Publications
La fréquentation touristique et ses effets économiques : des enjeux pour des politiques de gestion et de valorisation de sites naturels patrimoniaux
Tourist spending at the UNESCO-listed Chaîne des Puys - Limagne fault tectonic arena significantly outweighs that of excursionists, with accommodation costs dominating overall expenditures. While tourists contribute 74% to paid activities, excursionists still represent a substantial 26%, offering a more evenly distributed economic resource throughout the year. The study introduces an analytic framework to quantify and qualify tourist frequentation, visitor expenses, and local economic impacts, addressing methodological challenges in monitoring open, extended sites. By combining diverse data sources with face-to-face surveys, researchers reveal insights into visitor motivations, practices, and the broader tourism system linked to the site, providing critical guidance for sustainable management and valorization policies.
The UNESCO World Heritage Site of the Chaîne des Puys–Limagne Fault Tectonic Arena (Auvergne, France)
The Chaîne des Puys–Limagne fault tectonic arena, inscribed as a UNESCO World Heritage Site in 2018, serves as a natural scale model illustrating continental rift processes. This site uniquely combines the Limagne fault (a graben border), the granitic Plateau des Dômes with its Quaternary volcanic alignment (Chaîne des Puys), and an inverted relief from Pliocene lava flow erosion (Montagne de la Serre). The study highlights how these structural and volcanic features, when viewed globally, provide a tangible understanding of deep tectonic dynamics. As an inhabited environment supporting 30,000 residents with traditional agroforestry practices, the site now faces the challenge of balancing conservation, sustainable development, and international recognition post-inscription.
Lake Chauvet Maar in the Chaîne des Puys Volcano Group, Central France
The Chaîne des Puys - Limagne fault tectonic arena, located in central France, features the Lake Chauvet Maar, a volcanic crater formed approximately 10,000 years ago during the end of the last glacial period. This maar, with a diameter of 600 meters and a depth of 73 meters, is part of a larger group of about 100 scoria cones, maars, and lava domes that stretch along the western edge of the Limagne graben, a rift valley formed by the Alpine orogeny starting in the late Mesozoic era. The study highlights the geological significance of this region, which has experienced volcanic activity extending into the Quaternary period, with the most recent eruption dated to around 7,000 years ago at Lake Pavin Maar, located nearby.
Development of a New Type of Geodiversity System for the Scoria Cones of the Chaîne des Puys Based on Geomorphometric Studies
A new geodiversity system for scoria cones, developed through geomorphometric studies of the Chaîne des Puys UNESCO World Heritage site, addresses a critical limitation in existing methods. Traditional geodiversity indices often underestimate the aesthetic and scientific value of symmetrical volcanic features like scoria cones due to their regular shapes. The proposed approach modifies these indices by adapting them to cone geometry, enhancing the representation of uniformity and symmetry in larger landscape elements. This method is computationally simple yet effective, applicable to thousands of monogenetic volcanoes globally and extendable to other volcanic features such as domes or even larger volcanoes. It bridges the gap between scientific quantification and aesthetic appreciation, offering a robust tool for analyzing geodiversity in volcanic landscapes.
DTM-Based Morphometric Analysis of Scoria Cones of the Chaîne des Puys (France)—The Classic and a New Approach
A novel sectorial approach to analyzing scoria cones in the Chaîne des Puys (France) reveals that most cones exhibit asymmetry and elongation, with lithology influencing shape more than age. This DTM-based morphometric study contrasts classic descriptors with detailed slope distributions, uncovering systematic trends in cone symmetry and morphology. While regression models show partial success in linking parameters to age, further research is needed to fully understand the relationship between lithology, shape, and symmetry.
L’usage des trachytes de la chaîne des Puys depuis deux millénaires / The use of trachytic lava in the chaîne des Puys for two millennia
A groundbreaking study reveals that trachytic lavas from the Chaîne des Puys volcanoes exhibit unique petrographic identities, enabling precise sourcing of archaeological materials. The research, part of a collective project, identified distinct lava types for most volcanoes, with exceptions like Cliersou and Aumône sharing the same composition. Notably, the Puy de Dôme and Cratère Kilian each consist of two different lavas. This fine characterization allows archaeologists to trace trachyte materials used in ancient buildings, tombs, and sculptures—such as those from the Temple of Mercury and the Tourette d'Enval sanctuary—to their original volcanic sources. The study also uncovered extensive quarrying activities during antiquity and the High Middle Ages, including previously unknown underground exploitations. Additionally, it highlights the use of trachytes in Romanesque architecture and modern civil construction, offering new insights into ancient economic circuits and craft practices.
