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 21

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, Rosana
The 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.
Diagenesis, provenance and reservoir quality of Triassic TAGI sandstones from Ourhoud field, Berkine (Ghadames) Basin, Algeria
(Marine and Petroleum Geology, 2002) Rossi, Carlos; Kälin, Otto; Arribas Mocoroa, José; Tortosa, A.
The Triassic TAGI (Trias Argilo-Gréseux Inférieur) fluvial sandstones are the main oil reservoirs in the Berkine Basin, Algeria. Nonetheless, their provenance and diagenesis, and their impact on reservoir quality, are virtually unknown. Samples from the Ourhoud field, representing the Lower, Middle and Upper TAGI subunits, were studied using a combination of petrographic, mineralogical and geochemical techniques. The Lower TAGI sandstones have an average framework composition of Q98.3F0.6R1.1 and 95% of the quartz grains are monocrystalline. By contrast, the Middle–Upper TAGI sandstones have an average framework composition of Q88.3F9.8R1.9 and 79.7% of the quartz grains are monocrystalline. The Lower TAGI quartz arenites derived from Paleozoic siliciclastic rocks, whereas the Middle–Upper TAGI subarkoses originated mainly from metamorphic terrains. This change in provenance is a potential criterion for correlation within the TAGI. Also, this change has contributed to the significantly different diagenetic paths followed by the Lower TAGI quartz arenites and the Middle–Upper TAGI subarkoses. Grain-coating illitic clays are abundant in the Lower TAGI, where they exert a critical control on reservoir quality. These clays are interpreted as pedogenic and/or infiltrated in origin and to have had, in part, smectitic precursors. Shallow burial Fe-dolomite cementation was favored in the downthrown block of the field-bounding fault, where it contributed to the poor reservoir quality. Magnesite–siderite cements are multiphase. The earliest generation is composed of Fe-rich magnesite that precipitated during shallow burial from hypersaline fluids with high Mg/Ca ratios, probably refluxed residual brines associated with the Liassic evaporites. Later magnesite–siderite generations precipitated during deeper burial from waters with progressively higher Fe/Mg ratios. Authigenic vermicular kaolin largely consists of dickite that replaced previously formed kaolinite. Dickitization was followed by late-stage illitization related to the dissolution of detrital and authigenic K-feldspar. Quartz, the most abundant cement, was mainly sourced by the pressure- or clay-induced dissolution of detrital quartz and is a critical factor controlling the reservoir quality. Overall, quartz cement is more abundant in the Lower TAGI than in the Middle–Upper TAGI, and this increase correlates with a decrease in average porosity. Within the Lower TAGI, quartz cement abundance is stratigraphically very variable, which is in part related to facies controlled variations in grain-coating clay, resulting in major vertical variations in reservoir quality. Anhydrite and barite cements postdate quartz overgrowth. The sulfate necessary for their formation was likely sourced by deep subsurface dissolution of Late Triassic–Liassic evaporites.
Evolution of sandstone composititon in a continental foreland basin. Loranca Basin, Spain.
