Person:
Arribas Mocoroa, José

First Name

José

Last Name

Arribas Mocoroa

URI

https://hdl.handle.net/20.500.14352/81110

Affiliation

Universidad Complutense de Madrid

Faculty / Institute

Ciencias Geológicas

Department

Mineralogía y Petrología

Area

Petrología y Geoquímica

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Now showing 1 - 10 of 26

Sand provenance and implications for paleodrainage in a rifted basin: the Tera Group (N. Spain)
(Journal of iberian geology, 2010) González Acebrón, Laura; Arribas Mocoroa, José; Mas Mayoral, José Ramón
Fluvial-fan and fluvial siliciclastic strata, developed during the rifting that generated the Cameros Basin (North Spain), record important provenance changes that reveal source areas compositions and locations, paleodrainage evolution and rift patterns. The Tera Group represents the first rifting stage in the Cameros Basin, containing fluvial-fan sediments at the lower part of the sedimentary fill that evolve to fluvial and lacustrine systems in the upper part of the record. Our quantitative sandstone petrographic analysis evidences the presence of three main petrofacies related closely to the rift basin evolution. At the base of the sedimentary succession, Petrofacies 1 (quartzolithic) indicates that the fluvial-fans source areas included Jurassic marine carbonates and older siliciclastic Mesozoic units, as well as metamorphic supplies from the West Asturian Leonese Zone (WALZ). Variscan basement sources of this metamorphic area (WALZ) were more abundant in the upper fluvial record (Petrofacies 2, quartzofeldspathic). Further, the influence of plutonic source areas with a mixed potassic and calcium-sodium composition is also recorded, probably related to the Central Iberian Zone (CIZ). In addition, a local sedimentary input was active during the fluvial riftand lacustrine stages (Petrofacies 2 and 3, both quartzofeldspathic), as a function of the palaeogeographical position of the Jurassic marine rocks and the level of erosion reached. Plutonic rock fragments have not been observed in the Tera Group sandstones of the western part of the basin. Thus, deeper erosion of the basement in the eastern Cameros Basin is suggested. The provenance evolution from quartzolithic to quartzofeldspathic petrofacies registered in Tera Group siliciclastic deposits is due to the higher influence of transversal supplies during the fluvial-fan stage (quartzolithic) to more important axial inputs during the fluvial stage (quartzofeldspathic). This provenance change represents the evolution from an undissected rift shoulder stage to more advanced stages of rifting (dissected rift shoulder) and during the beginning of a provenance cycle in a rifted basin. [RESUMEN] Los sedimentos de abanicos fluviales y fluviales propiamente dichos desarrollados durante el proceso de rift que generó la Cuenca de Cameros (Norte de España) registraron importantes cambios de procedencia que proporcionan información sobre la composición y localización de sus áreas fuente, la evolución del paleodrenaje y los patrones de rift. Este estudio se centra en el Grupo Tera (Tithoniense) en el sector oriental de la Cuenca de Cameros. El Grupo Tera representa el primer estadio de rift en dicha cuenca, y está constituido por sedimentos de abanicos fluviales en la parte inferior del relleno sedimentario, que evolucionan a sistemas fluviales y lacustres hacia la parte superior del registro. El estudio petrográfico cuantitativo de las areniscas indica la presencia de tres petrofacies principales que muestran una estrecha relación con la evolución del rift. En la base del registro sedimentario, la Petrofacies 1 (cuarzolítica) manifiesta que las áreas fuente de los abanicos fluviales incluyen tanto carbonatos Jurásicos marinos como unidades siliciclásticas mesozoicas previas, así como influencias metamórficas de la Zona Asturoccidental Leonesa (WALZ). Los aportes del basamento varisco procedentes de esta área fuente metamórfica (WALZ) fueron más importantes en la parte alta del registro (Petrofacies 2, cuarzofeldespática). Además, se detecta la influencia de áreas fuente plutónicas con una composición mixta (potásica y calcosódica), probablemente relacionadas con la Zona Centroibérica (CIZ). También existió un aporte sedimentario local durante los estadios fluviales y lacustres (Petrofacies 2 y 3, ambas cuarzofeldespáticas), que tuvo lugar en función de la posición paleogeográfica de las rocas marinas Jurásicas y del nivel de erosión alcanzado. Si comparamos los dos sectores de la cuenca, los fragmentos de roca plutónica no han sido observados en las areniscas del Grupo Tera en el sector occidental de la cuenca. Por lo tanto, se deduce un nivel de erosión del basamento más profundo en el sector occidental. La evolución de la procedencia desde petrofacies cuarzolíticas a petrofacies cuarzofeldespáticas registrada en los depósitos siliciclásticos del Grupo Tera se debe a una mayor influencia de los aportes transversales durante la sedimentación de los abanicos fluviales (cuarzolíticos) hacia una mayor influencia de aportes axiales durante la etapa fluvial (cuarzofeldespática). Esta variación en la procedencia representa la evolución desde un estadio de hombrera de rift no erosionada a estadios más avanzados del rifting (hombrera de rift erosionada) y el comienzo de un ciclo de procedencia en una cuenca de rift.
