Mont Blanc and Aiguilles Rouges geology of their polymetamorphic basement (external massifs, Westerns Alps, France-Switzerland)

Les massifs du Mont Blanc et des Aiguilles Rouges appartiennent aux massifs dits cristallins externes de la chaîne alpine occidentale. Ils sont constitués de roches pré-mésozoïques et dessinent des nappes de socle dans le bâti alpin. Ces massifs ont enregistré une longue histoire géologique comprenant le dépôt de sédiments néoprotérozoïques à cambriens, la mise en place de roches magmatiques basiques et ultrabasiques au paléozoïque inférieur, ainsi que l’intrusion de granitoïdes ordoviciens en contexte de marge active. Ces roches sont considérées appartenir à un ensemble de blocs continentaux originaires de la marge septentrionale du Gondwana et accrétés à la marge sud-européenne après leur détachement du Gondwana et leur dérive vers le nord consécutif à l’ouverture de la Paléotéthys. Cet épisode d’accrétion correspond à l’orogenèse varisque (hercynienne), bien documentée dans les massifs du Mont Blanc et des Aiguilles Rouges, par une évolution tectono-métamorphique polyphasée essentiellement carbonifère avec formation de migmatites et intrusion de granitoïdes de types variés. Une érosion active, liée à une forte exhumation, est enregistrée au carbonifère supérieur dans les dépôts détritiques continentaux de bassins d’effondrement de type graben. Ce mémoire présente des cartes géologiques inédites et des suggestions d’excursions dans ces secteurs nouvellement cartographiés. Les lithologies sont abondamment illustrées et décrites en détail du point de vue structural, pétrologique et géochimique. Les analyses chimiques sont fournies en annexe.The Aiguilles Rouges and Mont Blanc external massifs belong to the pre-Mesozoic basement areas of the external domain of the Alps. Before their involvement into the Alpine building (basement nappes) they registered a multiple geological evolution comprising the deposition of Neoproterozoic to Cambrian sediments and emplacement of granitoid and metabasic to ultramafic magmatic rocks of Early Palaeozoic age at the Gondwanan border. After rifting and drifting (formation of Palaeotethys) all rocks underwent polyphase metamorphic and structural transformations during the Variscan orogeny, and were intruded by late Variscan granitoids. The resulting polymetamorphic basement was eroded during formation of Upper Carboniferous sedimentary troughs. New geological maps are presented in this volume, together with structural, petrological and geochemical characteristics of all lithologies. The geochemical data are presented in annexes

Organization of pre-Variscan basement areas at the north-Gondwanan margin

Pre-Variscan basement elements of Central Europe appear in polymetamorphic domains juxtaposed through Variscan and/or Alpine tectonic events. Consequently, nomenclatures and zonations applied to Variscan and Alpine structures, respectively, cannot be valid for pre-Variscan structures. Comparing pre-Variscan relics hidden in the Variscan basement areas of Central Europe, the Alps included, large parallels between the evolution of basement areas of future Avalonia and its former peri-Gondwanan eastern prolongations (e.g. Cadomia, Intra-Alpine Terrane) become evident. Their plate-tectonic evolution from the Late Proterozoic to the Late Ordovician is interpreted as a continuous Gondwana-directed evolution. Cadomian basement, late Cadomian granitoids, late Proterozoic detrital sediments and active margin settings characterize the pre-Cambrian evolution of most of the Gondwana-derived microcontinental pieces. Also the Rheic ocean, separating Avalonia from Gondwana, should have had, at its early stages, a lateral continuation in the former eastern prolongation of peri-Gondwanan microcontinents (e.g. Cadomia, Intra-Alpine Terrane). Subduction of oceanic ridge (Proto-Tethys) triggered the break-off of Avalonia, whereas in the eastern prolongation, the presence of the ridge may have triggered the amalgamation of volcanic arcs and continental ribbons with Gondwana (Ordovician orogenic event). Renewed Gondwana-directed subduction led to the opening of Palaeo-Tethy

The north-subducting Rheic Ocean during the Devonian: consequences for the Rhenohercynian ore sites

