Nota sobre la cronología de los fenómenos ígneos en el extremo oriental de la zona sudportuguesa

[Resumen] La sucesión magmática se inicia con el vulcanismo preorogénico de la Faja Piritífera, que en el área aquí considerada parece ser de edad Viseense inferiorViseense superior frente a la Tournaisiense-Viseense inferior generalmente admitida. Durante y después de la primera fase de plegamiento (Westfaliense medio) intruyeron gabros, dioritas y granito con moscovita. Tras las fases de plegamiento pero antes de la fracturación tardihercínica se emplazaron los siguientes tipos de rocas ígneas: granito y granodiorita de textura normal, granito y granodiorita de cuarzo globuloso, el granito con granate de El Berrocal, pequeñas masas de tonalitas de grano fino, y abundantes p6rfidos graníticos (Westfaliense D). En el período de fracturación tardía (Estefaniense inferior o medio) intruyeron abundantes diques básicos y algunas aplitas, así como pequeños cuerpos de granodiorita y tonalita de grano fino. Finalmente, extruyeron los basaltos olivínicos de la cuenca del Viar (Estefaniense superior o Autuniense) .[Abstract] The magmatic succesion begins with the geosynclinal volcanism of the Pyrite Belt (Lower to Upper Visean and not Tournaisian-Lower Visean as is established in other localities). During and after the first folding phase, gabbros, diorites and muscovite granite were intruded (Middle Wetphalian). After the phases of folding but before the tardihercynian faulting, there was the following intrusions: granite and granodiorite with normal texture, granite and granodiorite with globular quartz, the body of garnet bearing granite of "El Berrocal", fine grained tonalites, and a number of varied granitic porphyries (Westphalian D). At the time of faulting (Lower or Midle Stephanian) the magmatic activity was represented by abundant basic dikes, aplitic granite and fine grained granodiorite and tonalite. The last igneous rocks in the region are the olivine basalt of the Viar basin (Upper Stephanian or Autunian

Successful management of peri-implantitis around short and ultrashort single-crown implants: a case series with a 3-year follow-up

Introduction and Aim. In case of peri-implantitis, resective surgery is contraindicated for short and ultrashort implants, limiting the treatment options to regenerative surgery or to implant removal. 'is retrospective case series presents the clinical and radiographic outcomes of a surgical regenerative procedure to treat peri-implantitis around short and ultrashort implants. Materials and Methods. The study is a retrospective evaluation of patients suffering from peri-implantitis and those who underwent access flap surgery, concomitant chemical and mechanical decontamination of implant surface, and bone grafting using a self-hardening mixture of bone substitutes and biphasic calcium sulfate. No membranes were applied to cover the grafting material, and primary tension-free closure was achieved. The retrospective protocol was reviewed and approved by the Ethics Committee for Clinical Sperimentation (CESC) of Verona and Rovigo, Italy (based in the University of Verona) (Prog. 1863CESC. Date of approval: 2018-07-04). Results. 15 patients (17 implants) have been diagnosed with peri-implantitis after a mean follow-up of 24 months after loading. Implant length was between 5 and 8 mm. 8 patients (10 implants) had a history of periodontitis. At baseline, the mean PD (probing pocket dept) at the deepest site was 8.12 mm, with an average mBI (modified bleeding index) of 2.35 and a mean BD (bone defect depth) of 3.04 mm. At the 3-year follow-up, the CSR was 100%, the mean mBI was 0.88 (average reduction: - 1.47), the mean PD was 3.35 mm (mean PD reduction: 4.77 mm), and the mean bone defect was reduced by 1.74 mm, with a mean bone fill of 55%. Conclusions. The results of the present case series suggest that if accurate surface decontamination is achieved, high survival rate and good clinical and radiographic results can be obtained after 3 years. However, only the histological examination could confirm the growth of new bone in direct contact with the implant surface or if the grafted material only fills the space left by the peri-implant defect

Comparación del Neoproterozoico/Paleozoico inferior de Marruecos y del SO de Iberia. Interpretaciones geodinámicas

