Articles publicats en revistes (Mineralogia, Petrologia i Geologia Aplicada)

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New findings of lower Aptian charophytes from the Southern High Plateaus (Eastern Meseta, Morocco): biostratigraphic and biogeographic significance
(Elsevier Ltd., 2026-02-01) Haddoumi, Hamid; Pérez Cano, Jordi; Chennouf, Rachid; Amakrane, Jemaa; Mamoun, Sidi Mohamed
Two stratigraphic sections of the Southern High Plateaus (Eastern Meseta, Morocco) were sampled for the charophyte study. Seven clavatoracean taxa are described and illustrated from the Dekar 1 and Dekar 2 formations, including Echinochara lazarii, Atopochara trivolvis var. trivolvis, Clavator grovesii var. jiuquanensis, Clavator grovesii var. corrugatus, Clavator harrisii var. harrisii, Clavator harrisii var. reyi, and Clavator harrisii var. zavialensis. This assemblage is assigned to the upper part of the Eurasian Clavator grovesii var. jiuquanensis biozone. The occurrence of intermediate populations of C. grovesii var. jiuquanensis and C. grovesii var. corrugatus associated with intermediate populations of C. harrisii var. harrisii, C. harrisii var. reyi, and C. harrisii var. zavialensis, restricts the association to the lower Aptian. These new findings suggest that this area could be important for understanding the evolution of charophytes during the early Aptian. Furthermore, the study provides significant insights into the paleobiogeographic distribution of Lower Cretaceous charophytes, reporting the first record of C. grovesii var. jiuquanensis (previously described only from Eurasia) and C. grovesii var. corrugatus (previously known from the Iberian Peninsula and the United States) in Africa, along with the first report of Echinochara lazarii in the Western Atlas Domain. Similar lower Aptian assemblages had previously been described only in the Algarve Basin (South Portugal), suggesting a strong paleogeographic connection between these areas.
Measurement report: Ice nucleation ability of perthite feldspar powder
(European Geosciences Union (EGU), 2026-04-24) Canet, Julia; Rodríguez, Laura; Renze, Galit; Alfonso Abella, María Pura; Bonn, Mischa; Meister, Konrad; Garcia Vallès, Maite; Verdaguer, Albert
Feldspars are among the most efficient mineral ice-nucleating particles (INPs) in the atmosphere, yettheir ice nucleation behavior varies widely across natural samples. Here, we investigate six feldspar powdersselected for their perthitic or anti-perthitic textures and spanning a broad range of K= Na compositions. All sampleswere characterized in terms of mineralogy, bulk and surface chemistry, and microstructure. Droplet-freezingassays revealed consistent onset temperatures between 2 and 4 °C in high-concentration suspensions, suggestingthe presence of similar highly active nucleation sites across all tested feldspar types. On the other hand,cumulative and differential freezing spectra showed pronounced differences in the density and distribution of icenucleation sites, which correlate with both feldspar composition and microtexture. Heterogeneous Underlying-Based (HUB) analysis identified distinct subpopulations of ice nucleation sites. Perthites exhibiting ordered microclinestructures showed a continuous increase in nucleation site density with decreasing temperature, whereassamples lacking dominant microcline features displayed plateaus in cumulative spectra over specific temperatureranges, indicating decreased ice nucleation ability of the subpopulation. These results demonstrate that exsolutiontextures and crystallographic structure play a central role in controlling feldspar ice-nucleation efficiency,with important implications for atmospheric INP parameterizations and cloud microphysics.
A new sedimentary record from the Tabernas Basin: Implications for the Messinian Salinity Crisis in the Western Mediterranean
(Elsevier B.V., 2025-08-07) Lacerda-Orita, Gustavo Kenji; Pérez-Valera, Fernando; Soria, Jesús M.; Corbí, Hugo; Liu, Jiao; Sierra Ramírez, Núria; Gómez Rivas, Enrique; Gibert Beotas, Lluís
The Tabernas Basin (SE-Spain), renowned for its Tortonian turbidites, also records thick Messinian successions (>200 m) that offer valuable insights into the Messinian Salinity Crisis (MSC). Yet, the stratigraphic correlation of the Tabernas sediments with the classic successions of the nearby Sorbas Basin remains unclear. This study presents a composite stratigraphic section (named Yesón Alto) that covers the pre-evaporitic, syn-evaporitic, and supra-evaporitic stages of the MSC recorded in Tabernas Basin, offering detailed paleoenvironmental and chronostratigraphic characterization. We provide new constraints on the connections between two marginal basins of the Betic Cordillera and on the paleoenvironmental changes that took place in the Western Mediterranean during the MSC. During the Late Messinian pre-evaporitic phase, siltstones and shales alternating with distal turbidites recorded shifts between warm-oligotrophic and cold-eutrophic planktonic foraminiferal assemblages, indicating the influence of precession-driven climatic fluctuations on the water column. Progressive basin restriction led to the development of an incipient hybrid carbonate shelf, subjected to significant siliciclastic influx. 16 key planktonic foraminifera bioevents and a magnetic reversal (C3An.1n to C3r at 6.035 Ma) have been identified and correlated with the astronomically calibrated cycles of the Sorbas Basin, suggesting the possible synchronous onset of the MSC in both basins. The evaporitic stage in Tabernas is represented by four selenitic gypsum beds intercalated with siliciclastic and carbonate deposits. Facies analysis and gypsum isotopic compositions (δ34Ssulfate and δ18Osulfate) suggest that evaporites represent the initial cycles of the Primary Lower Gypsum (PLG) of the MSC Stage 1 in the Mediterranean. Below gypsum bed PLG 4, an inter-evaporitic level rich in marine fauna indicates the episodic re-establishment of near-normal marine conditions after periods of evaporite precipitation. The Supra-evaporitic unit, comprising deltaic-fluvial conglomerates and sandstones, reflects a regional regressive trend and marks the continentalization of the basin's margins. The progradation of these continental deposits over the evaporitic basin was favored by an eastward uplift trend in the Betic Cordillera, ultimately leading to exposure of the Tabernas Basin before or during Stages 2 and 3 of the MSC. The paleoenvironmental evolution of the Tabernas Basin indicates that marine connections with the Sorbas Basin persisted before and during the early MSC and that tectonics associated with climatic factors played a key role in the evolution of its sedimentary systems.
