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The northern subbelt in the western segment of the Yarlung Zangbo suture zone, Tibet, China, includes the Dajiweng, Kazhan, Baer, Cuobuzha, Jianabeng, and Zhalai ophiolitic massifs. These ophiolites are strongly dismembered, typically 1-2 km wide and 10-20 km long, and composed chiefly of peridotites with minor volcanic and siliceous sedimentary rocks. No cumulates have been observed in the northern ophiolitic belt. Harzburgites of the Dajiweng and Zhalai ophiolites have prominent light rare earth element (LREE)-enriched (U-shaped or spoon-shaped) chondrite-normalized rare earth element (REE) patterns. Such patterns have generally been interpreted as the result of modification by suprasubduction zone (SSZ) melts/fluids. However, the abundance of peridotites sampled from mid-ocean ridge with similar LREE-enriched REE patterns suggest that this feature is not unique to SSZ peridotites. The U-shaped REE patterns of the Dajiweng harzburgites, combined with their low heavy rare earth element (HREE) contents and their mineral chemistry, indicate that these rocks most likely have been modified by SSZ melts (e.g., boninitic melts) in a forearc setting. In contrast, the Zhalai harzburgites, which also have U-shaped REE patterns but are characterized by high HREE contents, high Al2O3/SiO2 ratios, low MgO/SiO2 ratios, and relatively fertile mineral compositions, most likely have been refertilized in a mid-ocean ridge setting. The Zhalai, Kazhan, Baer, and Cuobuzha peridotites are similar to abyssal and back-arc peridotites in mineral chemistry and whole-rock geochemistry. Combining the mafic intrusions from Jianabeng, Baer, and Cuobuzha massifs, we propose that the ophiolites in the northern belt of the western segments have been trapped in an intraoceanic forearc-arc-back-arc system. According to the zircon U-Pb age of mafic intrusions, the geochemical characteristics of both mafic and ultramafic rocks, a detrital zircon study of Zhongba terrane, and the klippen structure of ophiolitic massif in the southern belt, we conclude that the northern and southern ophiolitic belts were developed in the same intraoceanic subduction system.

Plus encore que les réserves naturelles, les parcs nationaux entretiennent dès l’origine une relation ambiguë au tourisme. Au début du XXe siècle, « l’idée de créer des parcs nationaux connaît un certain succès en France. Les nombreux articles publiés dans les revues du Club alpin français et du Touring club de France en témoignent. L’objectif est de disposer d’une institution capable de protéger des paysages exceptionnels, de favoriser et de réglementer leur fréquentation touristique ». Quant à l’élaboration de la loi du 22 juillet 1960, elle est « fortement influencée par les débats qui ont lieu depuis plusieurs années autour du projet du parc national dans le massif de la Vanoise en Savoie. Les scientifiques sont assez hostiles à l’idée d’ouvrir le parc au public, ce qui leur paraît contradictoire avec l’idée de protection et peu compatible avec leurs projets de recherches. D’autres veulent au contraire en faire un lieu largement ouvert pour offrir une compensation aux populations urbaines privées du contact avec la nature ». Le parlement réalise une synthèse des propositions, qui permet de créer le premier parc en 1963 : « les partisans d’une conception \"pure et dure\" des parcs nationaux auront des réserves intégrales ; les institutions cynégétiques une sorte de parc à bouquetins avec la zone centrale et les tenants d’un parc national culturel la zone périphérique ».

The Almogholagh–Dehgolan region is in the North Sanandaj–Sirjan zone of NW Iran. The granites of the region are metaluminous and display geochemical and textural characteristics of transitional granites between ferroan (A-type) and I-type granites. In geotectonic discrimination diagrams, the Almogholagh–Dehgolan granites plot mainly in the fields of within-plate granites and volcanic arc granites. With the exception of the Qalaylan granites, parts of other granites resemble A2-type granites. Granites of the Qalaylan intrusive body have petrographic and geochemical features close to I-type granites and are not A-type. Primary mantle and chondrite-normalized spider diagrams show enrichments in light rare earth elements relative to heavy rare earth elements. For an age of 150 Ma, the initial 87Sr/86Sr and 143Nd/144Nd ratios vary from 0.702769 to 0.706545 and from 0.512431 to 0.512558, respectively. Epsilon Nd values vary in a relatively limited range between −0.3 and +2.2, which corresponds to a mixed mantle–crustal source. On the basis of new geochemical and isotopic data, we suggest a geodynamic model involving partial melting of lower crustal rocks with the contribution of mantle magmas in a weakly extensional tectonic setting for the generation of the A-type granites of the region. The occurrence of ferroan (A-type) granites in this region of the Sanandaj–Sirjan zone indicates the existence of a partly extensional tectonic environment in a mainly compressional subduction-related regime in Late Jurassic time.

