Fernando Gázquez

• PhD in Environmental Sciences
• Researcher at University of Almería

Playa-lakes are highly sensitive to hydroclimate changes, which are often reflected in their sediments. In this study, we investigate the paleohydrological evolution of the Fuente de Piedra playa-lake (southern Spain), in connection to climate fluctuations during the Late Pleistocene-Holocene transition. Stable isotopes (δ18O and δ2H) of gypsum hyd...

This research investigates the influence of seasonal hydroclimate variability on the triple oxygen and hydrogen isotope composition of small, shallow lake systems that show substantial intra-annual and interannual fluctuations in the water level. The study was conducted at Laguna Honda, a semi-permanent lake located in the semiarid Mediterranean en...

We modelled the water level variations in a protected playa-lake system (La Ratosa Natural Reserve, S Spain) comprising two adjacent playa-lakes: La Ratosa and Herriza de los Ladrones. For this pourpose, daily water balances were applied to reconstruct the water level. Model results were validated using actual water level monitoring over the past 2...

Gypsum is one of the major evaporite minerals that can be used as a sensitive archive for past climate change, revealing variations in the hydrological cycle and dry‐wet climatic alternations. Measuring variations in gypsum content, rapidly and with high accuracy, will contribute to more extensive paleoclimate reconstructions. However, a fast, conv...

In recent decades, many wetlands in the Mediterranean watershed have dried up. We forecast the impact of climate change on the hydrology of three permanent lakes in a semiarid area of the southwestern Mediterranean region. To achieve this, we applied daily water balance models to calculate variations in water levels and validated our approach using...

Playa lakes that developed in semi-arid regions are sensitive to water input reductions, which may be influenced not only by climate changes and human management, but also by changes in the size of the watershed. We conducted an interdisciplinary study combining structural, geomorphic, sedimentological, mineralogical and hydrological analyses to be...

Los espeleotemas son una herramienta útil para investigar el clima del pasado. Sin embargo, la monitorización ambiental de la atmósfera de las cuevas es fundamental para una mejor interpretación de los resultados geoquímicos de estalagmitas. Este estudio se centra en la monitorización ambiental de Cueva Larga (Sierra de los Filabres, Almería). Se h...

Gypsum (CaSO4∙2H2O) is one of the most common evaporitic minerals on Earth. Its crystals exhibit diverse morphologies that can provide insights into their depositional environment. We analyzed the morphologies of gypsum deposits in a 14 m sedimentary sequence of Fuente de Piedra playa-lake (Málaga, Spain) to link its variations to sedimentary facie...

We investigate the oxygen and hydrogen stable isotopes of hydration water in gypsum (CaSO4·2H2O) from surface sediment of Laguna de la Ratosa playa-lake (northern Málaga Province, Spain). We aim to enhance the understanding of how lacustrine gypsum from playa-lakes can be used for paleoclimate reconstruction. Gypsum samples were collected at 30-met...

Las excavaciones arqueológicas llevadas a cabo en la Cueva del Arco (Cieza, Región de Murcia) han permitido desobstruir una gran cavidad. Se ha realizado una campaña preliminar de muestreo para estudiar su geomorfología, mineralogía y atmósfera subterránea. La cueva tiene un recorrido longitudinal conocido de 1360 m y alberga amplias salas y galerí...

Here, we explore the dynamic interplay of climate, tectonic forces and human impacts, that have shaped the current hydrology of the 27 main endorheic continental playa-lakes in southern Spain, most of them protected as Natural Reserves. This research offers a thorough examination of the hydro-geomorphic, geochemical, and tectonic characteristics th...

This research investigates the influence of seasonal hydroclimate variability on the triple oxygen and hydrogen isotope composition of small, shallow lake systems that show substantial intra- and interannual fluctuations in the water level. The study was conducted at Laguna Honda, a semi-permanent lake located in the semiarid Mediterranean environm...

The Sierra Seca aquifer system is located in the northeast (NE) of the province of Granada, in the Prebetic Domain (Betic Cordillera). It is composed of different aquifer units hosted in the Lower Cretaceous and Upper Cretaceous limestones. The two aquifers are separated by a low permeability marl layer, which effectively acts as a barrier between...

