Denis Bernardeau-Moreau
email: denis.bernardeau-moreau@univ-lille.fr

Health Crisis and the Dual Reflexivity of Knowledge

Keywords: health crisis, awareness, dual reflexivity of knowledge

Although successive pandemic episodes adversely affect populations and it remains difficult to assess their long-term extent and impact, they may, paradoxically, have a positive effect. In fact, they can promote awareness by reviving a form of reflexivity with respect to public health, economic and social policies, and by driving in-depth reflection on the measures that must be taken to limit the current and future imbalances caused by human activity. Habermas emphasises that the reflexive "push" is no longer just a matter for experts; it is also collective, historical, and political, in the sense that it involves citizens who intend to weigh in on the debate and make their voices and wishes heard by policy-makers and economic actors. Reflecting upon the ethics of responsibility (Weber) is therefore essential. If we are to follow Giddens and Habermas' thinking, this reflexivity represents an integral part of the modern age. Our intention, in this article, is to show how major events, beyond an initial period of shock, can help to awake different levels of reflexivity in individuals.

The Anxiety-Inducing Context of the Health Crisis

The number of scientific publications released increases exponentially during periods of an ongoing pandemic. According to the Scopus database, there were nearly 800 articles at the peak of Severe Acute Respiratory Syndrome (SARS) in 2003 and 980 articles at the peak of Middle East Respiratory Syndrome (MERS) in 2014/2015. In 2020, when COVID-19 cases were multiplying rapidly, the number of publications grew to 2000. According to the World Health Organization (WHO), almost 15,000 publications in total have been published since the start of the coronavirus pandemic. This health crisis, which is being felt on a global scale, has brought about a sharp increase in the stress felt by the population. A number of studies [START_REF] Cohen | A global measure of perceived stress[END_REF][START_REF] Conley | Promoting psychosocial adjustment and stress management in first-year college students: The benefits of engagement in a psychosocial wellness seminar[END_REF][START_REF] Eicher | I want to quit education: A longitudinal study of stress and optimism as predictors of school dropout intention[END_REF]) reveal high stress levels among students during their university studies. According to these surveys, 35% of students in higher education say that they are anxious and 30% even admit to being depressed. A survey conducted by the American College Health Association 1 shows that stress has become the most serious barrier to studying among American students. This stress is also felt by the general population. According to a survey commissioned by the American Psychological Association in 2021 2 , 32% of adults admit to being stressed by the pandemic. A quarter of those surveyed stated that stress impacts their eating habits and their ability to carry out their life plans. According to a study published in The Lancet in October 2021 3 , cases of depression and anxiety increased in 2020 by more than 25% worldwide due to the coronavirus pandemic. The world of work has also been severely affected. Interruptions of work activities due to lockdowns and the increasing frequency, then subsequent normalisation, of remote working and virtual meetings between colleagues have considerably disrupted working habits and professional relationships. According to a survey conducted by Dynamic Workplace and the Speak & Act school 4 , people in employment feel twice as stressed as they did before the health crisis. Remote working has, in particular, brought about a further blurring of the lines between people's professional and private lives. Over the course of two years, the percentage of employees who are contacted outside of their working hours has risen from one quarter to one third. The survey highlights the fact that prior to the COVID-19 crisis, 92% of employees felt that digital tools made their daily lives easier. However, only 60% feel this way today. While the aforementioned studies show that successive lockdowns have generated a great deal of stress and anxiety, there has also been a significant increase worldwide in situations involving loneliness and depression, alcohol consumption, drug use, and cases of self-harm or suicidal behaviour.

The "Revival" of a Collective Reflexivity

Although successive pandemic episodes adversely affect populations and it remains difficult to assess their long-term extent and impact, they may, paradoxically, have a positive effect. In fact, recent studies [START_REF] Aykut | Nouvelle réflexivité? Repenser la dynamique de la politique sanitaire entre tournant participatif, principe de précaution et transformations institutionnelles[END_REF] show that they also promote awareness by reviving a form of reflexivity with respect to public health, economic and social policies, and by driving in-depth reflection on the measures that must be taken to limit the current and future imbalances caused by human activity. Our intention, in this article, is to show how major events, beyond an initial period of shock, can help to awaken different levels of reflexivity in individuals. Habermas 5 emphasises that the reflexive "push" is no longer just a matter for experts; it is also historical and political in the sense that it involves citizens who intend to weigh in on the debate and make their voices and wishes heard by policymakers and economic actors. Health issues, which are closely linked to issues concerning the future of the planet and that of humans and animals, are now working their way, as announced Habermas, into our collective consciousness. In sociological terminology, reflexivity has several meanings; external when it concerns the social conditions of the production of sociological knowledge in modern societies and internal when it questions the individual's ability to think about the meaning of their actions, to use their own actions as a basis for analysing their origin and consequences (Akoun and Ansart 1999, pp. 441-42). Reflexivity is about engaging in the constant scrutiny of the self (Greene and Park 2021) and questioning your own ethical responsibility [START_REF] Creswell | Qualitative Inquiry and Research Design: Choosing among Five Approaches[END_REF]. Lapeyronnie writes that it conveys a form of self-analysis or "objectification of the self" (Lapeyronnie 2004, p. 639), which is a particular way of regarding and judging oneself in light of recent events that define one's existence. These current times, which have experienced massive upheaval because of the global COVID-19 pandemic (and also certainly due to global warming and the extinction of some species of animal), are particularly likely to prompt an individual to form an "awareness of themselves" (Touraine 2005, p. 157) by questioning the voluntary and involuntary, direct and indirect consequences of the social progress in which they play the role of both actor and driver. As we know, and as journalist Marie-Monique Robin [START_REF] Robin | La Fabrique des Pandémies[END_REF] has very clearly demonstrated from this perspective, successive pandemics are the consequence of our lifestyles and the changes that impact fauna and flora on a global scale. Reflecting upon the ethics of responsibility (Weber) is therefore essential. If we are to follow Giddens' and Habermas' thinking, this reflexivity represents an integral part of the modern age.

