Geogaceta -- Nº 08, (1990)

Permanent URI for this collectionhttps://hdl.handle.net/10272/14920

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Turbiditas oolíticas cretácicas al norte de Vélez Blanco (Subbético interno, provincia de Almería)
(Sociedad Geológica de España, 1990) Vera, J. A.; Aguado, Roque; Martínez Gallego, Julián; Ruiz Ortiz, Pedro Alejandro
In the Internal Subbetic Middle and Upper Cretaceous oolite turbidites occur. Two main type of facies are present: 1) Conglomeratic beds (A2 facies) composed of clasicts of very different lithologies and ages, and 2) Oolit beds (B2 facies) which cap the conglomeratic facies and also occur as individual beds. The presence of some microfossils lets identify the Dogger oolitic limestones as the main source of the oolites. Some areas, as Sa Larga, where just the oolitic limestones are absent, are considered as probable source areas. Present fault scarps boundering such kind of areas could be ancient faults in favour of which the Dogger limestones occurred in the basin floor
Trilobites y goniatites de la cuenca carbonífera de los Santos de Maimona: deducciones bioestratigráficas
(Sociedad Geológica de España, 1990) Palacios González, M. J.; Palacios Medrano, Teodoro; Gómez Valenzuela, J. M.
In the Santos de Maimona Carboniferous Basin (Badajoz, SW of Spain), trilobites and the goniatites have been distinguished for first time, given a new significant biostratigraphy precision. The recognised trilobites species are Pseudowaribole (Geigibole) af. sajambrensis, Cyrtoproetus (Crassibole) af. crassus (Dechenelloides planus?), Linguaphillipsia mattewsi y L. af. divergens; and the goniatites genus are Imitoceras, Gattendorfia, Ammonellipsites, Muensteroceras y Winchelloceras. These association are late Tournasian (Tn3c)—early Visean, for upper levels for Carboniferous Basin
Tectónica y sedimentación en el margen oeste del «rift» terciario del valle de Ayora-Cofrentes (Valencia)
(Sociedad Geológica de España, 1990) Santisteban, Carlos de; Sáiz, J.; Ruiz Sánchez, Francisco Javier; Bello, D.
The Ayora-Cofrentes valley (Valencia) presents a rift-like structure of probable Lower Tertiary age. Its western margin is formed by a system of lystric faults with a vertical displacement of 300 m. This main fault is affected by a zone of dextral E-W strike-slip, which caused the development of a symmetrical graben. This structure is active since the Tertiary
Sobre la conexión entre la Depresión de Guadix-Baza y el Corredor del Almanzora, (Cordilleras Béticas, Andalucía Oriental)
(Sociedad Geológica de España, 1990) Guerra Merchán, Antonio
The analysis of the literature about the Guadix-Baza Basin, shows some doubts and disputations concerning the connection between the basin and the open sea through the Almanzora Corridor. This connection is considered to have finished at the end of Late Tortonian. However, recently the hypothesis of a Early Pliocene transgression in the central and eastern aereas of the basin is suggested. In this paper bibliographic data are reviewed and the stratigraphic study of the materials involved provides arguments against the hypothesis of the Early Pliocene transgression
Sequence stratigraphy and facies analysis of the Arro-Broto Turbidite System in the Castisent-Broto depositional sequence of the Hecho Group (Eocene, South-central Pyrenees)
(Sociedad Geológica de España, 1990) Solá, J.; Montaner, J.
El presente artículo se basa en un detallado análisis de las facies del Sistema Turbidítico de Arro-Broto. Los autores distinguen cinco unidades en la Sequencia Deposicional de Castisent-Broto. La unidad superior (E) equivale al lowstand wedge representado por facies limosas de offshore. Las cuatro unidades inferiores (A, B, C y D) tipifican el intervalo temprano del lowstand system tract. La unidad A se corresponde con los fan lobes, mientras que las unidades B y C son comparables con los fan channels. La parte inferiorr de la unidad D representa el slope fan, y la superior, los intervalos iniciales del lowstand wedge. Finalmente la parte inferior de la unidad E correlaciona bien con el lowstand wedge, y la superior con el intervalo basal del transgressive system tract.