Many caves in Sicily have been shown to have a sulfuric acid or other hypogenic origin. We studied three caves (Palombara, Scrivilleri, Monello) near Syracuse (eastern Sicily), in an area that was strongly uplifted and faulted, creating multiple Pleistocene marine terraces. Mineralogy, stable isotopes and dating methods (paleomagnetism, U/Th) were...

Playa-lakes developed in semi-arid regions are sensitive to water input reductions, which may be influenced not only by climate changes and human management but also by changes in the size of the watershed. We accomplished an interdisciplinary study combining structural, geomorphic, sedimentological, mineralogical and hydrological analyses to bette...

Resultados preliminares sobre la relación hidrogeológica entre acuíferos mediante el análisis de los isótopos estables δ18O y δ2H. Sistemas jurásicos y cretácicos de la Sierra de Segura. SE de España. Preliminary results on the hydrogeological relationship between aquifers through the analysis of stable δ18O and δ2H isotopes. Jurassic and cretaceo...

The soils in the hyper-arid core of the Atacama Desert (Chile) harbor substantial quantities of soluble salts, including sulfates and nitrates. Gypsum (CaSO₄•2H₂O) is a prevalent mineral in the Atacama region. It manifests as ~10-cm-thick surface crusts exhibiting a spatial pattern resembling polygons, in mixtures with other minerals beneath the su...

El Niño-Southern Oscillation dynamics affect global weather patterns, with regionally diverse hydrological responses posing critical societal challenges. The lack of seasonally resolved hydrological proxy reconstructions beyond the observational era limits our understanding of boundary conditions that drive and/or adjust El Niño-Southern Oscillatio...

RESUMEN Las cuencas endorreicas albergan frecuentemente lagunas tipo playa, que permanecen se-cas en verano debido a que tienen un balance hídrico negativo. Muchas de estas lagunas del sur de España se localizan en el cinturón de pliegues y cabalgamientos de la cordillera Bética. A pesar de haber sido estudiadas desde un punto de vista hidrogeológi...

Riassunto Il Geode gigante di Pulpí è uno dei più importanti ritrovamenti mineralogici internazionali degli ultimi decenni. I suoi cristalli pinacoidali e i prismi di gesso di eccezionale purezza, lunghi fino a due metri, hanno suscitato l'interesse della comunità scientifica e del grande pubblico. Il presente lavoro fornisce una rassegna bibliogra...

During the Roman domain of the Iberian Peninsula (from 201 BCE to 460 CE) water management infrastructures were built to satisfy high water demand. However, whether the Roman activities affected the hydrological balance of Iberian wetlands remains unclear. Here, we investigate the paleo-hydrology of Lake Zóñar (southern Iberia) by using the stable...

Il sistema carsico di Toirano (Liguria) comprende diverse grotte, tra cui le-lombo (247 m s.l.m.), di Santa Lu-cia Superiore o del Santuario (215 m s.l.m.) e Inferiore (201 m s.l.m.), e la Grotta della Bàsura (186 m s.l.m.). In passato la genesi del sistema di grotte-to il reticolo di gallerie freatiche, impo-state sulle maggiori direttrici struttu...

The hydrological functioning of wetlands in S Spain is poorly understood. We perform a 22-years hydrological modelling of seven playa-lakes located in a semi-arid region of southern Spain, including dry and wet periods. To do that, we applied a hydrological balance model to reconstruct past lake water levels. In addition, we investigated the hydroc...

Las variaciones climáticas acontecidas durante el Holoceno en el sur de la Península Ibérica quedaron registradas en las secuencias sedimentarias de las numerosas lagunas que ocupan la depresión del Guadalquivir. En el presente trabajo se ha analizado la composición isotópica del oxígeno y el hidrógeno (δ18O, δ2H y d-exceso) del agua de hidratación...

Ice caves are one of the least studied parts of the cryosphere, particularly those located in inaccessible permafrost areas at high altitudes or high latitudes. We characterize the climate dynamics and the geomorphological features of Devaux cave, an outstanding ice cave in the Central Pyrenees on the French–Spanish border. Two distinct cave sector...

