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 36

Provenance of Triassic Feldspathic Sandstones in the Iberian Range (Spain): significance of Quartz Types
(Journal of Sedimentary Petrology, 1985) Arribas Mocoroa, José; Marfil Pérez, Rafaela; Peña, José Andrés de la
The base of the Triassic in the Iberian Range is represented by detrital sediments (Buntsandstein facies) deposited initially in a continental environment, finally evolving into a marine environment that is represented at the top of the sequence. The lithology of this facies is dominated by arkosic sandstones. The aim of this study is to reconstruct the nature and position of the source areas of these sandstones. Provenance research was carried out by quartz-grain typology. Eleven stratigraphic sections were sampled. The amount of interstitital matrix has been considered in selecting samples because mechanical compaction suffered by sandstones with little matrix may give rise to a significant increase in the undulosity of monocrystalline quartz. The 0110 de Sapo gneissic formation, located in the Hesperian Massif, has been mentioned as source rocks offeldspathic sandstones in previous works. In order to verify the provenance of feldspathic sandstones, in artificial sands derived by grinding gneisses, and sand samples collected at stream heads that drain the gneiss outcrops, we followed the methodology ofBasu et al. (1975). Analytical results indicate that two different areas within the Triassic basin were notably influenced by different source areas: a) a western zone, the nearest to the gneissic source rocks, where monocrystalline, nonunduIatory quartz grains predominate (Qm :s5"); and b) an eastern zone farther from the gneissic source area, where polycrystalline quartz grains (Qp) and undulatory, monocrystalline quartz grains (Qm > 5") increase. Sediment evolution during transport processes is markedly reflected by the increase in Qm :s 5°/(Qp + Qm > 5") ratios in the westernmost zone, away from the source area. Low values in the above-mentioned ratios in the eastern zone are interpreted as results oflocal influence by low-ranking metamorphic source areas. Finally, this method also allows for the monitoring of the evolution of sediment maturity throughout the basin.
Detrital modes in sedimentoclastic sands from first-order streams of the Iberian Range, Spain: the effect of source lithology
(Sedimentology at the dawn of the third millennium : Abstracts : 15th International Sedimentological Congress [held at the University of Alicante] April 12-17, 1998 [International Association of Sedimentologists (IAS)], 1998) Arribas Mocoroa, José; Peña, José Andrés de la; Tortosa, A.; Cañaveras, J.C.; García del Cura, M. Ángeles; Soria, Jesús
Interpretación de la procedencia mediante el estudio de la tipologia de los granos de cuarzo: aplicación a las areniscas del Buntsandstein de la Cordillera Ibérica.
(Actas del IX Congreso Nacional de Sedimentología, 1986) Arribas Mocoroa, José; Marfil Pérez, Rafaela; Peña, José Andrés de la
La procedencia de las areniscas ha sido abordada en los últimos años mediante el estudio de la tipologia de los granos de cuarzo. Gracias a las metodologías propuestas por diversos autores. Se pretende con este trabajo analizar la validez de las mismas, habiendo seleccionado para ello la de BASU et al. (1975) por considerarla la más idónea. Los materiales utilizados para este "chequeo" han sido las areniscas del Buntsandstein de la Cordillera Ibérica. El desarrollo del método empleado ha permitido confirmar la naturaleza gneisica de las áreas fuentes asi como poner de relieve la evolución espacial de la madurez de las areniscas estudiadas. Finalmente, se valora positivamente el método de BASU et al. (1975) frente a otras técnicas clásicas (minerales pesados, feldespatos, etc.) para ser aplicado en ciertos casos a problemas de procedencia. [ABSTRACT] The provenance of sandstones has been approached through the study of the quartz grains tipologies according to the methods proposed by several authors. This paper tries to check up the validity of these methods. Basu's et al method has been chosen to study the sandstones of the Buntsandstein of the Iberian Range for considering it the most suitable. The method has verified the gneissic nature of the source area, as well as the spatial evolution of the maturity of the studied sandstones. Finally, Basu's method, applied on certain provenance problems, la considered better than clasical ones (heavy minerals, feldspars, etc).