Robust Bayesian Joint Inversion of Gravimetric and Muographic Data for the Density Imaging of the Puy de Dôme Volcano (France)
Scientists have successfully created the most precise 3D density image of the Puy de Dôme volcano, revealing it to be dry and permeable with a dense trachytic core. This groundbreaking achievement was accomplished by jointly inverting gravimetric and muographic data using a robust Bayesian method, which automatically adjusts for data-specific artifacts and potential density offsets. The approach overcomes limitations of traditional methods, such as the non-uniqueness of solutions in gravimetry and the geometric constraints of muography. By combining these techniques, researchers have gained deeper insights into the volcano's internal structure, improving our understanding of magma pathways and structural weaknesses.
Rheological change and degassing during a trachytic Vulcanian eruption at Kilian Volcano, Chaîne des Puys, France
Trachytic magmas, such as those erupted at Kilian Volcano in France's Chaîne des Puys, exhibit unique rheological behaviors that influence effusive-explosive transitions during Vulcanian eruptions. This study reveals that trachytes can erupt explosively at higher ascent rates than more evolved subalkaline dacitic or rhyolitic magmas due to their distinct properties: high water solubility and diffusivity, rapid microlite growth, and lower melt viscosity. The research combines chemical and textural analyses of tephra with viscosity models to demonstrate how effusive activity transitions to explosive phases through processes like volatile loss, crystallization, and pore space sealing. These findings suggest that the periodicity of eruptive styles in trachytic volcanoes may differ from better-studied andesitic or rhyolitic systems, with implications for volcanic hazard assessment.
Une association bryophytique nouvelle, endémique du puy de Dôme (Puy-de-Dôme, Auvergne-Rhône-Alpes) : le Gymnomitrio corallioidis-Barbilophozietum sudeticae
Researchers have identified a new, micro-endemic bryophyte association, the Gymnomitrio corallioidis-Barbilophozietum sudeticae, uniquely found on the summit of Puy de Dôme in the Chaîne des Puys. This permanent, pioneer community thrives on pulverulent domite outcrops amidst cryophilic heathlands and is characterized by species such as Gymnomitrion corallioides and Barbilophozia sudetica. The association, likely once more widespread, exhibits high sensitivity to climate change, raising concerns about its long-term survival on this relatively low-altitude summit. The study highlights the ecological significance of this specialized community within a UNESCO World Heritage Site.
The Leaning Puy de Dôme (Auvergne, France) tilted by shallow intrusions
The iconic Puy de Dôme, a monogenetic lava dome in the Chaîne des Puys (France), was found to have been tilted by approximately 17° to the southwest due to shallow intrusions. This study reveals that the dome's asymmetry, with one side steeper than the other, resulted from further surface-bulging inflation of the Petit Puy de Dôme intrusion after its initial formation. Using mapping and paleomagnetism, researchers determined that this tilting process occurred over several hundred years, involving landslides and a small phreatomagmatic eruption. The findings extend the hazard period for such volcanic activity and suggest similar patterns in other monogenetic and polygenetic systems.
Un Observatoire photographique participatif des paysages et de la valeur universelle de la Chaîne des Puys-faille de Limagne ?
A participatory photographic observatory was developed to monitor and evaluate the landscapes of the Chaîne des Puys-Limagne fault tectonic arena, supporting its UNESCO World Heritage Site candidacy. This innovative approach combines repeated photography over time with other technical tools to engage local stakeholders—including elected officials and residents—in landscape preservation efforts. The study suggests that active involvement in observing and documenting changes can foster a deeper connection to the site, ensuring long-term commitment to its management and sustainable development. By integrating participatory methods, this observatory aims to enhance awareness of the site's universal value while providing a practical framework for future conservation strategies.
Why public policies face difficulties in protecting mountain pastoral landscapes: some lessons from the history of the volcanic landscape of the Chaîne des Puys / Limagne fault, France
Public policies aimed at preserving the unique volcanic landscape of the Chaîne des Puys / Limagne fault in France have faced significant challenges, despite spanning over 400 years. This study reveals that while some areas have seen improvements in biodiversity and landscape quality due to effective management practices, others have been abandoned or forested, leading to closed landscapes with reduced biodiversity. The research employs a systemic analysis of historical policies to identify the reasons behind their ineffectiveness and proposes principles for future policies to better protect mountain grazing landscapes with local community support.