El principal aporte hídrico hacia los acuíferos kársticos del Parque Natural Sierras de Cazorla, Segura y las Villas se debe a la recarga procedente de las precipitaciones, que se genera por infiltración tanto de la lluvia como del agua procedente de la fusión nival. En este Espacio Protegido, que presenta una superficie total de 214.519 ha, se enc...

Hypogenic morphologies in Cueva del Agua, Cartagena, Spain. Cueva del Agua of Cartagena (Region of Murcia, SE Spain) is a subaqueous cavity flooded by thermal water. It is one of the longest active hydrothermal caves in Spain (>6.000 m). The water level in de cave is marked by proximity of the Mediterranean Sea. The cave acts a thermal outlet and t...

En la Mina Rica de Pulpí (Almería) se lleva a cabo desde 2020 una estimación periódica y pormenorizada de los niveles-dosis de radiación ambiental recibidos por los guías turísticos, a partir de los datos de monitorización horaria de la concentración de gas radón en las diferentes salas y galerías por las que transcurren las visitas guiadas. Las va...

La Geoda gigante de Pulpí es uno de los hallazgos mineralógicos internacionales más importantes de las últimas décadas. Sus cristales pinacoidales y prismas de yeso de excepcional pureza de hasta dos metros de longitud han despertado el interés tanto de la comunidad científica como del público general. En este trabajo se hace una revisión bibliográ...

La Mina Rica de Pulpí (Almería) es conocida internacionalmente por albergar la mayor geoda de yeso descubierta en Europa hasta la fecha, que además es la única visitable a escala mundial. Sin embargo, antes del descubrimiento de la geoda en 1999, la mina ya era frecuentada por coleccionistas y aficionados a la mineralogía debido a la gran diversida...

Los espeleotemas se han convertido en una herramienta fundamental para estudiar el clima del pasado. Sin embargo, las reconstrucciones paleoclimáticas a partir de depósitos minerales de cuevas en el sur de la península Ibérica son todavía muy escasas. En este trabajo presentamos las primeras dataciones de espeleotemas holocenos de la Cueva de los Ó...

Present climate conditions impede the formation of calcite speleothems in the gypsum caves of the semi-arid region of Sorbas (Southern Spain). However, U-Th dating reveals the uninterrupted deposition of a 46 mm-thick carbonate flowstone in the Sorbas caves from ~78 to ~71 ka, during Marine Isotope Stage (MIS) 5a. This indicates that the area was v...

The Toirano karst system comprises different caves between altitudes of 340 m and 186 m asl. A detailed investigation of cave pattern, morphologies and of the sedimentary deposits attributes the origin of the caves to rising waters that followed the main vertical structural pathways. Many walls and roofs are sculpted with rising features (cupola an...

New biogenic forms were recently observed inside the caves of Palawan. They consist of perfectly rounded holes, developed over any kind of limestone surface interested by bat droppings. Their genesis is controlled by the peculiar Palawan climate, which is characterized by short but strong rainfalls followed by rather long dry periods.

Early investigations on stable isotopes (δ¹⁸O and δD) of structurally-bound gypsum (CaSO4·2H2O) hydration water (GHW) suggested that soon after gypsum precipitation, its primary isotopic composition could be altered via gypsum re-crystallization or by isotope exchange by diffusion of water into the intact crystals. If this occurs, the use of stable...

DOWNLOAD here: https://www.dropbox.com/scl/fi/xlomescmk456g4s6qn7ze/Cohen-et-al.-2022-QSR-Late-Quaternary-climate-change-at-Kati-Thanda.pdf?rlkey=m1kjcztftaud0c0ufjj7lznra&dl=0 _____________________________________________________________________________________Williams Point is an iconic late Quaternary sedimentary sequence exposed at the southern...

The Azerou massif is in Tellian nappes of the Algerian Atlas. This narrow Cenomanian carbonate ridge is surrounded by marly lowlands, the Soummam depression to the north and the Hodna plains to the south. The Azerou aquifer is drained toward the north by thermal springs (called Hamman al-Biban in Arabic) along the Azerou oued, which crosses the mas...

