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Cabrera M.C., Fernández-Turiel J. L., Muñoz F., Cruz T., Gimeno D. Trace elements in groundwater of La Aldea aquifer (Gran Canaria, Canary Islands). In: Candela L., Vadillo I., Aagaaard P., Bedbur E., Trevisan M., Vanclooster M., Viotti P., López-Geta J.A. (Eds.), WAter POllution in natural porous media at different scales. Assessment of fate, impact and indicators. WAPO2. IGME, Madrid, 2007, ISBN 978-84-7840-676-0. pp. 99-105. ; La Aldea area is dedicated to intensive agriculture for export. Irrigation water comes mainly from three dams located upstream, but groundwater is intensively used in drought periods. There are more than 370 large diameter wells (depths ranging from 4 to 47 m), cutting alluvial materials (20 m thick) in the valley axis, with Miocene basalts located under the alluvial material and in the surrounding mountains. Several hydrogeochemical groundwater families can be distinguished, depending on the exploited materials and/or the existence of some modifying processes. Cl-Mg and Cl-Na-Mg waters are related to basalts, while Cl-Na high saline waters are associated with the hydrothermal alteration of volcanic materials (Tabladas family). These waters mix with the alluvial groundwater, producing Cl-Na-Ca or Cl-Mg waters that can evolve to CI-SO4-Na and SO4-CI-Na, with high nitrate contents (reaching 500 mg.L- 1) when irrigation returns are present. The hydrochemical fingerprint of the trace elements studied reflects the natural influences of the volcanic materials of the region as well as its alteration due to hydrothermal processes. The hydrochemical fingerprint of the hydrothermal altered materials in the northern end of the La Aldea valley is distinguished by high concentrations of Sr and B and, in a lesser degree of Rb, Cs, Li, U, Mo and As. The anthropogenic influence on the trace element content is inexistent or too low to be detected. ; The present work has been financed by the CICYT Project 1FD 97-0525, together with funds from General Water Authority of Canary Government, Gran Canaria Water Authority, La Aldea de San Nicolas Municipality, COPAISAN, COAGRISAN and ROMERTOR. ; Peer reviewed

The volcanic complex of Mts. Cimini (~0.90-1.30Ma) represents the geographical and chronological transition between the Tuscan Magmatic Province (TMP) and the Roman Magmatic Province (RMP), in central Italy. Major and trace elements, and Sr, Nd and Pb isotopes of whole-rock, as well as mineral chemistry analyses, were carried out on samples representative of the different petrographic and chronological units of Mts. Cimini. In particular, we focused on the olivine-bearing latites of Mts. Cimini that are the most mafic magmas, belong to the last phase of this volcanic activity, and are heterogeneous in highly incompatible element ratios and Sr-isotope compositions. We suggest that such heterogeneity reflects the occurrence of a heterogeneous upper mantle beneath central Italy, in which different portions, e.g., the sources of both the TMP and RMP, are characterized by distinct geochemical and petrographic features. In this scenario, about 900ka ago, the olivine-bearing latites mark the progressive decline of the TMP magma production in favour of partial melting of the RMP mantle region, thus recording the coexistence of both ultrapotassic alkaline and calc-alkaline magmas in the same volcanic region. ; This work has been carried out in the framework of the Research Consolidated Group SGR-2009-972 PEGEFA (Applied and Basic Petrology and Geochemistry) recognized by AGAUR, Generalitat de Catalunya, and partially funded by the CGL2007-63727 project of the Spanish Government. Isotopic analyses benefited from analytical facility (2002) at Southampton Oceanographic Center (SOCFAC-UK) through an European Commision/Research Infrastructure and additional funds from ACES00073 project, DURSI, Generalitat de Catalunya (2002). Preliminary field work was sustained by ACES98-57/6, DURSI, Generalitat de Catalunya (1999-2000) and institutional funds of University of Barcelona (1999). F. Costa is thanked for editorial handling and, together with G. Bianchini and an anonymous journal reviewer, for careful and insightful comments that significantly improved the manuscript. Donatella de Rita, Ciro Giampaolo, Sergio Lo Mastro and Guido Giordano of the University of Roma 3 (Italy) for introducing MA to the Mts. Cimini volcanic geology, as well as for their advice and help on sample collection; MA benefited of an ERASMUS grant in a very early phase of he work (1999); Rex Taylor and Andy Milton of SOCFAC-UK and the staff of the Serveis Científico-Tècnics of the Universitat de Barcelona for their support for sample analysis are acknowledged. ; Peer Reviewed

