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
46 results
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Item La Cuenca de Cameros: desde la extensión Finijurásica -Eocretácica a la inversión terciaria - implicaciones en la exploración de hidrocarburos.(Zubía. Monográfico, 2002) Mas Mayoral, José Ramón; Benito Moreno, María Isabel; Arribas Mocoroa, José; Serrano, Ana; Guimerà Rosso, Joan; Alonso Millán, Ángela; Alonso Azcárate, JacintoLa Cuenca de Cameros, localizada en la parte NO de la Cordillera Ibérica, es una de las cuencas que constituyen el Sistema de Rift Mesozoico Ibérico o Cuenca Ibérica. Se formó en el contexto de la segunda fase de rifting intraplaca que, desde el Jurásico superior al Albiense inferior, tuvo lugar cuando Iberia se separó de Europa en relación con la apertura de la cuenca oceánica del Golfo de Vizcaya. Al mismo tiempo se formaron varias cuencas a lo largo del surco Ibérico de orientación NO-SE, siendo la de Cameros la más occidental en el Sistema de Rift Mesozoico Ibérico. El relleno de la Cuenca de Cameros (Titónico-Albiense inferior) corresponde a un gran ciclo o super-secuencia que está limitado por dos importantes discordancias en la base y en el techo. La Supersecuencia o Megaciclo Jurásico terminal - Cretácico inferior se organiza en ocho secuencias deposicionales limitadas por discontinuidades estratigráficas, este registro sedimentario es de carácter esencialmente continental (sistemas aluviales y lacustres) con sólo muy esporádicas incursiones marinas. Hay varios hechos distintivos que la diferencian de las otras cuencas del Sistema de Rift Ibérico: (1) influencia marina muy escasa; (2) retardo ele los procesos de diastrofismo, pues el rifting empezó primero en la parte SE del surco ibérico (Kimmeridgiense en la Cuenca del Maestrazgo) y después se propagó hacia el NO (Titónico en la Cuenca de Cameros); (3) sin embargo, y a pesar de su poslclon interna, esta cuenca fue la más subsidente, registrando el mayor espesor de sedimentos, llegándose a acumular 5000 m de espesor vertical de sedimentos desde el Titónico hasta el Albiense inferior, que representan hasta 9000 m de registro estratigráfico en el sentido de desplazamiento de los depocentros de las sucesivas secuencias de depósito; (4) a pesar de su gran registro sedimentario, se trata de una cuenca sinclinal que, durante su formación, no estuvo limitada por grandes fallas; y (5) esta cuenca es la única entre las cuencas mesozoicas del Rift Ibérico, en la que sus depósitos se han visto afectados por metamorfismo. Se trata de un metamorfismo de bajo y muy bajo grado que, durante el Cretácico medio-superior, afectó a la parte oriental de la cuenca. Su génesis y evolución son explicadas mediante un modelo de cuenca de bloque de techo ( <Item Sandstone petrography of continental depositional sequences of an intraplate rift basin: western Cameros Basin (North Spain)(Journal of sedimentary research, 2009) Arribas Mocoroa, José; Alonso Millán, Ángela; Mas Mayoral, José Ramón; Tortosa, A.; Rodas, Magdalena; Fernández Barrenechea, José María; Alonso Azcárate, Jacinto; Artigas, RosanaThe Cameros Basin in Central Spain is an intraplate rift basin that developed from Late Jurassic to Middle Albian time along NW–SE trending troughs. The sedimentary basin fill was deposited predominantly in continental environments and comprises several depositional sequences. These sequences consist of fluvial sandstones that commonly pass upward into lacustrine deposits at the top, producing considerable repetition of facies. This study focused on the western sector of the basin, where a total of seven depositional sequences (DS- 1 to DS-7) have been identified. The composition of sandstones permits the characterization of each sequence in terms of both clastic constituents and provenance. In addition, four main petrofacies are identified. Petrofacies A is quartzosedimentolithic (mean of Qm85F2Lt13) and records erosion of marine Jurassic pre-rift cover during deposition of fluvial deposits of DS-1 (Brezales Formation). Petrofacies B is quartzofeldspathic (mean of Qm81F14Lt5) with