43 research outputs found

    Triassic tholeiitic dolerites («ophites») of the El Grado diapir (Pyrenees, Huesca, Spain): emplacement and composition

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    Mesozoic dolerites in the south Pyrenean sector of El Grado (Huesca, Spain) preserve emplacement structures (fluidity structures at the top and load structures at the base) developed during their intrusion into unconsolidated marly-evaporitic Triassic sediments (Keuper facies). By analogy with other dolerites in the south Pyrenean domain, their emplacement age is equivalent to the uppermost Keuper facies terms, but prior to the final Triassic-early Liassic carbonated sediments. Radiometric ages (187-197±7 Ma) show that the emplacement occurred during the lower Liassic. The petralogical differentiation from the chilled margin facies to the central facies, and also to the late pegmatitoids, is consistent with that obtained from major elements, trace elements and REE. Their tholeiitic affinity, as defined by their geochemical composition, is equivalent to that of similar racks in the Pyrenean domain. However, the rocks analyzed here, which are located at the external sector of this domain, display a greater petralogical and geochemical differentiation as compared to similar rocks in the central sectors of the Pyrenean domain.Las doleritas mesozoicas del sector surpirenaico de El Grado (Huesca) conservan estructuras de emplazamiento (con desarrollo del movimiento de lava fluida al techo y de carga en su base) desarrolladas al instruir en los sedimentos margo-evaporíticos en facies Keuper, todavía inconsolidados. Por similitud con otras doleritas del dominio surpirenaico, la edad del emplazamiento es equivalente a la de los términos superiores de la facies Keuper y previa a la sedimentación carbonatada del Trías terminal-Lías inferior. Las determinaciones de edades radiométricas (187-197±7 Ma) indican que el emplazamiento debió tener lugar durante el Lías inferior. La diferenciación petralógica, desde la facies del borde enfriado a la central y, también, al posterior diferenciado pegmatoide concuerda con la obtenida con elementos mayores, trazas y REE. Su afinidad toleítica, definida por su composición geoquímica, coincide con la obtenida en rocas análogas para el dominio pirenaico; no obstante, estas rocas situadas en el borde más externo de dicho dominio representan una mayor diferenciación (petralógica y geoquímica) respecto a la obtenida, hasta el momento, para rocas análogas situadas en sectores más centrales del citado dominio pirenaico

    The triassic alkaline dolerites of the Valacloche-Camarena Area (SE-Iberian Chain, Teruel): Geodynamic implications

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    The dolerite sills outcropping in the Valacloche-Camarena area (SE Iberian Chain), are the expression of an alkaline magmatism, emplaced in Keuper facies sedimentary rocks. Their pre-Hettangian age is deduced from the development of fluidality structures at the top of the sills together with the very low grade contact metamorphism of the host rocks. A differentiation trend, represented by two rock-types, with variable Ti-augite content, is confirmed by geochemical data (REE). The alkaline composition of this magmatism is close to that of the OIB type. Crust-derived enclaves (metapelites and granitoids) are common in these sills, suggesting that magma ascent took place through a fracture system, related to a distensive tectonic regime, that affected different levels of the crust. This magmatism was one of the expressions of the triassic rifting events that are well represented in the SE border of the Iberian Chain.Un magmatismo alcalino, emplazado en sedimentos triásicos en facies Keuper, está bien representado en los sills doleríticos del área de Valacloche-Camarena (SE de la Cordillera Ibérica). La edad pre-Hettangiense ha sido deducida a partir de la presencia de estructuras de fluidalidad y de un metamorfismo de contacto de grado muy débil. Petrológicamente se identifica una fraccionación según dos litotipos (con contenido variable en Ti-augita) que está corroborada por los datos de composición geoquímica (en tierras raras); la composición alcalina de este magmatismo es próxima a la del tipo OIB. La presencia, frecuente, de enclaves de corteza (metapelitas y granitoides) indica una fracturación que, en condiciones distensivas, afectó a distintos niveles de dicha corteza. Este magmatismo está ligado al rifting triásico que está bien expresado en el borde SE de la Cordillera Ibérica

    Why Are Outcomes Different for Registry Patients Enrolled Prospectively and Retrospectively? Insights from the Global Anticoagulant Registry in the FIELD-Atrial Fibrillation (GARFIELD-AF).

