Linda Daniele | Universidad de Chile (original) (raw)

Papers by Linda Daniele

Proceedings, Jun 1, 2015

ABSTRACT This study reports textures and homogenization temperatures of primary fluid inclusions ... more ABSTRACT This study reports textures and homogenization temperatures of primary fluid inclusions on dolomites hosted in Upper Jurassic to Lower Cretaceous age carbonate sequence from the Riópar area (Mesozoic Prebetic Basin, SE Spain). Five dolomite texture-types have been identified: i) planar subhedral replacive dolomite (ReD); ii) transition between planar subhedral to euhedral dolomite (ReD-SuD); iii) planar euhedral sucrosic dolomite (SuD); iv) non-planar cloudy saddle dolomite (SaD-I); and v) non-planar clear saddle dolomite (SaD-II). Fluid inclusions in ReD-SuD dolomite show a Th mode value of 205ºC, while SaD-I and SaD-II show Th mode values of 235ºC and 195ºC respectively. Our research indicates that planar and non-planar dolomite textures are formed at high-temperatures under hydrothermal conditions in deep-burial diagenetic environments, unsupporting the accepted idea that planar dolomites are formed under temperatures around or less than 50-60ºC in shallow-burial diagenetic environments.

Chemical Geology, Sep 1, 2017

Thermal waters in the Southern Volcanic Zone (SVZ) of Chile between 36°-41°S were studied using m... more Thermal waters in the Southern Volcanic Zone (SVZ) of Chile between 36°-41°S were studied using major and selected trace element relationships to characterize their geochemistry, formation mechanisms, and to explore the influence of regional structural controls on fluid composition. Three sets of waters were identified based on physicochemical characteristics: (i) NaCl waters, (ii) acid-sulfate waters, and (iii) bicarbonate (HCO 3) waters. NaCl waters are the most abundant type in the studied region and their chemistry is controlled by significant water-rock interaction. They are characterized by an alkaline pH (7.2-9.3), generally lower temperatures (avg: 55°C), and relatively high concentrations of Cl, Na, B, As, Li, and Cs. Acid-sulfate waters are typically associated with volcanoes and have a strong magmatic/volcanic component due to the absorption of magmatic vapors. They are acidic (pH < 4), generally higher in temperature (avg: 85°C), and have elevated concentrations of SO 4 , Mg, and Ba. Bicarbonate waters are characterized by the highest concentrations of HCO 3 (> 892 ppm) in the region and are similar in temperature (< 47°C) and pH (> 6.2) to NaCl waters. They have elevated concentrations of most cations (Ca, K, Na, Mg, Ba, Sr) as a result of intense shallow cation leaching due to the absorption of CO 2-rich volcanic vapors on the peripheries of geothermal systems. The thermal waters were also characterized according to their spatial relation with the dominant fault systems of the region: the NNE-striking intra-arc Liquiñe-Ofqui Fault System (LOFS) and the WNW-striking Andean Transverse Faults (ATF). The inherent differences in fault nature between these fault systems constitutes the primary structural control influencing geothermal fluid development in the SVZ. The chemistry of waters spatially associated with the LOFS as a whole is defined by high vertical permeability networks and lack magmatic reservoir development. Therefore, these waters tend to have higher Cl/B ratios and strong correlations between trace alkali metals and Cl due to rapid, efficient upflow pathways. In contrast, waters spatially associated with the ATF have lower Cl/B ratios and show no correlation between trace alkali metals and Cl due to degassing magma chambers and decreased vertical permeability. The relationship between water type and structural domain in Cl/B ratios and trace metal behavior provides evidence that fault geometry and kinematics exert a fundamental control on geothermal fluid development in the SVZ of Chile.