Upper Eocene-Oligocene larger Foraminifera from the westernmost Tethys (Prebetic Range, SE Iberia). Revision of Austrotrillina and Risananeiza
(Association Carnets de Géologie, 2026-08-08) Ferràndez i Cañadell, Carles; Granero, Paula; Bover-Arnal, Telm
The study of upper Eocene-Oligocene larger foraminiferal assemblages in two sections of the Prebetic Range in south-eastern Iberia (Ibi and La Font Roja sections) revealed a rich diversity, including species previously known only from the Central Tethys, such as the Eocene Neorhipidionina cf. spiralis, and the Oligocene Pfendericonus globulus, Austrotrillina howchini, Idalina pignattii, and Archaias sp., as well as endemic forms such as Peneroplis peramplus, Spirolinella emmae, and Borelis sp. 1. The continuous record of Austrotrillina (Rupelian-Chattian) and Risananeiza (upper Chattian) showed evolutionary trends and allowed for a systematic revision. Austrotrillina asmariensis, A. striata, and A. brunni are considered morphotypes of a single species, A. striata, evolving anagenetically from the lower Rupelian A. paucialveolata, which originated from the Eocene A. eocaenica. The two known species of Risananeiza, R. crassaparies and R. pustulosa, were identified for the first time within the same stratigraphic section. They represent successive stages of an anagenetic species throughout the upper Chattian. The biostratigraphic results provide an improved characterization of Shallow Benthic zones SB 21 to 23 in the westernmost Tethys and allow the subdivision of SB 23 (upper Chattian) into two sub-biozones, 23A and 23B, based on the stratigraphic ranges of miogypsinids (Miogypsinella spp., Postmiogypsinella intermedia) and Risananeiza. The Priabonian-Chattian Neorotalia burdigalensis also exhibits evolutionary trends with potential biostratigraphic relevance. Overall, the biostratigraphic data obtained indicate diachronous, parallel evolution and extinction in several genera, improving our understanding of diversity patterns and migration pathways in Oligocene larger Foraminifera.
Lower Aptian ammonite and planktonic foraminifera integratedbiostratigraphy and the age of the OAE1a in the Morella sub-basin, Maestrat Basin (eastern Spain)
((UB). (ICTJA). (IDEA). (UAB). (CSIC), 2026-07-25) Garcia‐Artigas, Ruben; Moreno-Bedmar, Josep Anton; de Gea, Ginés A.; Aguado, Roque; Bover-Arnal, Telm; Company, Miquel; García-Penas, Álvaro; Salas, Ramon (Salas Roig)
A correlation between planktonic foraminifera and ammonite biostratigraphic biozonations has for the first time been established for the lower Aptian of the Morella sub-basin (northern Maestrat Basin). The planktonic foraminifera zones recognized are Globigerinelloides blowi, Globigerinelloides aptiensis, Leupoldina cabri and Hedbergella luterbacheri. The identified ammonite zones include the Deshayesites forbesi, Deshayesites deshayesi and Dufrenoyia furcata zones, and the Roloboceras hambrovi and Deshayesites grandis subzones. The boundary between the G. aptiensis and L. cabri zones was recorded in the uppermost part of the Deshayesites forbesi Zone, coinciding with the middle part of the R. hambrovi Subzone. The H. luterbacheri Zone spans almost the entire Deshayesites deshayesi Zone and the whole Dufrenoyia furcata Zone. The Oceanic Anoxic Event (OAE1a) has also been calibrated against the two biostratigraphic schemes. This event spans almost all the G. aptiensis and the basal part of the L. cabri planktonic foraminifera zones and largely coincides with the R. hambrovi ammonite subzone. This study provides an extended and accurate biostratigraphic framework for the Morella sub-basin, helping to better constrain the age of stratigraphic intervals where ammonites are scarce or absent, that may also serve as a correlation tool for the analysis of other coeval marine sedimentary successions in the western Tethys..