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    Background: Retrospective and prospective observational studies are designed to reflect real-world evidence on clinical practice, but can yield conflicting results. The GARFIELD-AF Registry includes both methods of enrolment and allows analysis of differences in patient characteristics and outcomes that may result. Methods and Results: Patients with atrial fibrillation (AF) and ≥1 risk factor for stroke at diagnosis of AF were recruited either retrospectively (n = 5069) or prospectively (n = 5501) from 19 countries and then followed prospectively. The retrospectively enrolled cohort comprised patients with established AF (for a least 6, and up to 24 months before enrolment), who were identified retrospectively (and baseline and partial follow-up data were collected from the emedical records) and then followed prospectively between 0-18 months (such that the total time of follow-up was 24 months; data collection Dec-2009 and Oct-2010). In the prospectively enrolled cohort, patients with newly diagnosed AF (≤6 weeks after diagnosis) were recruited between Mar-2010 and Oct-2011 and were followed for 24 months after enrolment. Differences between the cohorts were observed in clinical characteristics, including type of AF, stroke prevention strategies, and event rates. More patients in the retrospectively identified cohort received vitamin K antagonists (62.1% vs. 53.2%) and fewer received non-vitamin K oral anticoagulants (1.8% vs . 4.2%). All-cause mortality rates per 100 person-years during the prospective follow-up (starting the first study visit up to 1 year) were significantly lower in the retrospective than prospectively identified cohort (3.04 [95% CI 2.51 to 3.67] vs . 4.05 [95% CI 3.53 to 4.63]; p = 0.016). Conclusions: Interpretations of data from registries that aim to evaluate the characteristics and outcomes of patients with AF must take account of differences in registry design and the impact of recall bias and survivorship bias that is incurred with retrospective enrolment. Clinical Trial Registration: - URL: http://www.clinicaltrials.gov . Unique identifier for GARFIELD-AF (NCT01090362)

    Risk profiles and one-year outcomes of patients with newly diagnosed atrial fibrillation in India: Insights from the GARFIELD-AF Registry.

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    BACKGROUND: The Global Anticoagulant Registry in the FIELD-Atrial Fibrillation (GARFIELD-AF) is an ongoing prospective noninterventional registry, which is providing important information on the baseline characteristics, treatment patterns, and 1-year outcomes in patients with newly diagnosed non-valvular atrial fibrillation (NVAF). This report describes data from Indian patients recruited in this registry. METHODS AND RESULTS: A total of 52,014 patients with newly diagnosed AF were enrolled globally; of these, 1388 patients were recruited from 26 sites within India (2012-2016). In India, the mean age was 65.8 years at diagnosis of NVAF. Hypertension was the most prevalent risk factor for AF, present in 68.5% of patients from India and in 76.3% of patients globally (P < 0.001). Diabetes and coronary artery disease (CAD) were prevalent in 36.2% and 28.1% of patients as compared with global prevalence of 22.2% and 21.6%, respectively (P < 0.001 for both). Antiplatelet therapy was the most common antithrombotic treatment in India. With increasing stroke risk, however, patients were more likely to receive oral anticoagulant therapy [mainly vitamin K antagonist (VKA)], but average international normalized ratio (INR) was lower among Indian patients [median INR value 1.6 (interquartile range {IQR}: 1.3-2.3) versus 2.3 (IQR 1.8-2.8) (P < 0.001)]. Compared with other countries, patients from India had markedly higher rates of all-cause mortality [7.68 per 100 person-years (95% confidence interval 6.32-9.35) vs 4.34 (4.16-4.53), P < 0.0001], while rates of stroke/systemic embolism and major bleeding were lower after 1 year of follow-up. CONCLUSION: Compared to previously published registries from India, the GARFIELD-AF registry describes clinical profiles and outcomes in Indian patients with AF of a different etiology. The registry data show that compared to the rest of the world, Indian AF patients are younger in age and have more diabetes and CAD. Patients with a higher stroke risk are more likely to receive anticoagulation therapy with VKA but are underdosed compared with the global average in the GARFIELD-AF. CLINICAL TRIAL REGISTRATION-URL: http://www.clinicaltrials.gov. Unique identifier: NCT01090362