Reflexivity: The Hallmark of Modern Man

Giddens believes that the modern age is characterised by rationality and reflexivity. He writes that rationalisation is a long-term social process, in which traditional ideas and beliefs are replaced by methodical rules and procedures and formal reflection. Consequently, this rationality allows for habits and reflexes to be more easily called into question, "rolling social life away from the fixities of tradition" (Giddens 1994, p. 59). It questions ways of living and thinking. Acting rationally means acting reasonably. This demonstrates the capacity of the social individual to reflect on their actions and the consequences of these (while, in the Weberian tradition, the ethics of conviction bases action on values without regard for consequences, the ethics of responsibility views action solely in regard to the purposes and consequences of the actions). Modernity heightens reflexivity. As described by English sociologist, modernity is characterised by its high degree of reflex-ivity. This author believes that reflexivity is a kind of continuous reflection by the social actor on themselves and their immediate social context. "Social reflexivity refers to the fact that we have constantly to think about, or reflect upon, the circumstances in which we live our lives" (Giddens 2006, p. 123). It is the process by which social practices are constantly examined and reformed in the light of incoming information about those very practices (Giddens 1994, p. 45). If this reflexivity is the hallmark of humanity, modernity gives it a more systematic and indispensable quality for shaping and maintaining social systems. What modernity gives humanity are the tools to express itself and think more freely. It should be noted that humans, according to [START_REF] Huizinga | Homo Ludens. A Study of the Play Element in Culture[END_REF], are Homo sapiens and Homo faber. They are beings of knowledge who seek to understand their environment. They progress by learning from their mistakes. However, they are also workers and creators, capable of transforming the world and creating their own environment by altering the natural space around them. More so today than in the past, they have the ability to think for themselves. They are aware that their actions can change the established way of things. "Reflexivity is a defining characteristic of all human action", writes Giddens (1994, p. 43). It is, he believes, a key characteristic of modernity. Although most authors agree that reflexivity is not a new concept or a skill discovered by humanity at a late stage, they nevertheless consider it to have been reinforced and augmented by modernity and the distancing of the influence of environmental constraints. It is, adds Kaufmann, "the very opposite of an illusion, and its flourishing is even at the heart of the process of civilisation" (Kaufmann 2001, p. 208). Particularly as, it should be noted, the Industrial Revolution and subsequent technological revolutions have greatly increased the time available for thinking. In 1800, 48% of a person's waking hours throughout the course of their life were spent working. In 2020, this percentage is just 11%. It is estimated that by 2025, 50% of work will be performed by robots. As regards available time for thinking, this has increased fivefold since 1900 6 . However, this reflexivity is not experienced equally by everyone. It presents varying levels of development and sophistication, depending on the individual in question.

Practical Consciousness and Discursive Consciousness

As highlighted by Molénat (2006, p. 51), modernity has certainly given individuals an understanding of their actions. They are reflective actors, i.e., they are capable of examining their actions, determining the conditions that gave rise to these actions and, to a certain extent, the consequences. However, these skills present themselves to varying degrees depending on the individual in question and their cognitive potential. In his two major works, published in 1987 and 1994, Giddens differentiates between two types of reflexivity, attesting to these varying degrees of human competence. Reflexivity, which forms part of "practical consciousness" (Giddens 1994, p. 92), refers to the minimal control that the individual is capable of exercising over their actions in the process of performing them. "All human beings are competent agents", writes Giddens. "All social actors possess a remarkable understanding of the conditions and consequences of that which they do in their everyday lives" (Giddens 1987, p. 343). This action relates to rules and procedures that form part of daily life. The wearing of masks, safety measures, and respect for social distancing rules illustrate this practical reflexivity that now features in the daily lives of the billions of human beings who inhabit the planet. The majority of people follow the health guidelines because they find them meaningful and useful, a way of protecting both themselves and others, as well as slowing the spread of coronavirus variants. Routinisation is the term used by Giddens to refer to all those daily tasks that become embedded in practical consciousness. Bourdieu, who does not subscribe to the idea that individuals possess inherent knowledge [START_REF] Bourdieu | La misère du Monde[END_REF](Bourdieu , p. 1413)), also explains that they draw upon practical knowledge, or what he calls "routines of ordinary thought" (Bourdieu 1994, p. 9), on a daily basis, allowing them to access substantive realities, i.e., realities that are tangible and accepted as being selfevident (Ibid.) 7 . This pragmatic and causal understanding of the sequences of their actions allows individuals to influence their behaviour with relative efficiency (Dubet 1994, p. 225). However, there is a more sophisticated awareness that goes beyond practical awareness. At a higher level, Giddens explains that reflexivity relates to "discursive consciousness". This consciousness is exercised when the individual manages to explain the reasons for their action in a coherent manner, when they can "put things into words" (Giddens 1987, p. 93). In view of the fact that this higher form of reflexivity is essentially accessible through interactive discourse, it is important to stimulate debate and fuel conversation in order to prompt individuals to develop their ability to situate themselves in relation to both themselves and others by means of discussion and exchange. However, as Giddens (1994, p. 60) reminds us, this knowledge remains a sociocultural marker because it is often only accessible, in its varying degrees, to individuals who possess the power and cognitive skills (this differing capacity explains why some people are more influential than others, some nations more advanced than others). Discursive reflexivity is not available to everyone.

The Dual Reflexivity of Knowledge and the Role of Whistle-Blowers

This reflexivity is that found in rational individuals, but it cannot be fully expressed without the actions of scientists, intellectuals, influencers, and whistle-blowers. This is the "dual reflexivity of knowledge" described by Vrancken (2001, p. 319). Doctors Li Wenliang and Ai Fen were the first to issue a warning about the danger presented by the COVID-19 coronavirus. At the end of December 2019, the former alerted the population in a discussion forum before succumbing to the virus a few weeks later. The latter spoke to Renwu (People) magazine to reach the general public. Other scientists, bloggers, and journalists, such as the Russian journalist Tatiana Baïs and the Chinese journalist Chen Qiushi, then relayed the Chinese doctors' messages. There had also been warnings long before the COVID-19 public health crisis. SARS respiratory syndrome, Ebola virus, Lassa fever, HIV/AIDS, H1N1 avian flu, and chikungunya virus are all "zoonotic" diseases, i.e., they are transmitted from animals to humans as a result of profound transformations within ecosystems (transformations brought about by uncontrolled urbanisation and policies permitting unchecked deforestation). All these viruses have been the subject of publications warning of their potential danger by scientists such as Kate Jones, Thomas Lovejoy, Karl Johnson, Malik Peiris, James Mills, and Serge Morand. This is discussed by journalist Marie-Monique Robin in a book published by [START_REF] Robin | La Fabrique des Pandémies[END_REF], which explains that the destruction of biodiversity is likely to be the main factor in the emergence of infectious diseases. After the period of shock that preceded the lockdown and closure of schools, public awareness became real. This was accompanied by educational and explanatory actions by scientists and political leaders. An online survey conducted in India to examine the general public's knowledge, attitude, and anxiety levels during the COVID-19 pandemic showed that 98% of participants acknowledged the need for social distancing [START_REF] Anderson | COVID-19 spread in the UK: The end of the beginning?[END_REF]. A similar level of awareness among the general public has also been observed in other countries, such as Nepal [START_REF] Hussain | Knowledge, attitudes, and practices towards COVID-19 among Nepalese Residents: A quick online cross-sectional survey[END_REF] and Kenya [START_REF] Austrian | COVID-19 Related Knowledge, Attitudes, Practices and Needs of Households in Informal Settlements in Nairobi, Kenya[END_REF]. According to a 2020 study carried out in Saudi Arabia [START_REF] Alahdal | An analytical study on the awareness, attitude and practice during the COVID-19 pandemic in Riyadh, Saudi Arabia[END_REF]), 80% of those surveyed stated that they had changed their behaviour due to the virus. While these studies show that the majority of the population accepted the healthcare and preventive measures, other surveys [START_REF] Jun | The impact of the pandemic declaration on public awareness and behavior: Focusing on COVID-19 google searches[END_REF]) confirm that the pandemic raised the public's awareness regarding shared responsibilities, resulting in an increase of more than 20% in the number of searches for information on the coronavirus, most notably via Google searches. In another study [START_REF] Alam | General public awareness, knowledge and attitude toward COVID-19 infection and prevention: A cross-sectional study from Pakistan[END_REF]), 70% of participants reported being knowledgeable about the new disease. The most common sources for acquiring information are social media [START_REF] Abuhashesh | The Role of Social Media in Raising Public Health Awareness during the Pandemic COVID-19: An International Comparative Study[END_REF], followed by radio and television [START_REF] Owhonda | Awareness, perception and the practice of COVID-19 prevention among residents of a state in the South-South region of Nigeria: Implications for public health control efforts[END_REF]. Although this awareness is admittedly sudden, explains Le Monde 8 , it helps to open up a debate that has often remained limited prior to now. The evolution of the pandemic legitimises information gathering by the population and therefore contributes to an urgent growth in individual and collective awareness.