Macla: revista de la Sociedad Española de Mineralogía, Jun 1, 2012

Macla: revista de la Sociedad Española de Mineralogía, 2010

Geogaceta, 2016

A groundwater sampling has been carried out in Sierra de Gador (SE Spain) with the aim of determi... more A groundwater sampling has been carried out in Sierra de Gador (SE Spain) with the aim of determining the processes in which minor ions are involved. Previous works have allowed us to differentiate four groups according to the major ion content. This study enables to subdivide one of these groups. The SO 4 2-/Ba 2+ relationship shows two distinct trends, controlled by the precipitation of barite in the sulfated samples. Ions as lithium and boron are related to the existence of sulfate and to the groundwater thermalism. Last, the ion Br is a useful indicator of salinity in the samples.

Geogaceta, 2015

The town of Aguadulce, in Almeria province, receives its name due to the historical discharges of... more The town of Aguadulce, in Almeria province, receives its name due to the historical discharges of freshwater into the sea, which disappeared as a result of overexploitation of the aquifer in recent times. In this paper, a strip of cliff located just above those ancient discharges, in which a strong solution of the rock that can exceed 60%, has been studied. Dissolution surfaces are impregnated by manganese oxides, on which precipitated calcite and aragonite concretions. These karstic features, located beneath a marine terrace at 40 m a.s.l., had been interpreted as evidences of dissolution reactions and mineral precipitation occurred in a freshwater-seawater mixing zone during the Pleistocene.

Journal of South American Earth Sciences, Oct 1, 2022

Journal of Volcanology and Geothermal Research, Apr 1, 2022

Microbiology Spectrum

Temperature, pH, and hydrochemistry of terrestrial hot springs play a critical role in shaping th... more Temperature, pH, and hydrochemistry of terrestrial hot springs play a critical role in shaping thermal microbial communities. However, the interactions of biotic and abiotic factors at this terrestrial-aquatic interface are still not well understood on a global scale, and the question of how underground events influence microbial communities remains open. To answer this, 11 new samples obtained from the El Tatio geothermal field were analyzed by 16S rRNA amplicon sequencing (V4 region), along with 191 samples from previous publications obtained from the Taupo Volcanic Zone, the Yellowstone Plateau Volcanic Field, and the Eastern Tibetan Plateau, with their temperature, pH, and major ion concentration. Microbial alpha diversity was lower in acid-sulfate waters, and no significant correlations were found with temperature. However, moderate correlations were observed between chemical parameters such as pH (mostly constrained to temperatures below 70°C), SO 4 2− and abundances of member...

Geofluids, Apr 13, 2013

Sierra de Gádor is a complex, Triassic age aquifer system formed by dolostones and limestones wit... more Sierra de Gádor is a complex, Triassic age aquifer system formed by dolostones and limestones with interbedded gypsum. On top, a thick Neogene‐Quaternary series gives rise to shallow aquifers. F‐Pb‐Zn stratabound deposits are found within the Triassic carbonate formations. Their mineral paragenesis includes sphalerite, galena, pyrite, marcasite, fluorite and barite. The Sierra de Gádor groundwater is the principal water resource for this semiarid environment, and the population is potentially exposed to hazardous elements related to mining activities and wastes. In October 1966, an intensive precipitation event (190 mm day−1) broke several old tailing structures, flooding part of the Berja village with polluted sludge. Fluorine values in some boreholes and springs were found higher than 1.5 mg l−1, the maximum value permitted by Spanish regulation for human consumption. Hydrogeochemistry data, statistical tools and geochemical simulations were used in this study to assess the physicochemical processes and the fluorine sources within this carbonate aquifer. Most of the analysed water samples are close to equilibrium with respect to carbonate minerals but are undersaturated with respect to fluorite and gypsum. About 39% of the samples have fluorine concentration higher than the regulatory limit. A statistical analysis indicates that fluorine has a low correlation with other variables. Inverse and mixing models, performed with the code PHREEQC, differentiate the predominance of water–rock interaction processes within the carbonate aquifer and water mixing between the carbonate and shallow aquifers. The results indicate that some fluorite dissolution must occur in the carbonate Triassic aquifer, whereas the shallow aquifers leach fluorine from mining wastes. Both types of aquifers are interconnected, and their waters mix below the flooded area. There, the high fluorine values appear to have two sources: (i) the regional fluorine enrichment due to the mineralization; and (ii) the polluted 1966 flood that reached the deep carbonates via the shallow aquifer.

