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 30

Las facies superiores del Muschelkalk en el borde norte de la Rama Aragonesa de la Cordillera Ibérica
(Cuadernos de geología ibérica, 1987) Arribas Mocoroa, José
La litoestratigrafía de las facies superiores del Muschelkalk en la región de estudio (<
Petrografía de los depósitos arenosos generados por el sondeo surgente de Granátula de Calatrava (Ciudad Real): implicaciones genéticas de la surgencia
(Revista de la Sociedad Geológica de España, 2001) Ochoa, M.; Arribas Mocoroa, José
El sondeo surgente de Granátula de Calatrava (activo desde el 25 de julio de 2000 hasta el 16 de enero de 2001) generó un depósito eminentemente arenoso de 36 cm de espesor a 50 m de distancia del pozo. El estudio petrográfico de los materiales arenosos emitidos ha permitido aportar nuevos datos sobre la génesis de la surgencia. El registro arenoso es cuarzolítico con fragmentos de roca sedimentaria (areniscas con cemento ferruginoso y carbonático) y metasedimentaria (metacuarzoarenitas y pizarras), que se interpretan como procedentes de los niveles detríticos de la cuenca neógena de Granatula-Moral de Calatrava. A su vez, estos últimos materiales proceden de la erosión de las series metasedimentarias ordovícicas que constituyen el basamento hercínico local y los bordes de la cuenca sedimentaria. Los primeros depósitos generados por la surgencia se caracterizan por su elevado porcentaje de fragmentos de areniscas con cemento ferruginoso, carbonático y opalino. Estos clastos proceden de niveles ferruginosos generados por paleosurgencias hidrotermales durante el inicio de la actividad volcánica plio-cuaternaria desarrollada en el Campo de Calatrava (Poblete, 1994). La presencia mayoritaria de estos clastos en las capas basales del depósito generado por la surgencia indica que los niveles ferruginosos de los que proceden pudieron actuar como sello de un acuífero confinado, cuya rotura por el sondeo dio lugar a la surgencia. [ABSTRACT] The flowing-well of Granátula de Calatrava (active from 25 July 2000 to 16 January 2001) originated a 36 cm-thick sandy deposit far 50 m from the well-site. The petrographic study of the ejected sandy material permits to yield new data about the genesis of the flowing-well. The sandy record is quartzolithic with sedimentary rock fragments (sandstones with ferruginous and carbonate cements) and metasedimentary rock fragments (meta-quartzarenites and slates). The origin of the sand is related to the Tertiary clastic facies from the Neogene Granátula-Moral de Calatrava Basin. The metasediments were provided from the erosion of Ordovician metasedimentary rocks that constitute the local Hercynian basement. The presence of a higher content of sandstone rock fragments with ferruginous, opaline and carbonate ceinents at the base of the sandy deposit formed as a result of the well indicates that they formed the upper limit of a confined aquifer. These levels were generated by hot paleo-springs during the Pliocene-Quaternary volcanic activity developed in the Campo de Calatrava (Poblete, 1994).
Interpreting carbonate particles in modern continental sands: an example from fluvial sands (Iberian Range, Spain)
(Geological Society of America. Special Paper, 2007) Arribas Mocoroa, José; Arribas Mocoroa, María Eugenia
We analyzed modern fluvial sands in the Iberian Range in order to obtain an accurate description of the different typologies of carbonate grains and to interpret their origin. Head streams of the Iberian Range mainly receive carbonate sediments as (1) fragments from ancient carbonate rocks, and (2) penecontemporaneous car bonate grains generated in the fluvial channels or in associated subenvironments. The erosion of proximal carbonate sources (Jurassic and Cretaceous in age) contributes to the generation of carbonate rock fragments. In addition, erosion of recent freshwater tufas, carbonate soils, and other recent carbonates produces an important volume of penecontemporaneous carbonate particles. Temperate to subhu mid climate and short transport conditions promote good preservation of the composition and textures of carbonate grains in modern fluvial sands. Detailed petrographic analyses on penecon temporaneous carbonates provide diagnostic clues of their origin. Four main petro graphic classes of penecontemporaneous grains have been established: (1) penecon temporaneous micritic grains, which are composed of microcrystalline calcite with a filamentous or laminated microfabric, are derived from erosion of recent freshwa ter carbonate tufas. Penecontemporaneous micritic grains with alveolar microfabric are derived from recent carbonate soils. (2) Penecontemporaneous sparitic grains, which are composed of single crystals or of mosaics with filamentous microfabric, are the result of erosion of carbonate tufas. Other penecontemporaneous sparitic grains include Microcodium and speleothems fragments. (3) Penecontemporaneous coated grains, which are composed of a nucleus plus a coating of penecontemporane ous carbonate, represent bioinduced carbonate particles (cyanoliths) that originate in streams. (4) Penecontemporaneous bioclasts, made from charophytes, ostracods, and mollusks, are rare. ldentification of these grain categories in ancient deposits has implications for coeval carbonate supplies during fluvial sedimentation.