Sedimentación marina somera en el devónico del anticlinorio de Puebla de Guzmán, Faja Pirítica Ibérica
(Sociedad Geológica de España, 1990) Moreno Garrido, María Carmen; Sáez Ramos, Reinaldo
The sedimentary nature of the rocks outcroping near the Virgen de la Peña hermitage suggests a shallow marine sedimentation, with a main influence of swell, almost for a part of the PQ Group of the Iberian Pyrite Belt in the Puebla de Guzman Anticline
Rasgos estructurales de la Sierra de Salinas y zona de los Mallos (Sierras Exteriores, Prepirineo, provincias de Huesca y Zaragoza)
(Sociedad Geológica de España, 1990) Pocoví Juan, Andrés; Millán Garrido, H.; Navarro, J. J.; Martínez, M. B.
The structure of Sierra de Salinas and the area of «los Mallos» (External Sierras, Southern Pyrenees) is owed to the thrusting (overtsep sequence) and simultaneous folding (flexure) of the whole structure. The setting and folding of these thrusts are related to the syntectonic unconformities of Campodarbe and Uncastillo formations
Preservación de estructuras internas y externas primarias en pillow-lavas del Paleozoico medio-superior del Sarrabus (SE de la isla de Cerdeña, Italia)
(Sociedad Geológica de España, 1990) Gimeno, Domingo
This note describes the presence of pillow-lava within the palaeozoic marine materials (Silurian-Devonian) of Sarrabus region, SE Sardinia, Italy. Pillow structures are developed on basalts, and some primary structures (internal and external: hol/ow pillows, budding pillows, tensional cracks, vitreous skin, radial fractures, etc.) have been preserved without trace of tectonic deformation
Observaciones sobre algunos Diques de Pórfido NS del sector de Alpedrete (Sistema Central)
(Sociedad Geológica de España, 1990) Doblas, M.; Goicoechea, P.
Some NS-oriented porphyry dikes are studied in the area of Alpedrete in the Spanish Central System. These dikes display several structures indicative of the following: direction and sense of the magmatic flow (sheared borders and flow fines); cooling regime (retraction fractures); igneous differentiation processes (compositional banding); and, associated hydrothermal processes (pegmatitic bodies and altered granites). These dikes display anomalous NS orientations with respect to the ones normally found in the region (EW), and they are thought to correspond to the last tardihercynian tectonic event (with a NS trending compressional axis)
Nuevas aportaciones al conocimiento geológico de la Ría del Eo (NW España)
(Sociedad Geológica de España, 1990) Fernández Catuxo, J.
This paper deals with the geology of the Ría del Eo, preferently its eastern side. We have mapped in a more detailed way the different units of the Serie de los Cabos, not distinguished yet in this area. We propose a rotational component in the Figueras fault and the occurrence of a new fault in the Serantes beach
La transgresión del Cenomaniense superior en el Prebético
(Sociedad Geológica de España, 1990) Martín Chivelet, Javier
An assymetrical megasequence of uppermost Cenomanian-Turonian (?) age is delimited and studied in Prebetic area: After a rapid transgression (which produces platform drowning), a more pausible and progressive progradation of platform and coastal line takes place. Its relationships with a comparable genetic unit described in Iberian Ranges are analyzed. Then, we discussed their signification in the evolution of the Iberian Plate
Las unidades tectosedimentarias del margen septentrional de la Depresión del Ebro en el sector Luesia-Riglos (provincias de Zaragoza y Huesca)
(Sociedad Geológica de España, 1990) Arenas Abad, Concepción; Pardo, Gonzalo; Villena, J.
At the septentrional margin of the Ebro Basin, the conglomeratic facies of Uncastillo Formation correspond to two complex cyclic Tectosedimentary Units (TSU U1 and U2). Towards the West, these TSU lie on Campodarbe Formation whose upper section is recognizable as another cyclic TSU (C2), and towards the Fast lie on marine paleogene and mesozoic sediments of the Pyrenean External Sierras. The fining-up megasequences of the TSU C2, U1 and U2 represent the initial burial of the thrust units of the south Pyrenean frontal thrust complex, placed successively from West to East during the time of the coarsening-up megasequences of former TSU
Las diaclasas y diques en el Plutón de Caldas de Reyes (Provincias de La Coruña y Pontevedra. España)
(Sociedad Geológica de España, 1990) Cuesta, Andrés; Corretgé Castañón, Luis Guillermo; Suárez Hernando, Oier; Gallastegui, G.
