Rare Earth Elements behavior at Poás hyperacid crater lake (Costa Rica) during a cycle of frequent phreatic eruptions (2008-2016) (original) (raw)
Related papers
Frontiers in Earth Science, 2022
Decades of geochemical monitoring at active crater lakes worldwide have confirmed that variations in major elements and physico-chemical parameters are useful to detect changes in volcanic activity. However, it is still arduous to identify precursors of single phreatic eruptions. During the unrest phase of 2009–2016, at least 679 phreatic eruptions occurred at the hyperacid and hypersaline crater lake Laguna Caliente of Poás volcano (Costa Rica). In this study, we investigate the temporal variations of Rare Earth Elements (REE) dissolved in Laguna Caliente in order to 1) scrutinize if they can be used as a new geochemical tool to monitor changes of phreatic activity at hyperacid crater lakes and 2) identify the geochemical processes responsible for the variations of REE concentrations in the lake. The total concentration of REE varies from 950 to 2,773 μg kg−1. (La/Pr)N-local rock ratios range from 0.93 to 1.35, and Light REE over Heavy REE (LREE/HREE)N-local rock ratios vary from 0...
Applied Geochemistry, 2017
The geochemical behaviour of major elements, Fe, Al, Mn, and Rare Earth Elements (REE) was investigated in the "Laguna Verde" acidic crater lake of Azufral volcano (Colombia). The cold lake water (T close to 10 C) is sulphate-dominated, due to absorption and oxidation of H2S (pH 2.1e2.7, Eh 196e260 mV), and Na-enriched (Total Dissolved Solids 0.79 g L À1). The total amount of REE dissolved in the lake ranges from 3.3 to 9.1 ppb. The REE patterns normalized to the local rocks show a Light Rare Earth Elements (LREE) depletion quite constant in the 15 samples. Similar patterns were already found in the acidic sulphate springs of Nevado del Ruiz volcano-hydrothermal system, caused by the precipitation of alunite and jarosite, absorbing LREE and hence removing them from solution. Alunite and jarosite minerals are not oversaturated at chemical-physical conditions within the lake itself, but alunite becomes over-saturated for temperatures above z100 C, reigning in the underlying hydrothermal system. Water temperatures close to 75 C were found in the northern part of the lake. Coupling the distribution of REE in lake water (LREE depleted) and the saturation indexes, we suggest that the distribution of REE in the lake water is the result of the alunite precipitation in the northern part of the lake and/or in the deeper hydrothermal system. The acidic hydrothermal fluids mobilize the REE with contents up to z5 orders of magnitude higher than seawater; acidic-hydrothermal systems, such as acidic crater lakes, can hence be considered potential REE "reservoirs".
Gondwana Research, 2018
The critical role of Rare Earth Elements (Lanthanides plus Yttrium; hereafter REE) in high-tech technologies and consequently their increasing demand from the industry, in addition to the capability of REE to trace waterrock interaction processes, boosted the study of REE in unconventional extreme environments. This study is focused on the geochemical behaviour of REE in the hyperacid sulphate-rich brine of the crater lake of Poás volcano (Costa Rica), where the precipitation of gypsum occurs. This system can hence be considered as a natural laboratory to evaluate the fractionation of REE between the lake water (mother brine) and the precipitating gypsum mineral. Total REE concentrations dissolved in waters range from 1.14 to 2.18 mg kg-1. Calculated distribution coefficients (K D) for REE between the gypsum and the mother brine indicate a preferential removal of the light REE (LREE) with respect to the heavy REE (HREE), with K D values mainly decreasing from La to Lu. During the observation period (2007-2009), the distributions of REE concentrations dissolved in lake water normalized to the average local volcanic rock show two different trends: i) LREE depleted patterns, and ii) flat patterns. The identification of the LREE depleted pattern is justified by the K D calculated in this study. We demonstrate that the precipitation of gypsum is able to strongly fractionate the REE in hyperacid sulphate-rich brine, inducing changes in REE concentrations and distributions over time. X-ray computed tomography imaging was performed in gypsum crystals (precipitated from the lake waters) to gain insights on crystal-scale processes possibly controlling the REE geochemistry, i.e. surface processes vs. structural substitution. Accordingly, the heavy metals and possibly the REE seem to be mainly located on the crystal surface rather than inside the crystal, suggesting that a surface process could be the major process controlling REE removal from the water to the crystal.