Diagenetic paths in the margin of a Triassic Basin: NW zone of the Iberian Chain, Spain
(International journal of earth sciences, 2005) Ochoa, M.; Arribas Mocoroa, José
Buntsandstein deposits generated in a slowly subsiding basin on the western margin of the Iberian Chain are represented by a stratigraphic succession of fluvial deposits less than 100 m thick (conglomerates, sandstones, and shales). Diagenetic processes in sandstones can be grouped as eodiagenetic, mesodiagenetic, and telodiagenetic. Eodiagenesis can be associated with Muschelkalk, Keuper, and probably early Jurassic times. Mesodiagenesis is probably related to Jurassic times. Diagenetic chemical reactions suggest a maximum burial less than 1.5 km and low temperatures (<120ºC). Patterns of porosity reduction by compaction and cementation suggest four diagenetic stages: (1) Loss of primary porosity by early mechanical compaction; (2) early cementation (Kfeldspar and dolomite); (3) dissolution of cements; and (4) framework collapse by re-compaction. These stages are manifested by the presence of two types of sandstone. Type I sandstones present high intergranular volume (mean, 30%). Type II sandstones are characterized by high compactional porosity loss and exhibit low values of intergranular volume (mean, 16.9%). Type II sandstones are associated with the dissolution of cement and later re-compaction of type I sandstones. An intermediate telodiagenetic phase is deduced and related to the sharp unconformity between Lower Cretaceous sediments and the underlying sediments. This suggests that a mechanically unstable framework collapsed during the Cretaceous, generating type II sandstones. The analyzed diagenetic paths have a wide applicability on similar marginal areas of rift basins.
Composition of modern stream sand derived from a mixture of sedimentary and metamorphic source rocks (Henares River, Central Spain)
(Sedimentary Geology, 2000) Arribas Mocoroa, José; Critelli, Salvatore; Le Pera, Emilia
The Henares River, central Spain, flows westward from the Iberian Range (Mesozoic sedimentary rocks) under semiarid climatic conditions. In the middle and lower reaches, the Henares River receives sediment from three tributaries (Cañamares, Bornova and Sorbe rivers) that drain the Central System (Paleozoic crystalline rocks, low-grade metamorphic rocks, and minor amounts of Mesozoic sedimentary rocks). Modern sands from the Henares River and its tributaries offer an excellent opportunity to evaluate the importance of lithology and physiography in determining detrital modes from mixed metamorphic and sedimentary source terrain. Sand modes from the Henares River and its tributaries are quartzolithic. They plot in a restricted area on a QmFLt diagram, with low contents of feldspar and variable amounts of quartz, and carbonate, metamorphic and minor siliciclastic lithic fragments. Higher feldspar abundances in the Cañamares and Bornova stream sands are related to the erosion of gneissic rocks. By contrast, sands from Sorbe River are low in feldspar, reflecting the absence of coarse metamorphic sources. Thus, proportions of bedrock lithologies in the drainage sub-basins are the main control on detrital modes of the tributaries. In addition, slope acts on the sand productivity of source rocks. Sedimentary source rocks in the upper reaches of the three tributaries have a poor productivity in the carbonate lithic fragments (Lsc), compared with the Lsc productivity of sedimentary sources located downstream, with higher relief. The percentage of bedrock types in the source area versus petrographic indices (Lm/L, Lss/L and Lsc/L) provide a useful contrast between source and sand composition in the tributaries. Thus, the high content of metamorphic lithic grains in the lithic grain population over-represents this lithology (slate plus schist) at the source terrain. Lithic grains from sedimentary clastic sources generate few recognizable grains (Lss) in the lithic grain population. Local supplies from carbonate sources may produce important increases of Lsc in short reaches of the channels. Sand compositions in the Henares River seem to be very homogeneous in a QmFLt diagram, with only minor differences caused by the supplies from the tributaries. These differences can be modeled in terms of end-member mixing processes between Henares detritus and detritus from the relevant tributary. These mixing processes are more evident when lithic grain contents (LmLvLs and LmLssLsc diagrams) are compared. Changes produced by inputs from the Cañamares, Bornova and Sorbe rivers are not permanent along the Henares course. An important homogenization of Henares sand composition takes place by the mixing of tributary deposits with previously deposited Henares River terraces. Abrasion during transport does not appear to cause significant changes in the sand composition along the Henares River.