Science of The Total Environment, Jun 1, 2021

The Mountain-Block Recharge (MBR), also referred to as the hidden recharge, consists of groundwat... more The Mountain-Block Recharge (MBR), also referred to as the hidden recharge, consists of groundwater inflows from the mountain block into adjacent alluvial aquifers. This is a significant recharge process in arid environments, but frequently discarded since it is imperceptible from the ground surface. In fault-controlled Mountain Front Zones (MFZs), the hydrogeological limit between the mountain-block and adjacent alluvial basins is complex and, consequently, the groundwater flow-paths reflect that setting. To cope with the typical low density of boreholes in MFZs hindering a proper assessment of MBR, a combined geoelectrical-gravity approach was proposed to decipher groundwater flow-paths in fault-controlled MFZs. The study took place in the semiarid Western Andean Front separating the Central Depression from the Principal Cordillera at the Aconcagua Basin (Central Chile). Our results, corroborated by field observations and compared with worldwide literature, indicate that: (i) The limit between the two domains consists of N-S-oriented faults with clay-rich core (several tens of meters width low electrical-resistivity subvertical bands) that impede the diffuse MBR. The "hidden recharge" along the Western Andean Front occurs through (ii) focused MBR processes by (ii.a) open and discrete basement faults (mass defect and springs) oblique to the MFZ that cross-cut the N-S-oriented faults, and (ii.b) high-hydraulic transmissivity alluvial corridors in canyons. Alluvial corridors host narrow unconfined mountain aquifers, which are recharged by indirect infiltration along ephemeral streams and focused inflows from oblique basement faults. This study also revealed seepage from irrigation canals highlighting their key role in the recharge of alluvial aquifers in the Central Depression. The proposed combined geophysical approach successfully incorporated (hydro)geological features and geophysical forward/inverse modelling into a robust hydrogeological conceptual model to decipher groundwater flow-paths in fault-controlled MFZs, even in the absence of direct observation points.

Journal of Geochemical Exploration, Aug 1, 2015

Sierra de Gádor is a karstic macrosystem characterized by highly complex geometry. The two main e... more Sierra de Gádor is a karstic macrosystem characterized by highly complex geometry. The two main economic activities in this areathe highly profitable irrigated agriculture and tourismare supported by water resources from Sierra de Gádor, hence the interest in understanding this aquifer system. The highly variable precipitation in the area is characteristic of the arid conditions. The aim of the study presented in this paper was to define the principal hydrogeochemical and isotopic characteristics of the area and to characterize the different types of freshwater, some of which are affected by the process of mixing with saltwaterparticularly those at the east and west extremes of the Sierra de Gádor. The hydrogeochemical analysis enabled the principal geochemical processes occurring in the aquifer to be established. The waters can be grouped into four categories, each defined by a distinctive solute. Dissolution of dolomite determines the chemical composition of less mineralized water. Dedolomitization (dolomite dissolution together with calcite precipitation caused by dissolution of gypsum) becomes predominant when the water flows through interbedded gypsum. Marine intrusion results in highlymineralized waters and leads to base exchange reactions. The variation of δ 18 O content with altitude (−0.19‰/100 m) allows the main recharge areas to be determined: 2000-1500 m a.s.l., 1500-900 m a.s.l., and below 900 m a.s.l., according to the different hydrodynamic characteristics of each area. In some sectors, it is possible to detect the current recharge from rainwater infiltration or seawater intrusion, based on its tritium content.