(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) Tortosa, A.; Arribas Mocoroa, José; Cañaveras, J.C.; García del Cura, M. Ángeles; Soria, Jesús
Caracterización clastométrica de los depósitos detríticos de cabecera de arroyos en el Sistema Central: influencia de la litología del área fuente
(Boletín de la Real Sociedad Española de Historia Natural. Sección geológica, 1990) Palomares Herranz, Marta; Tortosa, A.; Arribas Mocoroa, José
Se caracterizan texturalmente los depósitos detríticos actuales generados en las zonas de cabecera de arroyos que drenan macizos constituidos por una única litología (granítica, gnéisica o pizarroso-esquistosa) en el Sistema Central. Dicha caracterización se basa en el análisis de las distribuciones clastométricas realizadas a partir de intervalos de tamaños de grano comprendidos entre 5,65 mm y 0,062 mm. Las distribuciones se caracterizan por presentar una o varias poblaciones, siendo la población transportada por saltación la más importante cuantitativamente. Las poblaciones transportadas por tracción y suspensión solamente están presentes en algunas muestras. Se han podido establecer los límites que separan cada una de las poblaciones, así las poblaciones de tamaños de grano inferiores a 0,27 mm han sido transportadas en suspensión y las de tamaños superiores a 1,5 mm lo han hecho por tracción. Por otra parte mediante los parámetros estadísticos de Md, So y Sk (mediana, selección y asimetría, respectivamente) es posible diferenciar entre depósitos de origen granítico, gnéisico y pizarroso-esquistoso. Los sedimentos de origen granítico poseen una mediana de 1,49 mm, selección «moderada» (So 1,63) y asimetría, en general, hacia tamaños gruesos (Sk = 0,92). Los depósitos de origen gnéisico poseen una mediana baja (Md 1,3 mm), selección «pobre» (So = 2, 23) Y asimetría hacia tamaños finos (Sk = 1,1); mientras que los depósitos de origen pizarroso-esquistoso poseen una mediana alta (Md = 4,47 mm), selección «muy pobre» (So = 2,45) Y asimetría hacia tamaños gruesos (Sk 0,98). Como conclusiones, cabe destacar que aparte de los factores que clásicamente se han venido considerando como determinantes de la morfología de las distribuciones clastométricas de los depósitos detríticos (medio de transporte y sedimentación), la litología del área fuente incide directamente en dicha morfología en sedimentos generados bajo condiciones de corto periodo de transporte y alta energía del mismo. De este modo, se abre una nueva vía de estudio para la caracterización litológica del área fuente en depósitos antiguos originados bajo condiciones similares a los analizados en el trabajo. [ABSTRACT] In this work we have analized the textural properties of modern detritaI deposits colected on head stream of the Central System (Spain). The source areas are single lithology (granitic, gneissic or sI ateschistic). The textural analysis is based on cumulative curves of grain size distributions between 5.65 mm and 0.062 mm. These distributions are composed by one or several populations. The main population is transported by saltation, while suspension and traction are represented only in sorne samples. We bear in mind that grain with size less than 0.27 mm are included in suspension population. Traction population is constituted by grains of more than 1,5 mm in size. On the other hand, the analysis of statistical parameters (median, sorting and skewness) permits us to discrimine between granitic, gneis sic and slate-schistic source deposits. The granitic so urce sediments have Md = 1.49 mm, «moderate» sorting (So = 1.63 mm) and skewness towards coarse sizes (Sk = 0.92). The gneissic source deposits have Md = 1.3 mm, «poor» sorting (So = 2.23) and skewness towards fine sizes (Sk = 1.1); however the slate-schistic source deposits have high median (Md = 4.47 mm), «very poor» sorting (So = 2.45) and skewness towars coarse sizes (Sk = 0.98). We conclude that the source area lithology falIs most heavily on morphology of grain size distributions than sedlmentary environments, in deposits generated on head streams (high energy and Iimited transport). Thus a new way of anaIyzing data concernig the lithological characterization of source area in old deposits originated in these environments, is open.
Estudio de la fracción pesada de arenas actuales derivadas del Sistema Central y su aplicación a los estudios de procedencia.
