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
48 results
Search Results
Now showing 1 - 10 of 48
Item Belemnite taphonomy (Upper Jurassic, Western Tethys) Part I: Biostratinomy(Palaeogeography, palaeoclimatology, palaeoecology, 2012) Benito Moreno, María Isabel; Reolid, MatíasA detailed taphonomic analysis was performed on 188 belemnites and 56 thin sections from the Pozo Cañada section (External Prebetic), as well as 101 belemnites and 31 thin sections from the Río Segura (Internal Prebetic), both from the Upper Oxfordian–Lower Kimmeridgian. This manuscript is focused on biostratinomic features and a second part is focused on fossildiagenetic aspects. The belemnites correspond to Hibolithes and, less commonly, Belemnopsis. Biostratinomic features, including size, fragmentation, corrasion, microboring and encrustation were analysed in each specimen, using petrographic (conventional, cathodoluminescence, epifluorescence and scanning electron microscopy) techniques. Fragmentation affects the phragmocone and the rostrum cavum, and is usually transversal and rarely longitudinal through the apical line. Isolated fragments of epirostrum are common. Corrasion produces irregular surfaces. Microborings are very common, represented by: a) Fungal hyphae; b) Fascichnus dactilus-like and Scolecia filosa-like borings (cyanobacteria); c) Entobia (sponges), d) large microborings with Y-shaped branching (diameter 100–500 μm) subparallel to rostrum surface; e) large cylindrical to ellipsoidal borings related to cirripeds; and f) Palaeconchocelis starmachii (rhodophyte). Microbes and sessile foraminifera (Vinelloidea, Bullopora, Tolypammina, Thurammina, Placopsilina and Subdelloidina) are the main encrusters. Microbial films are composed of dense micrite or clotted-peloidal microfabrics. The biostratinomic features analysed in the belemnite rostra are clearly influenced by the lithofacies and shelf setting. The intensity of corrasion, microborings and encrustation, by indicating time-exposure, help establish which lithofacies shows the highest sedimentation rate. The belemnites from Internal Prebetic lithofacies—that is, the outer shelf deposits (lumpy limestone and lumpy-oncolitic limestone)—present high values of corrasion, microboring and encrustation, thereby indicating long-time exposure. In sharp contrast, belemnites from the lithofacies of the External Prebetic represent deposition in mid-shelf environments (spongiolithic limestone, spongiolithic marl–peloidal limestone, and marl–limestone rhythmite) featuring higher clay content.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 Comparison of the Calcareous Shells of Belemnitida and Sepiida: Is the Cuttlebone Prong an Analogue of the Belemnite Rostrum Solidum?(Minerals, 2020) Benito Moreno, María Isabel; Reolid, MatíasThe microstructure of the rostrum solidum of Jurassic belemnites is compared with that of Sepia cuttlebones, in order to examine possible convergences in their style of growth. For this study, transmitted and polarized light, cathodoluminescence, epifluorescence, scanning electron and backscattered electron microscopy have been employed. Despite differences in the primary mineralogy of the studied belemnites and sepiids, calcite and aragonite, respectively, many similarities have been observed between the microstructure of the belemnite rostra and the prong of Sepia cuttlebone: (1) In both, crystals start growing from successive spherulites, from which crystals emerge radially towards the apex and the external walls, displaying internally micro-fibrous texture. (2) Both display concentric growth layering, comprising an alternation of organic-rich and organic-poor layers, which, in turn, is traverse by the radially-arranged micro-fibrous crystals. (3) The highest organic matter content and porosity have been observed along the apical area of the Sepia prong, similarly to that interpreted for belemnite rostra. The strong convergences observed suggest that the growth of belemnites occurred similarly to that of the prong of sepiids and that the Sepia prong is the analog of the belemnite rostrum. Additionally, non-classical crystallization processes are proposed to be involved in the formation Sepia endoskeleton.Item Belemnite taphonomy (Upper Jurassic, Western Tethys) part II: Fossil–diagenetic analysis including combined petrographic and geochemical techniques(Palaeogeography, palaeoclimatology, palaeoecology, 2012) Benito Moreno, María Isabel; Reolid, MatíasFossil–diagenetic features were analyzed on 56 belemnite rostra from the Pozo Cañada section (External Prebetic), as well as 31 belemnite rostra from the Río Segura (Internal Prebetic), both from the Upper Oxfordian–Lower Kimmeridgian. They mainly correspond to Hibolithes and, secondarily to Belemnopsis. Fossil–diagenetic processes were analyzed in each specimen, using petrographic (conventional, cathodoluminescence, epifluorescence and scanning electron microscopy) and geochemical (elemental and stable isotopes) techniques. The most common fossil–diagenetic processes are dissolution, calcite cementation, and recrystallization of the apical zone and outer growth rings of belemnite rostra. These processes may appear enhanced by fracturing and stylolite formation. Petrographic study also reveals that the alternation of cloudy and clear concentric growth areas displayed by many belemnite rostra corresponds to an early diagenetic feature in origin. However, an original concentric growth pattern is also observed under epifluorescent microscopy and BSEM. This growth pattern fits with changes in the Mg and S content of the rostra. Although fossil–diagenetic processes typically make specimens non-suitable for paleoenvironmental interpretations, microsampling of petrographically altered and non-altered areas from the same specimens, performed directly from thin sections after petrographic study, allowed us to obtain excellent geochemical results suitable for paleoenvironmental interpretations. These geochemical analyses moreover demonstrates that caution should be taken if elemental analyses are used as the most significant criteria for discriminating diagenetically