Person:
Fernández Barrenechea, José María

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First Name
José María
Last Name
Fernández Barrenechea
Affiliation
Universidad Complutense de Madrid
Faculty / Institute
Ciencias Geológicas
Department
Mineralogía y Petrología
Area
Cristalografía y Mineralogía
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Now showing 1 - 10 of 22
  • Publication
    Análisis de la evolución en la adquisición de competencias específicas y transversales en los Grados de Geología e Ingeniería Geológica
    (2019-06-28) García Lorenzo, Mari Luz; Abati Gómez, Jacobo; Orejana García, David; Castiñeiras García, Pedro; Crespo Feo, María Elena; Piña García, Rubén; García Romero, Emilia; Granja Bruña, José Luis; López García, José Ángel; Fernández Barrenechea, José María; Arribas Mocoroa, María Eugenia; Ortega Menor, Lorena; Pérez Moreno, Elisa María; Benito Moreno, María Isabel
  • Publication
    Sources of Sr and S in Aluminum-Phosphate–Sulfate Minerals in Early–Middle Triassic Sandstones (Iberian Ranges, Spain) and Paleoenvironmental Implications for the West Tethys
    (SEPM (Society for Sedimentary Geology), 2013) Galán Abellán, Ana Belén; Alonso Azcárate, Jacinto; Newton, Robert J.; Bottrell, Simon H.; Fernández Barrenechea, José María; Benito Moreno, María Isabel; Horra del Barco, Raúl de la; López Gómez, José; Luque del Villar, Francisco Javier
    Aluminum-phosphate–sulfate (APS) minerals, formed during early diagenesis in relation to acid meteoric waters, are the main host of Sr and S in the Early–Middle Triassic continental sandstones of the Iberian Ranges (east of the Iberian Peninsula). The sources of these elements and the effects of paleoenvironmetal changes on these sources and on the formation of APS minerals during Early–Middle Triassic times, were established on the basis of Sr and S isotopic analyses. The S and Sr data (d34S V-CDT = +11 to +14% and 87Sr/86Sr = 0.7099–0.7247, respectively) can be interpreted as resulting from mixing of different sources. Strontium was sourced from the dissolution of pre-existing minerals like K-feldspar and clay minerals inherited from the source areas, causing high radiogenic values. However, the isotopic signal must also be influenced by other sources, such as marine or volcanic aerosol that decreased the total 87Sr/86Sr ratios. Marine and volcanic aerosols were also sources of sulfur, but the d34S was lowered by dissolution of pre-existing sulfides, mainly pyrite. Pyrite dissolution and volcanic aerosols would also trigger the acid conditions required for the precipitation of APS minerals. APS minerals in the study area are found mainly in the Cañizar Formation (Olenekian?–Aegian), which has the lowest 87Sr/86Sr ratios. The lower abundance of APS minerals in the Eslida Formation (Aegian–Pelsonian) may indicate change in the acidity of pore water towards more alkaline conditions, while the increased 87Sr/86Sr ratios imply decreased Sr input from volcanic activity and/or marine aerosol inputs during Anisian times. Therefore, the decrease in abundance of APS minerals from the Early to Middle Triassic and the variations in the sources of Sr and S are indicative of changes in paleoenvironmental conditions during the beginning of the Triassic Period. These changes from acid to more alkaline conditions are also coincident with the first appearance of carbonate paleosols, trace fossils, and plant fossils in the upper part of the Cañizar Formation (and more in the overlying Eslida Formation) and mark the beginning of biotic recovery in this area. The presence of APS minerals in other European basins of the Western Tethys (such as the German Basin, the Paris Basin and the southeastern France and Sardinia basins) could thus also indicate that unfavorable environmental conditions caused delay in biotic recovery in those areas. In general, the presence of APS minerals may be used as an indicator of arid, acidic conditions unfavorable to biotic colonization.