Diagenetic albitization in the Tera Group, Cameros Basin (NE Spain) recorded by trace elements and spectral cathodoluminescence
(Chemical geology, 2012) González Acebrón, Laura; Götze, Jens; Barca, Donatella; Arribas Mocoroa, José; Más Mayoral, Ramón; Pérez Garrido, Carlos
This paper deals with the diagenetic albitization of both plagioclases and K-feldspars in the Tithonian fluvial sandstones of a rift basin (Cameros Basin). The sandstones in the lower part of the rift record have not suffered this albitization process. A clear relationship is observed between sodium contents, as the main element of some feldspars and their cathodoluminescence (CL) color (the higher the sodium content, the lower is their CL intensity). In conclusion, albitization processes are detectable by decreased CL intensities and changes in the CL spectra. In addition, very different trace element compositions are obtained by laser ablation when comparing trace elements of non-albitized feldspars in sandstones of the lower part of the rift record with those of albitized feldspars in sandstones of the infill top. Non-albitized K-feldspars show Rb, Sr, Ba and Pb contents of up to 1000 ppm. In contrast, very flat profiles of trace element contents (< 250 ppm) are recorded in albitized feldspars (both K-feldspars and plagioclases). Thus, albitization implies feldspars impoverished in trace elements, including REE, which suggests that albitization is a dissolution and reprecipitation process. Further, albitized plagioclases show higher REE contents than albitized K-feldspars. We report here that REE patterns partly depend on the initial composition of the feldspar (K-feldspar or plagioclase) as a useful geochemical criterion for distinguishing albitized detrital plagioclases from albitized detrital K-feldspars. CL spectra from non-albitized and albitized K-feldspars and plagioclases revealed marked differences. Non-albitized K-feldspars present blue (main emission band at 460 nm) and brownish CL colors (590 nm), sometimes in the same grain. Brownish colors are related to weathering processes. The primary blue emission is related to Al–O−–Al centers, enhanced probably by Al incorporation due to the coupled substitution of Ba2+ + Al3+ ↔ M+ + Si4+. Weathered K-feldspars present 4.8 times lower Ba content than fresh blue luminescent ones. The brownish colors are related to the external border or fractured grain zones, altered by weathering processes. Therefore, the observed 590 nm emission is assumed to be caused by structural defects resulting from weathering and alteration. Albitized K-feldspars are usually weak luminescent with a typical CL emission band at 620 nm. Sometimes, relicts of the original blue luminescence (460 nm band) are still present. The leaching of probably both Al and Ba can be responsible for the decrease in the blue band. The characteristic 620 nm band is also dominant in albitized weak luminescent plagioclases. Two additional emission bands at 440 nm (Al–O−–Al center) and 565 nm (Mn2+) occur, when albitized plagioclases preserved their original CL characteristics (green CL color). Another spectral peak at ca. 720 nm can be explained by Fe3+ activation due to Fe3+–Al3+ substitution. The spectral CL measurements indicate that changes in luminescence due to albitization (620 nm emission) seem to be more related to structural defects than to trace element activation or quenching.
Otras aplicaciones docentes del Atlas Digital de Petrología Sedimentaria a través del Campus Virtual UCM (www.ucm.es/info/petrosed)
(VII Jornada Campus Virtual UCM: valorar, validar y difundir Campus Virtual, 2012) Varas Muriel, María José; Arribas Mocoroa, María Eugenia; Arribas Mocoroa, José; Peña Blasco, José Andrés de la; Marfil, Rafaela; López Acevedo, Francisco Javier; Estrada Aliberas, R.
La Petrología Sedimentaria se adapta a las necesidades profesionales que demanda la sociedad y entre ellas el sector de la construcción. Preparar a los futuros profesionales plantea un reto no solo en la Facultad de CC. Geológicas (UCM) sino en otras muchas, sobre todo a la hora de diseñar y desarrollar el material y las herramientas didácticas que el alumno precisa en su autoaprendizaje. La asignatura Materiales de Construcción, impartida en la Facultad de CC. Geológicas (UCM) (Grado de Ingeniería Geológica), utiliza, a través de Campus Virtual, el Atlas de Petrología Sedimentaria: http://www.ucm.es/info/petrosed, ya que recoge un material didáctico fundamental para el desarrollo de gran parte de sus clases prácticas y teóricas. Esta asignatura muestra una gran afinidad con la temática y la metodología de trabajo que se emplea en la asignatura Petrología Sedimentaria, a pesar de pertenecer a campos científico-técnicos diferentes.