Coupled Use of Drone Imagery and Geophysical Methods for the Characterization of Horizontal Subsurface Flow Constructed Wetlands
(MDPI, 2026) Urruela, Aritz; Sendros Brea-iglesias, Alexandre; Casas i Ponsatí, Albert; Himi, Mahjoub; Galone, Luciano; Rivero Marginedas, Lluís
The growing need for sustainable wastewater treatment highlights the importance of low-energy solutions such as horizontal subsurface flow constructed wetlands (HSSF CWs). While effective, these systems often face clogging issues that reduce performance and lifespan. This study investigates clogging dynamics in a Water Treatment Plant (Lleida, Spain) using a multidisciplinary approach. Non-invasive geophysical methods such as Electrical Resistivity Tomography (ERT) and Induced Polarization (IP) were combined with high-resolution drone imagery to characterize surface and subsurface indicators of clogging. Drone data captured surface anomalies, while geophysical measurements revealed subsurface obstructions. The integrated analysis identifies clogged zones and shows a strong spatial correlation between surface features and geophysical anomalies. These results validate the use of drone imagery as a rapid, non-invasive diagnostic tool and demonstrate the effectiveness of combining remote sensing with geophysical techniques for wetland assessment. This approach supports improved monitoring, targeted maintenance, and optimized long-term performance of HSSF CWs.
Radioisotope dating of tephra layers challenges Messinian stratigraphy at Cabo De Gata (SE Spain)
(Society for Sedimentary Geology (SEPM), 2026-06-29) Bover-Arnal, Telm; Giner, Josep; Gibert Beotas, Lluís; Deino, Alan
This study presents the first radioisotope ages of tephra deposits interbedded with the carbonate succession of the Cabo de Gata Range in SE Spain. These carbonate rocks are a reference section of the Miocene sedimentary record for the western Mediterranean, which is marked by the widespread development of coral reefs dominated by the genus Porites. Although Porites reefs at Cabo de Gata, and across the western Mediterranean, have been assigned to the late Tortonian–Messinian, two new 40Ar/39Ar ages (11.71 ± 0.11 Ma just below the base and 11.64 ± 0.18 Ma in the Porites interval) constrain their formation in the type section of La Molatilla–La Molata to the terminal Serravallian–earliest Tortonian. The radioisotope dating of an additional tephra layer interbedded with coastal oyster- and bryozoan-bearing calcirudites, which overlie the volcanic basement in the Los Escullos area and were previously assigned to the late Tortonian, yields an earliest Tortonian age of 11.29 ± 0.03 Ma. The Los Escullos tephra lies c. 4 m above sea level and about 100 m below terminal Serravallian tephra at La Molatilla–La Molata, suggesting a major sea-level drop of tens of meters during the earliest Tortonian. These findings highlight a more complex Miocene chronostratigraphy in the Cabo de Gata than previously recognized, and indicates that lithostratigraphic units with similar facies and comparable stratigraphic positions, such as skeletal calcarenites and calcirudites overlying the volcanic basement or Porites reefs, may vary significantly in age here and across the western Mediterranean.
Structuration and sedimentary response to continental Mesozoicrifting in northeastern Iberia
((UB). (ICTJA). (IDEA). (UAB). (CSIC), 2026-06-01) Salas, Ramon (Salas Roig); Guimerà i Rosso, Joan J.; Bover-Arnal, Telm; Nebot, M.
Iberia and its oceanic margins provide evidence of a large rift system developed in three phases: i) latePermian–Middle Triassic, ii) Late Jurassic, and iii) Barremian–early Albian. These rifting events were coevalwith the opening of the Alpine Tethys, the North-Atlantic, and the Bay of Biscay domains, respectiely. Thethree Mesozoic rifting phases controlled the development of Iberian intraplate rift basins, including theMaestrat and Garraf basins, which are the focus of this study. Each of these rifting stages was followed bya period of decelerated or post-rift thermal subsidence. The first post-rift phase, spanning the Late Triassicto the early Late Jurassic, was interrupted by a short-lived interval of rapid syn-rift subsidence during theHettangian, here referred to as the Hettangian event. Rifting cycles 2 and 3 are separated by the Neocomianevent, which corresponds to an interval of decelerated subsidence. The earliest rifting phase is associated withan early inception of saline tectonics in the Maestrat Basin, and was accompanied by magmatism and tookplace in an arid climate setting, whereas the second and third rifting stages were essentially amagmatic andoccurred under humid (sub)tropical conditions. The structural style during polyphase rifting is characterizedby extensional systems involving the uppermost part of the crust, with basal faults located at a depth of 7 to10km. The Maestrat and Garraf basins developed during the Barremian–early Albian period were boundedby decakilometric normal faults with kilometric dip-slip, and were later inverted during the Paleogenecontraction, giving rise to the fold-and-thrust systems of the Iberian and Catalan Coastal chains. Verticalmovements, uplift and fault-induced subsidence, and the prevailing climate conditions were the two principalcontrols on the sedimentary record of the Iberian intraplate rift basins.
