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[en] Defining the occupation sequence of medieval rural farming sites in Northern Iberia is complicated, since they feature low density of stratigraphic relationships and few finds and because of the intensive agricultural activities developed there during the last few decades. This paper presents the chronological characterization of the medieval village of Zornoztegi, located in the Basque Country, in the province of Alava. At this site, dwellings extend over an area of approximately two hectares and consist mainly of negative structures excavated in the bedrock. Radiocarbon dating measurements carried out on 32 samples, together with mortar optical microscopic analyses and other information obtained from stratigraphic relationships, changes in the settlement organization and the study of material culture, allowed structuring and characterizing the occupation sequence of the site of Zornoztegi. Furthermore, Bayesian statistics was used to reduce the range of the calibrated dates and to refine the chronology of the sequence.
[en] Microsyenitic and microdioritic dykes from Alconera on the northern side of Burguillos del Cerro Anticlinarium give a K-Ar age of 281+-7 M.A. This age is close to that reported for the nearly Feria syenite which has similar petrographical and geochemical characteristics and whose intrusions fall on a common axis NW-SE. This confirms that these alkaline subvolcanic rocks were emplaced during a period from Stephanian to lower Permian, subsequent to the last phase of varisc deformation
[fr]Les dykes d'Alconera situes sur le flanc septentrional de l'Anticlinarium de Burguillos del Cerro et constitues de microsyenite et de microdiorite donnent un age K-Ar de 281+-7 M.A. Cet age est proche de celui indique pour la syenite de Feria, petrographiquement et geochimiquement voisine et dont les intrusions sont sur le meme axe NW-SE. Ces resultats semblent accrediter la these d'une mise en place de ces roches alcalines subvolcaniques entre le Stephanien et le Permien Inferieur, apres la derniere phase de deformation varisque
[en] Radiometric data for the Westcarpathian neovolcanites did not include basalts. Using the argon method a basanitoid group of ages of about 7,5 mil. years near B. Stiavnica and N from Lucenec (Maskova, Podrecany), and about 2,5 mil. years old basanites in the surroundings of Filakovo were identified. (author)
[en] Full text: Crustal and upper mantle xenoliths are hosted in basanitic dikes and necks that intruded into continental sediments of the Cretaceous Salta Rift at Qebrada Las Conchas, Province Salta, Argentina. Most of the crustal xenoliths have granitoid composition ( quartz - plagioclase - k-feldspar -garnet) whereas mafic compositions (plagioclase - clinopyroxene -garnet ±hornblende) are exceedingly rare. The xenoliths show a well equilibrated granoblastic structure and the minerals are compositionally unzoned. Metamorphic conditions have been of granulite facies temperature ca. 850 - 900 at lower crustal depth with pressure of ca. 10 kbar from thermo barometric calculations. Sm-Nd mineral isochron ages are 94.9±8.4Ma, 91.6±13.5Ma, 89.0±4.2Ma (granitoid composition), and 110.7±23.2Ma (mafic composition). These ages are within the errors in good agreement with the age of basanitic volcanism. Sm-Nd isochron ages are considered as closure ages and temperature at the respective time has been still above the Sm-Nd systems' closure temperature (>600-700 ). Sm-Nd and Rb-Sr isotopic signatures (147Sm/144Nd t0=0.1225 - 0.1608); 143Nd/144Ndt0 0.512000 - 0.512324; 87Rb/86Sr = 0.099 - 0.172; 87Sr/86Sr = 0.708188 - 0.7143161) and common lead isotopic signatures (206Pb/204Pb = 18.43 - 18.48; 207Pb/204Pb = 15.62-15.70; 208Pb/204Pb = 38.22 - 38.97) of the granitoid xenoliths are indistinguishable from the isotopic composition of the Early Paleozoic metamorphic basement from NW Argentina apart from the lower 208Pb/204Pb ratios of the Early Paleozoic basement. Sm-Nd depleted mantle model ages of c. 1.8 Ga from granitoid xenoliths and Early Paleozoic basement point to a Proterozoic protoliths for both with distinct ages of the last thermal overprint. Time constraints, the well equilibrated granulite fabric, P-T conditions and lack of chemical zoning of minerals point to a high temperature gradient in a crust of nearly normal thickness at c. 90 Ma and to a prominent thermal anomaly in the lithosphere. If this anomaly has been caused by uplift of the lithosphere/asthenosphere boundary by extensional tectonics the extension must have been restricted to the mantle lithosphere. Interpretation of the tectonic setting remains ambiguous and both a 'true rift' and a rifting in a possible Cretaceous back arc have to be considered in future investigations. The crustal composition is identical with the compositionally homogeneous Early Paleozoic crust of NW Argentina and N Chile. A thick mafic lower crust seems unlikely considering low frequency of mafic xenoliths and composition of the granitoid xenoliths. (author)
[en] Geochemical and geochronological data from Alumine riolitic welded tuffs are analysed. Minor elements show enrichment in Rb, Th and K and depletion in Nb, Ti, P and Sr. La/Yb ratios are low. The geochemical features are consistent with a volcanic arc genesis. The radiometric data obtained by K/Ar method point out a Paleocene age for these rocks, allowing to correlate them with the Ventana Formation or the equivalent Auca Pan Formation. (author)
[en] While uncertainty is ubiquitous in medical practice, minimal work to date has been performed to analyze the cause and effect relationship between uncertainty and patient outcomes. In medical imaging practice, uncertainty in the radiology report has been well documented to be a source of clinician dissatisfaction. Before one can effectively create intervention strategies aimed at reducing uncertainty, it must first be better understood through context- and user-specific analysis. One strategy for accomplishing this task is to characterize the source of uncertainty and create user-specific uncertainty profiles which take into account a number of provider-specific variables which may contribute to report uncertainty. The resulting data can in turn be used to create real-time report uncertainty metrics aimed at providing uncertainty analytics at the point of care, for the combined purposes of decision support, improved communication, and enhanced clinical/economic outcomes.