Person: Benito Moreno, María Isabel
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First Name
María Isabel
Last Name
Benito Moreno
Affiliation
Universidad Complutense de Madrid
Faculty / Institute
Ciencias Geológicas
Department
Geodinámica, Estratigrafía y Paleontología
Area
Estratigrafía
Identifiers
9 results
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Item Calcareous algae (dasycladales and charophytes), essential for the sedimentological interpretation of ancient coastal-lakes systems. The Barremian-Aptian Leza Fm., Cameros Basin, N Spain(Third circular. Program : 29th IAS Meeting of Sedimentology. Sedimentology in the Heart of the Alps. Schlaming, September, 10-13 2012, 2012) Suárez González, Pablo; Martín Closas, C.; Quijada, Isabel Emma; Benito Moreno, María Isabel; Mas Mayoral, José RamónItem Textbook example of tectonically controlled carbonate sedimentation at the active margin of a rift basin: the Leza Fm (Early Cretaceous, Cameros Basin, Spain)(Abstracts / 28th IAS Meeting of Sedimentology, Zaragoza, Julio 5-8 2011, 2011) Suárez González, Pablo; Quijada, Isabel Emma; Benito Moreno, María Isabel; Mas Mayoral, José Ramón; Omodeo Salé, S.; Bádenas, Beatriz; Aurell, Marcos; Alonso-Zarza, Ana MaríaItem Nuevas aportaciones sobre la influencia marina y la edad de los carbonatos de la Fm Leza en el sector de Préjano (SE de La Rioja). Cretácico Inferior, Cuenca de Cameros(Geogaceta, 2010) Suárez González, Pablo; Quijada, Isabel Emma; Mas Mayoral, José Ramón; Benito Moreno, María IsabelThe Cameros Basin is a rift basin whose sedimentary infill is essentially continental with some episodes of marine influence. The Leza Fm carbonates (Enciso Gr, Barremian-Aptian) correspond to one of these episodes and their depositional environment has been described as lacustrine with occasional marine incursions. A detailed facies analysis of these carbonates in the Préjano area has led to the conclusion that the depositional environment of the Leza Fm in this area is in fact a system of coastal-lakes filled with brackish water as shown by the abundance of marine microfossils (Dasycladales algae and foraminifera) coexisting with continental microfossils (charophytes). The age of the Dasycladales found in the studied area is Barremian-Albian and thus it confirms the Barremian-Aptian age proposed for the Leza Fm and the Enciso Gr.Item Micro-Sized Dolomite Inclusions in Ferroan Calcite Cements Developed During Burial Diagenesis of Kimmeridgian Reefs, Northern Iberian Basin, Spain.(Journal of sedimentary research, 2006) Benito Moreno, María Isabel; Lohmann, Kyger C.; Mas Mayoral, José RamónBurial diagenesis of the Upper Jurassic Torrecilla Reef Complex is recorded by a complex paragenetic sequence initiated with emplacement of ferroan calcite cements and followed by the precipitation of ferroan saddle dolomite. Ferroan calcite cements contain micro-sized dolomite inclusions (MDIs). Elemental and isotopic compositions of MDIs are virtually indistinguishable from those of ferroan saddle dolomite cements. In contrast to other scenarios for the formation of microdolomite inclusions that invoke either a magnesian calcite precursor or incomplete dedolomitization, the paragenetic relations of MDIs to their host ferroan calcite and their geochemical composition implies formation by fine-scale burial replacement of ferroan calcite by fluids associated with the emplacement of ferroan saddle dolomite. Petrographic observations and mass-balance considerations suggest that it is unlikely that Fe and Mg incorporated into ferroan dolomite could have been derived from the cannibalization of the reefal host rock. Rather, dolomitizing fluids were likely associated with the hydrothermal, low-grade metamorphic event that affected the Cameros Basin during the middle to Late Cretaceous. Interaction of these fluids with preexisting burial cements produced MDIs in the ferroan calcites.Item Eustatic versus tectonic control in an intraplate rift basin (Leza Fm, Cameros Basin). Chronostratigraphic and paleogeographic implications for the Aptian of Iberia(Journal of iberian geology, 2013) Suárez González, Pablo; Quijada, Isabel Emma; Benito Moreno, María Isabel; Mas Mayoral, José RamónThe Leza Formation is a carbonate unit of the northern Cameros Basin (N Spain) with controversial age, stratigraphic position, and sedimentological interpretation. It was deposited in a series of fault-bounded tectonic depressions along the northern margin of the basin. The Leza Fm overlies and changes laterally to the siliciclastic Jubera Fm, and the thickness of both units is also controlled by faults. Although the Leza Fm has been traditionally interpreted as lacustrine with sporadic marine incursions, detailed sedimentological analysis reveals new and very abundant evidences of marine influence: sedimentary structures of tidal origin, common marine fossils (dasycladales and foraminifers), and