P/F > 1 at the base. This petrofacies was derived from the erosion of low- to medium-grade metamorphic terranes of the West Asturian–Leonese Zone of the Hesperian Massif during deposition of DS-2 (Jaramillo Formation) and DS-3 (Salcedal Formation). Quartzose sandstones characterize the top of DS-3 (mean of Qm92F4Lt4). Petrofacies C is quartzarenitic (mean of Qm95F3Lt2) with P/F > 1 and was produced by recycling of sedimentary cover (Triassic arkoses and carbonate rocks) in the SW part of the basin (DS-4, Pen˜ - acoba Formation). Finally, depositional sequences 5, 6, and 7 (Pinilla de los Moros–Hortigüela, Pantano, and Abejar–Castrillo de la Reina formations, respectively) contain petrofacies D. This petrofacies is quartzofeldspathic with P/F near zero and a very low concentration of metamorphic rock fragments (from Qm85F11Lt4 in Pantano Formation to Qm73F26Lt1 in Castrillo de la Reina Formation). Petrofacies D was generated by erosion of coarse crystalline plutonics located in the Central Iberian Zone of the Hesperian Massif. In addition to sandstone petrography, these provenance interpretations are supported by clay mineralogy of interbedded shales. Thus, shales related to petrofacies A and C have a variegated composition (illite, kaolinite, and randomly interlayered illite–smectite mixed-layer clays); the presence of chlorite characterizes interbedded shales from petrofacies B; and Illite and kaolinite are the dominant clays associated with petrofacies D. These petrofacies are consistent with the depositional sequences and their hierarchy. An early megacycle, consisting of petrofacies A and B (DS-1 to DS-3) was deposited during the initial stage of rifting, when troughs developed in the West Asturian–Leonese Zone. A second stage of rifting resulted in propagation of trough-bounding faults to the SW, involving the Central Iberian Zone as a source terrane and producing a second megacycle consisting of petrofacies C and D (DS-4, DS-5, DS-6, and DS-7). Sandstone composition has proven to be a powerful tool in basin analysis and related tectonic inferences on intraplate rift basins because of the close correlation that exists between depositional sequences and petrofacies.Item The Iberian Chain: tertiary inversion of a mesozoic intraplate basin(Geotemas, 2000) Guimerà, J.; Salas, Ramón; Mas Mayoral, José Ramón; Martín Closas, C.; Meléndez Hevia, Alfonso; Alonso, A.The Mesozoic Iberian basin developed inside the Iberian plate in the eastern end of the Tethys sea. As a result of the Tertiary convergence between the Iberian plate with the European and African plates, the Iberian basin was contractionally inverted, giving rise to the Iberian and Catalan Coastal chains and the surrounding Tertiary basins. The Bouguer anomaly map of the area shows that the Iberian Chain has crustal roots which would have produced during the Tertiary contractional period.Item Los arrecifes coralinos del Malm en la Sierra de los Cameros (La Rioja, España)(Acta geológica hispánica, 1987) Alonso Zarza, Ana María; Mas Mayoral, José Ramón; Meléndez Hevia, María NievesEl ultimo episodio marino del Jurásico de la Sierra de los Cameros (La Rioja sur) se caracteriza por el desarrollo local de complejos arrecifales coralinos. El estudiado aquí está constituido por una progradación de arrecifes franjeantes que presenta acreción frontal casi exclusiva, aunque con cierta acreción vertical durante la maduración de cada edificio. Su funcionamiento estaría controlado por pulsos de levantamiento tectónico con emersión (mecanismo dominante) y eustatismo positivo (mecanismo subordinado).Item Evolución tectonosedimentaria de una cuenca extensional intraplaca: La cuenca finijurásica-eocretácica de Los Cameros (La Rioja-Soria)(Revista de la Sociedad Geológica de España, 1993) Mas Mayoral, José Ramón; Alonso, A.; Guimera, J.La Cuenca de Los Cameros, situada en el sector NW de la Cadena Ibérica, contiene una potente serie sedimentaria (hasta 9000 m) de carácter fundamentalmente continental y de edad Jurásico terminal-Cretácico inferior, que se depositó en un régimen distensivo muy subsidente. En