  • Publication
    Sedimentary evolution of the continental Early–Middle Triassic Cañizar Formation (Central Spain): Implications for life recovery after the Permian–Triassic crisis
    (Elsevier, 2012) López Gómez, José; Galán Abellán, Ana Belén; Horra del Barco, Raúl de la; Fernández Barrenechea, José María; Arche, Alfredo; Bourquin, Sylvie; Marzo Carpio, Mariano; Durand, Marc
    The Permian–Triassic transition (P–T) was marked by important geochemical perturbations and the largest known life crisis. Consequences of this event, as oxygen-depleted conditions and the unusual behavior of the carbon cycle, were prolonged during the Early Triassic interval delaying the recovery of life in both terrestrial and marine ecosystems. Studies on Lower Triassic sediments of continental origin, as in the case of Western Europe, are especially problematic due to the scarcity of fossils and absence of precise dating. The Cañizar Fm. is an Early–Middle Triassic unit of continental origin of the SE Iberian Ranges, E Spain. A detailed sedimentary study of this unit allows a shedding of light on some unresolved problems of the continental deposits of this age. The top of this unit is dated as early Anisian by means of a pollen association, while the age of its base is here estimated as late Smithian or Smithian–Spathian transition. Different facies associations and architectural elements have been defined in this unit. In the western and central parts of the basin, this unit shows sedimentary characteristics of fluvial deposits with locally intercalated aeolian sediments, while in the eastern part there is an alternation of both aeolian and fluvial deposits. Sedimentary structures also indicate changes in the climate conditions, mainly from arid to semiarid. Two marked arid periods when well-preserved aeolian sediments developed during early–middle Spathian and Spathian–Anisian transition. They alternated with two semiarid but more humid periods during the late Spathian and early Anisian. These conditions basically correspond with the general arid and very arid conditions described for central–western European plate during the same period of time. The Ateca–Montalbán High, in the northern border of the study basin, must have represented an important topographic barrier in the western Tethys separating aeolian dominated areas to the N and NE from fluvial dominated areas to the south. The Cañizar Fm. has been subdivided into six members (A–F) separated by seven (1–7) major bounding surfaces (MBS). These surfaces are well recognized laterally over hundred of km and they represent 104–105 My. MBS-5 is considered to be of late Spathian age and it is a clear indication of tectonic activity, represented by a mild unconformity. This event represents a change in the sedimentary characteristics (reactivation) of the unit and from here to the top of the unit are found the first signals of biotic recovery, represented by tetrapod footprints, plants, roots and bioturbation. All of these characteristics and the estimated age represented by the MBS-5 event permit this surface to be related to the coeval Hardegsen unconformity of Central–Western Europe. These first signals of biotic recovery can thus be related to an increased oxygen supply due to the new created paleogeographical corridors in the context of this tectonic activity. These biotic signals occurred 5 My after the Permian–Triassic limit crisis; a similar delay as occurred in other coeval and neighboring basins.
  • Publication
    Gossans, Slates, and the Red and Black Hamlets of Segovia (Spain): Interrelated Geological and Architectural Features
    (Springer, 2018-03) Oyarzun, Roberto; Martín Duque, José Francisco; Fernández Barrenechea, José María; López García, José Ángel
    The Sierra of Ayllón in Central Spain has a rich heritage from both the architectonic and geological perspectives. On one hand, the low lands flanking the northern side of the sierra in the Segovia Province host the so-called red hamlets and black hamlets (pueblos rojos-pueblos negros). The red and black terms derive from the traditional local building materials: Miocene red gossan breccias and Ordovician-Silurian black slates, respectively. Although these hamlets have a series of undeniable esthetic and historical values, it is the geology of this realm which accounts for most of the remarkable features in the studied zone. In this regard, near the hamlet of Madriguera, there are outstanding, unique outcrops of Miocene gossan deposits and deeply hydrothermally altered Silurian slates, forming what we have here defined as the “Madriguera Gossan Corridor” geosite. This, together with the intrinsic historical and esthetic values of the red and black hamlets, confers to the area (both at the regional and local scales) an immense scientific, educational, and touristic potential. The formal assessment of this site following the official methodology of the Geological Survey of Spain (IGME) confirms its highly valuable interest as a geosite.