Base metal mining in the Rhenohercynian Zone has a long history. Middle-Upper Devonian to Lower Carboniferous sediment-hosted massive sulfide deposits (SHMS), volcanic-hosted massive sulfide deposits (VHMS) and Lahn-Dill-type iron, and base metal ores occur at several sites in the Rhenohercynian Zone that stretches from the South Portuguese Zone, through the Lizard area, the Rhenish Massif and the Harz Mountain to the Moravo-Silesian Zone of SW Bohemia. During Devonian to Early Carboniferous times, the Rhenohercynian Zone is seen as an evolving rift system developed on subsiding shelf areas of the Old Red continent. A reappraisal of the geotectonic setting of these ore deposits is proposed. The Middle-Upper Devonian to Early Carboniferous time period was characterized by detrital sedimentation, continental intraplate and subduction-related volcanism. The large shelf of the Devonian Old Red continent was the place of thermal subsidence with contemporaneous mobilization of rising thermal fluids along activated Early Devonian growth faults. Hydrothermal brines equilibrated with the basement and overlying Middle-Upper Devonian detrital deposits forming the SHMS deposits in the southern part of the Pyrite Belt, in the Rhenish Massif and in the Harz areas. Volcanic-hosted massive sulfide deposits (VHMS) formed in the more eastern localities of the Rhenohercynian domain. In contrast, since the Tournaisian period of ore formation, dominant pull-apart triggered magmatic emplacement of acidic rocks, and their metasomatic replacement in the apical zones of felsic domes and sediments in the northern part of the Iberian Pyrite belt, thus changing the general conditions of ore precipitation. This two-step evolution is thought to be controlled by syn- to post- tectonic phases in the Variscan framework, specifically by the transition of geotectonic setting dominated by crustal extension to a one characterized by the subduction of the supposed northern slab of the Rheic Ocean preceding the general Late Variscan crustal shortening and oroclinal bending

Organization of pre-Variscan basement areas at the north-Gondwanan margin

Pre-Variscan basement elements of Central Europe appear in polymetamorphic domains juxtaposed through Variscan and/or Alpine tectonic events. Consequently, nomenclatures and zonations applied to Variscan and Alpine structures, respectively, cannot be valid for pre-Variscan structures. Comparing pre-Variscan relics hidden in the Variscan basement areas of Central Europe, the Alps included, large parallels between the evolution of basement areas of future Avalonia and its former peri- Gondwanan eastern prolongations (e.g. Cadomia, Intra-Alpine Terrane) become evident. Their plate-tectonic evolution from the Late Proterozoic to the Late Ordovician is interpreted as a continuous Gondwana-directed evolution. Cadomian basement, late Cadomian granitoids, late Proterozoic detrital sediments and active margin settings characterize the pre-Cambrian evolution of most of the Gondwana-derived microcontinental pieces. Also the Rheic ocean, separating Avalonia from Gondwana, should have had, at its early stages, a lateral continuation in the former eastern prolongation of peri-Gondwanan microcontinents (e.g. Cadomia, Intra-Alpine Terrane). Subduction of oceanic ridge (Proto-Tethys) triggered the break-off of Avalonia, whereas in the eastern prolongation, the presence of the ridge may have triggered the amalgamation of volcanic arcs and continental ribbons with Gondwana (Ordovician orogenic event). Renewed Gondwana-directed subduction led to the opening of Palaeo-Tethys

The Palaeozoic metamorphic evolution of the Alpine External Massifs

The pre-Mesozoic metamorphic pattern of the External Massifs, composed of subunits of different metamorphic histories, resulted from the telescoping of Variscan, Ordovician and older metamorphic and structural textures and formations. During an early period, the future External Massifs were part of a peri-Gondwanian microplate evolving as an active margin. Precambrian to lower Palaeozoic igneous and sedimentary protoliths were reworked during an Ordovician subduction cycle (eclogites, granulites) preceding Ordovician anatexis and intrusion of Ordovician granitoids. Little is known about the time period when the microcontinent containing the future External Massifs followed a migration path leading to collision with Laurussia. Corresponding rock-series have not been identified. This might be because they have been eroded or transformed by migmatisation or because they remain hidden in the monocyclic areas. Besides the transformations which originated during the Ordovician subduction cycle, strong metamorphic transformations resulted from Variscan collision when many areas underwent amphibolite facies transformations and migmatisation. The different subunits composing the External Massifs and their corresponding P-T evolution are the expression of different levels in a nappe pile, which may have formed before Visean erosion and cooling. The presence of durbachitic magmatic rocks may be the expression of a large scale Early Variscan upwelling line which formed after Variscan lithospheric subduction. Late Variscan wrench fault tectonics and crustal thinning accompanied by high thermal gradients triggered several pulses of granite intrusions

Ollo de Sapo Cambro-Ordovician volcanics from the Central Iberian basement—A multiphase evolution

The Cambro-Ordovician rhyodacitic to dacitic volcanics from the Central Iberian basement, currently known as Ollo de Sapo (toads eye), have been reported as a specific group of felsic porphyritic rocks with blue quartz and large phenocrysts of K- feldspar, in a partly vitreous or fine-grained matrix. Interpreted to form Cambro- Ordovician volcanic domes, they are accompanied by tuffs, ignimbrites and products of reworking in a near-surface environment. The coarse- to fine-grained rocks exhibit rather large K-feldspar phenocrysts, plagioclase and rounded blue quartz, representing former corroded phenocrysts. Their colouration indicates unmixing of TiO2 at around 900°C during cooling from relatively high crystallisation temperatures, indicating their origin at hot lower crustal conditions. We propose at least a two-step evolution (1) starting around 495 Ma in the lower crust of a collapsing cordillera, generating a phenocryst-rich mush and adiabatic melting of the lower crustal protolith to produce the spectacular Ollo de Sapo porphyrites, before (2) magma ascent and crustal extension leading to a different thermal regime around 483 Ma