41 páginas, 6 tablas y 2 figuras. ; The potential contribution to the local geochemical balance of five historical eruptions that occurred during the 20th Century has been investigated in the Southern Volcanic Zone (SVZ) of the Andean volcanic arc of South America (Lonquimay 1988, Hudson 1991, Copahue 2000, Llaima 2008, Chaitén 2008). These ashes were characterised by SEMEDX and XRD, and their potential released geochemical fluxes were examined using water and nitric acid batch leaching tests. Leachates were analysed by ICP-OES, ICP-MS and ISE. The major contents removed correspond to SO42– and Cl–. The potential toxic trace element (PTTE) content was highly variable among the ash samples following this order: Chaitén > Copahue > Hudson > Llaima > Lonquimay. The trace elements with significant load in water batch leaching tests include Fe > F > B > P > Zn > As > Mn > Sr > Ba > Ti > Cu > Ni > Li > Rb > Co > Cr > Cd > Sb. Some of these elements (As, Cu, F, Mo, Ni, Pb and Zn) are included in the drinking water guidelines due to their potential toxicity and must be especially monitored in the environmental assessment of these ashfall deposits. ; Acknowledgements to the technical support of ICTJA XRD Survey (J. Elvira) and 502 the Scientific-Technical Surveys of the University of Barcelona in the analytical 503 work. The sample from Chaiten volcano was supplied by Dr. A. Caselli from the 504 Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, 505 Argentina. We are grateful to the anonymous reviewers for their truly helpful 506 comments. This study was carried out in the framework of the PEGEFA Working 507 Group (Catalonian Government "Grup de Recerca Consolidat" 2009-SGR-972), 508 and was funded by the Project ASH of the Spanish Ministry of Science and 509 Technology (CGL2008-00099) and the FPU Grant of the Spanish Ministry of 510 Education of one of the authors (F. Ruggieri, Ref. AP2006-04592). ; Peer reviewed

This work presents the first detailed map of the Holocene eruptions of Gran Canaria (Canary Islands, Spain). It provides complete and detailed information for all 24 Holocene eruptions of Gran Canaria, improving the knowledge of this recent volcanism and the assessment of volcanic hazards on the island. This map is a synthesis of collated and interpreted field data and topographic maps. We have integrated information obtained from: (1) detailed geological field surveys, (2) morphometric analysis of eruptive deposits, (3) high-resolution digital elevation models, and (4) aerial photographs. ; The research carried out to develop this map, including field work, radiometric dating, geomorphology, petrology and geochemistry, was funded by the Spanish Ministry of Education and Science for the research project CGL2004-04039/BTE and the Canarian Government for the research project PI2002/148; Instituto de Estudios Ambientales y Rercursos natuales (i-UNAT), ULPGC. ; Peer reviewed

The environmental geochemical behaviour of the rhyolitic ashes from the 2008 eruption of Chaitén volcano, Southern Chile, has been studied. After the bulk characterisation, the potential contribution to the regional geochemical fluxes was examined using: i) single batch leaching tests to provide a rapid screening of the implied major and trace elements; and ii) column experiments to evaluate the temporal mobility of leached elements. The environmental concerns of these ashes are related to the fine grained component present in each sample (independent of distance from the source), in particular the presence of cristobalite, and the geochemical hazards posed by ash-water interaction. Leaching experiments show the fast dissolution of surface salts and aerosols, which dominate over glass dissolution during the first steps of the ash-water interaction. Chaitén ashes could transfer to the environment more than 1×10 10g or 10,000metric tonnes (mt) of Cl, S, Ca, Na, Si, and K; between 1000 and 10,000mt of F, Mg, and Al; between 100 and 1000mt of As, Pb, P, Fe, Sr, Zn, Mn, and Br; between 10 and 100mt of Ba, Li, Ti, Ni, Nb, Cu, Rb, Zr, V, Mo, Co, and Sc; and less than 10mt of Cr, Sb, Ce, Ga, Cs, and Y. These results show the fertilising potential of the ashes (e.g., providing Ca and Fe) but also the input of potentially toxic trace elements (e.g., F and As) in the regional geochemical mass balance. The Chaitén results evidence lower potentials for poisoning and fertilising than low silica ashes due to the lower contents released of practically all elements. © 2012 Elsevier B.V. ; We acknowledge the technical support of ICTJA-CSIC labGEOTOP and DRX Surveys (M. Rejas and J. Elvira) and the Scientific-Technical Surveys of the University of Barcelona in the analytical work. This study was carried out in the framework of the PEGEFA Working Group (Catalonian Government "Grup de Recerca Consolidat" 2009-SGR-972), and was partly funded by the Projects ASH and QUECA of the Spanish Ministry of Science and Technology (CGL2008-00099 and CGL2011-23307) and the FPU Grant of the Spanish Ministry of Education of one of the authors (F. Ruggieri, Ref. AP2006-04592). ; Peer Reviewed