altered and non-altered belemnite samples.Item Do stromatolites Need Tides to trap Oodis? insights from the Coastal-Lake carbonates of the Leza FM (Early Cretaceous, N Spain)(Abstract book / Tidalites 2012: 8th International Conference on tidal environments, Caen, France, july 31- august 2, 2012) Suárez González, Pablo; Quijada, Isabel Emma; Benito Moreno, María Isabel; Mas Mayoral, José RamónItem Evolution of an intra-plate rift basin: the Latest Jurassic-Early Cretaceous Cameros Basin (Northwest Iberian Ranges, North Spain)(Geo-guías, Post-Meeting Field trips 28th IAS Meeting, Zaragoza, 2011) Mas Mayoral, José Ramón; Benito Moreno, María Isabel; Arribas Mocoroa, José; Alonso Millán, Ángela; Arribas Mocoroa, María Eugenia; Lohmann, K.C.; González Acebrón, Laura; Hernán, J.; Quijada, Isabel Emma; Suárez González, Pablo; Omodeo Salé, S.; Arenas, Concha; Pomar, Luis; Colombo, FerránItem 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 Ichnofauna from coastal meandering channel systems (Upper Cretaceous Tremp Formation, South-Central Pyrenees, Spain): delineating the fluvial-tidal transition(Journal of paleontology, 2016) Díez Canseco, Davinia; Buatois, Luis A.; Mángano, M. Gabriela; Díaz Molina, Margarita; Benito Moreno, María IsabelThe Upper Cretaceous “redbeds” of the lower Tremp Formation (South-Central Pyrenees, Spain) contains an ichnofauna consisting of Taenidium barretti, Taenidium bowni, Loloichnus isp., Arenicolites isp., Planolites isp., and Palaeophycus isp. This ichnofauna occurs in deposits formed in tide-influenced meander loops and their associated overbank mudflats. Evaluation of the taphonomic controls on the Tremp ichnofauna shows that (1) two morphotypes of Taenidium barretti are controlled by the substrate consistence, (2) Arenicolites may be enlarged by erosion processes, and (3) Taenidium barretti and Planolites isp. are not the same ichnotaxa showing different types of preservation. The meniscate fill in Taenidium barretti suggests that this structure was produced by deposit feeders. The Tremp ichnofauna is grouped into two trace-fossil assemblages, a depauperate subaquatic monospecific Planolites suite and an assemblage representing the Scoyenia Ichnofacies.Trace-fossil distribution reflects paleoenvironmental changes in the meandering channels along the stratigraphic section with the Planolites suite in the lowermost part of the lower interval and the Scoyenia Ichnofacies in the middle and upper intervals. The lowermost suite may be likely formed seaward of the maximum salinity limit, under extreme brackish-water conditions, whereas the Scoyenia Ichnofacies records a freshwater assemblage that was formed landward of the maximum salinity limit, reflecting deltaic progradation.Item Influencia del Keuper y de la estructuración tardivarisca en la arquitectura de las unidades sin-extensionales del borde norte de la Cuenca de Cameros(Geotemas, 2016) Suárez González, Pablo; Benito Moreno, María Isabel; Mas Mayoral, José Ramón; Quijada, Isabel Emma; Campos Soto, SoniaEste trabajo aporta nuevos datos cartográficos y sedimentológicos para aclarar la controvertida evolución tectónica extensional de la Cuenca de Cameros (N de España). La geometría actual del borde norte de la cuenca representa la continuación de lineaciones tardivariscas NO-SE y SO-NE reconocidas en la Cuenca Vasco-Cantábrica, a lo largo de las cuales se produjo una importante tectónica salina sin-extensional. En la zona de estudio, la distribución irregular de los depósitos plásticos del Keuper es interpretada aquí como debida a una movilización sin-extensional. De este modo, la estructuración tardivarisca del basamento y las movilizaciones de Keuper, asociadas a ella, permiten explicar la arquitectura y distribución de las unidades sin-extensionales del relleno de la cuenca.Item Sedimentology of ancient coastal wetlands: insights from a cretaceous multifaceted depositional system(Journal of sedimentary research, 2015) Suárez González, Pablo; Quijada, Isabel Emma; Benito Moreno, María Isabel; Mas Mayoral, José RamónCoastal wetlands are prominent modern environments widely studied in geomorphology and ecology, but the term ‘‘coastal wetland’’ is still barely used for the sedimentological classification of ancient deposits. The depositional system studied here (Leza Formation, Cameros Basin, Early Cretaceous, N Spain) includes diverse carbonate and clastic facies deposited at the sea–land transition, and is an illustrative example of the wide array of sedimentary environments that may occur in coastal wetlands systems. The studied system was composed mainly of carbonate water bodies whose salinity ranged from fresh to brackish and near-marine, and which had variable input of clastic material due to their lateral connection with alluvial fans. In addition, the system also included carbonate water bodies with stronger marine influence, tide-influenced oolitic areas, and relatively restricted evaporative settings. The deposits of all these environments occur alternating with each other throughout a unit 30–280 m thick, and they range from continental to marine conditions in a relatively small area (approximately 10 km 3 30 km). Thus, this sedimentological study of the Leza Fm provides an ideal opportunity to investigate challenging ancient deposits with both continental and marine features. Comparison with other modern and ancient coastal settings allows the conclusion that ‘‘coastal wetland’’ may be the most accurate sedimentological classification for the Leza Fm, since it was not part of a major coastal system (e.g., delta or estuary). A series of general sedimentological characteristics of coastal wetland deposits are gathered from the Cretaceous case study and from the modern and ancient examples examined. These characteristics include: predominance of shallow-water facies; common subaerial exposure and edaphic features; great variety of interrelated continental, transitional, and marine environments with contrasting hydrodynamic and hydrochemical conditions; and low-diversity biotic communities, including both continental and marine fossils, as well as fossils of ambiguous affinities.