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This paper present new U–Pb geochronological data (LA-ICP MS on zircon) of granitoids from the Moroccan Meseta Variscan belt. Zircons from the Oulad Ouaslam granodiorite in the Jebilet massif in the Western Meseta highlight a peak of magmatic activity at 335.2 ± 0.8 Ma. In the Eastern Meseta, the ages obtained from several granitoids facies from the High Moulouya magmatic complex restrained its magmatic activity to the early Visean: 339.6 ± 1.9 Ma for the Perdreaux granite, 337 ± 1.6 Ma for the calc-alkaline «grey» granite and 343.1±1.2 Ma for the El Hassir granodiorite. Similar late Tournaisian – early Visean ages were obtained for the Zekarra granodiorite (348.1 ± 2.3 Ma) and the Merguechoum granite (345.2 ± 2.8 Ma) in the Horsts belt. This pre-orogenic Eovariscan magmatic activity is contemporaneous with the opening of early Carboniferous intracontinental basins in the whole Northwest Africa but its relationship with Eovariscan deformation typifying the Eastern Meseta remains temporally unclear. Then, the late Carboniferous ages of 308.2 ± 2.7 Ma obtained for the Beni Snassen monzogranite, 303.5 ± 1.7 for the Tanncherfi granodiorite and 305.2 ± 1.4 for the Boudoufoud granite in the Horsts belt show that they all are synchronous with the main late Carboniferous convergent Variscan event in Northwest Africa. This tectonic and magmatic tempos contrast with the one described in the European Variscan belt, where the syn-collisional magmatism forms coevally with the Northwest African Eovariscan event, re-interpreted as a possible extensional event. We proposed that the early Carboniferous intracontinental basins and magmatism in Northwest Africa are due to the propagation of the Paleotethys ocean within the Gondwana continent. In contrary, the late Carboniferous – early Permian tectono-magmatic activity could reflect the docking of the east Gondwana margin with the Iberian branch of the European Variscan belt.

International audience; The knowledge acquired on the exhumation of the Pyrenean chain and the evolution of the adjacent foreland basins makes this Alpine-type domain a good laboratory to better constrain a full sediment routing system in a compressive context and to apprehend the driving processes controlling the sediment routing in space and time. This integrated approach aims at enhancing our basin mastering approach as well as improving our predictions of reservoir properties. This Source-to-Sink study seeks to understand the evolution of sedimentary routing from the Source (orogenic relief, craton, basin recycling) through the transfer zone (peripheral or internal to the basin) to the final sink (flexural basin, deep turbiditic margin). Within this new cartography, we propose to compile the data over the entire peri-Pyrenean domain. We produced large scale quantitative and qualitative maps to better observe and interpret the tectonic, climatic and surface processes impacts of the SRS behavior. These maps include kinematic reconstructions of the Iberian-European-Mediterranean system, restored sequential cross-sections, history/magnitude of exhumation by thermochronology, source tracking, characterization of weathering and erosion surfaces, synthesis of the major structures activity, paleogeographic reconstructions, analysis of sedimentary geometries and transport directions as well as the quantification of volumes preserved in the basins. Their interpretation is combined with a time representation along the routing system, linking classical basin wheeler diagram representation to source erosion and lithologies to obtain a continuous view on the sediment journey. The time steps chosen for these 5 maps account for the different stages of tectono-sedimentary evolution of the peri-Pyrenean system at the early-, syn- and post-orogenic stages. The compilations carried out compare exhumed domains and sedimentation zones in terms of fluxes and volumes and make it possible to map the routing systems and point out the main drivers for the surface evolution during the construction/destruction cycle of an orogen. Research work financed and carried out as part of the BRGM-TOTAL Source-to-Sink program

Deformation in intraplate domains is usually considered as a consequence of tectonic events at plate boundaries. Nevertheless, the occurrence of intraplate earthquakes such as the recent Le Teil event in the south of France along the Cévennes Fault System (CFS), on 11 November 2019, Mw = 4.9, questions whether this far-field deformation only occurs during tectonic pulses at plate boundaries, or if it corresponds to low-intensity but regional continuous deformation through time. To address this question, we have coupled U–Pb geochronology of fault-related calcites with structural analysis along a major fault system (the CFS) in the South-East Basin, France. We evidence (1) an Albian activity of the CFS and (2) a continuous compressional activity of the CFS and satellite structures during the whole Eocene and probably during the Late Cretaceous – Palaeocene, including periods (e.g. Lutetian) usually considered as phases of tectonic quiescence. We thus demonstrate that the tectonic reactivation of this intraplate fault system is not restricted to periods of high rates of deformation at plate boundaries.

A multi-method approach aimed at characterizing carbonate parietal deposits and at proposing a chronology for these carbonate crusts is described. Dating was performed by radiometric methods (C-14 for recent samples, and U-series) on samples that had been characterized beforehand using optical and cathodoluminescence microscopy, and Fourier Transform Infrared microspectroscopy. For U-series, high precision on U-Th ages was achieved using liquid phase multicollector-ICP-MS applied to large samples, while laser-ablation single collector - ICP-SFMS provided information on the reliability of the sampling with a high spatial resolution. This methodology, based on the combination of these two techniques reinforced by the information obtained by the calcite characterization methods, was applied to carbonate deposits from the cave of the Trou du Renard (Soyons, France). The ages obtained with the two U-Th dating techniques are comparable and illustrate that different laminae were deposited at different rates in the samples. In the future, this procedure based on the mineralogical and geochemical characterization of the samples and their dating by radiometric methods will be applied to the layers of parietal carbonates deposited on Palaeolithic decorated walls. When the crystallization is slow, the U/Th dating method by imaging technique is of interest as well as that by multicollector-ICP-MS in liquid phase. The development of robust dating methods on very small quantities of material will make it possible to define the chronological framework of cave rock art.