[EN] New chemical and Sr–Nd–Pb isotopic data of the Plio-Quaternary mafic lavas of Gran Canaria are used to investigate their mantle source composition. The most prominent aspects of the new dataset are the slight isotopic differences between the Plio-Quaternary (Post-Roque Nublo Group) and the older Pliocene (Roque Nublo Group) mafic parental magmas, which reflect small-scale mantle heterogeneities. Melting of two mantle materials, one isotopically more depleted and similar to the Depleted Mantle (DM) and the other with more radiogenic Pb-isotope ratios comparable to a mantle with high U/Pb ratio (HIMU), accounts for the isotopic and trace element composition of the Pliocene–Quaternary magmas of Gran Canaria. Geochemical variations show that the Pliocene–Quaternary mantle source is compositionally and lithologically heterogeneous and supports the presence of a silica-deficient pyroxenite mantle component. The contribution of the pyroxenite component in the generation of the Roque Nublo and Post-Roque Nublo magmas is estimated to be in the range from 50 to 70%. Trace element ratios support mixing between the two mantle components (pyroxenite veins in a peridotite matrix) which obscure the original chemical and isotopic composition of these two end-members. ; This research was funded by the Spanish Ministry of Education and Science through projects CGL2004-04039BTE and PB96-0243. ; This research was funded by project PI2002/148 from the Canarian Government. ; It was carried out in the framework of the Consolidated Research Group PEGEFA (Refs. SGR-2005-795 and SGR-2009-972), funded by AGAUR-DURSI, Catalan Government. ; It was carried out in the framework of the Consolidated Research Group GEOVOL Research Group, Universidad de Las Palmas de Gran Canaria (Spain). ; Peer reviewed

Recent subaerial volcanism at El Hierro Island (Canary Islands, Spain) consists of monogenetic volcanic fields. This volcanism generated cinder cones, tephra air-fall deposits, and lava flows. The lava flows reach several kilometres in length extending through shore platforms and, sometimes, penetrating under the sea level. The volcanic landforms of El Hierro convert it into a natural laboratory for topographic and morphometric modelling and lava flow simulations. We perform the modelling and simulation of the Montaña de Aguarijo eruption, a cinder cone at the NE rift. The associated lava flow channelled through a V-shaped ravine until reaching a cliff, where formed cascades. The flow spread at the cliff base over a platform before reaching the sea modifying the coastline. Different maps were designed to show the results, including the geomorphologic reconstruction of the area affected by this eruption and the lava flow simulations obtained with the Q-LavHA plugin. © 2021 The Author(s). Published by Informa UK Limited, trading as Taylor & Francis Group on behalf of Journal of Maps. ; Financial support was provided by Project LAJIAL (ref. PGC2018-101027-B-I00, MCIU/AEI/FEDER, EU). This study was carried out in the framework of the Research Consolidated Groups GEOVOL (Canary Islands Government, ULPGC) and GEOPAM (Generalitat de Catalunya, 2017 SGR 1494). ; . ; Peer reviewed

A method to obtain robust information on short term leaching behaviour of volcanic ashes has been developed independently on the sample age. A mixed factorial design (MFD) was employed as a multivariate strategy for the evaluation of the effects of selected control factors and their interactions (amount of sample (A), contact time (B), and liquid to solid ratio or L/S (C)) on the leaching process of selected metals (Na, K, Mg, Ca, Si, Al, V, Mn, Fe, and Co) and anions (Cl - and SO 4 2-). Box plots of the data acquired were used to evaluate the reproducibility achieved at different experimental conditions. Both the amount of sample (A) and leaching time (B) had a significant effect on the element stripping whereas the L/S ratio influenced only few elements. The lowest dispersion values have been observed when 1.0g was leached with an L/S ratio equal to 10, shaking during 4h. The entire method is completed within few hours, and it is simple, feasible and reliable in laboratory conditions. © 2012 Elsevier B.V. ; This study was carried out in the framework of the PEGEFA Working Group (Catalonian Government "Grup de Recerca Consolidat" 2009-SGR-972), and was partly funded by the Project ASH of the Spanish Ministry of Science and Technology (CGL2008-00099) and the FPU Grant of the Spanish Ministry of Education of one of the authors (F. Ruggieri, Ref. AP2006-04592). ; Peer Reviewed