Efficacy and safety of dalbavancin in the treatment of acute bacterial skin and skin structure infections (ABSSSIs) and other infections in a real-life setting: data from an Italian observational multicentric study (DALBITA study)

Objectives: We evaluated the efficacy and safety of dalbavancin in ABSSSI and ‘other sites’ infections’ (OTA). Methods: Observational study involving 11 Italian hospitals including patients that received ≥1 dose of dalbavancin in 2016–2019. The outcome was end-of-treatment efficacy and safety in ABSSSI and OTA in a real-life setting. Results: 206 patients enrolled (males 50%, median age 62 [IQR 50–76] years), 60.2% ABSSSI, 39.8% OTA. 69.7% ABSSSI vs 90.7% OTA (p = 0.003) and 46.3% ABSSSI vs 37.2% OTA (p = 0.786) received previous and concomitant antibiotics, respectively. 82.5% reached clinical cure. Eleven (5.4%) patients had non-serious adverse events (AE). OTA patients showed longer hospitalization (13.5 days, 5.5–22 vs 3, 0–11.7; p<0.0001) and received longer previous (18 days, 9–30 vs 11, 7–19; p = 0.007)/concomitant antibiotic treatments (21 days, 14–52 vs 11, 8–14; p < 0.0001), compared to ABSSSI. ABSSSI and OTA showed similar efficacy (85.5% vs 75%, p = 0.459) and safety (no AE: 81.5% vs 64.3%, p = 0.258); efficacy was independent of previous/concomitant therapies. Conclusions: Dalbavancin demonstrated a success rate of >80%, with similar efficacy/safety in ABSSSI and off-label indications. The preferential use of dalbavancin as second-line or combination therapy would seem to suggest the need for in-depth studies focused on its off-label use

Infection-Related Ventilator-Associated Complications in Critically Ill Patients with Trauma: A Retrospective Analysis

Background: Trauma is a leading cause of death and disability. Patients with trauma undergoing invasive mechanical ventilation (IMV) are at risk for ventilator-associated events (VAEs) potentially associated with a longer duration of IMV and increased stay in the intensive care unit (ICU). Methods: We conducted a retrospective cohort study aimed to evaluate the incidence of infection-related ventilator-associated complications (IVACs), possible ventilator-associated pneu- monia (PVAP), and their characteristics among patients experiencing severe trauma that required ICU admission and IMV for at least four days. We also determined pathogens implicated in PVAP episodes and characterized the use of antimicrobial therapy. Results: In total, 88 adult patients were included in the main analysis. In this study, we observed that 29.5% of patients developed a respiratory infection during ICU stay. Among them, five patients (19.2%) suffered from respiratory infections due to multi-drug resistant bacteria. Patients who developed IVAC/PVAP presented lower total GCS (median value, 7; (IQR, 9) vs. 12.5, (IQR, 8); p = 0.068) than those who did not develop IVAC/PVAP. Conclusions: We observed that less than one-third of trauma patients fulfilling criteria for ventilator associated events developed a respiratory infection during the ICU stay

Clinical Experience with Ceftazidime-Avibactam for the Treatment of Infections due to Multidrug-Resistant Gram-Negative Bacteria Other than Carbapenem-Resistant Enterobacterales

Experience in real clinical practice with ceftazidime-avibactam for the treatment of serious infections due to gram-negative bacteria (GNB) other than carbapenem-resistant Enterobacterales (CRE) is very limited

Late-Proterozoic to Paleozoic history of the peri-Gondwana Calabria–Peloritani Terrane inferred from a review of zircon chronology

U–Pb analyses of zircon from ten samples of augen gneisses, eight mafic and intermediate metaigneous rocks and six metasediments from some tectonic domains along the Calabria–Peloritani Terrane (Southern Italy) contribute to knowledge of peri-Gondwanan evolution from Late-Proterozoic to Paleozoic times. All samples were equilibrated under amphibolite to granulite facies metamorphism during the Variscan orogeny. The zircon grains of all considered samples preserve a Proterozoic memory suggestive of detrital, metamorphic and igneous origin. The available data fit a frame involving: (1) Neoproterozoic detrital input from cratonic areas of Gondwana; (2) Pan-African/Cadomian assemblage of blocks derived from East and West African Craton; (3) metamorphism and bimodal magmatism between 535 and 579 Ma, within an active margin setting; (4) rifting and opening of Ordovician basins fed by detrital input from the assembled Cadomian blocks. The Paleozoic basins evolved through sedimentation, metamorphism and magmatism during the Variscan orogeny involving Palaeozoic and pre-Paleozoic blocks. The Proterozoic zircon records decidedly decrease in the high grade metamorphic rocks affected by Variscan pervasive partial melting. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1186/s40064-016-1839-8) contains supplementary material, which is available to authorized users