IGNOUS AND METAMORPHIC PETROLOGY

Author: GALÉ BORNAO CARLOS.
Year: 2004.
University: ZARAGOZA [www.unizar.es].
Place of defense: FACULTAD DE CIENCIAS.
Place of preparation: FACULTAD DE CIENCIAS.

Summary: During the Permian East, the stratigraphic framework and the tectonic regime was different in the two domains studied (Central and Western). In the central domain (sectors Aragón-Bearn and Sierra's Kadi), under a system of fractures transform direction EO was called the episode IV (sills of traquiandesitas) with a low volumetric representation, while in the western sector, this episode it is not present. The development of a more extensional allowed the site, in both domains, liquids for the episode V (sills and dikes) introducing differences in volume, composition and mode of emplacement petrológica. The age of emplacement of the intrusions is based on stratigraphic, from which it follows that the climax of took place in the Guadalupiense (Permian East). The criteria paleomagnéticos available and, in more detail, the analogy compositional of newer products, establishing a common age for these intrusions of 267Â ± 11 Ma, age amphibole obtained crystals of lamprófidos the central sector (Panticosa). The pooled data stratigraphic, structural and site has helped establish two geodynamic different domains: the western (Massif Five Villas), which follows guidelines domain Atlantic and Central (Aragón-Bearn and Sierra's Kadi) with a guideline own domain tethysiano. The composition of liquids petrológica considered, expressed in the form of sills (basalt) and dams (doleritas and lamprófidos), has enabled us to establish 7 litotipos different andesites, basalts, doleritas and lamprófidos. The mineral association of litotipos indicates an affinity alkaline magma. The presence of Ap both in andesites episode IV, as in lamprófidos's episode V, indicating molten partially metasomatizados. The elemental composition in geochemistry indicates a clear cogenetismo of litotipos studied, and an affinity alkaline nature differential. In addition, it shows a protolith mantélico enriched type MS I probably metasomatizado, with differences between the two domains, which gave rise to liquids as a process involving ACF crust, in an atmosphere post-colisional. The ACF modeling has shown differences, significant for this process in the two domains considered. In the Massif Five Villas (domain Atlantic) have a fraccionación minerals main (Cpx, Pl and Mag), the material had to be assimilated type UCC and the rate of assimilation is next ar = 0.15 for a moderate degree of crystallization ( F 90 to 65%). In the area of Panticosa (domain tethysiano) the role of fraccionación corresponds to accessories and Am, assimilation, slightly higher (r = 0.20) of LCC and fraccionación higher (F from 93 to 30%). The set of results is included in a proposal for a framework that includes geodynamic aspects: a) protoliths of the two sectors show some heterogeneity mantélica, for a symbol mantélica common type of MS I. This heterogeneity will be more apparent during the Alpine cycle in the Pyrenees Chain b) The proposed domains evolve their separate ways during the Triassic, as different rates of expansion, with a magmatism toleítico in the Atlantic and one domain alkali in the tethysiano c) The composition indicates a protolith partially metasomatizado, process more visible in the central sector (domain tethysiano), d) Differences in composition and gained at the rate of assimilation of the material involved to confirm geodynamic slightly different regimes in both domains, at least The end of this period Varisco Chain e) evidence that there was a significant decrease of cortical involvement in the orig 8 in the 625 s of magmas with the passage of the Second Cycle Prime f) The symbol geochemistry obtained for this magmatism is similar to that occurring in environments post-colisionales. The geodynamic more reasonable framework being proposed, according to a protolith partially metasomatizado, is the genesis of molten relatively peers, under conditions of a prior subduction. Subsequent developments during the Alpine Cycle, is reflected in liquid for a heterogeneous mantle, with distinct fusion rates, controlled by the development of two riftings with control extensional important. The developments described in the Pyrenees Chain is quite similar to those described by other authors for Mediterranean basin intramontañosas edge, resulting either manifest control, importantly, exercising extension in the characteristics and the geometry of the sedimentary basins, with a peak in the Higher Trias.

Author: SARRIONANDIA EGUIDAZU FERNANDO.
Year: 2005.
University: PAÍS VASCO [www.ehu.es].
Place of defense: FACULTAD DE CIENCIA Y TECNOLOGÍA.
Place of preparation: FACULTAD DE CIENCIA Y TECNOLOGÍA.

Summary: Complex Plutónico Valencia's Ventoso is located in the heart of antiforma of Monesterio, Zone Ossa Morea. This massif is comprised of stocks of Medina, Torres (GTS), Valencia's Ventoso (SVV) and Pozuelo (SP) by the pluton valence of Ventoso (PVV), and two cortejos filonianos different, one from the more liquid evolved from the bodies plutónicos and one more development facing the CPVV, spreading by encajante. In PVV, intruye to stocks, differs in the central part a basic unit (BU), which is surrounded and intruida by a unit acid (AAU). Stocks facies integrate basic and intermediate structures that show massive and cumulative. They are rocks cafémicas calcoalcalinas magnesianas with net trend monzonítica and media content to high K. The UB integrates gabbros and cuarzodioritas moderately alkaline, cafémicos monzoníticos rich in K, which defines partnerships magnesianas to slightly ferríferas. The AU is made up of intermediate to acid rock, cafémicas monozníticas ferríferas and with high content in K. The aplitas sltambién integrates No series set for stocks and the AU, but there prevails the peraluminoso. The set of demonstrations filonianas not spatially restricted to CPVV includes a wide variety of lithologies moderately alkaline, forming an association cafémica monzonítica ferrífera, with content in K moderated shoshniticos. The CPVV comes from the combination of lherzolita with spinel modified fluid and molten derived from oceanic crust and sediments subducidos. A strong alterantiva is the mixture of a lherzolita with spinel + + amphibolites sediments (eg 8:1:1). The origin of this source is closely related to the subduction Devono-Carbonífera. Variations in the terms of merger give rise to two types of parental magmas, one of nature calcoalcalina responsible for the generation of the three stocks and the AU, and other nature moderately alcalinza responsible for the generation of the UB. Prior to its final location (3 km), in contact socket precámbrico-cobertera paleozoica, magmas experiencing a prior fraccionación within the field of stability dela plagioclase. The diversification of magmas takes place in favor of fraccionación of plagioclase and pyroxene (+-phases accessory). The site is facilitated by the opening in a rotational system left an accident N30E, related cabalgamiento of Monesterio either with antiforma of Monesterio.