De la Limagne à la chaîne des Puys. Approche analytique intégrative pour l’étude des végétations actuelles et potentielles en moyenne montagne tempérée
A comprehensive study of the Chaîne des Puys - Limagne fault tectonic arena in central France has identified 81 distinct vegetation units, including 60 series and 21 geoseries, through an integrative analytical approach. This research, part of the CarHAB program, utilized a dynamico-caténale method to model current and potential vegetation across diverse habitats, integrating phytosociological data, ecological variables, and landscape dynamics. The study also developed predictive models for climate change impacts on vegetation series, using Ellenberg bio-indicator values to assess naturality and anthropization levels. Three detailed vegetation maps were produced, including a hypothetical scenario under future climate conditions, providing critical insights for conservation strategies in this UNESCO World Heritage Site.
Ascension et dégazage des magmas basaltiques : application aux volcans d'Islande et de la Chaîne des Puys (France)
Basaltic magmas exhibit rare explosive eruptions, whose physical properties remain poorly understood. This study reveals that subplinian and phreatomagmatic eruptions from the Grímsvötn volcano (Iceland) and the Chaîne des Puys (France) display distinct volatile concentrations and degassing behaviors, with subplinian eruptions showing higher volatile emissions due to greater gas exsolution. Thermobarometric analysis indicates that the Grímsvötn's shallow magma chamber acts as a reservoir for exsolved gases, while the Chaîne des Puys' eruption suggests a deeper magmatic contribution, challenging the notion of a mantle hotspot. Experimental data confirm clinopyroxene-liquid thermobarometry as a reliable method for estimating crystallization pressures and temperatures in tholeiitic magmas.
Etude géophysique de la structure interne d'un dôme volcanique : le Puy de Dôme et son environnement (Chaîne des Puys, France)
A groundbreaking geophysical study of the Puy de Dôme, a 11,000-year-old trachytic lava dome in France's Chaîne des Puys, reveals its complex internal structure and growth dynamics. The research, combining high-resolution Digital Terrain Modeling (DTM) with Electrical Resistivity Tomography (ERT), gravity, and magnetism, uncovered previously unknown features: a cluster of preexisting strombolian volcanoes beneath the dome, a massive central core surrounded by collapse breccia, and evidence of hydrothermal alteration at its summit. Additionally, intrusions beneath neighboring volcanic edifices were identified, suggesting intricate emplacement processes. This study provides new constraints on the dome's evolution and the mechanisms driving deformations in its vicinity.
Des zones humides pas si sauvages que cela : apport des données historiques et paléo-environnementales à la réflexion sur la gestion des paysages de la chaîne des Puys (France)
Historical and paleo-environmental data reveal that the wetlands of the Chaîne des Puys, often perceived as 'wild' due to their current untended state, are actually products of complex geomorphological and societal evolution. This dual natural and cultural heritage challenges conventional conservation approaches, offering a model for balancing UNESCO's requirement to preserve the site's exceptional universal value with local demands for sustainable land use. The study demonstrates that integrating historical dynamics into management strategies can better address both ecological and cultural values, ensuring long-term preservation while accommodating local activities.
Endogenous and exogenous growth of the monogenetic Lemptégy volcano, Chaîne des Puys, France
The Lemptégy volcano in France's Chaîne des Puys reveals the complex endogenous and exogenous growth of monogenetic scoria cones, characterized by dynamic changes in shape, structure, and eruptive style. The study, facilitated by decades of controlled quarrying, uncovered a shallow plumbing system and detailed stratigraphy that record two temporally separated eruptions from closely spaced vents. These eruptions involved diverse volcanic activities such as Hawaiian, Strombolian, and Vulcanian explosions, lava effusion, cryptodome formation, partial collapse, satellite vent development, eruptive pauses, and intrusive uplift. The volcano's internal architecture and microtectonic structures provide insights into the local stress field and magmatic flow direction changes, illustrating the intricate evolution of monogenetic volcanoes.
"Dynamiques végétales contemporaines dans les estives de la Chaîne des Puys : Pour une approche intégrée"
A shift from traditional linear vegetation succession models is observed in the Chaîne des Puys, France. Unlike the common narrative of land abandonment leading to woodland expansion, this study reveals a more complex, stochastic or chaotic trajectory where herbaceous layers dominate over shrublands. The research integrates phytosociological and agronomic field analyses with agropastoral surveys, examining vegetation dynamics across multiple spatio-temporal scales. It introduces the concept of an 'anthropic phyto-morphological mosaic' to describe these non-linear patterns, challenging assumptions about land-use intensification and its ecological consequences in mountainous regions.