International audience; Unlike the richly documented rock art of the Sahara or southern Africa, that of sub-Saharan Africa often remains poorly known. With 117 inventoried sites (including 20 decorated caves), the Lovo Massif contains one of the largest concentrations of rock sites in the entire region, representing more than 5700 images. Dating this rock art is a real challenge, and only a few direct dates of drawings made with charcoal have been obtained so far (Heimlich et al., 2013). In this paper, we present the first chronology for the red geometric paintings of the Lovo Massif. We used uranium-series and 14C on secondary carbonates deposited above a series of geometric paintings at the M'Bubulu rock art site, in order to propose a minimum age for these motifs. The cross-dating shows evidence of a close system behavior for these secondary carbonate layers, thereby validating the ages obtained. They can thus be used to constrain the chronology of the red geometric paintings, which were made before the seventeenth century. Thus, this art could be attributed to a specific Kongo ritual.

The North Pyrenean foreland basin evolved from underfilled to overfilled during the Eocene time in mirror of the development of the Pyrenean orogeny. The resulted Eocene syn-orogenic conglomerate series, known as “Poudingues de Palassou”, recorded the evolution of the mountain belt and the draining system. Three units are classically differentiated in the eastern part: the first and third units deposited during the late Ypresian – Lutetian and Priabonian times respectively, contain clasts from the Meso-Cenozoic regional sedimentary cover. A second unit deposited during the Bartonian corresponds to clasts of magmatic and metamorphic origin (including granites). The objective of this study is to identify the sources of the sediments and to reconstruct the drainage evolution during the Eocene. To this end, U/Pb zircon dating was carried out on granite clasts from Unit 2 and on the conglomerate matrix of the three units using laser ablation-ICP-MS. These analyses are coupled with sedimentary characterization of depositional environments, paleocurrent directions measured in the fluvial deposits and Raman analyses performed on black flysch clasts from the Unit 1/Unit 2 transition. The zircon U/Pb results show a dominance of Variscan ages (290-360 Ma) in the upper part of the Unit 1 and for the matrix of Unit 2 conglomerates. Granite clasts of Unit 2 show mostly ages between 324±2 and 335±1 Ma. For Unit 3, the age spectrum is broader, ranging from Variscan to Cadomian (290 – 600 Ma). Sedimentary analysis of units 1 and 2, show an increase of the amount of sediments and a greater alluvial system during the deposition of the unit 2. The Raman analyses on the black flysch show temperature peaks ranging from 495 to 587°C, comparable to those obtained in the eastern part of the North Pyrenean Zone (NPZ) on black flysch deposits. Interpretation of the results shows that the deposits of Unit 1 are mainly derived from the erosion of the Meso-Cenozoic cover of the NPZ in the Late Ypresian and Lutetian, ending with black flysch of the NPZ, followed by erosion of the Variscan massifs. For Unit 2, the deposition is accompanied by a change in the nature of the clasts and a widening of the depositional zone reflecting wider drainage area including the Axial Zone (AZ). For Unit 3, the broad spectrum of ages obtained, as well as the nature of the clasts, suggest a fairly large catchment area drained from the AZ and significant recycling from the actively deformed foreland sedimentary cover during Priabonian. This research work was financed and carried out as part of the BRGM-TOTAL source-to-sink program.

The Variscan belt in NW Africa represents an intraplate orogen, which mainly developed from Late Carboniferous (ca. from the Bashkirian: 323–315 Ma) to the end of Cisuralian (283–273 Ma), in response to the closure of an oceanic domain between NW Gondwana and Laurentia. The orogenic events were accompanied by an important magmatic activity, distributed across the whole northern Morocco, north of the South Meseta Fault Zone which separates the Meseta domain in the north from the Anti-Atlas domain to the south, where no magmatic activity was recorded at that time. Moreover, an older magmatic phase occurred during the Late Devonian-Early Carboniferous however the associated geodynamic context remains under debate.In northern Morocco, existing geochronological results for these magmatic activities are mainly obtained using Rb-Sr methods (whole rock or on different minerals). However, recent U-Pb datings on different massifs in Morocco have revealed older ages. Therefore, Rb-Sr ages should be considered with caution.In this contribution, we present new U-Pb geochronological data (LA-ICP MS on zircons) for several plutonic massifs of northern Morocco from the Western (Jebilet) and Eastern Meseta. In the later, we provide new datings on 3 magmatic facies in the High Moulouya massif, but also for the Boudoufoud, Beni Snassen, Tanncherfi, Zekkara and Merguechoum massifs. These new data reinforce the idea that two main magmatic events must be properly separated in northern Morocco. First, a clear Early Carboniferous event, possibly beginning as soon as the end of Late Devonian, is recorded within both Western and Eastern Meseta, and this magmatic event ends at around 330 Ma. Afterwards, from ca. 310–305 Ma to ca.280–275 Ma, the second magmatic event is also expressed across both Western and Eastern Meseta. While this second magmatic event is clearly related to the Variscan orogenic events, the unclear geodynamic context for our new Early Carboniferous ages allows the re-opening of the discussion about the « Eovariscan » phase in NW Africa. Finally, these two magmatic phases are compared to the magmatic records from West Europe Variscan belt.