REPLY: Answer to the comment of Casas et al. about González Acebrón et al.’s (2011) paper
(International journal of earth sciences, 2012) González Acebrón, Laura; Goldstein, R.H.; Mas Mayoral, José Ramón; Arribas Mocoroa, José
Petroleum systems modelling in a fold-and-thrust belt setting: the inverted Cameros basin, north-central Spain
(Journal of Petroleum Geology, 2019) Omodeo Salé, S.; Ondrak, R.; Arribas Mocoroa, José; Mas Mayoral, José Ramón; Guimerà, J.; Martínez, L.
The Mesozoic Cameros Basin, northern Spain, was inverted during the Cenozoic Alpine orogeny when the Tithonian – Upper Cretaceous sedimentary fill was uplifted and partially eroded. Tar sandstones outcropping in the southern part of the basin and pyrobitumen particles trapped in potential source rocks suggest that hydrocarbons have been generated in the basin and subsequently migrated. However, no economic accumulations of oil or gas have yet been found. This study reconstructs the evolution of possible petroleum systems in the basin from initial extension through to the inversion phase, and is based on structural, stratigraphic and sedimentological data integrated with petrographic and geochemical observations. Petroleum systems modelling was used to investigate the timing of source rock maturation and hydrocarbon generation, and to reconstruct possible hydrocarbon migration pathways and accumulations. In the northern part of the basin, modelling results indicate that the generation of hydrocarbons began in the Early Berriasian and reached a peak in the Late Barremian – Early Albian. The absence of traps during peak generation prevented the formation of significant hydrocarbon accumulations. Some accumulations formed after the deposition of post‐extensional units (Late Cretaceous in age) which acted as seals. However, during subsequent inversion, these reservoir units were uplifted and eroded. In the southern sector of the basin, hydrocarbon generation did not begin until the Late Cretaceous due to the lower rates of subsidence and burial, and migration and accumulation may have taken place until the initial phases of inversion. Sandstones impregnated with bitumen (tar sandstones) observed at the present day in the crests of surface anticlines in the south of the basin are interpreted to represent the relics of these palaeo‐accumulations. Despite a number of uncertainties which are inherent to modelling the petroleum systems evolution of an inverted and overmature basin, this study demonstrates the importance of integrating multidisciplinary and multi‐scale data to the resource assessment of a complex fold‐and‐thrust belt.
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, Ferrán
Role of sandstone provenance in the diagenetic albitization of feldspars A case study of the Jurassic Tera Group sandstones (Cameros Basin, NE Spain)
(Sedimentary Geology, 2011) González Acebrón, Laura; Arribas Mocoroa, José; Mas Mayoral, José Ramón
The Cameros Basin (Iberian Chain, NE Spain) formed during the latest Jurassic–Early Cretaceous rifting stage in an extensional regime characterized by high subsidence rates. Its sedimentary infill (thicker than 6000 m) has been subdivided into eight depositional sequences (DS) mainly composed of continental sediments. DS 1 and DS 2 represent the first rifting stage (Tera Group, Tithonian), mainly formed by fluvial and lacustrine sediments. Sandstone petrofacies evolved from quartz-sedimentolithic in DS 1 to quartz-feldspathic in DS 2 due to the rifting process. In DS 2, three different types of detrital feldspars (K-feldspars, albites and polysynthetic plagioclases) with similar sodium-rich compositions (mean: Ab94.0 An4.5 Or1.5) can be recognized. Chemically pure nonluminescent albites (AbN99%) are common. In DS 2, diagenetic albitization of both plagioclases and K-feldspars is inferred from conventional microscopy observations, cathodoluminescence and electron microprobe analyses. DS 1 contains few plagioclase grains, which showno evidence of transformation into albite.Although the albitization is characterized as diagenetic it seems to be provenance-controlled since it affects the units showing higher original plagioclase/Kfeldspar ratio (DS 2), due to the greater influence of plutonic and metamorphic source areas in DS 2. Possible Na sources are: (1) the percolation ofmoderate to high salinity residual brines fromrelated alkaline lakes developed at top of DS 2 in the eastern sector of the basin, (2) clay mineral reactions (sodium smectite to illite and chlorite) indicated by mudstone composition in the interlayered mudstones, and (3) the replacement of detrital sodium plagioclases by carbonate. These three sources can be complementary.