    El volcanismo neógeno-cuaternario de Catalunya: caracteres estructurales, petrológicos y geodinámicos

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    El volcanismo neógenocuaternario de Catalunya está asociado al sistema de fracturas escalonadas, de orientación preferente SW-NE y NW-SE, que condiciona también las depresiones tectónicas o fosas neógenas. Las dataciones radiométricas ponen de manifiesto una actividad volcánica entre 10 y 0.1 m.a., localizándose las erupciones más antiguas en la fosa del Empordà, mientras que el volcanismo cuaternario se concentra en las proximidades de Olot (La Garrotxa). El magmatismo es de carácter alcalino, con términos exclusivamente básicos (basanitas), salvo un afloramiento traquítico. Son frecuentes los xenolitos de rocas sedimentarias y plutónicas básicas y ácidas, presentando estos últimos el mayor grado de transformación. Los caracteres estructurales, geoquímicos y mineralógicos, junto a las relaciones isotópicas Sr8YlSr86 apoyan un origen profundo, subcrustal, del magma, y definen un volcanismo intraplaca como el que corresponde a un modelo de rift embrionario sin atenuación litosférica y con escasas manifestacio

    Jurassic voicanicíastic rocks of Albentosa-1 (Iberian Chain, Teruel): fragmentation and emplacement mechanisms

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    In the Sierra de Javalambre a volcaniclastic outcrop (Albentosa-1) showing monomict volcanic breccia and polymict volcanic sandstone and breccia, with planar and festoon cross lamination, is analysed. Data suggest that this volcanism was extruded in a subaerial or shallow water marine environmen

    Fragmentation and emplacement mechanisms of volcaniclastic rocks: a terminological review

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    Recent volc anic erup tion s have p ro v id e d firs t-h a n d data fo r the study o f «pyroclastic» deposit mechanisms. This study adds to the term «pyroclastic» a depositional meaning. As a result of this expanded meaning, the term «pyroclastic» is not only used for a fragmentation mechanism, but also for a way of em pla cem ent. Taking in to ac c o u n t th e im p o rta n c e , o f volcaniclastic deposits fo r basin analysis, we propose, when using the term «pyroclastic», to clearly state the differences between fragmentation and emplacement mechanism

    Mineralogical composition of the jurassic volcanism (pre-Middle Bajocian) in the Sierra of Javalambre (Iberian Chain, Teruel): preliminary data

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    The study of olivine, plagioclase, clinopyroxene and opaque minerals from volcanic rocks, which are included in volcaniclastic deposits o f pre -m id d le Bajocian age from the Sierra o f Javalambre (Iberian Chain, Teruel), shows that this volcanism has an alkaline affinity. The compositional trend of this alkaline magma is recognized by studying the clinopyroxene compositio

    The alkaline jurassic magmatísm In the SE area of Iberian Chain: composition and structure

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    Jurassic volcanic rocks are well exposed in the Sierra de Javalambre (Teruel)., This multiepisodic volcanism is mainly volcaniclastic , showing a large variety of fragmentation and emplacement mechanisms, and it is intercalated between carbonade rocks spanning from Pliensbachian through Bajocian. The mineral and chemical composition indicates a volcanism with alkaline affinity and little magmatic differentiation. From a geotectonic point of view, this volcanism corresponds to a late-volcanism within the postrift thermal subsidence (lower and middle Jurassic) that took place during the mesozoic development of the Iberian Basin (Iberian Chains
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