Bringing about the Cognitive Conditions for Self-Reflexive Analysis

The individual certainly assumes greater responsibility on the whole today than in the past, but this is the consequence of an increased awareness of their reflexive power and ability to understand the world around them. Endowed with the skills of reflexivity, people most commonly mobilise their practical consciousness and regularly mobilise their discursive consciousness to explain how they act and why they act this way. In view of the fact that this higher form of reflexivity is principally accessible through interactive discourse, it is important that debate is initiated and that conversation is nurtured in order to prompt individuals to develop their ability to become oriented in relation to themselves, others, and the world in which they live. This is similar to Bourdieu's method, with the countless interviews he conducted with people who were suffering. It is a matter of creating the conditions for a "prompted and supported self-analysis" [START_REF] Bourdieu | La misère du Monde[END_REF](Bourdieu , p. 1408)). When questioned about their lives, people are encouraged to recount their daily lives and question themselves. By engaging in "continuous commentary on their activities" (Molénat 2006, p. 53), they thereby undertake useful, even life-saving, explanatory work. When faced with threats and dangers, individuals become aware of their individual and collective responsibility, and of the actions that they can take to change things. Reflective work is a dynamic process of self-construction, says Giddens. Simply having an attentive interlocutor prompts individuals to express themselves and find the words to expose their doubts and feelings of unease. To a certain extent, the whistle-blower helps to create favourable conditions for this self-reflexivity. Of course, not all influencers are a force for good. As Bronner explains, the cognitive bubble also shows forms of echo chamber thinking; closed, community-based worlds that can fuel fake news and misinterpretations. The sought-after "proxemic" (a term used by [START_REF] Hall | La Dimension Cachée[END_REF]) aims to reduce the information gap between individuals to the greatest possible extent. Individuals use social media in particular to inform each other about political, social, and cultural events without always relying on journalists, scientists, and experts on the topics addressed, who are sometimes considered untrustworthy [START_REF] Massé | Perceptions populaires du risque et savoirs experts en contexte de pandémie: Le cas du A(H1N1) au Québec[END_REF]. Consequently, there is a risk that untruths and other conspiracy theories will be perpetuated. However, it is then up to the whistleblowers and influencers, whether they be scientists, intellectuals, or ordinary citizens, to open up the debate and create the conditions to affirm, on a basis of reason and rationality, the dual reflexivity of knowledge and the self-analysis of the thinking subject.

Awareness in a State of Crisis

Giddens, of course, knows that people cannot explain everything verbally, nor examine all their actions in a lucid and cognitive light, many of which are unintentional. Some forms of cognition are repressed and can be considered as an unconscious state. Some intentions do not lead to action and some actions are not carried out intentionally. Expanding upon the English sociologist's thinking, researchers such as Dubet, Kaufmann, Lahire, and Hamel (2007) have questioned the role of reflexivity in explaining human behaviour. All these debates question the ambivalent nature of the actor's reflexivity, which alternates between permanence and exception, oneness and fragmentation, novelty and continuity. It is the view of some authors that reflexivity does not appear spontaneously. Bourdieu stated that we are reflexive in a state of crisis, which is when there is an imperative to adapt to a new or unusual situation, when there is a pressing obligation to change our habits and customs. [START_REF] Kaufmann | Ego: Pour une Sociologie de L'individu[END_REF] concentrates on the fragmented and multifaceted dimension of reflexivity, which he regards as uncertain and lacking in unity. For [START_REF] Lahire | L'homme Pluriel. Les Ressorts de L'action[END_REF], reflexivity is by no means unified. Humanity uses a multitude of minor reflexivities that arise in daily life on an ongoing basis, in moving from one social sphere to another, when they are confronted with cultural (moving house and population displacement), social (accident and isolation), or even individual (dismissal and death) disturbances. Putting Giddens' hyper-reflexivity into perspective, Ehrenberg does not believe that lifestyles are chosen freely. He adds that it is wrong to believe that "the individual alone, subjectively and by virtue of their reflexive capacity, generates the social link in their interactions with other subjects" (Ehrenberg 2005, p. 201). Contemporary individualism is in fact the result of an extended maturing period of the human species, born of progress and learning, but also of forgetfulness, repression, and resilience. This individual and collective reflexivity must be sought out, brought about, and maintained through warning signs that pre-empt disasters, by means of scientific publications, messages in the national and local press, and clips and videos posted on social networks, which, once the state of shock has passed, will allow for reflection and a profound and lasting change in human activities.