(Boletín Geológico y Minero, 1989) Palomares Herranz, Marta; Tortosa, A.; Arribas Mocoroa, José
En el presente trabajo se caracteriza la fracción pesada de las arenas actuales generadas en el Sistema Central a partir de áreas fuentes con litología única: plutónica, gneísica o pizarroso-esquistosa. Se analiza la proporción de fracción pesada en relación al total de la muestra en función de la litología de partida y del tamaño de grano, observándose cómo dicha fracción es más abundante en las arenas derivadas de pizarras y esquistos. Asimismo la proporción de fracción pesada aumenta con la disminución del tamaño de grano en todos los casos. Se describe una asociación de minerales pesados transparentes para la fracción de tamaño más fina, 0,125-0,062 mm., en arenas de origen plutónico (turmalina, apatito, andalucita, hornblenda, circón, epidota y monacita), otra en arenas de origen gneísico (sillimanita, apatito, andalucita, turmalina, granate, circón y monacita) y otra en arenas de origen pizarroso-esquistoso (sillimanita, apatito, circón, epidota, distena, rutilo y esfena). Se pone en duda la utilidad de dichas asociaciones como medio de deducir la litología del área de procedencia de los depósitos arenosos fósiles; en primer lugar por su alta dependencia con el tamaño de grano de la arena, y en segundo lugar por la semejanza de las mismas entre unas litologías de partida y otras. [ABSTRACT] In this work we have analized the heavy mineral fraction of modern sands derived from Single source lithology (plutonic gneis sic or slate-schists) in the Central System (Spain). The amount of heavy mineral fraction is very high in slate-sehists derived sand, and in all samples heavy mineral fraction increases when grain-size reduces. Transparent heavy mineral associations are described on finest grain-size fraetion (0,125-0,062 mm.) to sands with plutonic provenance (tourmaline, apatite, andalueite, hornblende, zircon, epidote and monacite); one other to sands with gneissic provenance (sillimanite, apatite, andalucite, tourmaline, granet, zircon and monacite); and one other to sands with slateschists provenance (sillimanite, apatite, zircon, epi dote, distene, rutile and sphene). We put in doubt the usefulness of heavy mineral associations as a tool to provenance analysis in aneient sand deposits; first by the high dependence of the associations with grain-size sand, and second by the similitude of associations in sand of different parent rocks.
Caracterización composicional de los depósitos arenosos actuales generados en el Sistema Central.
(Estudios Geológicos, 1989) Tortosa, A.; Palomares Herranz, Marta; Arribas Mocoroa, José
Se caracteriza composicionalmente la fracción ligera arenosa de los depósitos detríticos actuales generados en zonas de cabecera de arroyos que drenan macizos del Sistema Central con distintas litologías (plutónicas, gnéisicas o pizarras-esquistos). Dicha caracterización se ha basado en el análisis petrográfico de las muestras recogidas. Este análisis se ha efectuado, en cada muestra, en cinco fracciones de tamaño con intervalos de l 0 entre 2 mm y 0,062 mm. De este modo se estudia el control que ejercen tanto la litología del área fuente como el tamaño de grano en la composición modal de los depósitos. Con la disminución del tamaño de grano se produce una disminución del contenido en fragmentos de roca. Por el contrario, el porcentaje de feldespatos aumenta en las fracciones de tamaño más fino debido a su inestabilidad mecánica. Dicha inestabilidad nos hace dudar, por otro lado, de la utilidad del índice K/P (relación entre feldespato potásico y plagioclasa) en análisis de procedencia de areniscas ya que hace variar considerablemente su valor de unas fracciones a otras. El contenido en granos de cuarzo es independiente del tamaño de grano en arenas de procedencia plutónica, mientras que en los depósitos derivados de áreas metamórficas aumenta con la disminución del tamaño de grano. Las tendencias de variación de todos los componentes en función del tamaño de grano son similares en todos los depósitos, sin embargo, el contenido en cadá uno de ellos difiere mucho en función de la litología de partida. El lugar de proyección de los depósitos estudiados en un diagrama de composición QFFR (Pettijohn et al., 1973) está controlado por el tamaño de grano y por la litología del área de procedencia. Así, las arenas de origen pizarroso-esquistoso aparecen proyectadas en todas sus fracciones cerca del margen QFR. Por el contrario, el lugar de proyección de las arenas de procedencia plutónica y gnéisica varía con el tamaño de grano desde el polo FR hasta las proximidades del margen QF, por lo que consideramos que la proyección de una única fracción de tamaño específico (0,5-0,25 mm.), si bien permite la discriminación de litologías, hace que se pierda una importante información acerca de la composición global del depósito. [ABSTRACT] In this work we have studied the light mineral fraction of modern sands derived from single source lithologies (plutonic, gneissic or slate-schists) in the Sistema Central (Central Spain). In this way we can analize the control of the source area lithology in sand composition. First we pay attention on the control of grain size sand in composition. Rock fragments decrease when grain size decreases. However, the amount of feldspar increases due to its low mechanical stability. Thus, the K/P index (K-feldspar/plagioclases) is highly variable with grain size, because the different mechanical stabilities of both minerals. The trends of the amounts of components in relation with grain size are very similar, in all deposits. However, each percentages vary markedly between source areas with different lithologies. The projection area of the studied sands in a QFFR diagram is highly controled by grain size and lithology of source area. Thus, sands derived from slate-schists lithology appear near QFR fringe in all grain size fractions. Sands derived from plutonic or gneissic rocks have a high dispersion in the diagram, from FR pole to QF fringe, depending on grain size of the sand. We conclude that the use of a single sand size fraction (0,5-0,25 mm) to provenance analysis permits to discrimine source lithologies, but with a loss of information about global deposit composition.