  • Publication
    Shallow burial dolomitisation of Middle–Upper Permian paleosols in an extensional tectonic context (SE Iberian Basin, Spain): Controls on temperature of precipitation and source of fluids
    (Elsevier, 2011) Benito Moreno, María Isabel; Horra del Barco, Raúl de la; López Gómez, José; Fernández Barrenechea, José María; Luque del Villar, Francisco Javier; Arche, Alfredo
    This work is focused on carbonate paleosols developed in three stratigraphic sections (Landete, Talayuelas and Henarejos) of theMiddle–Late Permian Alcotas Formation in the SE Iberian Basin. The Alcotas Formation, of alluvial origin, was deposited in semi-connected half-grabens developed during the early stages of the Permian–Triassic rifting stage that affected the Iberian Basin. The studied sections were located in two of these half-grabens, the Henarejos section being much closer to the basin boundary fault than the other two sections. The mineralogy and texture of the carbonate precursor of paleosols in the three studied sections are not preserved because original carbonate is replaced by coarse crystals of dolomite and/or magnesite. Dolomite crystals are typically euhedral, displaying rhombohedral shapes and reddish luminescence, although in the Henarejos section dolomite displays non-planar boundaries and frequently saddle habit. Micas are deformed and adapted to dolomite crystals, which, in turn, are affected by stylolites, suggesting that dolomite precipitated before mechanical and chemical compaction. Carbon and oxygen isotopic compositions of dolomite fromthe three sections showdifferent values (δ13CVPDB mean values=−6.7‰,−5.5‰ and −7.5‰; δ18OVPDB mean values=−4.0‰; –5.6‰and−8.2‰, at Landete, Talayuelas and Henarejos sections, respectively). The 87Sr/86Sr ratios are similar in the three sections yielding values between 0.71391 and 0.72213. The petrographic and geochemical features of dolomite in the three studied sections suggest precipitation fromsimilar fluids and during shallow burial diagenesis. Assuming that theminimum temperature for dolomite precipitation in the Henarejos sectionwas 60 °C (as suggested by the presence of non-planar saddle habit), and that the dolomitizing fluid had similar δ18O values at the three localities, then dolomite in the Talayuelas and Landete sections precipitated at temperatures around 16 and 25 °C cooler, respectively. In addition, the δ18OVSMOW values of the water from which dolomite precipitated would have ranged between −0.3 and −2.9‰. Dolomite is partially or totally replaced by non- to dark dull luminescent magnesite in the Landete and Talayuelas sections. Magnesite crystals are affected by stylolites, indicating that it precipitated before chemical compaction. The δ13C mean values are −6.5 and −6.0‰ and the δ18OVPDB mean values are −6.7 and −7.8‰, in the Landete and Talayuelas sections, respectively. The 87Sr/86Sr ratios of magnesite are similar in both sections yielding values between 0.71258 and 0.72508. This suggests that they probably precipitated from similar fluids during progressive burial and at higher temperatures than dolomites at the same sections. Assuming thatmagnesite precipitated froma fluid with similar δ18O values in both sections, then it had to precipitate at a temperature around 8 °C higher in Talayuelas than in the Landete section. Dolomitisation and magnesite precipitation probably occurred via reflux of saline to hypersaline brines from the overlying Mid-Late Triassic Muschelkalk and/or Keuper facies. The temperatures inferred for dolomite precipitation, however, are too high for shallow burial if a normal geothermal gradient is applied. Thus, it can be inferred that salinefluidswere heated as theyflowed through the syn-sedimentary extensional faults that controlledMiddle Permian to Middle Triassic sedimentation; consequently fluidswould have been at higher temperatures near the Henarejos area, which was closer to the basin boundary fault than at the Talayuelas and Landete areas, whichwere situated further away. This contention is in agreement with recent studies which demonstrate that an important thermal event took place during Late Triassic–Early Jurassic times in the Iberian Peninsula.