su evolución se pueden distinguir tres eventos geotectónicos principales: 1) la extensión sin-rift y relleno sincrónico (Jurásico terminal-Cretácico inferior); 2) el metamorfismo post-rift (Cretácico medio-superior) y 3) la inversión tectónica o destrucción en régimen compresivo (Terciario). El relleno de la cuenca (Titónico-Albiense inferior) constituye un gran ciclo limitado por discontinuidades estratigráficas mayores, que se puede dividir en seis secuencias deposicionales. En el desarrollo de la cuenca se diferencian dos etapas de rifting. En la primera (Jurásico terminal) se formaron también las otras dos cuencas principales del Rifting Ibérico: Ibérica meridional y Maestrazgo. Durante el Valanginiense-Hauteriviense, como resultado de la atenuación del proceso de rifting, se redujeron en las tres cuencas tanto la tasa como las áreas de sedimentación. La segunda etapa de rifting (BmTemiense-Albiense inferior) ocasionó una aceleración en la acumulación de sedimentos en las tres cuencas, que fue especialmente acusada en Los Cameros. Además, se reconoce un marcado paralelismo entre los ciclos de extensión de las facies lacustres en la cuenca de Los Cameros y los ciclos eustáticos globales. Estructuralmente, la Cuenca de Los Cameros es interpretada como una cuenca sinclinal formada sobre una rampa de buzamiento sur que conecta dos rellanos de una falla extensiva situada a varios kilómetros de profundidad, dentro del zócalo. El desplazamiento de dicha falla produjo la cuenca e hizo aumentar sus dimensiones progresivamente. Los depocentros de la secuencias de depósito fueron migrando hacia el norte en las unidades progresivamente más modernas, a consecuencia del desplazamiento de la falla. Durante la compresión tercim'ia (durante el Paleógeno y hasta el Mioceno inferior), se produjo la inversión de la cuenca, mediante un cabalgamiento neoformado en su margen norte (sobre la cuenca del Ebro, con un desplazamiento de hasta 30 km) y un sistema de cabalgamientos en su borde sur (sobre las cuencas del Duero y de Almazán).Item Clay minerals as provenance indicators in continental lacustrine sequences: the Leza Formation, early Cretaceous, Cameros Basin, northern Spain(Clay minerals, 2005) Alonso Azcárate, Jacinto; Rodas, Magdalena; Fernández Barrenechea, José María; Mas Mayoral, José RamónVariations in clay mineral assemblages, changes in KuÈbler index (KI), and the chemical composition of chlorites are used to identify source areas in the lacustrine materials in the Lower Cretaceous Leza Limestone Formation of the Cameros Basin, northern Spain. This formation has fairly homogeneous lithological characteristics and facies associations which do not allow for identification and characterization of local source areas. The Arnedillo lithosome of the Leza Limestone Formation contains a clay mineral association (Mg-chlorite, illite and smectite) indicative of its provenance. Chlorite composition and illite KI values indicate that these minerals were formed at temperatures higher than those reached by the Leza Formation which indicates its detrital origin. The similarity in the Mg-chlorite composition between the Arnedillo lithosome and the Keuper sediments of the area indicates that these materials acted as a local source area. This implies that Triassic sediments were exposed, at least locally, at the time of deposition of the Leza Formation. The presence of smectite in the Leza Formation is related to a retrograde diagenesis event that altered the Mg-chlorites in some samples.Item Mid Cretaceous events Iberian field conference 77. Guide III partie: Chaine iberique et prebetique. Deuxime jour.