fluids
AbstractThis work analyzes REE behavior during the delivery of volcanic ash into a marine system and highlights the effects induced by dissolved carbonate and humate complexes on REE release. Kinetic experiments were carried out during a 6-month period using a batch method approach. Results show that the highest degree of REE leaching occurs during the early stage. Altered phases that crystallize induce REE sorption and dissolved complexation towards surface complexation, concurrent processes that are enhanced by Y/Ho, La/Yb, and Ce/Ce* changes, whereas dissolved humates and carbonates influence the dissolution rate of ash and the dissolved REE behavior.
Source and Nature of Inhaled Atmospheric Dust from Trace Element Analyses of Human Bronchial Fluids
International audience; Rapid volcanic eruptions quickly ejecting large amounts of dust provoke the accumulation of heavy metals in people living in surrounding areas. Analyses of bronchoalveolar lavage samples (BAL) collected from people exposed to the paroxysmal 2001 Etna eruption revealed a strong enrichment of many toxic heavy metals. Comparing the BAL to the dust composition of southeastern Sicily, we found that only V, Cr, Mn, Fe, Co, and U enrichment could be related to the volcanic event, whereas Ni, Cu, Cd, and Pb contents come from the dissolution of particles of anthropogenic origin. Furthermore, the nature of these inhaled anthropogenic particles was revealed by anomalous La and…