  • Publication
    First report of a Middle-Upper Permian magmatism in the SE Iberian Ranges: characterisation and comparison with coeval magmatisms in the western Tethys
    (Universidad Complutense de Madrid, 2012) Lago San José, Marceliano; Horra del Barco, Raúl de la; Ubide Garralda, Teresa; Galé, Carlos; Galán Abellán, Ana Belén; Fernández Barrenechea, José María; López Gómez, José; Benito Moreno, María Isabel; Arche, Alfredo; Alonso Azcárate, Jacinto; Luque del Villar, Francisco Javier; Timmerman, Martin J.
    A multiple basic to intermediate sill is reported for the first time in the south-eastern Iberian Ranges. It is composed of several tabular to irregular levels intercalated within the fluvial sediments of the Alcotas Formation (Middle-Upper Permian). The sill could represent the youngest Paleozoic subvolcanic intrusion in the Iberian Ranges. The igneous rocks are classified as basaltic andesites. They show a subophitic microstructure constituted by plagioclase (An62 – An6), augite (En48Wo44Fs7 –En46Wo39Fs15), pseudomorphosed olivine, minor amounts of oxides (magnetite and ilmenite)and accessory F-apatite. According to the mineralogy and whole-rock composition, their geochemical affinity is transitional from subalkaline to alkaline. Radiometric dating of the sill is not feasible due to its significant alteration. Field criteria, however, suggest an emplacement coeval to the deposition of the Alcotas Formation (Middle-Upper Permian). This hypothesis is supported by the transitional affinity of these rocks, similar to other Middle-Upper Permian magmatisms in the western Tethys, e.g., from the Pyrenees. Taking into account their isotopic signature (εSr: -6.8 to -9.2; εNd:+1.7 to +8.3), an enriched mantle source with the involvement of a HIMU component has been identified. This interpretation is supported by the trace element contents. Some of these HIMU characteristics have been recognised in the Middle-Upper Permian magmatisms of the Central Pyrenees (Anayet Basin) and the High Atlas (Argana Basin). However, none of these source features are shared with other Middle-Upper Permian magmatisms of the western Tethys (Catalonian Coastal Ranges, Corsica-Sardinia and southern France), nor with the Lower Permian magmatism of the Iberian Ranges. These differences support the presence of a heterogeneous mantle in the western Tethys during the Permian.
  • Publication
    Vein graphite deposits: geological settings, origin, and economic significance
    (Springer Science Business Media, 2014) Luque del Villar, Francisco Javier; Huizenga, Jan-Marten; Crespo Feo, Elena; Wada, Hideki; Ortega Menor, Lorena; Fernández Barrenechea, José María
    Graphite deposits result from the metamorphism of sedimentary rocks rich in carbonaceous matter or from precipitation from carbon-bearing fluids (or melts). The latter process forms vein deposits which are structurally controlled and usually occur in granulites or igneous rocks. The origin of carbon, the mechanisms of transport, and the factors controlling graphite deposition are discussed in relation to their geological settings. Carbon in granulite-hosted graphite veins derives from sublithospheric sources or from decarbonation reactions of carbonate-bearing lithologies, and it is transported mainly in CO2-rich fluids from which it can precipitate. Graphite precipitation can occur by cooling, water removal by retrograde hydration reactions, or reduction when the CO2-rich fluid passes through relatively low-fO2 rocks. In igneous settings, carbon is derived from assimilation of crustal materials rich in organic matter, which causes immiscibility and the formation of carbon-rich fluids or melts. Carbon in these igneous-hosted deposits is transported as CO2 and/or CH4 and eventually precipitates as graphite by cooling and/or by hydration reactions affecting the host rock. Independently of the geological setting, vein graphite is characterized by its high purity and crystallinity, which are required for applications in advanced technologies. In addition, recent discovery of highly crystalline graphite precipitation from carbonbearing fluids atmoderate temperatures in vein depositsmight provide an alternative method for the manufacture of synthetic graphite suitable for these new applications.