(Cuadernos de geología ibérica, 1979) Meléndez, F.; Ramínez del Pozo, J.; Mas Mayoral, José Ramón; García, A.; Rincón, R.Item A refraction/wide-angle reflection seismic profile through the Iberian Chain: preliminary report(Geotemas, 2004) Gallart Muset, Josep; Salas, Ramón; Guimerà, J.; Mas Mayoral, José Ramón; Díaz, J.; Ruiz, M.As a result of the Eurasian and African plates convergence, Tertiary intraplate deformation of the Iberian plate gave rise to the basement-involved thrust-system of the Iberian Chain. Subsequently, a crustal thickening beneath the Iberian Chain was produced, as deduced from Bouguer anomaly maps. A very preliminary interpretation of a new seismic profile through the Iberian Chain is presented, which leads us to infer a crustal thickening beneath the central part of the profile, where Moho depths of at least 40 km should be reached.Item Significance of geochemical signatures on provenance in intracratonic rift basins: Examples from the Iberian plate(Geological Society of America Special Paper, 2007) Ochoa, M.; Arribas Mocoroa, José; Arribas Mocoroa, María Eugenia; Mas Mayoral, José RamónFollowing the Variscan orogeny, the Iberian plate was affected by an extensional tec-tonic regime from Late Permian to Late Cretaceous time. In the central part of the plate, NW-SE–trending rift basins were created. Two rifting cycles can be identified during the extensional stage: (1) a Late Permian to Hettangian cycle, and (2) a latest Jurassic to Early Cretaceous cycle. During these cycles, thick clastic continental sequences were deposited in grabens and half grabens. In both cycles, sandstone petrofacies from periods of high tectonic activity reveal a main plutoniclastic (quartzofeldspathic) character due to the erosion of coarse-grained crystalline rocks from the Hesperian Massif, during Buntsand-stein (mean Qm72F25Lt3) sedimentation and during Barremian–early Albian times (mean Qm81F18Lt1). Geochemical data show that weatheringwas more intense during the second rifting phase (mean chemical index of alteration [CIA]: 80) due to more severe climate conditions (humid) than during the arst rifting phase (mean CIA: 68) (arid climate). Ratios between major and trace elements agree with a main provenance from pas-sive-margins settings in terms of the felsic nature of the crust. However, anomalies in trace elements have been detected in some Lower Cretaceous samples, suggesting additional basic supplies from the north area of the basin. These anomalies consist of (1) low contents in Hf, Th, and U; (2) high contents in Sc, Co, and Zr; and (3) anomalous ratios in Th/Y, La/Tb, Ta/Y, and Ni/V. Basic supplies could be related to the alkaline volcanism during Norian-Hettangian and Aalenian-Bajocian times. Geochemical composition of rift deposits has been shown to be a useful and complementary tool to petrographic deduction in prov-enance, especially in intensely weathered sediments. However, diagenetic processes and hydrothermalism may affect the original detrital deposits, producing changes in geochemi-cal composition that mislead provenance and weathering deductions.Item Aalenian pulses of tectonic activity in the Iberian Basin, Spain(Sedimentary Geology, 2008) García Frank, Alejandra; Ureta Gil, María Soledad; Mas Mayoral, José RamónIn the northwest Iberian Range the Aalenian to Bajocian interval is represented by condensed, as well as more expanded marine carbonate strata deposited in a shallow epicontinental-sea setting. Precise biochronological data (successive ammonites assemblages) from 29 measured sections, along with a bedby- bed facies analysis, allowed a detailed correlation between sections, the definition of a number of successive transgressive–regressive cycles and of two distinct sedimentation areas, as well as the compilation of isopach maps for short time intervals (duration of ammonites Zone/Subzone) and the assessment of sediment accumulation rates. Differences in facies and thickness in the studied interval, and the sequential organization, reveal significant changes in the depositional environment. A tectonically-controlled compartmentalization of the sedimentation area is suggested by a detailed reconstruction of the accumulation history. An active extensional tectonic regime is supported by contemporaneous volcanic activity in the southeastern Iberian Basin. A precise timing of the main tectonic pulses recorded in NW Iberian Basin for the Upper Toarcian–Lower Bajocian interval is presented, which may help to better resolve the stratigraphy in otherW European during this time interval.