El Neoproterozoico del sudoeste de Iberia (Serie Negra y Formación Malcocinado) es contemporáneo de un magmatismo calcoalcalino (Precámbrico PIII del Anti-Atlas de Marruecos) que sella la Orogenia Cadomiense. El Cámbrico inferior y medio está representado, tanto en Iberia como en Marruecos, por secuencias detríticas y vulcanosedimentarias formadas en un contexto de rifting. Sin embargo, la evolución de estas dos regiones se diferenció a partir del Cámbrico superior: en el sudoeste de Iberia, la actividad extensional continuó durante el Ordovícico, desarrollándose dominios oceánicos; en Marruecos, dominó durante el resto del Paleozoico inferior un régimen de plataforma débilmente extensiona

Steel cathodic protection afforded by zinc, aluminium and zinc/aluminium alloy coatings in the atmosphere

Zinc has traditionally been the metallic material most widely used to protect steel against atmospheric corrosion due to its ability to afford cathodic protection to steel in all types of natural atmospheres. In recent decades, aluminium and zinc/aluminium alloy coatings have been used instead of zinc in certain atmospheric applications. Although these coatings present some advantages over zinc, they are not able to cathodically protect steel substrates in all types of natural atmospheres. The present paper assesses the cathodic protection afforded by Al (flame spraying), Al/13 Si (hot dipping), 55Al/Zn (hot dipping), Zn/15Al (flame spraying), Zn/5Al (hot dipping), Zn (hot dipping), Zn (discontinuous hot dipping) and Zn (electroplating). Aluminium and aluminium-rich alloy coatings (55%Al/Zn) provide cathodic protection to the steel substrate only in atmospheres that are highly contaminated with chloride ions (>100 mg Cl- m-2 day-1) where these coatings become active. © 2004 Elsevier B.V. All rights reserved.Peer Reviewe

La estructura sísmica de la corteza de la Zona de Ossa Morena y su interpretación geológica

El experimento de sísmica de reflexión profunda IBERSEIS ha proporcionado una imagen de la corteza del Orógeno Varisco en el sudoeste de Iberia. Este artículo se centra en la descripción de la corteza de la Zona de Ossa Morena (OMZ), que está claramente dividida en una corteza superior, con reflectividad de buzamiento al NE, y una corteza inferior de pobre reflectividad. Las estructuras geológicas cartografiadas en superficie se correlacionan bien con la reflectividad de la corteza superior, y en la imagen sísmica se ven enraizar en la corteza media. Ésta está constituida por un cuerpo muy reflectivo, interpretado como una gran intrusión de rocas básicas. La imagen de las suturas que limitan la OMZ muestra el carácter fuertemente transpresivo de la colisión orogénica varisca registrada en el sudoeste de Iberia. La Moho actual es plana y, en consecuencia, no se observa la raíz del orógeno

Deep seismic exploration of the Iberian Microplate

[EN]This presentation was a key-note lecture at the International Symposium on Deep Exploration and Practices. It describes the acquisition of controlled source seismic data in the Iberian Peninsula during the last decade

A new microporous zeolitic silicoborate (ITQ-52) with interconnected small and medium pores