The Toirano karst system comprises different caves between altitudes of 340 m and 186 m asl. A detailed investigation of cave pattern, morphologies and of the sedimentary deposits attributes the origin of the caves to rising waters that followed the main vertical structural pathways. Many walls and roofs are sculpted with rising features (cupola an...

Ice caves are one of the least studied parts of the cryosphere, particularly those located in inaccessible permafrost areas at high altitudes or high latitudes. We characterize the climate dynamics and the geomorphological features of Devaux cave, an outstanding ice cave in the Central Pyrenees on the French-Spanish border. Two distinct cave sector...

Evaporitic lakes such as playa-lakes are characteristic of many arid regions and are unique environments with respect to fauna and flora, while being very vulnerable to climate and environmental fluctuations and threatened by the current global change scenario. Water balance oscillations in these systems can trigger the precipitation or dissolution...

Centimeter-thick layers of gypsum (CaSO4·2H2O) were deposited at the bottom of Laguna de Zoñar (Córdoba Province, southern Spain) from ~2120 to ~1900 cal yr BP [1], coinciding with the apogee of the Roman Empire in the Iberian Peninsula. The presence of gypsum deposits in lake sediments is generally interpreted as evidence of dry climatic periods i...

The North Atlantic Oscillation (NAO) has a major effect on the modern precipitation patterns in the southern Iberian Peninsula and also controlled the hydroclimate of this region in the past [1,2]. The oxygen and hydrogen stable isotopes (δ 18 O and δD) of lake waters are sensitive to long-term changes in hydrological conditions (e.g. relative humi...

The network of lava tubes is one of the most unexploited natural wonders of the Galapagos Islands. Here, we provide the first morphological, mineralogical, and biogeochemical assessment of speleothems from volcanic caves of the Galapagos to understand their structure, composition, and origin, as well as to identify organic molecules preserved in sp...

Subaqueous gypsum (CaSO4·2H2O) crystals are relatively common in epithermal systems where sulfide ore deposits are present. The Giant Geode of Pulpí (Almería, SE Spain) hosts some of the largest (up to 2 m in length) subaqueous gypsum crystals discovered to date. Here, we present the first U-series ages of its crystals and reconstruct the oxygen an...

A better understanding of ENSO dynamics is essential for modelling future climate change and its impacts on the ecosystems and lives of the inhabitants of the tropical Pacific islands, which face considerable environmental risk in the coming decades. This study reconstructs past ENSO dynamics using a multi-proxy approach applied to a stalagmite fro...

In cave environments, water vapor condensation occurs naturally when warmer/wet air masses flow close to colder cave surfaces. Artificial microclimate perturbations in show caves can enhance this process, leading to potential deterioration of rock art and degradation of speleothems. Here we investigate the triple oxygen and hydrogen isotopic compos...

Environmental characterisation of the epiphreatic zone in hypogenic contexts: an example from the Cueva del Agua (Cartagena, SE Spain). The environmental conditions that control hypogenic speleogenesis in coastal carbonate aquifers have hardly been monitored in situ due to the inaccessibility of areas where thermal groundwater interacts with seawat...

The neo-born Majella UNESCO Global Geopark hosts more than one hundred mapped caves, some of which represent important geosites and touristic attractions. Underground karst systems are often excellent environments to investigate and characterize the stratigraphical relations, tridimensional spatial organization of geological structures, morphologie...

We investigated speleogenetical processes and the formation of unusual endo- and exokarstic features within carbonates rocks in the Sierra de Mollina mountain range (southern Spain), a sector affected by salt tectonics. Allochthonous Triassic evaporites partially overlie younger subsalt Jurassic limestones and dolostones. The carbonate beds show si...

Due to their potential to support chemolithotrophic life, relic hydrothermal systems on Mars are a key target for astrobiological exploration. We analysed water and sediments at six geothermal pools from the rhyolitic Kerlingarfjöll and basaltic Kverkfjöll volcanoes in Iceland, to investigate the localised controls on the habitability of these syst...