Conclusions: Reflexivity of Popular Knowledge

The successive lockdowns, the alarming development in the numbers of daily deaths, and the huge coronavirus vaccination campaigns are all circumstances that trigger what Massé, Weinstock, Désy, and Moisan refer to as a "reflexivity of popular knowledge" [START_REF] Massé | Perceptions populaires du risque et savoirs experts en contexte de pandémie: Le cas du A(H1N1) au Québec[END_REF]. Faced with a threat that is indeed on their doorstep, humans develop a capacity to adapt, to question, and to adopt a critical perspective (admittedly varying in its degree of permanence) that is likely to alter behavioural habits in the long term. Awareness can be life-saving if it is followed up with actions. In the case of the pandemic, this involves changing lifestyles and consumption habits, preserving natural areas and biodiversity, restoring ecosystems, stopping invasive species, combatting climate change, and curbing energy consumption. The road is long and full of obstacles, and there are other disasters yet to come, but the efforts of individual and collective reflexivity are essential in pointing the way to a safer path, via which we can protect the planet and all the living beings that inhabit it. It should be noted that, according to Bourdieu, the reflexivity of the individual stops at this practical and routine level. Due to the difficulty involved in distancing themselves from common sense, the author believes that individuals cannot, for the most part, comprehend the principle underlying their action, unease or dissatisfaction [START_REF] Bourdieu | La misère du Monde[END_REF](Bourdieu , p. 1413)). By contributing theoretical knowledge to the practical knowledge of the individual (Bourdieu talks about "knowledge of knowledge"), the sociologist thus fully fulfils their explanatory role within society. 8 Editorial in the newspaper Le Monde dated 17 March 2020 entitled "Coronavirus: le pari de la prise de conscience citoyenne" ("Coronavirus: the gamble of raising public awareness").

Figures

  Figures reported by Bronner in his book published in 2021 (cf. in Bronner 2021, particular pp. 78 to 86).

  7

Soc. Sci. 2022, 11, 161. https://doi.org/10.3390/socsci11040161 https://www.mdpi.com/journal/socsci

Interview with Jürgen Habermas for the newspaper Le Monde, "During this crisis, we must act in the explicit knowledge of our lack of knowledge", published on 10 April 2010 (interviewed by Nicolas Truong).

Funding: This research received no external funding. Data Availability Statement: Not applicable.

Conflicts of Interest:

The authors declare no conflict of interest.


Nicolas Klee
email: nklee@parc-monts-ardeche.fr

Jean-Paul Raynal

Emmanuelle Defive

Roxane Buso

Didier Laporte

A Tale of Old and Young Volcanoes in Monts d'Ardèche UNESCO Global Geopark (South-Eastern France)

Keywords: UNESCO Global Geopark, Ardèche, Haute-Loire, Velay oriental, Bas-Vivarais, Volcanism, Magmas, Cchronology

The Regional Natural Park of the Monts d'Ardèche, located in

Introduction

The Regional Natural Park of the Monts d'Ardèche, located in south-eastern France on the eastern range of Massif Central, obtained the status of UNESCO Global Geopark in September 2014. At this point, it became integrated with the network of 177 UNESCO Global Geoparks throughout the world. It is the fifth labeled geopark in France out of the seven in this country and the only one with a clear volcanic heritage (39 of the 61 geosites; Fig. 1). The UNESCO Global Geopark label promotes territories with international geological significance, and which combine protection, education, geotourism and sustainable development by involving local communities and various actors. Amongst its many commitments, the Monts d'Ardèche UNESCO Global Geopark is strengthening its involvement in scientific research and outreach to better understand and promote its young and old volcanic heritage. The Geopark addresses several scientific questions, for example, magmatic processes, eruptive dynamics, morphological evolution of landscapes, and relationships between humans and volcanoes. We develop here three significant examples of geo-.sites which fully illustrate these different topics Monts d'Ardèche UNESCO Global Geopark has been associated with volcanism for 10 Ma (million years). The volcanic activity is diverse, providing many different landscapes including strombolian craters, phonolite extrusions, maars, dykes, necks, and basaltic flows, all of which have shaped the landscape we observe today [START_REF] Klee | The Land of phonolite domes and basaltic flows[END_REF]. Three major volcanic episodes have been identified in Monts d'Ardèche and these created different volcanic provinces.

The first episode created the Eastern Velay volcanic province. It began in Mont Mézenc-Mont Gerbier with the building of a vast plateau made of piled basaltic to trachy-andesitic lava flows. During the second episode (8-6 Ma), trachytic to phonolitic magmas created intrusions and extrusions (domes and peaks locally called "Sucs"). These forms and the later intense erosion have shaped a unique and scenic landscape, including one of the largest phonolitic massifs in Europe. The best-known places are Mont Gerbier de Jonc, easily identifiable with its typical sugarloaf shape which hosts the source of the Loire River, and Mont Mézenc, which reaches an altitude of 1753 m (Fig. 2).

At the same time (8-6 Ma), another volcanic province formed, the nearby massif of Coiron, which is characterized by more fluid basaltic lavas fossilizing the paleo-course of the Ardèche River which ran towards the Rhône Valley. The landscape exhibits various features here including intruded dykes, volcanic necks, and lava flow stacks (Fig. 3). The last major period began some 200,000 years ago and created the Bas-Vivarais volcanic province (named also the "Ardèche Young Volcanoes") (Fig. 4). These eruptions have generated almost perfect strombolian volcanoes, still easily visible in the landscape despite the vegetation cover (Fig. 5 A). Most of them are relatively young, aged between 40,000 and 12,000 years ago depending on the dating methods used. The oldest ones were contemporary with Neandertal occupation, then with Homo sapiens prehistoric settlements in Ardèche, notably marked by the Chauvet cave mural drawings that are known to be part of the oldest in the world (36,000 years) and certainly one of the first chef-d'oeuvres [START_REF] Pastre | Un téphra-repère du volcanisme phréatomagmatique du Vivarais dans la séquence pléistocène supérieur de l'abri Moula (Soyons, Ardèche, France)[END_REF][START_REF] Sanzelle | Datation par thermoluminescence: étude d'une corrélation possible entre le maar de la Vestide-du-Pal et un niveau de téphra de la Baume-Moula-Guercy (Ardèche, France)[END_REF]Raynal & Defive 2019 and references herein). While cooling down, lava flows originating from these volcanoes created basalt columns showing a remarkable prismatic shape (columnar jointing; Fig. 5B), well described by the pioneers of volcanology: Faujas de Saint-Fond (1778), Giraud-Soulavie (1780) and Poulett-Scrope (1827). The longest lava flow is about 21 km long, starting at the Ray-Pic waterfall and ending at Pont-de-La-baume. Among the young volcanoes, there are a number of maars, created by intense and violent phreatomagmatic activity. The largest one in Monts d'Ardèche is the Vestide du Pal, with a diameter of 1.7 km and a circumference of over 5 km, which is one of the largest maars in continental Europe.

