Person: Arribas Mocoroa, José
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First Name
José
Last Name
Arribas Mocoroa
Affiliation
Universidad Complutense de Madrid
Faculty / Institute
Ciencias Geológicas
Department
Mineralogía y Petrología
Area
Petrología y Geoquímica
Identifiers
31 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 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, JoséEl 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).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 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 EugeniaWe 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.Item 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, JoséBuntsandstein 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.Item 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.Item Chert in bioturbated sediments of Sabkha paleoenvironment(Abstracts: Flint production and exchange in the Iberian Southeast, III Millennium B.C : VI International Flint Symposium, post-symposium field trip, OCtober 5th-10th,1991, Granada-Almería / by A. Ramos Millán ... [et al.], 2001) Arribas Mocoroa, José; Bustillo Revuelta, María Ángeles; Díaz Molina, Margarita; Bustillo Revuelta, María Ángeles; Ramos Millán, A.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 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, EmiliaThe 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.Item Diagenetic paths in a low subsident Triassic Basin: NW zone of Iberian Range Spain.(Plinius (Milano), 2002) Ochoa, M.; Arribas Mocoroa, José