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 González, 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.
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
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.
Detrital modes in sedimenticlastic sands from low-order streams in the Iberian Range, Spain: the potential for sand generation by different sedimentary rocks
(Sedimentary Geology, 2003) Arribas Mocoroa, José; Tortosa, A.
The composition of modern stream sands derived from sedimentary source rocks in the Iberian Range has been analyzed in order to evaluate the contributions of the different bedrock types (mainly sandstones, limestones and dolostones). Temperate to subhumid climate and short transport conditions promote a weathering-limited denudation regime. As expected, sand composition proved to be essentially quartzolithic, with variable amounts of penecontemporaneous carbonates. Sand compositional data were compared with the exposure areas of the different bedrocks in the drainage sub-basins considered for semi-quantitative assessment of the sand generation potential of each bedrock type. Siliciclastic formations (sandstones) appear to be by far the most significant sand producers, with Sand Generation Indices (SGIs) in the medium sand fraction ranging from 4 to 20; i.e., 4 to 20 times greater than the SGI of carbonate rocks. Composition and texture are the main factors controlling carbonate sand generation. Sparitic limestones yield higher SGIs (2.8 to 20) when source terrains are constituted exclusively by carbonate rocks. High sparite grain content in the sands is enhanced by supplies from additional sources, such as calcitized dolostones. Dolomicrite sources are strongly under-represented in the sands analyzed (very low SGI), whereas the proportion of micritic limestone grains tends to be an accurate reflection of that bedrock at the source. Even though the results presented here refer to the first stage of sand generation with negligible transport effects, we think they may be helpful in the analysis and reconstruction of source terrains in ancient sedimenticlastic deposits
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.
Sand composition in an iberian passive margin fluvial course: the Tajo River
(Plinius (Milano), 2002) Le Pera, Emilia; Arribas Mocoroa, José; Tortosa, A.
Can geochemistry help in the discrimination of the provenance of sediments from a recicled orogen? A case study from the Betic Cordillera
(Plinius (Milano), 2002) Dinelli, E.; Arribas Mocoroa, José; Critelli, Salvatore; Le Pera, Emilia; Mongelli, G.; Tortosa, A.
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
Factors controlling compaction in a fluvial sequence: Oligocene-early Miocene of Lorance Basin, Central Spain
(17th Regional African European Meeting of Sedimentology : abstracts, March 26th-28th 1996 / IAS, International Association of Sedimentologists...[et al.], 1996) Arribas Mocoroa, José; Arribas Mocoroa, María Eugenia; Tortosa, A.