Diagenetic paths in a low subsident Triassic Basin: NW zone of Iberian Range Spain.
(Plinius (Milano), 2002) Ochoa, M.; Arribas Mocoroa, José
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
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.
Sandstone petrofacies in the northwestern sector of the Iberian Basin
(Journal of iberian geology, 2007) Arribas Mocoroa, José; Ochoa, M.; Mas Mayoral, José Ramón; Arribas Mocoroa, María Eugenia; González Acebrón, Laura
During the most active rifting stages in the northwestern sector of the Iberian Basin (Cameros Basin and Aragonese Branch of the Iberian Range), thick sequences of continental clastic deposits were generated. Sandstone records from Rift cycle 1 (Permo-Triassic) and Rift cycle 2 (Late Jurassic-Early Cretaceous) show similarities in composition. Based on the most recent data, this paper describes sandstone petrofacies developed during both rifting periods. Six petrofacies can be distinguished: two associated with Rift cycle 1 (PT-1 and PT-2) and four with Rift cycle 2 (JC-1 to JC-4). All six petrofacies can be classifi ed as sedimentoclastic or plutoniclastic. Sedimentoclastic petrofacies developed during early rifting stages either through the recycling of pre-rift sediments or signifi - cant palaeogeographical changes. These facies comprise a thin succession (<100 m) of clastic deposits with mature quartzose and quartzolithic sandstones containing sedimentary and metasedimentary rock fragments. Carbonate diagenesis is more common than clay mineral diagenesis. Sedimentoclastic petrofacies have been identifi ed in Rift cycle 1 (Saxonian facies, PT-1) and Rift cycle 2 (JC-1 and JC-3; Tithonian and Valanginian, respectively). In the absence of the pre-rift sedimentary cover, metasedimentoclastic petrofacies sometimes develop as a product of the erosion of the low- to medium-grade metamorphic substratum (Petrofacies JC-2, Tithonian-Berriasian). Plutoniclastic petrofacies were generated during periods of high tectonic activity and accompanied by substantial denudation and the erosion of plutonites. Forming thick stratigraphic successions (1000 to 4000 m), these feldspar-rich petrofacies show a rigid framework and clay mineral diagenesis. In Rift cycle 1, plutoniclastic petrofacies (PT-2) are associated with the Buntsandstein. This type of petrofacies also developed in Rift cycle 2 in the Cameros Basin (JC-4) from DS-5 to DS-8 (Hauterivian-Early Albian), and represents the main basin fi ll interval. Sedimentoclastic and plutoniclastic petrofacies can be grouped into three pairs of basic petrofacies. Each pair represents a ‘provenance cycle’ that records a complete clastic cycle within a rifting period. Petrofacies PT-1 and PT-2 represent the ‘provenance cycle’ during Rift-1. In the Cameros Basin, two provenance cycles may be discerned during Rift cycle 2, related both to the Tithonian-Berriasian and the Valanginian-Early Albian megasequences. Tectonics is the main factor controlling petrofacies. Other factors (e.g., maturation during transport, local supply) may modulate the compositional signatures of the petrofacies yet their main character persists and even outlines the hierarchy of the main bounding surfaces between depositional sequences in the intracontinental Iberian Rift Basin.