Chemical Geology, 2005
The Rio Agrio watershed in northern Patagonia, Argentina is naturally acidic due to discharges of volcanic H2SO4, HCl, and HF at its headwaters near the summit of Copahue Volcano. A suite of water samples was collected from the summit of the volcano to a point roughly 40 km downstream where the pH of the Rio Agrio rose above 6.0. This suite included a sample of the hyperacidic (pH < 1) crater lake at the summit of Copahue, the hot-spring source of the Upper Rio Agrio (pH < 2), two depth profiles through Lake Caviahue (a large glacially-carved lake with pH ∼ 2.6, located 10 km east of the volcano summit), and several samples of the Lower Rio Agrio downstream of Lake Caviahue where pH increased due to the influx of tributary streams. Both filtered and non-filtered samples were collected and analyzed for major ions, trace metals, and rare earth elements (REE).The concentrations of REE in the Rio Agrio decreased by several orders of magnitude through the study area, as a result of dilution and chemical attenuation. A subtle shift in the slope of shale-normalized profiles of dissolved REE concentration was observed, from being weakly positive near the source of the Rio Agrio, to showing a weak middle REE enrichment trend in Lake Caviahue, to being weakly negative in the lower reaches of the river. The trend to a negative slope across the lanthanide series in the lower river is explained by selective partitioning of the heavier REE to hydrous oxides of Fe and Al suspended in the water column, and accumulating on the riverbed. Most of the decrease in REE load occurred immediately downstream of the confluence with a tributary that increased the pH of the Rio Agrio from 4.3 to 6.1. Although the mixed water was supersaturated with REE phosphate compounds, precipitation of LnPO4 is not believed to have been a dominant process because the predicted pattern of inter-element fractionation from phosphate deposition is inconsistent with the observed trends. Instead, REE attenuation most likely occurred from adsorption onto freshly precipitated hydrous aluminum oxide. The behavior of REE in the Rio Agrio watershed is broadly similar to what has been observed in watersheds that owe their acidity to oxidation of sulfide minerals.
Rare earth geochemistry in sediments of the Upper Manso River Basin, Río Negro, Argentina
Earth and Planetary Science Letters, 1995
The abundance, distribution and fractionation of rare earth elements was studied in solid material transported by the Upper Manso River and in the sediments deposited in Lake Mascardi, Argentina. The pristine condition of the area offers an ideal environment for assessing geochemical processes, and the seasonal cycles to which the basin is subjected permit us to study seasonal variations that are mainly influenced by glacial pulses. The most remarkable characteristics observed in the REE-normalized patterns are a strong HREE enrichment and a positive Eu anomaly. These normalized patterns are atypical as compared to those considered representative of the world's major rivers and are caused by drainage basin geology. Due to the dissected topography and the small size of the basin, intense mixing phenomena are not favoured and the weathering reactions are inhibited by the fast-flowing river. These physicochemical conditions and near-neutral pH values have an important influence on the REE patterns of the sediments, which mainly originated by glacial erosion, that are transported by the river. The feldspars and their secondary products, which are both enriched in Eu, might be the cause of the Eu anomaly.HREE enrichment, which is mainly associated with high-pH systems or with the presence of accessory phases, shows a clear dependence on source rocks. The calculated(La/Yb)N ratios oscillate between 0.5 and 0.6, contrasting with the values reported in the literature as average values for suspended load material. Nevertheless, these values are consistent with the dependence of(La/Yb)N values on the age of drainage area rocks as was observed by Goldstein and Jacobsen [3].Seasonal variations are not manifested in REE concentrations, and additional elemental determinations showed coherent behaviour during weathering for all elements except Sr and Ba, which exhibited selective elemental mobilization during periods of minimum discharge.
Chondrite-normalized REE patterns of Lake Acıgöl sediments show generally high abundance of REE compared to chondritic concentrations, with particular enrichment in LREE [(La/Lu) N = 4.85-19.90], [(La/Lu) N = 7.09-15.14], [(La/Lu) N = 9.42-15.52] and [(La/Lu) N = 7.69-15.63] for the surface sediment and 0-10 cm-, 10-20 cm-and 20-30 cm-subsurface sediments respectively. Also these samples showed flat HREE normalized to Chonderite as (La/Sm) N ranging from 2.98 to 4.8 for surface sediments and for subsurface sediments from 3.28 to 3.97 (0-10 cm), 3.57 to 3.94 (10-20 cm) and 3.36 to 3.94 (20-30 cm) while (Gd/Yb) N ranging from 2.14 to 2.93, from 2.03 to 2.76, from 2.26 to 2.79 and from 2.05 to 2.76 from the surface and subsurface sediments respectively. Moreover, their REE profiles are similar to profiles of the continental collision basin (CCB) with negative Eu anomalies. In addition, their REE patterns illustrate generally low abundance of REE compared to concentrations of NASC, PAAS and UCC with very slight enrichment of LREE and positive Eu* anomalies. Therefore there is no comparable between our samples of surface and subsurface sediments and these types of international sediments..