The prehistoric (< 7 ka) Zaro eruption at Ischia island (Southern Italy) produced a lava complex overlaying a pyroclastic deposit. Although being of low energy, the Zaro eruption might have caused casualties among the neolithic population that inhabited that area of Ischia, and damages to their settlements. A similar eruption at Ischia with its present-day population would turn into a disaster. Therefore, understanding the magmatic processes that triggered the Zaro eruption would be important for volcanic hazard assessment and risk mitigation, so as to improve a knowledge that can be applied to other active volcanic areas worldwide. The main Zaro lava body is trachyte and hosts abundant mafic and felsic enclaves. Here all juvenile facies have been fully characterized from petrographic, geochemical and isotopic viewpoints. The whole dataset (major and trace element contents; Sr-Nd isotopic composition) leads to rule out a genetic link by fractional crystallization among the variable facies. Thus, we suggest that the Zaro mafic enclaves could represent a deep-origin mafic magma that mingled/mixed with the main trachytic one residing in the Ischia shallow magmatic system. The intrusion of such a mafic magma into a shallow reservoir filled by partly crystallized, evolved magma could have destabilized the magmatic system presumably acting as a rapid eruption trigger. The resulting processes of convection, mixing and rejuvenation have possibly played an important role in pre- and syn-eruptive phases also in several eruptions of different sizes in the Neapolitan area and elsewhere in the world. ; The authors are grateful to Roberto de Gennaro for his precious help in obtaining SEM-EDS-WDS data. This study was carried out in the framework of the GEOPAM Research Group (AGAUR, Generalitat de Catalunya, Ref. 2017 SGR 1494). We acknowledge the technical support of M. Rejas of ICTJA-CSIC Laboratory of Geochemistry labGEOTOP, infrastructure co-funded with resources from the ERDF, European Union, (CSIC08-4E-001, and partner of Project EPOS Implementation Phase, EPOS IP, Grant Agreement no. 676564-EPOS IP Call H2020-IFRADEV-12015-1). The INGV, OV laboratories have been financially supported by the EPOS Research Infrastructure through the contribution of the Italian Ministry of University and Research (MUR). Reviews by Prof. Dr. Gerhard Franz, as well as comments and suggestions by the Editor, greatly contributed to the improvement of the original manuscript and are kindly acknowledged. Funding Open access funding provided by Università degli Studi di Napoli Federico II within the CRUI-CARE Agreement ; Peer reviewed

We compare the silicophytolith record of current soils and Holocene palaeosols from two sedimentary sequences in a region between the Chaco-Pampean Plain and the Puna (Tolombón section in Santa María Valley, and Tafí del Valle section in Tafí Valley), NW Argentina. These two geographic areas are separated by the Aconquija-Cumbres Calchaquíes ranges, a climatic barrier to the wet Atlantic winds. These sequences contain volcanic ash deposits recording two large eruptions occurred during Holocene in the Southern Puna in the Central Volcanic Zone of the Andes, from the Cueros de Purulla volcano (ca. 7820 BP) and the Cerro Blanco Volcanic Complex (ca. 4200 cal BP). These ash-fall deposits buried soils and preserved their silicophytolith record, allowing the use of this palaeoenvironmental proxy to clarify the vegetation prior these two volcanic events. The silicophytolith assemblages yield evidence for a mega/mesothermal xerophytic grassland when Tolombón palaeosol was formed, similar to the present-day environment in the Santa María Valley, with presence of C4 grasses (Chloridoideae and Panicoidae). Instead, the climate was cooler and wetter ca. 4200 cal BP than currently in the Tafí Valley, increasing over time aridity and abundance of C4 grasses (Chloridoidae, Panicoideae), and decreasing the quantity of C3 grasses (Pooideae). Prehistorical and historical land use also contributed to this change. The impact of these large volcanic ash-falls on vegetation did not translate in an abrupt change on phytodiversity. Results point out a stable arid environment during Holocene in the Santa María Valley whereas the Tafí Valley was more sensitive to environmental changes due to its location in the eastern slopes of Aconquija-Cumbres Calchaquíes ranges, more exposed to the wet Atlantic winds. ; MINECO, Spain, CGL2011-23307, Project QUECA Agencia-Ministerio de Ciencia y Técnica, Argentina, PICT-1583-2013 Universidad Nacional de Mar del Plata, EXA 643/13 Canary Islands Government, ULPGC, Research Consolidated Group GEOVOL Generalitat de Catalunya, 2017 SGR 1494, Research Consolidated Group GEOPAM ; Peer reviewed