  • Publication
    Key factors controlling massive graphite deposition in volcanic settings: an example of a self-organized critical system
    (Geological Society of London., 2012) Luque del Villar, Francisco Javier; Ortega Menor, Lorena; Fernández Barrenechea, José María; Huizenga, Jan-Marten; Millward, David
    Massive graphite deposition resulting in volumetrically large occurrences in volcanic environments is usually hindered by the low carbon contents of magmas and by the degassing processes occurring during and after magma emplacement. In spite of this, two graphite deposits are known worldwide associated with volcanic settings, at Borrowdale, UK, and Huelma, Spain. As inferred from the Borrowdale deposit, graphite mineralization resulted from the complex interaction of several factors, so it can be considered as an example of self-organized critical systems. These factors, in turn, could be used as potential guides for exploration. The key factors influencing graphite mineralization in volcanic settings are as follows: (1) an unusually high carbon content of the magmas, as a result of the assimilation of carbonaceous metasedimentary rocks; (2) the absence of significant degassing, related to the presence of sub-volcanic rocks or hypabyssal intrusions, acting as barriers to flow; (3) the exsolution of a carbon-bearing aqueous fluid phase; (4) the local structural heterogeneity (represented at Borrowdale by the deep-seated Burtness Comb Fault); (5) the structural control on the deposits, implying an overpressured, fluid-rich regime favouring a focused fluid flow; (6) the temperature changes associated with fluid flow and hydration reactions, resulting in carbon supersaturation in the fluid, and leading to disequilibrium in the system. This disequilibrium is regarded as the driving force for massive graphite precipitation through irreversible mass-transfer reactions. Therefore, the formation of volcanic-hosted graphite deposits can be explained in terms of a self-organized critical system.
  • Publication
    Microstructure and mineralogy of lightweight aggregates produced from washing aggregate sludge, fly ash and used motor oil
    (Elsevier Applied Science, 2010) González Corrochano, B.; Alonso Azcárate, Jacinto; Rodas, Magdalena; Luque del Villar, Francisco Javier; Fernández Barrenechea, José María
    The microstructures and mineralogical compositions of lightweight aggregates (LWAs) manufactured with washing aggregate sludge (WS), fly ash (FA) and used motor oil (UMO) have been studied. Most LWAs with WS and FA exhibited an external layer and a glassy core with isolated pores. LWAs with WS and UMO did not present external shells or signs of bloating. Iron oxides, within the external layer, and pyrrhotite, in the inner glass, were observed. The mineralogical analyses revealed the neo-formation of plagioclase and pyroxene, along with minor gehlenite. Some relationships could be established: (i) the presence of larger pores is related to a decrease in the dry particle density values, (ii) when the LWA lacks the external layer, the water absorption values were dependent on the size and amount of each type of pore (open or closed), and (iii) the neo-formation of Ca-plagioclase and the consumption of quartz improved the compressive strength values.
  • Publication
    Quantifying aluminium phosphate–sulphate minerals as markers of acidic conditions during the Permian–Triassic transition in the Iberian Ranges, E Spain
    (Elsevier Science B.V., Amsterdam., 2016-07) Borruel Abadía, Violeta; Fernández Barrenechea, José María; Galán Abellán, Ana Belén; Alonso Azcárate, Jacinto; Horra del Barco,, Raúl, De la; Luque del Villar, Francisco Javier; López Gómez, José
    In this paper, a method based on element mapping of randomly selected areas of thin sections on electron microprobe is proposed to quantify the relative contents of strontium-rich hydrated aluminium phosphate-sulphate (APS) minerals in siliciclastic continental sedimentary rocks. The main problems for these minerals to be quantified are related to their small size, low concentrations, and optical properties. By comparing the element maps obtained for the rocks in the study area of the Iberian Ranges (E Spain) with the results of whole rock analysis and with factors indicating the presence of life (bioturbation, palaeosols, and macro-plant remains), it has been possible to correlate relatively high levels of APS minerals in the first sedimentary record (Cañizar Formation) after the Permian–Triassic boundary, with the lack of living organisms. The APS are related to early diagenetic phases precipitated at low pH conditions and are therefore markers of formation in an acidic environment. Our findings suggest a long period of sustained acidic conditions followed by an environmental change linked with the recovery of life and with lower APS mineral contents. This change is detected at the top of the Cañizar Formation, at the end of the Sphatian. The method proposed could be used as a tool to address the environmental changes that took place during the Permian–Triassic transition in continental environments