homogeneous populations of porocharacean charophytes, indicative of brackish conditions. Thus, this unit is interpreted as deposited in a system of coastal-wetlands with both fresh-water and sea-water influence, laterally related with the alluvial deposits of the Jubera Fm and the fluvio-lacustrine deposits of the Enciso Gr towards the centre of the basin. Using the chronostratigraphic ranges of the marine fossils and the lateral relationship with adjacent units, the Leza Fm is confirmed as part of a depositional sequence late Barremian - early Aptian in age. Furthermore, a transgressive trend is defined in the Leza Fm, which is compared with the eustatic evolution of the neighbouring Basque-Cantabrian, Iberian and Pyrenean marine basins, allowing correlation of the upper part of this unit with the widespread eustatic maximum of the middle-upper part of the early Aptian. This eustatic influence provided additional accommodation space to that created by tectonics. These data from the Cameros Basin are contrasted with a thorough compilation of paleogeographic data, showing that, during the early Aptian transgression, marine influence was likely to reach the northern Cameros Basin, not only coming from the SE Iberian Basin, as previously interpreted, but also from the NW Basque-Cantabrian Basin. This resulted in a probable link between Boreal and Tethyan marine realms [RESUMEN] La Formación Leza es una unidad carbonática del norte de la Cuenca de Cameros (N España), cuya edad, posición estratigráfica e interpretación sedimentológica son controvertidas. Se depositó en una serie de cubetas tectónicas limitadas por fallas a lo largo del borde norte de la cuenca. La Fm Leza yace sobre y pasa lateralmente a los depósitos siliciclásticos de la Fm Jubera, estando el espesor de ambas unidades también controlado por fallas. Pese a que la Fm Leza ha sido tradicionalmente interpretada como lacustre con incursiones marinas esporádicas, el análisis sedimentológico detallado revela nuevas evidencias muy abundantes de influencia marina: estructuras sedimentarias de origen mareal, y habituales fósiles marinos (dasycladales y foraminíferos), así como poblaciones homogéneas de carofitas porocaráceas, que indican medios salobres. Esta unidad se interpreta como formada en un sistema de humedales costeros con influencia tanto de agua dulce como de agua marina, relacionado lateralmente con los depósitos aluviales de la Fm Jubera y con los depósitos fluvio-lacustres del Gr Enciso hacia el centro de la cuenca. Usando los rangos cronoestratigráficos de los fósiles marinos y las relaciones laterales con unidades adyacentes, se confirma la pertenencia de la Fm Leza a la secuencia deposicional de edad Barremiense superior - Aptiense inferior. Además, se define una tendencia transgresiva en la Fm Leza, que al ser comparada con la evolución eustática de las cuencas marinas coetáneas, Vasco-Cantábrica, Ibérica y Pirenaica, permite la correlación de la parte superior de esta unidad con el máximo eustático generalizado de la parte media-superior del Aptiense inferior. Esta influencia eustática produjo un espacio de acomodación adicional al producido por la tectónica. Estos datos de la Cuenca de Cameros son contrastados con una recopilación exhaustiva de datos paleogeográficos, mostrando que durante la transgresión del Aptiense inferior, la influencia marina probablemente alcanzó el norte de la Cuenca de Cameros no sólo desde la Cuenca Ibérica al SE, como ha sido interpretado previamente, sino también desde la Cuenca Vasco-Cantábrica al NO. Esto produciría la probable unión entre los ámbitos del Océano Boreal y del Tetis.Item New insights on stratigraphy and sedimentology of the Oncala Group (eastern Cameros Basin): implications for the paleogeographic reconstruction of NE Iberia at Berriasian times(Journal of iberian geology, 2013) Quijada, Isabel Emma; Suárez González, Pablo; Benito Moreno, María Isabel; Mas Mayoral, José RamónThe Berriasian Oncala Group of the eastern Cameros Basin is a key element for the paleogeographic reconstruction of NE Iberia during this period of time, due to its intermediate position between the Basque-Cantabrian, southern Iberian, and Pyrenean Basins. The Oncala Group, which comprises up to 2500 m of sediments, consists of siliciclastic deposits in western areas of the basin, which pass gradually eastwards and upwards to carbonate-evaporitic deposits. The siliciclastic deposits consist of an alternation of laterally extensive laminae of siliciclastic mudstone and sandstone, and meander loop bodies. The carbonate deposits are made up of an alternation of laminae of carbonate mudstone and pseudomorphs after gypsum, interbedded with shales and carbonate breccias. These deposits had been traditionally interpreted as formed in fluvial and alluvial systems, and laterally related lakes, but recent and new sedimentological data discussed in this paper suggest