Overview of Some Monts d'Ardèche Geosites

Longetrée/Longetraye at Freycenet-la-Cuche (Haute-Loire), An Archaeological Geosite The "basaltic and prehistoric cliff of Longetraye" is the 55th geosite of the Monts d'Ardèche UN-ESCO Global Geopark (Fig. 1). It combines the highest prehistoric site in the Massif Central (1210 m) with an exceptional geological situation that allows us to observe the Miocene morphological context, the initial volcanism of the Mézenc plateau, and the impact of Pleistocene climatic variations on the landscape (Fig. 6). It thus makes it possible to question current climate change and the economic future of this mid-mountain area.It is located on the south-western edge of the Mézenc massif, in the heart of the Eastern Velay volcanic province, where basaltic to trachy-andesitic lava Rochette 1993, modified). The ages admitted before 2014, according to palaeomagnetism, TL, and 14C, are marked in red, green and orange [START_REF] Rochette | La province volcanique Pléistocène Supérieur du Bas-Vivarais (Ardèche, France) : propagation de fentes crustales en échelons ?[END_REF][START_REF] Guérin | Nouveaux éléments de chronologie du volcanisme Pléistocène du Bas Vivarais (Ardèche, France) par thermoluminescence[END_REF][START_REF] Pastre | Un téphra-repère du volcanisme phréatomagmatique du Vivarais dans la séquence pléistocène supérieur de l'abri Moula (Soyons, Ardèche, France)[END_REF][START_REF] Sanzelle | Datation par thermoluminescence: étude d'une corrélation possible entre le maar de la Vestide-du-Pal et un niveau de téphra de la Baume-Moula-Guercy (Ardèche, France)[END_REF]. The black numbers in the map are ka ages produced by 39Ar/40Ar method [START_REF] Nomade | Dating of the youngest volcanoes of Ardeche (Massif Central, France) using 40Ar/39Ar and unspiked K/Ar[END_REF][START_REF] Sasco | Développement d'un outil chronostratigraphique pour les archives[END_REF][START_REF] Sasco | 40Ar/39Ar and unspiked 40K-40Ar dating of upper Pleistocene volcanic activity in the Bas-Vivarais (Ardèche, France)[END_REF]. The bold black numbers in the map are ka ages produced by the authors (see [START_REF] Defive | New investigations about three young volcano-sedimentary systems of Velay-Vivarais (France) and co-evolution humans-volcanoes in perspective[END_REF]. flows, emitted between 10 and 8 Ma, formed a vast plateau above the granitic basement (Fig. 2). Between 8 and 6 Ma, the latter was pierced by trachytic to phonolitic lavas (domes, dome-flows and lava flows) which form all the visible summits. This ensemble is extended to the south and southeast by plateaus gently sloping towards the northwest (1300 m to 1250 m approximately; [START_REF] Defive | L'encaissement du réseau hydrographique dans le bassin supérieur de la Loire[END_REF][START_REF] Defive | Carte géologique de la France à[END_REF]. At Longetraye, two basaltic flows with regular columnar jointing and thick entablature are stacked. The upper one was dated by the Potassium/Argon (K/Ar) method at 8.81 ± 0.13 Ma [START_REF] Defive | New investigations about three young volcano-sedimentary systems of Velay-Vivarais (France) and co-evolution humans-volcanoes in perspective[END_REF][START_REF] Raynal | Longetrée/Longetraye à Freycenet-la-Cuche (Haute-Loire). Un géosite archéologique[END_REF] and has been quarried since the 1970s. These lavas covered a poorly differentiated topography, in the hollows of which were present clayey-sandy lacustrine deposits, themselves covered by coarse alluviums with cherts and quartz pebbles which were depos-ited under warm climates in a very wide, shallow, cradle-shaped valley, the axis of which lies slightly further west of the site.

At the time the Longetraye lava flows were emitted, the Orcival Valley did not exist, and we must imagine then a vast plateau on which the watercourses settled and then became entrenched, downcutting the lava flows and the granitic basement. This happened under the hot climatic conditions of the end of the Miocene, then during the finally cooling climates of the Pliocene, none of these conditions were favourable to the development of narrow valleys. This gave birth to the slopes that frame the Orcival Valley today.

The last phases of their evolution took place in the cold atmosphere of the Quaternary glacial times, which lasted several tens of thousand years and were separated by shorter, more temperate interglacials, such as the Holocene in which we live. During the last of these glacial episodes, all the massifs of the western Massif Central were glaciated [START_REF] Defive | L'englacement quaternaire du Massif central[END_REF][START_REF] Ancrenaz | Last glacial fluctuations in the southwestern Massif Central, Aubrac (France): First direct chronology from cosmogenic 10Be and 26Al exposure dating[END_REF][START_REF] Ancrenaz | Les fluctuations glaciaires au Pléistocène supérieur dans l'ouest du Massif central (Aubrac et Cantal, France): reconstitutions géomorphologiques et chronologiques et implications paléoclimatiques[END_REF]) but most authors consider this sector of the Mézenc massif evolved under periglacial but not glacial conditions, i.e. in very cold and more or less dry environments, marked by the great efficiency of all the erosion processes linked to frost and snow, but without the presence of glaciers. It was in this context that the Longetraye rock shelters were finally hollowed and that the valley-side of the Orcival below evolved, giving rise to the shape that characterizes it today [START_REF] Defive | Réponses des bassins versants aux modifications climatiques et anthropiques : signatures environnementales des archives sédimentaires dans les têtes de bassin du réseau hydrographique Loire -Allier depuis le Tardiglaciaire[END_REF]Fig. 7). This slope is broken by a succession of flats and scarps linked to the past creep of thick slope formations rich in basaltic boulders resulting from the dismantling of the summit cornice, by gelifraction and gravity. In these cold contexts, the sandy-clay deposits present at the contact between the base and the lava flows have favored creep dynamics. Entire portions of the lava flow's entablature were gradually detached from the cornice and line the slope on which they were dragged after having slowly subsided in the middle of the debris produced by gelifraction. Forming a cornice above the Orcival valley, the rim of the upper flow is marked by a line of rock shelters developed at the expense of the columnar jointing, under the overhang of the entablature. The formation of shelters at the foot of a basaltic flow with false-prisms entablature is generally explained by the differential resistance to the frost of the different parts of the lava mass, which is responsible for a more rapid retreat of the columnar jointing [START_REF] Kieffer | De l'éruption au site archéologique en Haute-Loire (France) : mise place, prismation, altération et érosion des coulées de lave, formation et évolution des abris sous-basaltiques[END_REF][START_REF] Raynal | À l'abri des falaises de basalte[END_REF]. The most important cavity in this line of shelters, Longetraye Cave, seems to have developed at the expense of a voluminous breccia package whose covering by the lava flow locally thwarted the formation of the columnar jointing, the prisms reappearing and then lengthening on either side of this accident. Configurations of the same type, clearly visible on the working faces of the neighboring quarry, give a clear image of the situation before the hollowing out of the cavity.