Ammonite biostratigraphy of uppermost Barremian – Aptianstratigraphic sequences in the Maestrat Basin (E Iberia)
((UB). (ICTJA). (IDEA). (UAB). (CSIC), 2026-06-01) Moreno-Bedmar, Josep Anton; Bover-Arnal, Telm; Forner i Valls, Enric; Lehmann, Jens; Frau, Camille; Simpson, Martin I.; García-Penas, Álvaro; Salas, Ramon (Salas Roig)
In the current work, three relevant new ammonite finds from the Maestrat Basin are reported and analyzed froma biostratigraphical point of view. Additionally, another important ammonite, originally published in the late1950th, is reviewed. The relevance of these four specimens lies in the fact that they come from stratigraphicintervals in the Maestrat Basin where ammonites are exceptionally rare. The purpose of this study was to analyzethese ammonites from the latest Barremian-Aptian interval from a biostratigraphic perspective, with the goal ofaccurately determining the age of the stratigraphic intervals. The analysis of these ammonites has confirmed theage of previously defined transgressive-regressive sequences within the Maestrat Basin and led to the revision ofsome of these age assignments. To enhance the correlation potential of the Maestrat Basin within a broader context,its sedimentary and ammonite records have been compared with one European basin and one North African basin.This more precise ammonite-based age calibration significantly advances the chronostratigraphic understanding ofsequence stratigraphy in the Maestrat Basin, establishing it as one of the best age-calibrated basins of the Tethys.Thus, the Maestrat Basin serves as a key reference point for correlating other Tethyan basins within this timeinterval.
Global carbon cycling linked to eustatic changes in the aftermath of the early Aptian Oceanic Anoxic Event (OAE1a)
(Elsevier B.V., 2026-08-01) Muñoz López, Daniel; Bover-Arnal, Telm; Herlambang, Adhipa; Koeshidayatullah, Ardiansyah
he Aptian experienced significant carbon-cycle disruptions, marked by notable paleoclimatic and paleoceanographic shifts. While the mechanisms behind the Aptian oceanic anoxic events (OAE) are relatively well-understood, the interplay between global carbon-cycle dynamics and sea-level changes immediately following the early Aptian OAE1a remains enigmatic. By analyzing a carbonate succession from the western Tethys (eastern Spain), dated using ammonite biostratigraphy as Deshayesites deshayesi and Dufrenoyia furcata zones, we identify a temporal correlation between a sea-level highstand and a subsequent fall, aligning respectively with a global carbon-isotope excursion exceeding +4‰, unprecedented in the Cretaceous, and a sharp negative isotopic shift from +4.3‰ to −0.7‰. The concurrence of these sea-level fluctuations and carbon isotope variations across multiple regions underscores the eustatic origin of sea-level change and its profound impact on global carbon cycling. We propose that during highstand and transgressive stages, sea expansion acted as a carbon sink, facilitating the increased burial of isotopically light carbon. Conversely, rapid sea-level falls likely triggered sediment reworking, reintroducing this light carbon into the dissolved inorganic carbon (DIC) of the global ocean. This study highlights the overlooked role of remobilized sediments as a source of carbon during the Aptian, commonly attributed to volcanic degassing, and emphasizes the immediate and significant response of the carbon cycle to eustatic changes.
Responses of a hybrid carbonate shelf to progressive basin restriction: Pre- and Messinian Salinity Crisis environmental shifts in the Western Mediterranean (Tabernas Basin)
(Elsevier B.V., 2026-07-01) Lacerda-Orita, Gustavo Kenji; Pérez-Valera, Fernando; Corbí, Hugo; Soria, Jesús M.; Bover-Arnal, Telm; Gómez Rivas, Enrique; Gibert Beotas, Lluís
Before and during Stage 1 of the Messinian Salinity Crisis (MSC), carbonate platforms developed in marginal basins of the Western Mediterranean, recording some of the last manifestation of fully tropical climatic conditions in the region. In the Tabernas Basin (SE Spain), a mixed carbonate-siliciclastic succession was deposited between 6.080 and 5.971 Ma, recording a detailed archive of the environmental, ecological, and sedimentological changes that occurred during an advanced phase of Mediterranean restriction preceding the Messinian Salinity Crisis. Systematic semiquantitative micropaleontological analysis reveals five different benthic foraminiferal assemblages, which respond to a progressive shallowing-upward trend and shifting environmental conditions at the seafloor. In the upper epibathyal environment, the coexistence of planktonic foraminifera with dysoxia-tolerant benthic taxa suggests pronounced stratification within the water column. Enhanced primary productivity in the upper waters fuelled organic matter flux to the bottom waters, driving pyrite precipitation and conditioning benthic ecosystems. The transition to a shelf setting was recorded by an increased diversity of shallower-water benthic fauna and the deposition of bioclastic limestones. Further environmental stress produced by progressive restriction drove a general decline in the marine fauna, culminating in the deposition of barren limestones. The flourishing of microbial mats in the inner-shelf marked the climax phase of restriction preceding evaporite deposition at the onset of the Messinian Salinity Crisis.