20th Anglo-French Physical Acoustics Conference (AFPAC 2023)FOREWORDAfter two successive postponements due to a well-known malicious virus, the twentieth AFPAC was organized in France in Fréjus at the Villa Clythia, from January 24 to 27, 2023. To celebrate this twentieth edition by something special to be remembered, a picnic on the beach followed by a magnificent walk in the Estérel massif were organized, in very favorable weather (as shown by the picture below).This year again, the bet was successful! During the five half-days of conferences, 33 oral presentations including four invited talks were given, on very varied themes, all in the area of physical acoustics.The four high quality invited talks concerned subjects as varied as “The cochlea seen as an active metamaterial” by Fabrice Lemoult, “Guided wave testing of pipelines” by Mike Lowe, “Miniature ultrasonic surgical devices for integration with surgical robots” by Margaret Lucas and “Ultrasound backscattering by aggregating red blood cells for hematopathology” by Émilie Franceschini. The number of questions at the end of each of the 33 presentations was only a reflection of their high quality, sparking interest and cross-disciplinary scientific discussions, entirely in line with what the AFAPC wishes to promote.The two Rocard 2022 prizes (prize of the Société Française d’Acoustique to distinguish promising young researchers after their PhD) were awarded to Xinxin Guo and Matthieu Malléjac during this edition.Alain Lhémery (CEA-LIST, France), Samuel Raetz (Le Mans Université, France), SFA / GAPSUS, Nader Saffari (UCL, UK), Theodosia Stratoudaki (University of Strathclyde, UK), IOP / PAG.

Le site de la ville antique de Bibracte, qui occupe l'un des sommets du Morvan, le mont Beuvray, doit une partie de sa valeur patrimoniale à la forêt qui sert d'écrin aux vestiges archéologiques. Domaine public de près de 1 000 hectares, c'est un haut lieu patrimonial de la Bourgogne, protégé au titre des Monuments historiques et à celui des Sites, qui accueille environ 100 000 visiteurs par an. Les effets déjà notables du changement climatique sur les peuplements forestiers du site induisent une situation nouvelle à tous points de vue, y compris celui des interrogations montantes du public, qui peuvent prendre parfois la forme de critiques véhémentes, sur la façon dont est conduite la gestion de ce massif forestier. Pour affronter ces difficultés, a été mis en place un dispositif de recherche qui participe d'une expérimentation plus large conduite sous couvert de la démarche Grand Site de France et qui comprend une composante de dialogue territorial.

L'ameublement est au cœur du quotidien des Français : à la maison, au bureau, dans les tiers-lieux, dans l'espace public... Le bois occupe une place prépondérante dans les matériaux mis en œuvre par les fabricants français d'ameublement et d'agencement : sous forme de panneaux à base de bois ou de bois massif, il représente 85 % du poids total des matériaux mis en œuvre dans la fabrication française. À l'heure où les forêts françaises doivent s'adapter au changement climatique, quels défis se présentent à la filière française de la fabrication d'ameublement ? Deux études récentes conduites respectivement par EY et Carbone 4 ont permis d'éclairer les industriels sur les enjeux et leviers qui les attendent pour contribuer à l'atteinte des objectifs 2030-2050 de décarbonation de l'économie française. Avec un défi majeur : allonger la durée de vie des produits pour contribuer à stocker du carbone et préserver les ressources.

