Person: Mas Mayoral, José Ramón
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First Name
José Ramón
Last Name
Mas Mayoral
Affiliation
Universidad Complutense de Madrid
Faculty / Institute
Ciencias Geológicas
Department
Area
Estratigrafía
Identifiers
9 results
Search Results
Now showing 1 - 9 of 9
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 Sedimentary evolution and provenance of the Last Fluvial episodes of the Cameros Basin (Lower Cretaceous, North Spain)(Fluvial Sedimentology. Abstract: The 8th International Conference on Fluvial Sedimentology (8th ICFS) will be hosted by the Delft University of Technology during August 7-12, 2005., 2005) Najarro, María; Arribas Mocoroa, José; Mas Mayoral, José Ramón; Ochoa, M.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.Item Origin and significance of lamination in Lower Cretaceous stromatolites and proposal for a quantitative approach(Sedimentary geology, 2014) Suárez González, Pablo; Quijada, Isabel Emma; Benito Moreno, María Isabel; Mas Mayoral, José RamónStromatolite lamination is typically defined as alternation of dark and light laminae. Study of Lower Cretaceous stromatolites fromthe Leza Fm(N Spain) supports this statement, but recognises additional complexities in lamination that have implications for interpreting accretion processes. These stromatolites are partial analogues of present-day coarse-grained carbonate stromatolites in the Bahamas and Shark Bay (Australia) that mainly form by trapping and binding carbonate sand. The Leza examples contain both grain-rich and micrite-rich laminae with scarce particles, suggesting that they accreted both by trapping and not trapping grains. Lamination in modern and ancient coarse-grained stromatolites is commonly defined by thinmicritic crusts that formed during interruptions in accretion and separate contiguous grainy laminae (repetitive lamination). Leza examples also contain these thin hiatal crusts and locally showrepetitive lamination, but their conspicuous macroscopic lamination is defined by thicker alternating grain-rich and micrite-rich laminae (alternating lamination). This indicates that, although hiatuses in accretion occurred, change in accretion process was the main cause of macroscopic lamination. These differences in accretion processes and lamination styles between Leza examples and modern coarse-grained stromatolites may reflect differences in their environmental settings. Modern examples occur in shallow marine tidal environments, whereas Leza Fm coarse-grained stromatolites developed in ideinfluencedwater-bodies in coastal-wetlands that experienced fluctuations inwater salinity and hydrochemistry. Analysis of lamina-thickness in these Cretaceous stromatolites and similar published examples provides a quantitative approach to the processes that underlie stromatolite lamination.Item A coastal paradise for Aptian microbialites (Early Cretaceous, N Spain(11th Workshop on Alpine Geological Studies & 7th IFAAn, September, 7-14, 2013) Suárez González, Pablo; Quijada, Isabel Emma; Benito Moreno, María Isabel; Mas Mayoral, José Ramón; Riding, R.Item Diagénesis temprana meteórica de la Formación Torrecilla en Cameros (Kimmeridgiense inferior; Preriff) y de los carbonatos de la base del GrupoTera (Tithónico; Sinriff) en el sector de Soria. Cuenca de Cameros. N. España(Geotemas, 2001) Benito Moreno, María Isabel; Mas Mayoral, José RamónThe last marine Jurassic episode of sedimentation in the Soria area corresponds to the deposition of the Torrecilla en Cameros Fm. during Lower Kimmeridgian. This formation is mainly composed by sandstones, coral reefs and oolites, and is overlain by the Tithonian continental sediments (clays, conglomerates, sandstone and lacustrine and palustrine limestones) of the Âgreda Afm. (Tera Croup). The limit between both units corresponds to an edaphic surface overlain by a ferruginous crust. Associated to the subaerial exposure of the Torrecilla en Cameros Fm. during Upper Kimmeridgian, and prior to the deposition of Âgreda Afm., marine aragonite was dissolved. Both primary and secondary porosity were then cemented by meteoric non-ferroan calcite. Isotopic composition of this calcite ranges between -3.7 and -7.3 ‰ in δ13C and -4.7 and -5.9 ‰ in δ18. Carbonates situated at the base of the Âgreda Afm. correspond to some layers of palustrine limestones as well as conglomerates, basically composed by lacustrine and oolitic pebbles. The isotopic composition of both palustrine limestones and limestone pebbles is very similar to the isotopic composition of the meteoric cement precipitated in the Torrecilla en Cameros Fm. This suggests that the climatic conditions and the isotopic composition of the meteoric waters were very similar during precipitation of meteoric calcite in both Torrecilla en Cameros Fm. and the base