Easily altered minerals and reequilibrated fluid inclusions provide extensive records of fluid and thermal history: gypsum pseudomorphs of the Tera Group, Tithonian-Berriasian, Cameros Basin
(Central European Journal of Geosciences, 2012) González Acebrón, Laura; Goldstein, Robert H.; Arribas Mocoroa, José
This study reports a complex fluid and thermal history using petrography, electron microprobe, isotopic analysisand fluid inclusions in replacement minerals within gypsum pseudomorphs in Tithonian-Berriasian lacustrine de-posits in Northern Spain. Limestones and dolostones, formed in the alkaline lakes, contain lenticularly shapedgypsum pseudomorphs, considered to form in an evaporative lake. The gypsum was replaced by quartz andnon-ferroan calcite (Ca-2), which partially replaces the quartz. Quartz contains solid inclusions of a preexistingnon-ferroan calcite (Ca-1), anhydrite and celestine.High homogenization temperatures (Th) values and inconsistent thermometric behaviour within secondary fluidinclusion assemblages in quartz (147-351◦C) and calcite (108-352◦C) indicate high temperatures after precipita-tion and entrapment of lower temperature FIAs. Th are in the same range as other reequilibrated fluid inclusionsfrom quartz veins in the same area that are related to Cretaceous hydrothermalism.Gypsum was replaced by anhydrite, likely during early burial. Later, anhydrite was partially replaced by Ca-1associated with intermediate burial temperatures. Afterward, both anhydrite and Ca-1 were partially replacedby quartz and this by Ca-2. All were affected during higher temperature hydrothermalism and a CO2-H2O fluid.Progressive heating and hydrothermal pulses, involving a CO2-H2O fluid, produce the reequilibration of the FIAs,which was followed by uplift and cooling
Atlas digital de microscopía óptica de rocas sedimentarias (www. ucm.es/info/petrosed): un enlace de apoyo para las asignaturas de Petrología Sedimentaria en el campus virtual de la UCM
(VI Jornada Campus Virtual UCM: Campus Virtual crece: retos del EEES y oportunidades para la UCM, 2011) Arribas Mocoroa, María Eugenia; Arribas Mocoroa, José; Peña, José Andrés de la; Marfil, Rafaela; Varas Muriel, María José; López Acevedo, Francisco Javier; Estrada Aliberas, R.
Se presenta por primera vez una página web de carácter docente dedicada a imágenes de microscopía óptica de rocas sedimentarias. Esta página web está vinculada a varias asignaturas de Petrología Sedimentaria que se imparten en el Dpto. de Petrología y Geoquímica de la Facultad de Ciencias Geológicas de la UCM. La utilización de esta web ha tenido resultados muy satisfactorios en las prácticas de estas asignaturas así como en aquellas afines a la Geología Sedimentaria.
Holocene transgression recorded by sand composition in the mesotidal Galician coastline (NW Spain)
(The Holocene, 2010) Arribas Mocoroa, José; Alonso Millán, Ángela; Pagés Valcarlos, José Luis; González Acebrón, Laura
This study confirms several inferences regarding Holocene coastal dynamics and climate through a petrographic modal analysis of 60 Holocene sand samples recovered in seven sites along the NW coast of the Iberian Peninsula. Fluvial sand can be discriminated from more mature intertidal and aeolian sand according to texture and composition. Fluvial sand contains soil products and coastal sand has significant bioclasts. Quartzofeldspathic sand appears in the western area (produced by the erosion of granite and granitoid), and quartzolithic sand occurs in the eastern area (produced by the erosion of metasediment). Changes in sand composition during Holocene deposition are manifested by an increase in modern carbonate clasts (MC) correlated with the Holocene transgression. Episodes of faster sea-level rise and subsequent erosion of surrounding cliffs are indicated by the preservation of high proportions of feldspar in intertidal sand. In contrast, fluvial sand is characterized by greater quartz enrichment. These inferences were confirmed by petrographic indices (carbonate clasts/total clasts, MC/T; total feldspars/monocrystalline quartz, F/Qm; and plagioclase/total feldspars, P/F). The different maturity of intertidal and aeolian sands is revealed by their variable quartz contents, despite similar proportions of plagioclase and K-feldspar. This suggests mechanical abrasion as the main factor controlling maturity. In contrast, fluvial sand shows depleted plagioclase contents as the result of inland weathering processes. Intertidal, beach and aeolian sands are essentially the products of the erosion of coastal cliffs and head deposits, with only the scarce contribution of fluvial drainages. The long-distance transport of Galician coastal sands is discarded based on the close relationship between their composition and that of local sand sources. Our findings indicate that short-distance transport of sediments from the west closed off coastal wetlands and occluded estuarine mouths during the Holocene transgression by deposition on sediment-trap zones along the irregularly shaped Galician coast.