Ambient-Noise HVSR signatures of deep and shallow impedance structure in a quaternary Plain (Pampean Region, Argentina)
(Elsevier B.V., 2026-07) Galone, Luciano; D'amico, Sebastiano; Fucks, Enrique; Colica, Emanuele; Carol, Eleonora; Rivero Marginedas, Lluís; Panzera, Francesco; Rosa, Maria Laura
Sedimentary plains host extensive Quaternary sequences whose internal impedance architecture is often poorly constrained, limiting the resolution of subsurface layering and its lateral continuity. We conducted a dense single-station ambient-noise HVSR survey (82 sites) across the La Plata–Berisso–Ensenada area, in the northeastern Pampean Region of Argentina, to characterize both deep and shallow impedance contrasts. The data consistently reveal two frequency modes. The fundamental resonance (f₀ ≈ 0.30–0.40 Hz) exhibits a compact spatial distribution and a smooth basinward increase, indicating a laterally continuous, deep impedance contrast that reflects the large-scale sedimentary thickening toward the Salado Basin. In contrast, the higher-frequency peak (f₁ ≈ 2–12 Hz) displays strong geomorphic and lithogenic controls. Inland, heterogeneous values are consistent with stiffness contrasts produced by pedogenic horizons and loess–paleosol variability within the Pampeano Formation. Across the coastal plain, lower and more organized f₁ values form shore-parallel bands that delineate the Holocene cover overlying Pampeano sediments. A short vertical transect at a quarry constrains the inland f₁-generating contrast to the upper ∼10–15 m, supporting its interpretation as a near-surface mechanical boundary. Together, these patterns show that systematic HVSR mapping can resolve both basin-scale impedance gradients and intra-sedimentary contrasts within thick Quaternary successions. The approach provides a scalable, non-invasive framework for integrating subsurface impedance structure, surface geomorphology, and stratigraphic interpretation in data-limited plain environments.
TephAta – an online collection of tephra datafrom the Atacama Desert
(Copernicus Publications, 2026-06-02) Sáez, Alberto; Gimeno Torrente, Domingo; Cabrera, Lluís; Rodríguez-Araneda, Inés; Wagner, Bernd; Bareth, Georg; Wennrich, Volker; Leicher, Niklas; Feldmar, Vincent; Quezada, Andrés; Vásquez, Paulina; Sepúlveda, Fernando; Frank Wombacher, Frank; Lagos, Markus; Kramm, Tanja; González, Gabriel; Kuiper, Klaudia; Breitkreuz, Christoph
Tephrostratigraphy and tephrochronology are powerful tools using volcanic ash (tephra) layers for establishing stratigraphic correlations and/or to obtain chronological information for different kinds of sedimentary archives. To develop robust tephrostratigraphic frameworks it is essential to precisely characterize the physical, geochemical and chronological properties of tephra layers and their sampling sites. These frameworks allow newly discovered tephra layers to be correlated with established sequences, providing stratigraphic and chronological context and enhancing reconstructions of the spatial and temporal patterns of regional volcanic activity. Tephrostratigraphic frameworks have been developed or are currently emerging in many regions of the world. However, for some regions their potential remains underutilized. One such region is the Atacama Desert of northern Chile, despite its long history of frequent volcanism and associated tephra deposition. Within the framework of the Collaborative Research Centre “Earth – Evolution at the Dry Limit” (CRC1211), the glass phase geochemical compositions of Pleistocene tephra layers were recently systematically investigated to refine their stratigraphic and chronological placement. Alongside this effort, a dedicated tephra database, TephAta was created to provide a long-term repository for tephrochronological research in the Atacama Desert. TephAta enables the comprehensive digital documentation of diverse tephra-related datasets within a single platform and offers search functionalities that support and streamline ongoing expansion of the regional framework, following FAIR (findability, accessibility, interoperability, and reusability) data principles. A first data release contains 106 tephra samples from 91 deposits, with continued spatial and temporal growth planned. All data are accessible via the TephAta portal (https://www.crc1211db.uni-koeln.de/tephata, last access: 29 May 2026) and datasets described in this paper are available at https://doi.org/10.60520/IEDA/114209 (Leicher, 2026). Beyond serving as a stratigraphic and chronological tool for paleoenvironmental or mapping studies, TephAta also facilitates investigations into the regions explosive volcanic history and supports volcanic hazard and risk assessment.