Studies of rainfall isotopic composition in the Iberian Peninsula are scarce, and to date, none of them have provided analyses of the triple oxygen isotopes, preventing from the complete understanding of current atmospheric processes in this region. We investigate the rainwater δ¹⁷O, δ¹⁸O, and δD and derived parameters ¹⁷O-excess and d-excess in a...

Though hundreds of caves are known across Mongolia, few have been subject to systematic, interdisciplinary archaeological surveys and excavations to understand Late Pleistocene and Holocene environments. Previous cave excavations in Mongolia have demonstrated their potential for preservation of archaeological and biological material, including Pala...

Water is the most limiting factor in dryland ecosystems, and plants are adapted to cope with this constraint. Particularly vulnerable are phreatophytic plants from groundwater-dependent ecosystems (GDEs) in regions that have to face water regime alterations due to the impacts of climate and land-use changes. We investigated two aspects related to t...

The Toirano karst system is located in the Ligurian Alps (north Italy), around 4.5 km inland from the coastline and carved in Middle Triassic dolostone. It comprises five cave levels over a 154 m altitudinal range, specifically Ulivo (340 m a.s.l.), Colombo (247 m a.s.l), Upper Santa Lucia (215 m a.s.l.), Lower Santa Lucia (201 m a.s.l.) and Bàsura...

The Galapagos Islands (Ecuador) have a unique ecosystem on Earth due to their outstanding biodiversity and geological features. This also extends to their subterranean heritage, such as volcanic caves, with plenty of secondary mineral deposits, including coralloid-type speleothems and moonmilk deposits. In this study, the bacterial communities asso...

In caves, know the quality of the air or in spaces without ventilation such as post-siphon bubbles, mine galleries, etc. and other places where non-breathable gases or low concentrations of O2 can be stored, it is a fundamental and mandatory question to guarantee the safety of explorers. At present, the study of gases in cavities is allowing to kno...

Preliminary results obtained in Phase I of the Thermal Research 2019 project, this project analyzes the dynamics of the climate of water and air in Cueva del Agua-Cartagena, this cavity is mostly flooded and the waters maintain temperatures around 29 ° C coming from a thermal aquifer. For a year, water temperatures are recorded at various fixed poi...

Folia are speleothems that resemble bells, inverted cups, or bracket fungi, and whose origins are still controversial. Cenote Zapote (an underwater cave) in the Yucatán Peninsula (México), is home to some of the largest folia reported to date. These speleothems are currently growing in an active underwater system, meaning this site offers an excell...

Carbonate cave deposits (speleothems) have been used widely for paleoclimate reconstructions; however, few studies have examined the utility of other speleothem-forming minerals for this purpose. Here we demonstrate for the first time that stable isotopes (δ17O, δ18O and δD) of structurally-bound gypsum (CaSO4 ·2H2O) hydration water (GHW) can be us...

Carbonate cave deposits (speleothems) have been used widely for paleoclimate reconstructions; however, few studies have examined the utility of other speleothem-forming minerals for this purpose. Here we demonstrate for the first time that stable isotopes (δ17O, δ18O and δD) of structurally-bound gypsum (CaSO4·2H2O) hydration water (GHW) can be use...

Cave microclimate and geochemical monitoring is vitally important for correct interpretations of proxy time series from speleothems with regard to past climatic and environmental dynamics. We present results of a comprehensive cave-monitoring programme in Waipuna Cave in the North Island of New Zealand, a region that is strongly influenced by the S...

Abstract. Cave microclimatic and geochemical monitoring is vitally important for correct interpretations of proxy time series from speleothems with regard to past climatic and environmental dynamics. We present results of a comprehensive cave monitoring programme in Waipuna Cave in the North Island of New Zealand, a region that is strongly influenc...

Gypsum (CaSO 4 •2H 2 O) speleothems (i.e. stalactites, stalagmites, etc.) in caves form frequently through dissolution of the gypsum host-rock by seepage water and subsequent secondary mineral re-precipitation from gypsum-saturated solutions [1]. Gypsum takes its structurally-bound hydration water (GHW) from the liquid; the isotopic composition (δ...