The Basque-Cantabrian junction corresponds to an inverted rift accommodation zone at the limit between the former hyperextended Pyrenean and Cantabrian rift segments. The recognition of an inherited rift segment boundary allows to investigate the reactivation associated with large-scale rift segmentation in an orogenic system. We use criteria from published field observations and seismic data to propose a new map of rift domains for the Basque-Cantabrian junction. We also provide balanced cross-sections that allow to define the along-strike architecture associated with segmentation during rifting and subsequent Alpine reactivation. Based on these results, this study aims to characterize and identify reactivated and newly formed structures during inversion of two rift segments and its intermitted segment boundary. It also aims to describe the timing of thin-skinned and thick-skinned deformation associated with the inversion of segmented rift systems. During convergence, two phases have been recognized within the rift segment (eastern Mauléon basin). The Late Cretaceous to Paleocene underthrusting/subduction phase was mostly governed by thin-skinned deformation that reactivated the former hyperextended domains and the supra-salt sedimentary cover. The Eocene to Miocene collisional phase, controlled by thick-skinned deformation that took place once necking domains collided and formed an orogenic wedge. At the rift segment boundary, the underthrusting/subduction phase was already controlled by thick-skinned deformation due to the formation of shortcutting thrust faults at the termination of overlapping V-shaped rift segments. This led to the formation of a proto-wedge composed of the Basque massifs. We suggest that this proto-wedge is responsible for the preservation of pre-Alpine structures in the Basque massifs and for the emplacement of subcontinental mantle rocks at a crustal level beneath the western Mauléon basin. These results argue for a first order cylindrical orogenic architecture from the Central Pyrenean segment to the Cantabrian segment (up to the Santander transfer zone) despite rift segmentation. They also highlight the control of 3D rift-inheritance for the initial phase of orogenic evolution and for the local architecture of mountain belts. La jonction pyrénéo-cantabrique correspond à une zone d’accommodation entre les segments de rifts hyper-étirés cantabrique et pyrénéen, qui ont été par la suite inversés lors de l’orogénèse alpine. La reconnaissance d’une telle zone de segmentation permet d’étudier les conséquences d’un héritage de rift en 3 dimensions sur l’évolution orogénique. A partir de nos précédents résultats ainsi que de la compilation de données de terrain et de sismique, nous proposons une nouvelle carte des domaines de rift dans la zone étudiée. L’élaboration de coupes restaurées permet de définir et comparer l’architecture actuelle et syn-rift entre la zone d’accommodation et les segments de rift (c.à.d. à distance de la zone de segmentation). A partir de ces résultats, cette étude vise à identifier et caractériser les structures réactivées et néo-formées à travers la zone d’étude. Elle entreprend également de décrire l’évolution de la déformation « thin-skinned » et « thick-skinned » au cours de la convergence dans ce type de système très segmenté. Lors de la convergence, deux phases de déformation peuvent être distinguées dans les segments de rift (bassin Est Mauléon). Une phase de sous-charriage tardi-Crétacé à Paléocène, principalement contrôlée par la déformation « thin-skinned » et qui réactive les domaines de rift hyper-étirés ainsi que la couverture Mésozoïque décollée sur les évaporites du Trias Supérieur. Une phase de collision Éocène à Miocène, qui s’initie lorsque les domaines d’étranglement des marges conjuguées se rencontrent et qui mène à la formation d’un prisme orogénique (« thick-skin »). Dans la zone d’accommodation, la phase de sous-charriage semble déjà contrôlée par la déformation « thick-skinned » par la formation de structures crustales néo-formées à vergences opposées à la terminaison des bassins. Ces dernières transfèrent la déformation entre les deux segments de rifts et forment un proto-prisme orogénique composé des massifs basques. Nous suggérons que ce proto-prisme orogénique est responsable de la préservation des structures pré-alpines dans les massifs basques ainsi que de l’emplacement à faible profondeur du manteau sous-continental sous le bassin Ouest Mauléon. Cette étude montre que l’architecture orogénique apparaît au premier ordre cylindrique des Pyrénées Centrales au segment cantabrique (jusqu’à la zone de Santander), malgré la segmentation du système de rift sur lequel la déformation s’initie. Elle souligne enfin le rôle de l’architecture héritée en 3 dimensions lors des phases précoces de l’évolution orogénique ainsi que pour l’architecture locale de l’orogène.