Hydrological Processes, Oct 30, 2008

ABSTRACT Isotopic fractionation of 10B/11B provides a sound tool for identifying hydrogeochemical... more ABSTRACT Isotopic fractionation of 10B/11B provides a sound tool for identifying hydrogeochemical processes in complex areas, owing to its ability to discriminate between various scenarios. In addition, the occurrence of boron as a minor element in areas of active volcanism allows its use in comparison with concentrations of other conservative or non-conservative ions. This allows the detection of water mixtures of diverse origin and temperature, deep or shallow, including fresh water, seawater and even brines. This tool was applied in studies of the volcanic islands of Ischia and São Miguel, across widely differing geographical and climatic contexts. Five groups of waters have been identified in Ischia Island: marine, transition, hot carbonated, cold carbonated and fresh waters. For São Miguel Island the identified groups are cold carbonic, hot carbonic, boiling and acidic boiling waters. Copyright © 2008 John Wiley &amp; Sons, Ltd.

Geofluids, Feb 28, 2013

ABSTRACT Dedolomitization or calcitization, the replacement of dolomite by calcite, modifies the ... more ABSTRACT Dedolomitization or calcitization, the replacement of dolomite by calcite, modifies the porosity and permeability of carbonate rocks. This study evaluates the effects of dedolomitization on the porosity of carbonates by means of geochemical and reactive transport simulations. The obtained results indicate that dedolomitization is a slow process that may be triggered by cold meteoric water but also by warm groundwater at temperatures of ≤50°C. Dedolomitization is more efficient with fluid fluxes on the order of tens of metres per year. Most of the simulations performed in this study resulted in a loss of porosity due to calcitization. The rate of the dedolomitization reaction increases significantly when calcium-bearing minerals with faster dissolution kinetics and smaller molar volume than calcite, such as anhydrite, are present in the system. In such situations, the porosity of the rock increases significantly (approximately 10%) during a time span of hundreds of thousands of years. Therefore, depending on its original composition, fluid flow conditions and fluid composition, the porosity of a tight dolostone can be enhanced and reach porosity values of reservoir rocks after being calcitized.

Water Air and Soil Pollution, Sep 15, 2007

Use of δ 11 B provides a solid tool for discriminating hydrogeochemical processes in complex coas... more Use of δ 11 B provides a solid tool for discriminating hydrogeochemical processes in complex coastal aquifers. Its efficiency increases markedly when it is applied along with other major or minor constituents. Nevertheless, various factors may affect its interpretation: the presence of clays, which favour adsorption and desorption, the influence of wastewaters, and even the presence of geothermalism. The δ 11 B has been applied to the study of a series of aquifers in southeastern Spain: Castell de Ferro (Granada), Campo de Dalías, Lower Andarax and Sorbas (Almería), all of which are complex and heterogeneous. The results obtained demonstrate that the concentration of Br, the SO 4 /Cl and Cl/Br ratios are good indicators of marine intrusion. Inland some negative values of δ 11 B (−16.7 and −8.1‰) are related to a geothermal influence (34.8 and 51.5°C). The boron solubility is directly related to temperature favours boron mobilization, even from the associated metapelitic deposits. The difference in the boron isotope content in two carbonate units must be caused by the different composition of the carbonate rocks, as well as a long residence time.

Quaternary Research, Jul 1, 2014

The hydrogeochemical characteristics of the Cabo de Gata coastal aquifer (southeastern Spain) wer... more The hydrogeochemical characteristics of the Cabo de Gata coastal aquifer (southeastern Spain) were studied in an attempt to explain the anomalous salinity of its groundwater. This detritic aquifer is characterised by the presence of waters with highly contrasting salinities; in some cases the salinity exceeds that of seawater. Multivariate analysis of water samples indicates two groups of water (G1 and G2). Group G1 is represented in the upper part of the aquifer, where the proportion of seawater varies between 10 and 60%, whilst G2 waters, taken from the lower part of the aquifer, contain 60−70% seawater. In addition, hydrogeochemical modelling was applied, which reveals that the waters have been subject to evaporation between 25 and 35%. There was a good agreement between the modelled results and the observed water chemistry. This evaporation would have occurred during the Holocene, in a coastal lagoon environment; the resulting brines would have infiltrated into the aquifer and, due to their greater density, sunk towards the impermeable base. The characteristics of this water enabled us to reconstruct the interactions that must have occurred between the coastal aquifer and the lagoon, and to identify the environmental conditions that prevailed in the study area during the Middle Holocene.