that they were deposited in broad, siliciclastic tidal flats, laterally associated with a fluvial system to the west, and with shallow, coastal, carbonate-sulphate water bodies to the east. The development of these coastal environments in the Oncala Group indicates that a wide, shallow, coastal embayment was developed in the eastern Cameros Basin during the Berriasian. This new paleoenvironmental interpretation makes necessary a revision of the paleogeographic reconstruction of this area of Iberia during the Berriasian because it implies that the connection of the Cameros Basin with marine areas was much more important than previously considered. The presence of very similar facies associations in the Basque-Cantabrian Basin, which include siliciclastic tidal and lagoonal deposits in the western areas, and evaporites and carbonates of restricted marine environments in the eastern areas, the similar sulphur isotope compositions of the sulphates of the Basque-Cantabrian and Cameros Basins, and the similar vertical evolution of the Berriasian deposits of both basins, suggest that the Cameros Basin was connected with marine and transitional areas of the Basque-Cantabrian Basin during Berriasian times. Nevertheless, a connection with the southern Iberian Basins, which also contain siliciclastic and carbonate tidal deposits, cannot be excluded.Item Can stromatolite lamination be explained by present-day marine examples? An answer from the Cretaceous Leza Fm (Cameros Basin, Spain)(Abstracts / 28th IAS Meeting of Sedimentology, Zaragoza, Julio 5-8, 2011) Suárez González, Pablo; Quijada, Isabel Emma; Benito Moreno, María Isabel; Mas Mayoral, José Ramón; Riding, R.; Bádenas, Beatriz; Aurell, Marcos; Alonso-Zarza, Ana MaríaItem Depositional depth of laminated carbonate deposits: Insights from the lower Cretaceous Valdeprado formation (Cameros Basin, Northern Spain)(Journal of sedimentary research, 2013) Quijada, Isabel Emma; Suárez González, Pablo; Benito Moreno, María Isabel; Mas Mayoral, José RamónThe Lower Cretaceous (Berriasian) Valdeprado Formation (Cameros Basin, northern Spain) contains more than 900 m of laminated carbonates and pseudomorphs after sulfates. Traditionally, many sedimentary packages of different ages and lithologies have been interpreted as deep-water deposits based essentially on the abundance of laminations and the absence of subaerial exposure features. In contrast, the Valdeprado Formation provides an example of a shallow-water deposit dominated by laminations with scarce evidence of subaerial exposure, and gives criteria to solve the challenge of distinguishing shallow-water and deep-water, ancient laminated deposits. The two most abundant facies all along the Valdeprado Formation are: a) parallel-laminated limestone, formed by alternating carbonate mudstone and calcite and quartz pseudomorphs after displacive gypsum, and b) graded-laminated limestone, consisting of quartz, mica, ostracodes, and pseudomorphs after detrital gypsum grains at the base, which changes gradually upwards to carbonate mudstone. Parallel-laminated limestone and graded-laminated limestone could have been deposited in either deep or shallow environments as a result of salinity fluctuations driven by alternation of flooding and evaporation and by sediment resuspension processes, respectively. Subaerial exposure features, such as desiccation mudcracks, are scarce in most of the succession, except in a few meter-scale stratigraphic intervals where they are very abundant. Interestingly, in these intervals desiccation cracks are present at the tops of several successive laminae (up to 25 mudcracked laminae per meter of deposit), indicating that, at least during those periods of time, deposition occurred in shallow water bodies that were desiccated frequently. In the upper part of the stratigraphic section, parallel-laminated and graded-laminated limestones are associated with current-ripple and wave-ripple cross-laminated arenites, and ostracode mudstone to wackestone with centimeter-size pseudomorphs after lenticular gypsum, and abundant desiccation mudcracks and tepees, which also suggest sedimentation in shallow-water environments. Moreover, the laminated carbonates display continuous, parallel layering, and the same facies along the 40-km-long outcropping area. These deposits are directly interbedded with, and pass laterally to, siliciclastic sandy–muddy flat deposits in the western area of the basin, without clinoforms, slump structures, or slide masses in between. All of these features suggest deposition in shallow, perennial carbonate–sulfate water bodies and their peripheral mudflats, developed in a flat-bottomed basin with no marked gradients.Item 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(Journal of sedimentary research, 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 JavierAluminum-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.