Here we present the first record of Marine Isotope Stage (MIS) 7 from Sardinia, based on a U-Th-dated speleothem from Crovassa Azzurra cave, which also grew during MIS 5. Carbonate precipitation was continuous during MIS 7, while two multi-millennial hiatuses interrupted growth during MIS 5. These hiatuses occurred during times of unstable climate,...

We provide first insights into the speleogenesis of Ejulve cave (Teruel province, Iberian Range, NE Spain) by studying cave morphologies and cave deposits, combined with regional geomorphological and hydrothermal observations. Three main hydrogeomorphic evolutionary stages can be distinguised to explain the origin and evolution of the Ejulve endoka...

Plain Language Summary Europa, a moon of Jupiter, has become a priority target in the search for life off the Earth, due to the presence of a liquid water ocean under its icy shell. Salts on the moon's surface might originate from this ocean and therefore offer a way of studying the ocean without requiring direct access. Our knowledge of these salt...

The dissolution of carbonate host-rock by freshwater in phreatic or vadose conditions is the most common mechanism for the formation of caves; however, circulation of saline solutions through carbonate materials and precipitation of soluble salts may also play an important role. We studied the stable isotope composition (d18O and d34S of sulfate, d...

The stable isotopes (¹⁸O/¹⁶O, ¹⁷O/¹⁶O and ²H/¹H) of structurally-bound water (also called hydration water) in gypsum (CaSO4·2H2O) and bassanite (CaSO4·0.5H2O) can be used to reconstruct the isotopic composition of paleo-waters. Understanding the variability of the isotope fractionation factors between the solution and the solid (α¹⁷Omineral-water,...

Rationale Triple oxygen isotopes (¹⁶O/¹⁷O/¹⁸O) in nitrate are a valuable tool to ascertain the pathways of nitrate formation in the atmosphere and the fate of nitrate in ecosystems. Here we present a new method for determining Δ¹⁷O values in nitrates, based on nitrate‐water isotope equilibration (IE) and subsequent isotopic analysis of water using...

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Falling from a fall in rainfall How much did rainfall have to decrease to trigger the collapse of Lowland Classic Maya civilization during the Terminal Classic Period? This collapse is a well-cited example of how past climate change—in this case, drought—can disrupt a population. Evans et al. measured the isotopic composition of water in Lake Chich...

Resumen La región de Murcia presenta una geografía singular caracterizada por las cadenas montañosas interiores y litorales que la recorren de oeste a este. Las calizas son abundantes y aunque el paisaje kárstico no es muy notorio, si lo es el número de acuíferos que se distribuyen por toda la región con un importante termalismo regional. Estas mas...

Aunque los procesos espeleogenéticos que generaron la Gruta de las Maravillas de Aracena (Huelva) han sido abordados en diversos estudios, aún se desconocen las condiciones ambientales que predominaron en la cueva durante las etapas más recientes de precipitación de espeleotemas. Mecanismos de karstificación derivados de la oxidación de masas de pi...

The caves of the Irazú volcano (Costa Rica), became accessible after the partial collapse of the NW sector of the Irazú volcano in 1994, offering the opportunity to investigate active minerogenetic processes in volcanic cave environments. We performed a detailed mineralogical and geochemical study of speleothems in the caves Cueva los Minerales and...

Here we track the water-table position and temperature of the Mount San Giovanni aquifer (Iglesiente-Sulcis mining district, SW Sardinia, Italy) during the past 600 ka by determining the ages (U/Th dating) and stable isotope compositions (δ¹⁸O, δ¹³C and Δ47) of a variety of subaqueous carbonate speleothems (e.g. calcite spars, dogtooth calcite crys...

Mineral ballasting enhances carbon export from the surface to the deep ocean; however, little is known about the role of this process in the ice-covered Arctic Ocean. Here, we propose gypsum ballasting as a new mechanism that likely facilitated enhanced vertical carbon export from an under-ice phytoplankton bloom dominated by the haptophyte Phaeocy...

This work analyzes the different morphologies that are located in the cave of Puerto, Murcia and its distribution, these have their origin in processes derived from hydrothermal and hypogenic processes. The numerous morphologies of hypogenic character of the Puerto cave make it a reference cavity for the study and evolution of hydrothermal networks...