Modern stream sands from compound crystalline sources: Coniposition and sand generation index
(Geological Society of America, Processes controlling the composition of clastic sediments, 1993) Palomares Herranz, Marta; Arribas Mocoroa, José
Compositions of modern first-cycle sands derived from granitic and metamorphic terrains in the Spanish Central System have been analyzed in order to evaluate the contributions of different bedrock types. The results of this work indicate that sand composition normally does not permit quantitative statements concerning sourceland composition. This is due to the fact that each rock type has a different potential to generate sand, dependent on such properties as its mineralogy, average crystal size, and microfabric. We introduce the concept of sand generation index (SGI), which is a relative measure of the capacity of one bedrock type to generate sand with respect to another in a compound source area. SGI of granitoid is 14 to 20 times greater than SGI of slate-schist when these rock types appear in a dual crystalline source. In the case of a gneiss + slate-schist source rock association, the SGI of gneiss is about five times greater than the SGI of slate-schist, whereas the SGI of gneiss is similar to that of granitoid in case of a dual granitoid + gneiss source. Finally, our results show that quantitative estimates of source land composition based on QFR diagrams are hazardous if the concept of the SGI is disregarded.
Análisis petrológico de depósitos de terrazas aplicado al estudio de los procesos de captura en los ríos Adaja, Voltoya y Eresma (provincias de Segovia y Valladolid)
(Revista de la Sociedad Geológica de España, 1997) Tortosa, A.; Arribas Mocoroa, José; Garzón Heydt, Guillermina; Fernández García, Paloma; Palomares Herranz, Marta
La caracterización composicionaI y textural de los depósitos arenosos de terrazas de los ríos Adaja, Voltoya y Duero ha permitido resolver la procedencia de otras secuencias de terrazas, relacionadas con estos ríos pero hasta ahora de difícil asignación genética, como son las situadas al SE de Pozáldez y en el área de Olmedo. La secuencia de terrazas del área de Pozáldez se ha dividido en dos grupos: el primero, correspondiente a las terrazas más antiguas, está relacionado con el retrabajamiento de las terrazas del Duero por el río Voltoya durante su encajamiento. El segundo grupo, formado por las terrazas más modernas, se relaciona con los depósitos del río Adaja, marcando el límite de ambos grupos el momento de la captura de este último por el Voltoya. Por otra parte, la secuencia de terrazas del área de Olmedo refleja una gran similitud con las arenas del sistema del Voltoya, pudiendo ser considerado como parte del mismo. La integración de los datos geomorfológicos y petrológicos ha permitido elaborar un modelo de evolución de la red fluvial basado en capturas sucesivas entre los ríos Adaja, Voltoya y Eresma. [ABSTRACT] The analysis of the composition and texlures of the sandy deposits of terraces of Adaja, Voltoya and Duero rivers permits to solve the provenance of other terrace sequences, as those appearing at the SE of Pozáldez and near Olmedo, without a clear parentage with the rivers mentioned aboye. TheAdaja terraces are constituted by arkoses with crystalline rock fragments and a light dominance of k-feIdspar over plagioclase grains, representing the more immature deposits analysed. The Voltoya terraces al so consist of arkoses with a greater dominance of k-feldspar over plagioclase and with the occurrence of metamorphic rock fragments. The Duero terraces are formed of subarkoses with low content in rock fragments, showing a great dispersion of the contents in feldspars and rock fragments typologies. Based on these data, the upper terraces appearing near Pozáldez are constituted by the reworking product of Duero terraces by lhe Volloya river during the incision of its channel. The lower terraces are constituted by recent terraces whose origin is related to the Adaja river. Thus the limit between these two groups of terraces represents the capture of the Adaja by the Voltoya river. On the other hand, the terrace sequence near Olmedo shows a great similarity with the deposits of the VoItoya terraces, so that its origin is related to this terrace system. The integration of geomorphologic and petrologic data permits lhe reconstruction of the evolution of the fluvial network, based on successive channel piracy. Firslly, lhe Adaja river was captured by the Voltoya river, and subsequently both the Adaja and Voltoya rivers were captured by the Eresma river. The origin of this set of captures is the general trend to the NE of the groundwater flow, caused by tectonic tilting, and improving the hydraulic efficiency of the basin. Finally, the composition of the terrace deposits was greatly influenced by the piracy processes that produced a new input of sediments with different provenance. Incision of lhe channels also affected composition by reworking of intrabasinal sediments. Both processes acted by mixing sediments producing a homogenisation of its composition. As a consequence, an important loose of detailed information about the source area of the different feeders occurs.