This paper deals with the role of the arrangement of joint systems and dykes of the latehercynian Caldas de Reyes granitic pluton. Despite of the role of late and posthercynian deformation phases on the genesis of the joint systems and emplacement trend of dykes, the drift of the joint systems observed in the external facies of the pluton proves its relationship with trend changes in the «magmatic foliation» of the pluton
La Formación Marín: redepósito de material jurásico durante el Mioceno (zona Subbética)
(Sociedad Geológica de España, 1990) Rey Arrans, Javier; Martínez Gallego, Julián; Vera, J. A.
An important volume about resedimented materials during the Burdigalian has been confused with the oolite Dogger even today. This article determines the Marin Formation, litostratigraphic unit that includes these rocks. It will be caracterized by the prevalence of the conglomeratic beds (A facies), with planktonic foraminifera in the matrix
«La Falla de Urriza (Pirineo Occidental): Neotectónica en materiales del cretácico superior del norte de Navarra»
(Sociedad Geológica de España, 1990) Martínez Torres, Luis M.; Ramón Lluch, R.; Eguiluz, Luis
In the north of Navarra (Western Pyrenees), subvertical folds with characteristic density of diaclases in the hinge zone outcrop in upper cretaceous beds. Its genesis has been associated to a sinistral wrench affecting quaternarian terraces. So, a neotectonic genesis can be assumed to explain the folds developed in cretaceous materials
La estructura del anticlinal de La Massana (Hercínico del Pirineo central)
(Sociedad Geológica de España, 1990) Cirés Fortuny, Jordi; Casas, J. M.
Detailed work on the La Massana anticline reveals that it represents a structural unit bounded by late thrusts. Its internal structure results from the superposition of premainphase and mainphase folds. This complex structure is not reflected in the cartographic pattern which had been interpreted as a simple anticline. As a result, the revision of the previously defined major structural units from the Variscan rocks cropping out in the Pyrenees is posed
Implicaciones de los enclaves máficos microgranulares en la petrogénesis de los granitoides calcoalcalinos hercínicos
(Sociedad Geológica de España, 1990) Castro Dorado, Antonio; Moreno-Ventas Bravo, Ignacio; Rosa Díaz, Jesús de la
Hercynian calc-alkaline granitoids are characterized by the presence of microgranular magmatic enclaves of tonalitic to diorite composition. Recent studies of these enclaves and host granitoids reveal that they were generated from disruption of synplutonic dikes of hybrid tonalites. Two stages of hybridization can be distinguished: (1) Injection mixing giving to a hybrid tonalite from a mafic magma, and (2) convective mixing, giving rise to homogeneous hybrid rocks of calc-alkaline composition
Granates en el Plutón de Caldas de Reyes (Provincia de La Coruña y Pontevedra. España)
(Sociedad Geológica de España, 1990) Cuesta, Andrés
In the late-hercynian calc-alkaline pluton of Caldas de Reyes, garnets occur scarcely in the most evolved facies. In this paper we intend to characterize their typology. We have been able to distinguish two different types on the basis of the mineral assemblage and their relationship to the host-rock. We discuss herein the possible igneous origin of this two pyralspite garnets and the most probable conditions of formation
Formación de una cubeta sinclinal en un contexto extensivo: la cuenca miocena de Rubielos de Mora (Teruel)
(Sociedad Geológica de España, 1990) Guimerà, J.
The Rubielos de Mora basin developped during early and middle Miocene in an extensional context Mesozoic layers beneath the basin are synclinally folded and Miocene beds are located in the core of the fold and show an attenuation of this structure. This synclinal basin was produced by the hanging-wall deformation of Mesozoic rocks on two steepping-downwards normal faults, which bound the syncline and produced the basin subsidence. Balanced and restored cross-section is shown
Extensión de la unidad «Limos y areniscas abigarrados de Torete» al sector NW de la Cordillera Ibérica (provincias de Soria y Guadalajara) (1)
(Sociedad Geológica de España, 1990) Gacía Gil, S.
«Torete variegated Silstones and Sandstones» Formation extends to the central System surroundings. The Fm. is characterised within the region, permitting the linkage to the Muschelkalk sedimentary cycle, instead of Buntsandstein

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