Tipologías de cuarzo como indicadores de la procedencia en areniscas: excepciones al método de Basu et al. (1975)
(Estudios Geológicos, 1988) Tortosa, A.; Palomares Herranz, Marta; Arribas Mocoroa, José
En el presente trabajo se analiza el contenido de las distintas tipologías de cuarzo, definidas por Basu et al. (1975) para análisis de procedencia, en depósitos arenosos actuales, generados a partir de macizos del Sistema Central con distintas litologías (granitos, gneises, pizarras-esquistos). Aplicando la metodología de dichos autores se observa que, para los depósitos estudiados, pierde validez para discriminar áreas de procedencia plutónica y metamórfica de alto grado en función del contenido en las tipologías monocristalinas. No obstante, se corrobora la utilidad del contenido en las tipologías policristalinas para diferenciar áreas metamórficas de bajo grado. [ABSTRACT] In this study we have analized the content of the different detrital quartz types (Basu et al., 1975) in recent sands derived fram single source areas (granitic, gneissic and slate-schists lithologies) in the Sistema Central. Fallawing the methadalagy af Basu el al. (1975), far sand provenance interpretation, we have observed that, in these deposits, the cantent of monocrystaline quartz types is not useful to discriminate plutonic and high rank metamorphic sources. However, we can canfirm the validity of the policrystaline types content to distingllish sands of low rank metamorphic parentage
Petrographic characterization of coeval carbonate grains in recent fluvial sands (Serranía de Cuenca, Spain)
(Plinius (Milano), 2002) Arribas Mocoroa, María Eugenia; Tortosa, A.; Arribas Mocoroa, José
The effects of source rocks and chemical weathering on the petrogenesis of siliciclastic sand from the Neto River (Calabria, Italy): implications for provenance studies
(Sedimentology, 2001) Le Pera, Emilia; Arribas Mocoroa, José; Critelli, Salvatore; Tortosa, A.
Plutonic and gneissic rocks of the Sila Massif in the uppermost portion of the Neto drainage basin (Calabria, Southern Italy) weather and erode under a humid Mediterranean climate. During the development of weathering pro®les, a combination of chemical weathering and granular disintegration processes occurred. Chemical weathering involves a loss of both plagioclase (mainly during grus generation) and K-feldspar (mainly during soil formation). This loss is attributed to transformation of plagioclase to clay minerals and to leaching and dissolution of K-feldspar. Sand composition is quartzofeldspathic and nearly homogeneous along the main channel of the Neto River, even where the river cuts across a blanket of sedimentary cover. Thus, ¯uvial transport does not alter sand composition within the Neto drainage basin. Petrographic indices are effective in (1) discriminating between contributions from similar (granite and gneiss) source rocks (Qm/F); (2) relating the provenance of plutoniclastic and gneissiclastic sand found in the headwaters to grus horizons (Qm/F; Q/Rg); and (3) distinguishing between upstream ®rst-cycle and downstream multicycle sand (Q/Rg). This last distinction is further emphasized by considering both aphanitic and phaneritic varieties of rock fragments (RgRmRs diagram). Chemical weathering is the main sand producer within the regolithic environment in northern Calabria. In addition, rapid erosion resulting from steep slopes removes weathered products, and rapid and short transport leads to minimal sediment maturation. In general, the F/Q index is climate and relief dependent; thus, it should be used in conjunction with palaeoclimatic and palaeophysiographic evidence for provenance interpretations of ancient quartzofeldspathic sandstones.
Sand composition in an iberian passive margin fluvial course: the Tajo River
(Plinius (Milano), 2002) Le Pera, Emilia; Arribas Mocoroa, José; Tortosa, A.