of the Âgreda Afm.Item Controls destroying a fluvial reservoir in Cameros Basin, Spain(Fluvial Sedimentology. Abstract: The 8th International Conference on Fluvial Sedimentology (8th ICFS) will be hosted by the Delft University of Technology during August 7-12, 2005., 2005) Ochoa, M.; Arribas Mocoroa, José; Mas Mayoral, José Ramón; Najarro, MaríaItem Control tectónico e influencia del eustatismo en la sedimentación del Cretácico inferior de la cuenca de Los Cameros(Cuadernos de geología ibérica, 1993) Alonso Zarza, Ana María; Mas Mayoral, José RamónLa sedimentación durante el Jurásico terminal y el Cretácico inferior en la Cuenca de Los Cameros se desarrolla en cuatro Secuencias deposicionales de forma tal que todas comienzan con facies siliciclásticas fluviales y terminan (excepto la IV) con facies calcáreas de origen lacustre. El control tectónico durante la sedimentación es muy claro y se manifiesta de diversas maneras y escalas, pero el control eustático también parece jugar un papel importante. Para estudiar estos factores se ha analizado con detalle una de las etapas lacustres en la cuenca, concretamente la que termina la Secuencia deposicional III (Barremiense - Aptiense), y se ha elegido la franja mas nororiental de la misma. En esta unidad (la Formación Calizas de Leza), y en ese sector, se ha realizado un análisis sedimentológico detallado identificando cuatro grupos de facies que corresponden a la sedimentación en lagos carbonáticos costeros, con etapas de influencia marina neta. También se ha reconstruido la cuenca para la etapa Barremiense - Aptiense, que formaba una gran rampa basculada hacia el NE, en cuyo borde nororiental se desarrollaba la sedimentación lacustre-costera que nos ocupa. La influencia marina proviene del SE, del Tetis, ya que durante esa etapa en el resto de la cuenca Ibérica se produjo la mas importante transgresión del Cretácico inferior en la zona. Por otro lado, la Formación Leza está formada por seis litosomas carbonáticos claramente diferenciados, limitados por paleofracturas que funcionaron durante la sedimentación de la unidad y que fueron fosilizadas posteriormente. El control tectónico está ejercido por una fractura de bajo ángulo en el margen noreste, buzando hacia el sur, que durante la etapa distensiva, de formación de la cuenca, actuó como “detachment” y que durante la etapa de inversión alpina actuó de nuevo originando un cabalgamiento de cerca de 30 km claramente apreciable en los perfiles sísmicos disponibles.Item El Jurásico superior marino en el Sector Demanda-Cameros (La Rioja-Soria)(Cuadernos de geología ibérica, 1990) Alonso Zarza, Ana María; Mas Mayoral, José RamónEste trabajo aborda los aspectos litoestratigráficos y paleogeográficos del Malm marino de la Cuenca de Los Cameros, depositado en un estrecho surco de dirección NW-SE limitado entre los Macizos del Ebro e Ibérico. Además ha sido interpretado como dos secuencias deposicionales en el sentido de Mitchum ci al (1977). Estas dos secuencias de depósito se corresponden con las dos unidades litoestratigráficas con rango de Eormación que se han diferenciado: Calizas negras de Aldealpozo, de edad Oxfordiense medio y superior, y Calizas con corales de Torrecilla en Cameros, de edad Kimmeridgiense inferior. Se describe de forma detallada cada una de ellas, analizando sus variaciones laterales de facies y su interpretación sedimentológica. La Formación inferior se interpreta como depositada en una rampa carbonática, basculada hacia el NW, donde hay facies mas profundas y con situaciones muy someras, con continuas emersiones, en el SE, donde se realizaría su unión con el Surco Ibérico. En los márgenes SW y NE la influencia siliciclástica fue grande. La unidad superior constituyó un episodio con abundancia de bioconstrucciones. La plataforma muestra dos sectores con diferentes tipos de márgenes bioconstruidos: Arrecifes franja, con predominio de la acrección frontal, en el NW, y arrecifes barrera, con predominio de la acrección vertical en S y SE. Estos márgenes separan un surco sedimentario mas profundo, al NE, de la plataforma somera situada al SW. El otro margen del estrecho no muestra tendencia a la bioconstrucción, por el contrario, los aportes siliciclásticos son abundantes. En el trabajo se analiza además el carácter de las discontinuidades que limitan las secuencias deposicionales. La inferior constituye un nivel de removilización, de parada de la sedimentación y me-elaboración. Incluiría al Calloviense superior p.p.-Oxfordiense inferior. La superior constituye una discordancia cartográfica, así como un cambio paleogeográfico y paleoambiental radical en la cuenca. La discontinuidad intermedia es de menor rango, estando generalmente caracterizada por señales de emersión (paleokarstificaciones) y de forma más local por la existencia de un hardground.