At the foot of the line of rock shelters and the "cave", in a deposit of more than 2 m, several archaeological levels of the Late Upper Palaeolithic, Mesolithic, Neolithic and Iron ages, were revealed by several excavations. The archaeo-sequence of the Longetraye site attests to a repeated presence at high altitudes since the end of the Ice Age and to the circulation of materials and/or humans within extended spaces, which are essential elements for understanding human activities in the terminal Pleistocene and Holocene in this high-altitude area at the junction of the Mediterranean and Atlantic domains. It is a key complement to the information delivered by the sites in the upper Loire and Allier valleys, Le Puy basin and the Vivarais region.

The severe climatic conditions mentioned by successive excavators from last century have perhaps been mitigated today, but the annual snow cover (Fig. 8) still causes significant percolation in the mass of the archaeological deposit, which is well protected by suitable backfill, and the route adopted for the visit of this part of the geosite does not affect it in any way. The same cannot be said of the Miocene basalt flow, which has been vigorously eaten away over the last five decades by a lithophagous quarry, which nevertheless offers to the visitor some remarkable views of its internal archi-tecture. The delicate connection between economics, heritage conservation, and scientific tourism is thus achieved here in relative harmony. This geosite has many facets and a virtual extension that goes far beyond the perimeter of its formal presentation with the help of various adapted furnishings (Fig. 9). These allow us to address the geological history of the Vivaro-Vellave plateau, repeated changes in the past climate and its future, digging and shaping of the slopes of the Orcival Valley and, finally, the dynamics of human circulation and settlements at altitude since the end of the Ice Age. In this way, hunting and gathering, pastoralism and agriculture provide a rich conservatory from flaked stone to polished stone, ceramics and metals; from the open spaces of prehistory to historical appropriations of all kinds. Therefore we see many entries into the various "eohistorical" registers, suggested by the graphic and textual information brought to our attention on this atypical geosite.

Borée: An Outstanding Collection of Volcanic Sites!

The commune of Borée is located in the heart of the Hautes Boutières graben, in the Eyrieux basin, a right bank tributary of the Rhône. It occupies a remarkable place within the Monts d'Ardèche UNESCO World Geopark, with six geosites, all related to volcanism, i.e. about 20 % of the volcanic geosites and nearly 10 % of the geosites of the Geopark (Fig. 1). Borée territory also concentrates a quarter of the Geopark sites included in the National Inventory of Geological Heritage.

The geological and geomorphological history can be approached in great temporal depth. The spectrum of landscape forms ranges from the flattened and low-lying topography, punctuated by lacustrine and fluvial deposits covered by the lava flows of the Eastern Velay at the end of the Miocene (10-8 Ma), to the current anthropized landscapes. Local manifestations of recent volcanism of the Bas-Vivarais (here dated between 229,000 and 147,000 years, taking into account the margins of uncertainties), are contemporary with the glacial-interglacial alternations of the Middle and Upper Pleistocene (Fig. 10).

At the western extremity of the commune and on the southern side of Mont Mézenc, the Cirque des Boutières geosite is popular for its striking topographical contrast and the sumptuous scenery of- fered to the Alpes at the Croix de Boutières, from Mont Blanc to Mont Ventoux. The cirque itself, at the Saliouse headwaters, has been sculpted by millions of years of erosion which has torn open the heart of an ancient polygenic volcano (Fig. 11). The latter appears to be made up of lava flows, scoriaceous projections and hyaloclastic breccias with palagonite which characterize Surtseyan hydro-magmatic activity. All are cut by mugearitic dykes and a phonolite intrusion. Here, as at the Saint-Clément geosite (a plateau at the north-eastern limit of the Hautes Boutières where 13 lava flows evolving from basanite to trachyte were superimposed between 10 and 8 Ma) we observe a progressive differentiation of the magma within an intracrustal reservoir [START_REF] Berger | Contribution à l'étude des laves alcalines du Velay oriental (France) : le secteur de la croix des Boutières[END_REF]). The other striking features of the relief, whether you look eastwards from the Croix de Boutières or westwards from the Borée Virgin or the Molines quarry, are the numerous "sucs" (trachytic to phonolitic lavas) which create a rugged topography and give the landscape a monumental character.

They correspond to the "pasty" lava flows which, between 8 and 6 Ma, made their way through the Eastern Velay basaltic plateaus previously established (10-8 Ma). In this heart of the massif, which is the richest in Europe in terms of phonolitic occurrences, the commune of Borée concentrates the greatest number of sites. Most of them are lavas that protruded and did not reach the surface (Touron, Chabrières, Gouleïou, Roches de Borée, Rocher des Pradoux, Pialoux, Combeyre). Only the Suc de Sara (Fig. 12), a remarkable annular structure close to that of the Rocher des Pradoux (Fig. 12), seems to have just poked its nose above the basement, while 500 m lower down, the vein, deeply exposed by erosion, presents a micrograined structure typical of a hypovolcanic facies [START_REF] Mergoil | Gisement en filons annulaires de phonolites du Velay (Massif central français)[END_REF]. Similar examples are found in the western part of Eastern Velay, where most of the phonolitic lavas which reached the surface formed the peaks that currently dominate the plateau (extrusion of Mont Gerbier de Jonc; domes of Mont Signon, Suc de Montfol or Bachat; dome-flows of Mont d'Alambre or Rocher Tourte; lava flows of Les Roches, La Lauzière or Les Coux), and the Mézenc which is a composite dome and a geosite of the commune of Borée (Fig. 12). Being the highest point of the plateau (1753 m) and the 4th highest peak in the Massif Central, it straddles the divide between the Atlantic and Mediterranean watersheds. A certain number of remarkable petrographic characteristics come in addition to the interest in the structures and reliefs of these multiple "sucs".

Two groups can be distinguished within the Eastern Velay phonolites, according to the order of crystallization of the minerals. The lava from Rocher des Pradoux represents the group of miaskitic phonolites with a normal order of crystallization; the tingaïte from the Suc de Sara represents the group of agpaïtic phonolites with an inverse order of crystallization.