Investigating isotopic markers for hazelnut geographical authentication: Promising variables and potential applications
(Elsevier B.V., 2024-08-15) Torres Cobos, Berta; Rosell, Mònica; Soler, Anna; Rovira, Mercè; Romero, Agustí; Guardiola Ibarz, Francesc; Vichi, S. (Stefania); Tres Oliver, Alba
Hazelnuts' features and price are influenced by their geographical origin, making them susceptible to fraud, especially counterfeit claims regarding their provenance. Stable isotope analysis is a recognised approach to establish the geographical origin of foods, yet its potential in hazelnut authentication remains unexplored. In this prospective study, we assessed multiple isotopic markers in hazelnuts from different origins and evaluated the most promising variables for geographical authentication by chemometric tools. Our findings indicate that bulk δ18O, along with δ2H and δ13C in the main fatty acid methyl esters, exhibit significant potential in discriminating geographical origins, and 87Sr/86Sr analysis could serve as a proficient confirmatory tool. Though no single marker alone can differentiate between all the studied origins, employing a multi-isotopic approach based on PLS-DA models achieved up to 92.5 % accuracy in leave-10 %-out cross-validation. These findings will probably lay the groundwork for developing robust models for hazelnut geographical authentication based on larger datasets.
Lava deltas, a key landform in oceanic volcanic islands: El Hierro, Canary Islands
(Elsevier B.V., 2022-11) Rodriguez-Gonzalez, Alejandro; Fernandez-Turiel, Jose-Luis; Aulinas Juncà, Meritxell; Cabrera, M.C.; Prieto-Torrell, Claudia; Rodriguez, G.A.; Guillou, H.; Perez-Torrado, Francisco Jose
Marine and subaerial erosion of volcanic ocean islands form coastal cliffs and shore platforms, particularly during stable sea levels. Posterosional lava flows can spill over these coastal cliffs and fill the platforms, leading to the progradation of lava deltas. This work aims to analyze this volcanic rocky coast setting at the island scale and to assess the volcanic constructional and erosive degradational effects on the coast at the scale of one volcanic edifice. El Hierro Island, Canary Islands, exemplifies a rocky coast with an active sea-cliff profile, reflecting its early evolutionary stage as a young ocean volcanic island with no fringing reef. The occurrence of a contemporary insular shelf formed during the Holocene sea-level highstand (<7 ka) allows constraining the ages of those eruptions forming lava deltas affecting this geomorphological landform. A detailed bathymetry around the island allowed us to distinguish 17 eruptions fulfilling this criterion. The Montaña del Tesoro, which occurred about 1050 years BP, is one of these eruptions and was selected as a case study for morphometric modeling integrating subaerial and submarine data at the scale of a volcanic edifice. This eruption was a Strombolian basaltic volcanic event that produced a scoria cone, pyroclastic fall deposits, and lava flows that reached the ocean in the eastern rift zone of El Hierro island. We combine field-based observations with topographic and bathymetric data analysis to reconstruct the pre- and post-eruption Digital Elevation Models (DEMs) and, comparing with present-day DEM, to analyze morphometrically the influence of volcanism on the coastal landscape's development. The resulting landform complexity required the discretization of the lava field according to the coastline evolution and lava front sectors, and the subaerial or submarine lava placement. The pyroclastic materials' total erupted bulk volume (12,829,578 m3) corresponds to a volcanic eruption index (VEI) of 3. This event was primarily effusive. From a dense rock equivalent (DRE) volume of 25,615,424 m3, 87 % flowed as lava, 10 % formed the cinder cone, and 3 % the tephra fall deposits. We quantitatively demonstrate that dominant degradation occurs in the lava field, mainly disturbed by marine erosion. Marine erosion removed 9 % of the erupted volume of lava flows against 1 % by fluvial erosion. This work provides methods and results of great interest with different implications in oceanic volcanic islands, among which we can mention coastal planning (e.g., rock coast evolution) and volcanic risk assessment (e.g., the importance of Holocene sea-level rise on the development of shore platforms facilitating the progradation of lava deltas).
Stratigraphic evolution of a salt-walled basin: the influence of diapirism and compressional tectonics on the sedimentary record of the Estopanyà syncline (South-Central Pyrenees)
(Elsevier B.V., 2024-01-18) Ramirez-Perez, Pedro; Cofrade Rivas, Gabriel; Martín, Juan Diego (Martín Martín); Travé i Herrero, Anna
This contribution describes the influence of diapirism and compressional tectonics in the sedimentary record ofthe Estopany`a and Boix synclines (salt-walled basins) in the South-Central Pyrenees (NE Spain). Based onmapping and logging of five stratigraphic sections, two lithostratigraphic units (LU-1 and 2) along the easterndiapir margin of these synclines and five more (LU-3 to 7) in their inner parts are defined. LU-1 and 2 consist ofmonomictic breccias deposited probably during the Upper Triassic-Oligocene and the Upper Cretaceous,respectively. LU-3 to 7 constitute a marine to fluvial succession of the Tremp Group deposited during the UpperCretaceous to Paleocene. The stratigraphic and sedimentological record indicates that the topography, position,and accommodation space of the Estopany`a and Boix synclines was actively controlled by the evolution of saltstructures from the Late Cretaceous to the Oligocene in response to the advance of the Alpine compression in theSouth-Central Pyrenees. The growth of salt-inflated ridges with a near parallel orientation to the axis of thestudied synclines since the Upper Cretaceous, progressively compartmentalized the Boix syncline until inhibitingsedimentation during the lower Paleocene. In the upper Paleocene, the Alpine compression approached the studyarea increasing salt evacuation and the subsidence of the Estopany`a and Boix synclines. During the early tomiddle Ypresian, onset of compression led to salt expulsion by piercing the sedimentary roof of the inherited saltinflatedridges and forming two salt walls at the eastern margin of the Estopany`a and Boix synclines that weresqueezed and welded (possibly through secondary welds) due to tectonic compression during the Oligocene. Thiscontribution provides a new interpretation of the structural and stratigraphic evolution of the Estopany`a andBoix synclines, proposing an evolutionary model that includes the rejuvenation, growth, and extrusion of saltwalls as deciphered from the stratigraphy, sedimentology, and petrology of the diapir margin breccias and thesedimentary succession of the adjoining salt-embedded basins. Hence, it provides a new analogue study forunderstanding the interplay between compressional tectonics, diapirism, and sedimentation to other inverted saltbasins with precursor salt walls worldwide.