Grain size, composition, porosity and permeability contrasts within cross-bedded sandstones in Tertiary fluvial deposits, central Spain
(Sedimentology, 1993) Hartkamp, Christel A.; Arribas Mocoroa, José; Tortosa, A.
Permeability measured with a portable probe pcrmcflmeter on outcrops of cross·bcdded sandstones ranges betwecn 0·9 and 19 O. The highest pcrmeability (2-19 0 with an avcrage of8·5 D) occurs in thc coarsest grained foresct laminae (CFL). intermediate values (2-120 with an average of 5·3 D) occur in fincr grained foreset laminac (FFL) and thc lowest values (0·9-1 0 0 with un avcrage of 4·8 D) occur in boltomsct laycrs (BL). In the cross·bcds the uverage grain sizc rangcs from medium graincd sand in the CFL to finc grained s,lnd in thc FFL and BL. In all three subf'lcies. the average size of the primary pores is approximately It/> unit smaller than the averagc grain size. The abundance of unstablc carbonatc clasts correlatcs with incrcasing avcrage grain size, micritic clasts being most abundant in the CFL. Converscly. quartz content incrcascs with decreasing grain size and is highest in the FFL and BL. Oiagenetic destruction of primary porosity by compact ion and cementation. as well �IS generation of sccondary porosity through dissolution, were controlled by the original mineralogical composition of the sand. Contrasts in grain size detcrmine the primary pore size contrasts and differences in composition bctwecn CFL. FFL and BL. Permeability contrasts reflect variations in averagc primary pore size rather than differenccs in total porosity. Probe permeability contrasts between eFL. FFL and BL depend on contrasts in llverage pore size and contrasts in mineralogical composition between the subfacies.
Interpretación de la procedencia mediante el estudio de la tipología de los granos de cuarzo: aplicación a las areniscas del Buntsdandstein de la Cordillera Ibérica.
(IX Congreso Nacional de Sedimentología : Salamanca, octubre de 1980. 1, Resúmenes y comunicaciones, 1980) Arribas Mocoroa, José; Marfil Pérez, Rafaela; Peña, José Andrés de la
Geological modelling of a reservoir analogue: Cenozoic meander belts, Loranca Basin, Spain
(Petroleum geoscience, 1995) Díaz Molina, Margarita; Arribas Mocoroa, José; Gómez Fernández, Juan José; Tortosa, A.
The reconstruction of meander belts was approached by detailed geological mapping, the interpretation of exposed sandstone bodies and the application of sedimentological concepts. The single reconstructed meander belts were integrated, considering stratigraphic position and thickness in a threedimensional model of the depositional architecture. Some useful reservoir parameters, such as volume of meander loops, areas of interconnection and fluid flow barriers, are calculated from the obtained model. Sandstone porosity is mainly of primary origin and mechanical compaction is the most iotense diagenetic feature. Models of estimated permeability evolution in the point bar sequences have been developed. Gamma ray readiogs from different lithologies were obtained and grouped accordiog to their palaeoenvitonmental classification. The results are comparable to well logs and aid subenvitonmental characterization of continental deposits.