Renewable Energy, Apr 1, 2015

This work presents the results of a regional-scale estimation of low-enthalpy geothermal resource... more This work presents the results of a regional-scale estimation of low-enthalpy geothermal resources for district heating in the Santiago basin. The purpose of this work is to identify promising areas for the development of this type of renewable energy. The estimation was based on comparison of soil thermal properties and hydrogeological parameters, using Geographic Information System (GIS). To determine the geothermal potential, Ground Source Heat Exchanger (GSHE) coupled with heat pump was used to supply a fixed demand equivalent to the energy required to heat a Chilean standard house. The main barrier for the implementation of a GSHE coupled with heat pump is the well drilling cost, therefore the potential is presented as meters to be drilled in order to install 2 types of GSHE: 1) Borehole Heat Exchanger (BHE) and 2) Groundwater Heat Exchanger (GWHE). To assess the BHE, we used specific Heat Extraction (sHE) of sediments. To evaluate a GWHE, we used depth of groundwater table and groundwater drawdown caused by pumping water to the heat pump. The depth to be drilled ranges from 35 to 105 m in case of the BHE, while in case of the GWHE it ranges from 10 to 400 m.

Desalination, Aug 1, 2011

This study provides geochemical data with the aim of assisting in the proper managing of groundwa... more This study provides geochemical data with the aim of assisting in the proper managing of groundwater resources and so avoiding negative impacts on the aquifers. The area covers the coastal aquifer of Cabo de Gata, which supplies a new desalination plant. Groundwater samples, to different depths, were characterized to identify the main processes occurring in the system, as well as

Applied Geochemistry, Feb 1, 2013

ABSTRACT a b s t r a c t The hydrogeological unit of Aguadulce (Campo de Dalías aquifers, SE Spai... more ABSTRACT a b s t r a c t The hydrogeological unit of Aguadulce (Campo de Dalías aquifers, SE Spain) has a complex geometry. This fact, together with a continuous rise in water demand due to intensive agriculture and tourism create problems for groundwater quantity and quality. In this paper classic geochemical tools managed by means of GIS software and geochemical simulations are combined to delineate, identify and locate the possible physicochemical processes acting in the Aguadulce groundwater. Two main aquifers can be dis-tinguished: the carbonate or lower aquifer of Triassic age, and the calcodetritic or upper aquifer of Plio-Quaternary age. Groundwaters from the latter are more saline and, assuming all chlorinity originates from seawater intrusion, the seawater contribution to their composition would be up to 7%. Nevertheless the carbonate aquifer appears not to be homogeneous: it is compartmentalised into 4 zones where dif-ferent processes explain the different groundwaters compositions. Zone 4 samples (E margin of the car-bonate aquifer) resemble those of the Plio-Quaternary aquifer, where calcite precipitation, dolomite and gypsum dissolution and some cation exchange (water–rock interaction) together with seawater–fresh-water mixing occur. In contrast, water–rock interaction predominates in zones 1 and 3 of the carbonate aquifer. Moreover, zone 2 samples, located between zones 1 and 3, are explained by water–rock interac-tion in addition to mixing with Plio-Quaternary aquifer waters. The combination of geochemical simula-tions with GIS and hydrogeochemical analyses has proven to be effective in identifying and locating the different physicochemical processes in the aquifer areas, thus improving understanding of hydrogeo-chemistry in complex aquifers.