Isotopic and geochemical modeling approach to evaluate abiotic nitrite reduction by ferrous iron
(Elsevier B.V., 2024-01-17) Abu, Alex; Carrey Labarta, Raúl; Navarro Ciurana, Dídac; Margalef Marti, Rosanna; Soler i Gil, Albert; Otero Pérez, Neus; Domènech Ortí, Cristina
Nitrite reduction has often been treated as a biotic process in water treatment systems, but it also occurs abiotically, and it is difficult to distinguish both reactions as they can co-occur at field-scale. The potential reduction of NO2− was tested in 3 anaerobic experimental scenarios using a NO2− bearing solution amended with: i) siderite (FeCO3) (Sid experiment); ii) Fe(II) solution from FeCl2.4H2O(s) (DFe experiment); and iii) siderite mixed with Fe(II) solution (Sid+DFe experiment). Non-sterilized batch experiments were carried out in anaerobic conditions with an initial ratio of nitrogen to dissolved iron of 5 in DFe and Sid+DFe (Sid had no initially dissolved Fe(II)) and 1000 mg L−1 of siderite in Sid and Sid+DFe experiments. At the end of the experiments, the NO2− removed was 3% for Sid, 54% for DFe and 84% for Sid+DFe. The NO2− concentration decrease over time was characterized by an enrichment in the δ15NNO2 of the unreacted NO2−, increasing from −26.9 ‰ to −26.4 ‰ (Sid), −18.0 ‰ (DFe) and −15.9 ‰ (Sid+DFe). The calculated ε15NNO2 for Sid was −11.8 ‰, whereas for DFe was −12.0 ‰ and Sid+DFe was −13.0 ‰, suggesting a common NO2− degradation mechanism in all experiments. The Rayleigh distillation equation showed that the generated N2O was the final product of the abiotic nitrite reduction reaction, and the calculated N2O site preference (SP) was 22.5 ± 0.7 ‰ for DFe and 23.5 ± 0.5 ‰ for Sid+DFe. The continuous N2O measurement showed that only 25.3 ± 5.1% in DFe and 31.0 ± 6.3% in Sid+DFe of the generated N2O in water was recovered in the headspace vials, suggesting that a large portion of the produced N2O(aq) in solution did not diffuse from water. The coupled NO2− reduction and Fe(II) oxidation followed a second-order kinetic reaction with a rate equal to (9.39 ± 0.36)·10−4·[NO2−]·[Fe(II)] (mol L−1 s−1) in all experiments. The experimental conditions supported by the Rayleigh distillation equation using the experimentally calculated ε15N values, coupled with NO2− isotopic data and N2O SP values, showed that biological denitrification had a negligible influence on nitrite reduction and that chemodenitrification was the main NO2− attenuation pathway. A geochemical model coupling the kinetic chemodenitrification, isotope fractionation, aqueous speciation in equilibrium and precipitation and dissolution of calcite has been implemented and reproduced the experimental results. The geochemical model developed in our study can be applied to similar experimental studies and to field-scale studies to predict the efficiency of abiotic nitrite reduction treatments using Fe(II).