The remarkable Suc de Sara also offers the possibility to observe the contact modalities between the ascending lava and the surrounding basement and the consequences for its texture. Various clues prove that the lava, which usually rises temperatures around 800-900°C, was at the limit of consolidation: at the external contact with the granite, the phonolite forms rocky blades linked to the shearing that affected the almost solidified lava during its ascent; these blades are absent in the heart of the vein. In this same edge zone, the arrangement of crystals in the rock, where dark veins of aegyrin appear, also testifies to the shear stress, which is absent in the heart of the vein where the aegyrin crystals are homogeneously distributed (Fig. 13). At the inner edge of the vein, the appearance of the rock shows a more rapid cooling, interpreted as being linked to the maintenance of a void between the very pasty lava and its granitic casing. Finally, at the edges of the vein, large quantities of gases and fluids of varying degrees of heat and aggression must have circulated before, during and after the lava was emplaced, and these have profoundly transformed the surrounding granite. The Suc de Chabrières, another geosite in the commune of Borée, opens up other petrographic and magmatic questions which make it a unicum in the Eastern Velay volcanic province (Fig. 14). Aged 8.2 ± 0.2 Ma, it presents a good example of "ball phonolite", a classic facies for this type of rock in which spheric figures develop (ocelles or spherulites). Under the effect of erosion, they take on the appearance of large lumps, the famous "balls", which eventually break off, contributing to the degradation of the rock. These structures seem to develop preferentially at the edge of the intrusion in connection with the fluids and gases that circulated there at the time and in the late phases of the setting and solidification of the lava [START_REF] Machin | Phonolites "à billes" du Velay : textures sphérolitiques développées à la périphérie des intrusions / extrusions[END_REF]. They also appear to be associated with fine tubular conduits, perhaps linked to these circu-lations. More original is the trachytic explosion breccia with ignimbrite facies which is spacially associated with the intrusion but is more recent and without a genetic relationship with it. It can be observed over a thickness of nearly 200 m and within a radius of 1,000 m at the foot of the "suc" and in the neighboring Valley of the Saliouse. It is thought to be the result of the sudden emptying of a chamber containing magma infused with carbonatite fluids [START_REF] Hodges | Petrogenesis of the phonolitic rocks of the Velay Oriental[END_REF]; see also in Ray-Pic chapter infra). An uncharred sequoia trunk was discovered there, testifying to a setting temperature below 200°C during a very violent eruption that must have erased the surrounding plant cover [START_REF] Naud | Sur les traces d'une forêt disparue[END_REF].

The recent volcanism of the Bas-Vivarais is also represented in the commune of Borée by the geo- site of the Echamps-Molines maar (Fig. 15). Its age is now estimated between 219,000 and 156,000 yr [START_REF] Nomade | Dating of the youngest volcanoes of Ardeche (Massif Central, France) using 40Ar/39Ar and unspiked K/Ar[END_REF][START_REF] Sasco | Développement d'un outil chronostratigraphique pour les archives[END_REF][START_REF] Sasco | 40Ar/39Ar and unspiked 40K-40Ar dating of upper Pleistocene volcanic activity in the Bas-Vivarais (Ardèche, France)[END_REF]. At that time, the valleys were already dug almost to their present level. The volcano was established on a ridge bearing only remnants of the old Eastern Velay volcanism (10-6.5 Ma), between the Eysse and Saliouse valleys and at the head of the small Azette valley. The activity began with a phreatomagmatic phase, forming the deposits visible in the Molines quarry where all the typical sedimentological features of this eruptive dy- namism can be observed. A gradual transition to a strombolian phase is recorded, during which several cones were built around the maar. A basaltic lava, rich in xenocrysts and xenoliths from the basement and the mantle [START_REF] Berger | Géologie du maar de Borée (Ardèche). Pétrologie comparée de ses enclaves de péridotites et de celles d'autres gisements[END_REF], was emitted and filled up the crater forming the Échamps plain, an unusual topographical plane perched above deep valleys. From there, the basalt overflowed at two points and then followed the Eysse Valley as far as Saint-Martial and the Azette Valley as far as the Pont des Lièvres, 8 km downstream at the confluence with the Saliouse valley. In both valleys, the arrival of the lava flow was preceded by syneruptive lahars reworking the freshly emitted phreatomagmatic products, and covering the coarse alluvium of the talwegs. The lava flows preserved them from total erosion. These spectacular outcrops are regularly integrat-ed into scientific excursions and training courses organized by French and foreign universities and leading scientific graduate schools.

The rich volcanic heritage of the commune of Borée is expressed first and foremost through its relief. The monumental character of the landscape, which has already been highlighted, is of course due to the geological structures created by internal geodynamics, but also to the erosion which, over the last 8 Ma, has progressively loosened these structures as the valleys were excavated and favored the dismantling of the rocky masses by gelifraction during the cold periods of the Quaternary (Figs. 10,16). This dismantling was particularly active because the fluidal structure of the phonolites renders them particularly sensitive to frost action at all scales. The imposing scree slabs thus produced which surround the "sucs" make them even more visible in the landscape. The periglacial context which ruled these dynamics did not prevent the development of large firms or small glaciers in the most favorable cirques that border the western edge of the Hautes Boutières. This was the case at the Cirque des Boutières already mentioned and at the north-eastern extremity of the Mézenc, at the Cirque de Médille and in the Antraygues Valley (a tributary of the Saliouse), where a black glacier that was not very active built a frontal moraine, still visible in the landscape [START_REF] Valadas | Les hautes terres du Massif central français. Contribution à l'étude des morphodynamiques récentes sur versants cristallins et volcaniques[END_REF][START_REF] Veyret | L'englacement quaternaire de la montagne auvergnate[END_REF][START_REF] Veyret | Les modelés et formations d'origine glaciaire dans le Massif central français : problèmes de distribution et de limites dans un milieu de moyenne montagne[END_REF][START_REF] Neboit | Sur l'existence de formes d'origine glaciaire dans le massif du Mézenc (Massif central français)[END_REF][START_REF] Defive | L'englacement quaternaire du Massif central[END_REF].

The variety of environments and landscapes that currently characterize the commune of Borée is the result of this long history and of the different ways in which peoples have developed their habitations (Fig. 17). Numerous signs of the complex web of interactions between societies and environments which, for thousands of years, have shaped the environments and landscapes and include a variety of soils, parcels of land, specificities of the vernacular architecture using the petrographic spectrum of local rocks, the Échamps dolmen made of large slabs of phonolite, the management of water supplied in abundance by the Molines spring draining the imposing natural reservoir of the Échamps maar diatrem, and finally the development of the paths to the summit of the Mézenc to channel the flow of tourists to reduce the degradation of the plant cover and sensitive soils. All these fully justify the advent of geo-patrimonial values.

Highlighting Magmatic and Effusive Processes at the Ray-Pic Geosite

The Ray-Pic is one of the most visited volcanic geosites in the Monts d'Ardèche UNESCO Global Geopark (around 35,000 visitors per year according to the counter installed at the site, but with significant inter-annual variability). It is located at Péreyres in Ardèche, less than 2 km as the crow flies southwest of Lachamp-Raphaël village, at the headwaters of the Bourges (Figs. 1,4). Here, at the transition between the high valleys and the first gorges down-cut nearly 400 m below the summit planes, the valley had already been dug to its present level 34,000 years ago (34 ± 8 ka by 39Ar/40Ar in [START_REF] Nomade | Dating of the youngest volcanoes of Ardeche (Massif Central, France) using 40Ar/39Ar and unspiked K/Ar[END_REF][START_REF] Sasco | Développement d'un outil chronostratigraphique pour les archives[END_REF][START_REF] Sasco | 40Ar/39Ar and unspiked 40K-40Ar dating of upper Pleistocene volcanic activity in the Bas-Vivarais (Ardèche, France)[END_REF].

