THE MIDDLE-UPPER CAMBRIAN TRANSITION IN THE IBERIAN CHAINS, NE SPAIN. AN INTEGRATED APPROACH

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The Ediacaran-early Palaeozoic Cadomian zircon province fringing Northwest Gondwana

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Shifts in the Ediacaran to Lower Ordovician sedimentary zircon provenances of Northwest Gondwana: the Pyrenean files

Detrital zircon grains from Cambrian–Lower Ordovician sandstones and quartzites sampled in the Pyrenees were dated by LA-ICPMS in order to assess their provenance sources. Resulting age distributions are compared to other available datasets from neighbouring margins, such as Morocco, the Iberian Peninsula, southern France and Sardinia. Kolmogorov-Smirnov (K-S) test and Crystallization Age-Depositional Age (CA-DA) diagrams were used to compare zircon populations estimating their possible correlation with the arc/rift/drift geodynamic evolution of the northwestern Gondwana margin. During Terreneuvian times, zircon populations allowed the distinction of i) a southwesternmost edge (Atlas-Ossa-Morena Rift) mostly influenced by Panafrican and Anti-Atlasian sources (ca. 0.63–0.54), ii) a northeasternmost edge (Sardinia) recording the influence of the Saharan Metacraton and the Arabian Nubian Shield, with an distinct Stenian–Tonian shift (ca. 1.25–0.85Ga) and iii) an intermediate palaeogeographic transect, where lies the Central Iberian, West Asturian-Leonese and Cantabrian Zones, the Montagne Noire and the Pyrenees sharing similar populations and a chronologically progressive influence from Anti-Atlasian/Panafrican to Saharan Metacraton/Arabian Nubian Shield sources. This gradual modification in zircon percentage populations supports similar trends based on climatically sensitive indicators, biogeographic patterns of Cambrian Epoch 2 archaeocyathan and microfossil assemblages, and laterally correlatable episodes of carbonate production, all of them pointing to a Cambrian setting for the Pyrenean Basin between the Montagne Noire (Occitan Domain) and the Sardinian margins of NW Gondwana. The Terreneuvian zircon patterns recorded in the Pyrenees gradually evolved from Cambrian Epoch 2 to Early Ordovician times, reflecting the geodynamic evolution from Panafrican and Cadomian arc-related to rift-dominant conditions. During Furongian and Ordovician times, the relative percentage of zircon populations led to a more spread age curve, characteristic of extensional settings and pointing to rift (passive margin) conditions

Advances in the Lower Ordovician of the western Iberian Chain, NE Spain

The western Iberian Chain of NE Spain represents a lateral prolongation of the West Asturian-Leonese Zone. As other proximal sectors fringing NW Gondwana, the chain comprises a con­formable and continuous FurongianâTremadocian transition, comprising a thick (3600â4500 m) Lower Ordovician sedimentary succession, exclusively composed of siliciclastic strata and deposited in mid-latitude (temperate) waters. Although the shelly fossil record is not abundant, some key trilobites and brachiopods allow the identification of distinct biogeographic links with the Argentinian margin of West Gondwana, Oaxaca (Mexico), and the neighbouring Montagne Noire (France), with which a common biostratigraphic biozonation can be enviaged. Two phosphoritic interbeds rich in linguliformean brachiopods punctuate the Valconchán and Borrachón formations, and represent event beds related to condensation processes and sedimentation of explosive ignimbritic tuffs, respectively

Syn-rift unconformities punctuating the lower-middle Cambrian transition in the Atlas Rift, Morocco

The Cambrian Tamdroust and Bab n’Ali Volcanic Complexes represent two magmatic episodes developed in the latest Ediacaran–Cambrian Atlas Rift of Morocco. Their rifting pulses were accompanied by accumulation of volcanosedimentary edifices (dominated by effusive lava flows in the former and explosive acidic aprons in the latter) associated with active tilting and uplift. Sealing of their peneplaned horst-and-graben palaeotopographies led to the onset of distinct onlapping geometries and angular discordances capping eroded basements ranging from the Ediacaran Ouarzazate Supergroup to the Cambrian Asrir Formation. Previous interpretations of these discordances as pull-apart or compressive events are revised here and reinterpreted in an extensional (rifting) context associated with active volcanism. The record of erosive unconformities, stratigraphic gaps, condensed beds and onlapping patterns across the traditional “lower–middle Cambrian” (or Cambrian Series 2–3) transition of the Atlas Rift must be taken into consideration for global chronostratigraphic correlation based on their trilobite content

Identifying unbound strong bunching and the breakdown of the Rotating Wave Approximation in the quantum Rabi model

We use a recently derived gauge-invariant formulation of the problem of an incoherently-driven two-level system coupled to an optical cavity, to explore the transition between different coupling regimes -- in particular, between the weak, and the ultra-strong coupling regimes. We explore this transition using the second-order intensity correlation $g^{(2)}(\tau)$ of the emitted light, and find strong, unbounded bunching of the emission from systems governed by the Rabi Hamiltonian. Surprisingly, this effect is observed not only in the ultra-strong coupling regime, but also in the regime of coupling typically recognized as weak coupling, where the Jaynes-Cummings Hamiltonian predicts the opposite, strongly antibunched emission. This suggests that the intensity correlations are a particularly sensitive probe of the divergence between the Jaynes-Cummings and Rabi Hamiltonians, and can serve as an indicator of the breakdown of the rotating wave approximation

A characterization of EM coupling in a fully electric 4-wheel drive vehicle

Electric vehicles are complex systems in which EMC must be approached in a significantly different way to the one in conventional cars. The presence of high power supplies assembled in a very small room together with signalling, control and communications devices brings about new issues related to EM disturbances and noise coupling that must be addressed in order to ensure a good performance of the systems. To achieve this, the understanding of the way noise is generated, propagates and couples within the system is critical so as to improve the immunity of the components and, eventually, the whole car. This paper presents the results of an EMC study focused on the electromagnetic interferences that take place in a fully electric vehicle. The outcome in this work is part of an EMC approach that involves an analysis of the emissions and coupling phenomena that may cause an impact on the system safety and performance. To perform this analysis, a campaign of experimental tests has been carried out on the vehicle. This task has been performed within the E-VECTOORC project (FP7-INFSO-284078), in collaboration with Jaguar Land Rover and r¿koda

Exercise Intolerance in Post-Acute Sequelae of COVID-19 and the Value of Cardiopulmonary Exercise Testing- a Mini-Review

Coronavirus disease (COVID-19) is an infectious disease caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), with systemic organ damage in the most severe forms. Long-term complications of SARS-CoV-2 appear to be restricted to severe presentations of COVID-19, but many patients with persistent symptoms have never been hospitalized. Post-acute sequelae of COVID-19 (PASC) represents a heterogeneous group of symptoms characterized by cardiovascular, general, respiratory, and neuropsychiatric sequelae. The pace of evidence acquisition with PASC has been rapid, but the mechanisms behind it are complex and not yet fully understood. In particular, exercise intolerance shares some features with other classic respiratory and cardiac disorders. However, cardiopulmonary exercise testing (CPET) provides a comprehensive assessment and can unmask the pathophysiological mechanism behind exercise intolerance in gray-zone PASC. This mini-review explores the utility of CPET and aims to provide a comprehensive assessment of PASC by summarizing the current evidence