Synergies of chemodenitrification and denitrification in a saline inland lake
(Elsevier Ltd., 2024-05-07) Margalef Marti, Rosanna; Thibault de Chanvalon, Aubin; Anschutz, Pierre; Amouroux, David; Sebilo, Mathieu
The interconnection between biotic and abiotic pathways involving the nitrogen and iron biogeochemical cycles has recently gained interest. While lacustrine ecosystems are considered prone to the biotic nitrate reduction (denitrification), their potential for promoting the abiotic nitrite reduction (chemodenitrification) remains unclear. In the present study, batch incubations were performed to assess the potential for chemodenitrification and denitrification in the saline inland lake Gallocanta. Sulfidic conditions are found in top sediments of the system while below (5–9 cm), it presents low organic carbon and high sulfate and ferrous iron availability. Anoxic incubations of sediment (5–9 cm) and water from the lake with nitrite revealed potential for chemodenitrification, especially when external ferrous iron was added. The obtained isotopic fractionation values for nitrite (ɛ15NNO2) were −6.8 and −12.3 ‰ and therefore, fell in the range of those previously reported for the nitrite reduction. The more pronounced ɛ15NNO2 (−12.3 ‰) measured in the experiment containing additional ferrous iron was attributed to a higher contribution of the chemodenitrification over biotic denitrification. Incubations containing nitrate also confirmed the potential for denitrification under autotrophic conditions (low organic carbon, high ferrous iron). Higher reaction rate constants were found in the experiment containing 100 μM compared to 400 μM nitrate. The obtained ɛ15NNO3 values (−8.5 and −15.1 ‰) during nitrate consumption fell in the range of those expected for the denitrification. A more pronounced ɛ15NNO3 (−15.1 ‰) was determined in the experiment presenting a lower reaction rate constant (400 μM nitrate). Therefore, in Gallocanta lake, nitrite generated during nitrate reduction can be further reduced by both the abiotic and biotic pathways. These findings establish the significance of chemodenitrification in lacustrine systems and support further exploration in aquatic environments with different levels of C, N, S, and Fe. This might be especially useful in predicting nitrous oxide emissions in natural ecosystems.
Paleoenvironmental constraints influencing charophyte communities in an Early Cretaceous Karstic Lake, La Pedrera de Meià Konservat-Lagerstätte (Southern Pyrenees): combining geochemical and palaeoecological analyses.
(Springer Verlag, 2025-01-08) Pérez Cano, Jordi; Gil Delgado, Alejandro; Oms, Oriol; Mercedes Martín, Ramon
The combined sedimentological and palaeoecological analysis of charophyte-rich carbonate microfacies is proven to be a useful methodology for the palaeoenvironmental reconstruction of continental settings. However, the integration of these charophyte assemblages with geochemical proxies has not been explored, yet. In the present work, the charophyte-rich muddy carbonates of the Barremian La Pedrera de Meià Konservat-Lagerstätte (Southern Pyrenees, Spain) were studied from a taxonomic, taphonomic, and palaeoecological viewpoint, and the results were later integrated with previously published paleoenvironmental proxies (δ13C, δ18O, and elemental geochemistry). In the studied locality, monospecific Echinochara sp.–Charaxis spicatus meadows are only found in the temporary lakes recorded in the lower stages of lake infilling. The high Al, K, Fe and Ti concentrations and δ18O values previously described in these carbonates indicate meteoric infilling followed by evaporation periods. Freshwater and brackish communities are found in the upper stage of lake infilling. Freshwater settings had mixed meadows with Atopochara–Clavatoraxis, Clavatoroidae utricles–Clavatoraxis, and Ascidiella–Favargerella plants, while the brackish environments, that occurred laterally to freshwater, contain meadows dominated by porocharacean– Charaxis sp., and Echinochara sp.–Charaxis spicatus plants. Miliolids and broken dasycladaceans also occur in these facies. Sr/Ba ratios, REE + Y concentrations, and δ18O values previously reported in these lacustrine carbonates indicate prevalence of freshwater environments with occasional marine influence, which agrees with the occurrence of distinct brackish and freshwater charophyte assemblage and marine-affinity organisms, suggesting that during the last stage of lake evolution, the system was part of a coastal wetland. This work demonstrates that the integration of geochemical, palaeontological and palaeoecological datasets improves the understanding of the fossil continental carbonate settings and their evolution.
Modelling antecedent soil hydrological conditions to improve the prediction of landslide susceptibility in typhoon-prone regions
(Springer Verlag, 2024-04-08) Abancó, Clàudia; Asurza, Flavio Alexander; Medina, Vicente; Hürlimann, Marcel; Bennett, Georgina L.
Most regional landslide susceptibility models do not consider the evolving soil hydrological conditions leading up to a multiple occurrence regional landslide event. This results in inaccurate predictions due to the non-linear behaviour of the terrain. To address this, we have developed a simple and efficient model that incorporates the mid-term evolution of soil hydrological conditions. The model combines a water balance model and a geotechnical model based on infinite slope theory. The analysis of 561 high-intensity rainfall events in a typhoon-prone region of the Philippines revealed that the percolation of water during the 5-month wet season is crucial in determining landslide susceptibility. Consequently, high-intensity rainfall events at the start of the wet season are less likely to trigger landslides, while later events are more hazardous. We analysed the change in landslide susceptibility during the 2018 rainy season by comparing the probability of failure (PoF) before and after three high-intensity rainfall events (July, August and September). Only the event in September caused a significant increase in the probability of failure (PoF). The model showed an accuracy of 0.63, with stable cells better represented than unstable cells. The antecedent hydrological conditions on the lower soil layers are responsible for changes in landslide susceptibility. Our findings support the hypothesis that new approaches to developing hydro-meteorological thresholds for landslide early warning systems should be evaluated, especially in regions with strong seasonality.

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