The recent installation of new broadband seismic stations in the French Massif Central (FMC) has resulted in the detection of a few “deep” earthquakes located near the crust‐mantle boundary beneath volcanic regions. Analysis of the spectral content of the respective waveforms has shown that the spectra of these “deep” earthquakes are significantly depleted in high frequencies. Based on these observations of anomalous depth and spectral content, these earthquakes can be classified as Deep Long Period (DLP) events. This is a specific class of volcanic seismicity observed beneath many active volcanoes around the World. While the exact physical origin of this type of earthquakes is still debated, they are often considered as indicators of the presence of magma near the crust‐mantle boundary. Therefore, observation of DLP earthquakes can bring new insights into understanding the state and the activity of the recent FMC volcanoes.

Groundwater is an important source for drinking water supply in hard rock terrain of Bundelkhand massif particularly in District Mahoba, Uttar Pradesh, India. An attempt has been made in this work to understand the suitability of groundwater for human consumption. The parameters like pH, electrical conductivity, total dissolved solids, alkalinity, total hardness, calcium, magnesium, sodium, potassium, bicarbonate, sulfate, chloride, fluoride, nitrate, copper, manganese, silver, zinc, iron and nickel were analysed to estimate the groundwater quality. The water quality index (WQI) has been applied to categorize the water quality viz: excellent, good, poor, etc. which is quite useful to infer the quality of water to the people and policy makers in the concerned area. The WQI in the study area ranges from 4.75 to 115.93. The overall WQI in the study area indicates that the groundwater is safe and potable except few localized pockets in Charkhari and Jaitpur Blocks. The Hill-Piper Trilinear diagram reveals that the groundwater of the study area falls under Na+-Cl−, mixed Ca2+-Mg2+-Cl− and Ca2+-HCO3- types. The granite-gneiss contains orthoclase feldspar and biotite minerals which after weathering yields bicarbonate and chloride rich groundwater. The correlation matrix has been created and analysed to observe their significant impetus on the assessment of groundwater quality. The current study suggests that the groundwater of the area under deteriorated water quality needs treatment before consumption and also to be protected from the perils of geogenic/anthropogenic contamination.

The Rhenish Massif in Central Europe, which includes the Eifel Volcanic Fields, has shown ongoing ground deformation and signs of possible unrest. A buoyant plume exerting uplift forces at the bottom of the lithosphere was proposed to explain such deformation; the hypothesis of (possibly concurrent) melt accumulation in the crust/lithospheric mantle has not been explored yet. Here, we test deformation models in an elastic half‐space considering sources of varying aspect ratio, size and depth. We explore the effects of data coverage, noise and uncertainty on the inferred source parameters. We find that the observed deformation would require melt accumulation in sub‐horizontal sill‐like structures expanding at the rate of up to ∼0.045 km3/yr. We discuss feasibility, limitations and possible interpretations of our resulting models and elaborate on further observations which may help constrain the structure of the Rhenish Massif magmatic system. Plain Language Summary Geodetic observations over the last 20 years recorded small but steady ground deformation over a wide area centered on the Eifel Volcanic Fields, Germany, where volcanism has occurred as recently as 11,000 years ago. Together with geophysical and geochemical evidences of possible ongoing unrest, the observed deformation has renewed interest over the origin of volcanism in the region. The deformation has been tentatively related to a buoyant plume in the asthenosphere. Here, we test whether the deformation may be, at least partially, originating in the lithosphere. We find that deformation data would be consistent with melt intrusions in one or more horizontal lenses located in the lithosphere, but limitations exist due to models simplifications. We discuss feasibility, limitations and possible interpretations of our results, and what additional data may improve our knowledge on the underlying magmatic system. Key Points We explore the hypothesis that the ongoing uplift in the Rhenish Massif is (partly) due to melt accumulating in the lithosphere Observed ground deformation would require the intrusion of up to ∼0.045 km3/yr into one or more horizontal magma lenses We test different deformation sources and discuss the feasibility, limitations and possible interpretations of the resulting models