Procedencia y evolución diagenética de las areniscas Permo-triásicas de la Cordillera Ibérica (Sierra de Albarracín-Boniches-Talayuelas, provincias de Teruel y Cuenca)
(Cuadernos de geología ibérica, 1987) Cruz, Berta de la; Marfil Pérez, Rafaela; Peña, José Andrés de la; Arribas Mocoroa, José
Las series detríticas rojas atribuidas al Permo-Triásico en esta zona de la Cordillera Ibérica comprenden una potente sedimentación terrígena depositada en ambiente fundamentalmente fluvial, controlada por la tectónica que, según ALVARO el al. (1982), representa las primeras etapas de relleno de cuencas de tipo semigraben del aulacógeno celtibérico. A partir de sondeos de testificación continua, realizados por la J. E. N. para una campaña de prospección de uranio, se ha llevado a cabo un estudio petrológico de las areniscas, haciendo hincapié en la procedencia y evolución diagenética de las mismas. Para la realización de este trabajo se han adoptado las unidades litoestratigráficas propuestas por VIALLARD (1973) para el Permo-Triásico en este área de la Cordillera Ibérica. La composición de las areniscas (fig. 1) varía de sublitoarenitas a cuarzoarenitas e incluso subarcosas en la unidad basal. En la unidad intermedia la composición es más homogénea, arcosas y subarcosas, salvo en el área de Talayuelas, donde continúan siendo sublitoarenitaso En la unidad superior vuelven de nuevo a ser sublitoarenitas, con subarcosas subordinadas; excepto en el área de Boniches, donde las arcosas dominan hasta el techo. El análisis de los datos composicionales y texturales nos ha permitido deducir la existencia de diferentes áreas fuentes para cada uno de los sectores estudiados, así como también su variación a lo largo de la sedimentación permo-triásica. Para la unidad basal hemos deducido una procedencia de áreas fuentes volcánicas y metamórficas observándose un cambio de los aportes en la unidad intermedia, con macizos granítico-gneísicos como principales contribuyentes. En la unidad superior se produce un cambio no tan generalizado, con aportes metamórficos a excepción del sector de Boniches y Talayuel donde persisten las áreas fuentes granítico-gneísicas hasta el techo. Respecto al medio de sedimentación, el hecho de encontrar en la unidad basal niveles de areniscas con caracteres texturales eólico junto con la presencia de magnesita relacionada con costras ferruginosas y cantos blandos oxidados, nos indican la existencia de los períodos climáticos más áridos dentro de las tres unidades. Los procesos diagenéticos más importantes sufridos por estas areniscas varían a lo largo de las unidades como queda reflejado en la figura 2. Según la composición y secuencia de formación de los cementos y otros minerales autigénicos, se puede sintetizar la evolución de la naturaleza de los fluidos intersticiales de la manera siguiente: unidad basal: aguas ácidas y óxicas durante la eodiagénesis y telodiagénesis y alcalinas en la mesodiagénesis. Unidad intermedia: aguas alcalinas y alternancia de óxicas y anóxicas en la eodiagénesis y mesodiagénesis; aguas óxicas y localmente alcalinas durante la telodiagénesis. Unidad superior: igual que en la anterior pero con dominio de ambientes óxicos en las dos primeras etapas y ácido en la telodiagénesis. Asimismo, la secuencia típica de precipitación de cementos a partir de aguas dulces : ilita-caolinita-cuarzo-dolomita (ALMON & I VIES, 1979) sería válida para la unidad inferior pero no para las unidades intermedia y superior. En éstas, la secuencia coincidiría con la de precipitación a partir de aguas diagenéticas marinas propuesta por BURLEy el al. (1985): feldespato potásico-ilita-interestratificados tal esmectita-cuarzo-dolomita. La porosidad presente en las areniscas (fig. 6) es de origen seco dario, con valores máximos (alrededor del 15%) en la unidad intermedia arcósica. Genéticamente la relacionamos con la disolución feldespato potásico y del cemento dolomítico durante la telodiagénesis, como consecuencia de la circulación de aguas meteóricas. El rango de los carbones asociados indica que las areniscas perritriásicas estudiadas han sufrido un enterramiento relativamente somero (no más de 3.000 m), con temperaturas próximas a los 100ºC
Petrographic evidence of different provenance in two alluvial fan systems (Palaeogene of the northern Tajo Basin, Spain)
(Special publication - Geological Society of London, 1991) Arribas Mocoroa, José; Arribas Mocoroa, María Eugenia
Palaeogene detrital deposits of the northern Tajo Basin are coalescent alluvial fan systems interfingering distally with lacustrine carbonates. Non-carbonate extrabasinal clasts increase to the east while carbonate extrabasinal clasts decrease. Rock fragments increase to the west, while the feldspar/quartz ratio remains constant. Rock fragments define two sedimentary domains: the Iberian, in the east, was derived from Mesozoic rocks of the Iberian Range, and the Central System, to the west, was derived from Cretaceous cover and Palaeozoic metamorphic basement. Evolution of sandstone composition is related to erosion of the source areas and is different in the two domains. The tectonic setting is apparently "recycled orogen", providing calcareous rock fragments are included in the total lithic clasts.