A new zeolite (named as ITQ-52) having large cavities and small and medium channels has been synthesized. This was achieved by using a new family of amino-phosphonium cations as organic structure directing agents (OSDA). These cations contain P−C and P−N bonds, and therefore they lie between previously reported P-containing OSDA, such as tetraalkylphosphonium and phosphazenes. In this study, it has been found that 1,4- butanediylbis[tris(dimethylamino)]phosphonium dication is a very efficient OSDA for crystallization of several zeolites, and in some particular conditions, the new zeolite ITQ-52 was synthesized as a pure phase. The structure of ITQ-52 has been solved using high-resolution synchrotron X-ray powder diffraction data of the calcined solid. This new zeolite crystallizes in the space group I2/m, with cell parameters a = 17.511 Å, b = 17.907 Å, c = 12.367 Å, and β = 90.22°. The topology of ITQ-52 can be described as a replication of a composite building unit with ring notation [435461] that gives rise to the formation of an interconnected 8R and 10R channel system.We thank financial support by the Spanish Government (MAT2012-38567-C02-01, MAT2012-38567-C02-02, Consolider Ingenio 2010-Multicat CSD-2009-00050 and Severo Ochoa SEV-2012-0267). R.S. acknowledges to UPV for a FPI predoctoral fellowship. Authors thank ALBA Light Source for beam allocation at beamline MSPD. We thank G. Sastre and J. A. Vidal for computational calculations and MAS NMR experiments, respectively.Simancas Coloma, R.; Jorda Moret, JL.; Rey Garcia, F.; Corma Canós, A.; Cantin Sanz, A.; Peral, I.; Popescu, C. (2014). A new microporous zeolitic silicoborate (ITQ-52) with interconnected small and medium pores. Journal of the American Chemical Society. 136(9):3342-3345. doi:10.1021/ja411915cS33423345136

The Aguablanca Ni–(Cu) sulfide deposit, SW Spain: geologic and geochemical controls and the relationship with a midcrustal layered mafic complex

The Aguablanca Ni–(Cu) sulfide deposit is hosted by a breccia pipe within a gabbro–diorite pluton. The deposit probably formed due to the disruption of a partially crystallized layered mafic complex at about 12– 19 km depth and the subsequent emplacement of melts and breccias at shallow levels (<2 km). The ore-hosting breccias are interpreted as fragments of an ultramafic cumulate, which were transported to the near surface along with a molten sulfide melt. Phlogopite Ar–Ar ages are 341– 332 Ma in the breccia pipe, and 338–334 Ma in the layered mafic complex, and are similar to recently reported U–Pb ages of the host Aguablanca Stock and other nearby calcalkaline metaluminous intrusions (ca. 350–330 Ma). Ore deposition resulted from the combination of two critical factors, the emplacement of a layered mafic complex deep in the continental crust and the development of small dilational structures along transcrustal strike-slip faults that triggered the forceful intrusion of magmas to shallow levels. The emplacement of basaltic magmas in the lower middle crust was accompanied by major interaction with the host rocks, immiscibility of a sulfide melt, and the formation of a magma chamber with ultramafic cumulates and sulfide melt at the bottom and a vertically zoned mafic to intermediate magmas above. Dismembered bodies of mafic/ultramafic rocks thought to be parts of the complex crop out about 50 km southwest of the deposit in a tectonically uplifted block (Cortegana Igneous Complex, Aracena Massif). Reactivation of Variscan structures that merged at the depth of the mafic complex led to sequential extraction of melts, cumulates, and sulfide magma. Lithogeochemistry and Sr and Nd isotope data of the Aguablanca Stock reflect the mixing from two distinct reservoirs, i.e., an evolved siliciclastic middle-upper continental crust and a primitive tholeiitic melt. Crustal contamination in the deep magma chamber was so intense that orthopyroxene replaced olivine as the main mineral phase controlling the early fractional crystallization of the melt. Geochemical evidence includes enrichment in SiO2 and incompatible elements, and Sr and Nd isotope compositions (87Sr/86Sri 0.708–0.710; 143Nd/144Ndi 0.512–0.513). However, rocks of the Cortegana Igneous Complex have low initial 87Sr/86Sr and high initial 143Nd/144Nd values suggesting contamination by lower crustal rocks. Comparison of the geochemical and geological features of igneous rocks in the Aguablanca deposit and the Cortegana Igneous Complex indicates that, although probably part of the same magmatic system, they are rather different and the rocks of the Cortegana Igneous Complex were not the direct source of the Aguablanca deposit. Crust–magma interaction was a complex process, and the generation of orebodies was controlled by local but highly variable factors. The model for the formation of the Aguablanca deposit presented in this study implies that dense sulfide melts can effectively travel long distances through the continental crust and that dilational zones within compressional belts can effectively focus such melt transport into shallow environments