L’éruption phréatomagmatique du Montchié, chaîne des puys, Massif Central français (13,6 ± 1,0 ka)
A previously unknown phreatomagmatic eruption, dated to 13.6 ± 1.0 thousand years ago, has been identified at the Montchié volcano within the Chaîne des Puys UNESCO World Heritage Site in France's Massif Central. This discovery challenges the existing understanding of the volcano as a simple basaltic Strombolian cone with multiple craters, revealing instead a complex final eruptive phase characterized by trachy-andesitic (latite) magma containing amphibole, pyroxene, and feldspar phenocrysts. The study employed thermoluminescence dating at four distinct sites and LiDAR surveys to reconstruct the relative chronology of the volcano's craters, providing new insights into the late Pleistocene construction of this UNESCO-listed tectonic arena.
La séquence sédimentaire des Gravanches / Gerzat : enregistrement d’événements « catastrophiques » à valeur chronologique en Limagne d’Auvergne (Massif Central, France)
A sedimentary sequence from the Gravanches/Gerzat area in the Limagne d'Auvergne, France, reveals a series of catastrophic events that provide precise chronological markers for the region. These include seven volcanic ash layers (téphras) linked to the Chaîne des Puys, seismic deposits, and evidence of a potential cosmic event ('Niveau Rouge'). The sequence spans from the Late Glacial to the Subatlantic period, with key dates such as 13,500 cal. BP for CF1a/CF1b, 12,064 ± 316 cal. BP for CF3, and 7,741 ± 74 cal. BP for the 'Niveau Rouge'. Additionally, dark humic deposits ('terres noires de Limagne') are dated between the Boreal period (CF7 téphra) and the 4th/5th century CE, marking a regional humid crisis. This study combines archaeological data with tephrochronology to establish a robust chronological framework for palustrine sequences in Grande Limagne.
A 3-D genetic approach to high-resolution geological modelling of the volcanic infill of a paleovalley system. Application to the Volvic catchment (Chaîne des Puys, France)
A novel 3D geological model of the Volvic catchment, part of France's Chaîne des Puys - Limagne fault tectonic arena (a UNESCO World Heritage Site), reveals the complex volcanic infill of a paleovalley system. The study combines genetic and geometric approaches to reconstruct the morphology of both the crystalline bedrock and overlying lava flows, emitted between 75,000 and 10,000 years ago. Using data from 99 boreholes, geoelectric profiles, morphologic clues, and petrographic analysis, researchers achieved high-resolution reconstruction despite challenges like variable borehole density and limited geological descriptions. The model provides insights into the chronology of volcanic events, though precision is constrained by the homogeneity of lava flow compositions and data gaps.
Revised chronology of the youngest volcanoes of the chaîne des puys (french Massif central)
A revised chronology of the youngest volcanoes in the Chaîne des Puys, French Massif Central, reveals that a period of active volcanism—characterized by two to three eruptions per millennium—ended around 7,000 years ago. This marks the conclusion of a volcanic cycle initiated approximately 80,000 years prior, involving deep magma reservoirs and shallow chamber differentiation. The study, using tephrostratigraphy, thermoluminescence dating, and radiocarbon dating, also corrected previously assumed relative chronologies between volcanoes like Pariou and Chopine while identifying previously unknown eruptions. These findings provide critical insights into the Upper Pleistocene and Holocene volcanism of the region.
The ultimate summit eruption of Puy de Dôme volcano (Chaîne des Puys, French Massif Central) about 10,700 years ago
A recent study challenges the long-held belief that the Puy de Dôme volcano's eruption was non-explosive, instead revealing evidence of a significant explosive summit eruption approximately 10,700 years ago. Researchers discovered pyroclastic layers on the volcano's summit and flanks, containing fresh trachytic lapilli, basement lithics, basaltic lava, and clinker fragments, indicative of an open vent eruption. Radiocarbon dating of carbonized plant fragments suggests a prolonged period of volcanic rest, allowing vegetation to develop before the final eruption. This finding reshapes our understanding of the volcano's eruptive history within the Chaîne des Puys - Limagne fault tectonic arena.
You are here:
World Heritage Explorer > World Heritage Research > World Heritage Sites > Chaîne des Puys - Limagne fault tectonic arena