Chemical Geology, 2018
Total and dissolved rare earth elements (REE) were studied in a river reach affected by several inputs of acid mine drainage. The first four acidic discharges were of lesser importance compared to the last (Agrio River, coming from the Río Tinto mines), which transported high loads of Fe and Al (2.1 and 4.2 ton/day, respectively) together with REE (16.4 kg/day) and other trace elements. In the acid mine drainage (AMD) sources, practically all the REE were dissolved and the North American Shale Composite (NASC)-normalized patterns showed an enrichment in medium REE, although some differences exist between the patterns of each source. The pH values in the river reach upstream of the confluence with the Agrio River ranged between 8.01 to 7.03, and most of the Fe and Al from the AMD sources precipitated. Downstream of this acidic discharge, the pH decreased to 2.98. Upstream of the first AMD input, the dissolved and total concentrations of REE were very low (< 0.6 µg/L). In the river reach affected by AMD that maintains pH values > 7, concentrations of REE increased (up to 25 µg/L), mainly transported by the particulate phase. In the reach downstream of the Agrio River with acidic conditions, REE behaved conservatively. The REE NASC-normalized patterns of the river samples resemble that of the AMD sources, although an enrichment of heavy REE in the dissolved phase is observed linked to complexation by carbonates. Cerium and particularly La also show higher dissolved percentages, similar to HREE, which must be due to the lower affinity of these elements to be sorbed onto Fe oxyhydroxides. Variations in Ce and Eu anomalies are observed along the river reach as a consequence of the different AMD inputs. However, the values of the Ce anomaly are higher in total samples than in dissolved samples. Speciation results indicate that these differences are not caused by differences in oxidation states but by slight differences in the hydrogeochemical behaviour of Ce with respect to La and Nd.
Polish Journal of Environmental Studies
The crater lake of El Chichón active volcano represents one of the most important extreme ecosystems in the world due to its high temperatures, low pH and the appearance of high concentrations of heavy metals because of volcanic activity. The latter is of great importance in nearby volcano sites due to heavy metal pollution, which is one of the worst types of environmental problems in the world. In this study, the concentration of heavy metals was evaluated in soils and sediments from different sections in the crater lake of El Chichón volcano. Representative samples were collected from four sediments and soils in 2015 and 2017. These samples were analyzed for 20 metals by inductively coupled plasma-optical emission spectrometry (ICP-OES). The most abundant elements in sediments of the crater lake of "El Chichón" volcano were Fe, Na, Si, Ca, K and Al and not found in soil samples. Be and Tl were more abundant in the soil, but the concentration of Se was higher in soil without showing statistically significant differences. Principal component analysis (PCA) showed that the abundance of metals was influenced by sample type. That is, a higher concentration of heavy metals and trace elements was found in volcanic sediments as compared to soil samples. This difference may be related to metals originating from the magma, which is partially transported in the water stream that gives way to the volcano lake. The most toxic heavy metals identified and quantified in high concentrations in crater soils and sediments were As and Cd. This study suggests that sediments and soils of El Chichón crater lake could be an important source of heavy metals and toxic elements such as As and Cd.
Chemical Geology, 1995
A lake column profile was collected in 24 m of water from Colour Lake, Axe1 eiberg Island, Northwest Territories, Canada, in early June of 199 1 beneath 1.8 m of lake-ice. The rare-earth element (EE) co~ce~trat~o~s of the acidic, fresh waters of Colour Lake were analyzed, along with the major solute chemist in order to investigate REE distribution and speciation in the low-p waters. Previous studies indicate the lake is dominated by Ca'+, Mg*+ and SO,'-, and has no measurable carb Shale-normalized REE patterns for the lake waters are all enriched in the middle REE's (MREE's j as compared to the light REE's (LREE's) and heavy REE's (NREE's). Eij;olved REE concentrations in Colour Lake (e.g., 2.3-22 nmol kg-' for Nd, mean value of 20 nmol kg-') are typically less than values obtained for the acid, saline waters of the Lake Tyrrell playa system in Australia as well as the slightly acidic groundwaters of the region of E.ngland but greater than REE concentrations measured in the alkaline, saline waters o California, U.S.A. The speciation of the REE's in Colour Lake was modelled based on the major solute chemistry, using a combined specific ion interaction and ion pairing model. These calculations suggest that in the relatively high-sulfate, low-pH waters of Colour Lake, the REE's exist as either fret metal, SO:-, or F-complexes. Our calculations indicate that SO,'-complexes dominate over the free metal and fluoride species for the majority of the REE's in the lake water and that, in general, for acidic, high-sulfate waters, sulfate complexes with the REE's may increase the dissolved concentrations of the REE's over natural waters where relatively low sulfate concentrations prevail. Rare-earth elements (REE's) are important