Modeling of volcanic morphometry provides reliable measurements of parameters that assist in the determination of volcanic landform degradation. Variations of the original morphology enable the understanding of patterns affecting erosion and their development, facilitating the assessment of associated hazards. A total of 24 volcanic Holocene eruptions were identified in the island of Gran Canaria (Canary Islands, Spain). 87% of these eruptions occurred in a wet environment while the rest happened in a dry environment. 45% of Holocene eruptions are located along short barrancos (S-type, less than 10 km in length), 20% along large barrancos (L-type, 10–17 km in length) and 35% along extra-large barrancos (XL-type, more than 17 km in length). The erosional history of Holocene volcanic edifices is in the first stage of degradation, with a geomorphic signature characterized by a fresh, young cone with a sharp profile and a pristine lava flow. After intensive field work, a careful palaeo-geomorphological reconstruction of the 24 Holocene eruptions of Gran Canaria was conducted in order to obtain the Digital Terrain Models (DTMs) of the pre- and post-eruption terrains. From the difference between these DTMs, the degradation volume and the incision rate were obtained. The denudation of volcanic cones and lava flows is relatively independent both their geographical location and the climatic environment. However, local factors, such as pre-eruption topography and ravine type, have the greatest influence on the erosion of Holocene volcanic materials in Gran Canaria. Although age is a key factor to help understand the morphological evolution of monogenetic volcanic fields, the Gran Canaria Holocene volcanism presented in this paper demonstrates that local and regional factors may determine the lack of correlation between morphometric parameters and age. Consequently, the degree of transformation of the volcanic edifices evolves, in many cases, independently of their age. ; This research was partially funded by the Spanish Ministry of Education and Science (Ref. CGL2004-04039/BTE). ; This research was funded by project PI2002/148 from the Canary Islands Government. ; It was carried out in the framework of the Consolidated Research Group PEGEFA SGR-2005-795 and SGR-2009-972, funded by AGAUR-DURSI, Catalan Government. ; It was carried out in the framework of the Consolidated Research Group GEOVOL Research Group, Universidad de Las Palmas de Gran Canaria (Spain). ; Peer reviewed

The Holocene volcanism at El Hierro consists of basaltic monogenetic volcanic fields associated with o the three rift systems present in this island. In this work we report preliminary petrological and geochemical data of Holocene lava flows belonging to the WNW-striking rift. Sampling was focused in three zones: Orchilla, Verodal-Sabinosa, and Tanganasoga. Petrography of the studied lavas shows that they are homogeneous. All samples are porphyritic with macrocrysts of clinopyroxene and olivine immersed in a groundmass formed by microcrysts of plagioclase, Fe-Ti oxides and clinopyroxene. Clinopyroxenes are diopsides, olivines have forsterite contents ranging from 74 to 84 % and anorthite in plagioclase varies from 66 to 76% (labradorite). Whole-rock geochemical results evidence that all magmas are basic in composition, ranging from picrobasalts to phonotephrites. Major, trace elements and isotope support fractional crystallization as the main process of magma evolution. However, petrography and chemistry of clinopyroxene cores agree with a xenocrystic nature of some of them. We suggest that these clinopyroxene cores crystallized from a genetically related magma and subsequently were entrapped or cannibalized by the basic rising magmas. © 2019 Sociedad Geologica de Espana. All rights reserved. ; This work has been funded by the Agencia Canaria de Investigación, Innovación y Sociedad de la Información (Sol-SubC200801000047). It was carried out in the framework of the Research Consolidated Groups GEOVOL (Canary Islands Government, ULPGC) and GEOPAM (Generalitat de Catalunya, 2017 SGR 1494). ; Peer reviewed