Linked to the volcanism of the Bas-Vivarais, better known to the public as the "Ardèche Young Volcanoes", this volcano was mentioned in the 18th century by the first scientific visitors who explored this region and recognized the volcanic nature of peculiar edifices and associated rocks (Faujas de Saint-Fond 1778). Two phases of activity succeeded one another during the opening of this crater, as for many other volcanoes in the Bas-Vivarais. The activity began with a violent phreatomagmatic phase, which resulted in typical bedded deposits more or less loaded with pebbles and blocks, essentially from crystalline rocks. Then the eruptive dynamism changed quite abruptly to a strombolian phase (Fig. 18). In addition to the scoriaceous accumulations, a lava lake formed, and a lava flow poured into the Bourges valley. The subsequent re-entrenchment by the river allows the observation of the intra-crateric contact between the basalt and the surrounding basement and of the spectacular prismatic sheaf-like structure of the lava mass, about 50 m thick and cascaded by the Bourges (Fig. 19). The Ray-Pic flow cannot be separated from the geosite sensu stricto. The 21 km it covered in the Bourges Valley and then in the Fontolière Valley as far as Pont-de-Labeaume, at the confluence with the Ardèche, make it one of the longest flows in the Massif Central. This testifies to both the huge volume of lava emitted and its great fluidity, to the point of having left no traces of its passage between the crater and Péreyres [START_REF] Berger | Les jeunes volcans d'Ardèche[END_REF]. Further on, it is preserved in places perched on the left or on the right bank or still occupying the Bourges talweg and causing the development of beautiful waterfalls, as at Chastagnas bridge between Péreyres and Burzet. It thus appears that in a certain number of places, the work of re-incision after the outpouring of the flow was not successful in retrieving the talweg of 34,000 years ago. Because of its length, the Ray-Pic lava flow has also allowed, since the pioneer researches, the establishment of a relative chronology concerning several of the Bas-Vivarais volcanoes whose lava flows met at various confluence points. At the Bourges-Fontolière confluence, the Ray-Pic lava flow is thus covered by the Gravenne de Montpezat lava flow. The absence of paleosol and erosion marks at the contact between the two lava flows suggests that the Gravenne de Montpezat erupted shortly after the Ray-Pic. Further downstream, at the confluence between Fontolière and Ardèche, the Souilhol flow overlaps the extremity of the Ray-Pic lava flow, there with clear evidence of a time lag marked by an intermediate phase of erosion, successive fluvial deposition and then pedogenesis (Berger 2007, p. 105).

Along with the other volcanoes of the Bas-Vivarais, the Ray-Pic geosite finally allows us to address questions of magmatology, which are the subject of the most recent works on this exceptional volcanic province [START_REF] Buso | Les magmas parentaux du volcanisme régional récent du Massif Central Français (Bas-Vivarais): compositions et conditions pré-éruptives[END_REF][START_REF] Schiavi | Quantifying magmatic volatiles by Raman microtomography of glass inclusion-hosted bubbles[END_REF][START_REF] Buso | High-pressure homogenization of olivine-hosted CO2-rich melt inclusions in a piston cylinder: insight into the volatile content of primary mantle melts[END_REF][START_REF] Buso | Les magmas parentaux du volcanisme récent du Bas-Vivarais (Ardèche, France) : composition, conditions de genèse et origine de leur richesse en CO2[END_REF]. These works aim to answer two fundamental questions: where and how did the magmas form? How long did it take for magma to reach the surface? To answer the first question, we studied the tiny glassy inclusions contained in the olivine crystals of volcanic products (Fig. 20). These inclusions, often less than 50 µm in size, are small droplets of magma that were trapped during the growth of the olivine crystals and that recorded the early stages of the host magma's history. Their systematic characterization by different chemical analysis techniques and high pressure-high temperature experiments has allowed the composition and formation conditions of the magmas at depth to be specified. The Bas-Vivarais magmas have basanitic compositions and were formed at a depth of more than 70-80 km and temperatures close to 1300 °C. Their most remarkable feature is a very high carbon dioxide content, with values up to 4-5 wt % CO 2, which is a world record for this type of volcanism [START_REF] Buso | High-pressure homogenization of olivine-hosted CO2-rich melt inclusions in a piston cylinder: insight into the volatile content of primary mantle melts[END_REF][START_REF] Buso | Les magmas parentaux du volcanisme récent du Bas-Vivarais (Ardèche, France) : composition, conditions de genèse et origine de leur richesse en CO2[END_REF]. It is probable the percolation of carbonatitic fluids of deep origin in the source mantle of the Bas-Vivarais magmas that explains their CO 2 richness. Moreover, it is in the strombolian projections of Ray-Pic, whose lava is reputed to be rich in mantle enclaves, that we have found the largest peridotite enclave known in the Massif Central (approximately 50 x 32 x 26 cm, i.e. an estimated mass of 120 kg; Fig. 21). How could such a large enclave, denser than the containing magma, reach the surface? Calculations made considering the characteristics of the Bas-Vivarais lavas (composition, dissolved water content, viscosity) give a fall velocity of the enclave in the magma of more than 50 km/h (for a magma temperature of 1275°C), and therefore an even higher magma ascent velocity for the enclave to reach the surface. Apart from this huge enclave, peridotite enclaves rarely exceed 20 kg and correspond to an average ascent velocity of the Bas-Vivarais lavas of around 10 km/h [START_REF] Buso | Les magmas parentaux du volcanisme régional récent du Massif Central Français (Bas-Vivarais): compositions et conditions pré-éruptives[END_REF]. These high ascent rates are presumably related to the exceptional content of dissolved CO2 in the magmas. This information takes on another dimension in terms of volcanic risk management. It turns out that such an ascent velocity, with mag- ma source regions located at a little more than 70-80 km depth, would result in their arrival at the surface in less than ten hours, leaving very little time for the detection of possible precursor signals of an eruption.

The Ray-Pic geosite is, therefore, a very good example of the links that can be established and emphasized between scientific values, heritage values and societal utility. Its high level of use requires adapted facilities and management that also considers the preservation of the environment and the risks inherent in rocky rugged topographies and torrential rivers. This raises the delicate question of how to reconcile the preservation of the "natural" character of the sites, freedom of movement and controlled (managed, channeled) use for the benefit of knowledge, environmental education, and the local economy (tourism).

Geotourism, Education and Conservation in Monts d'Ardèche Geopark

When the Monts d'Ardèche Regional Nature Park embarked on the process of obtaining the UNE-SCO Global Geopark label in 2012-2013, it was primarily for tourism and heritage reasons. Sustainable tourism is of course a major pillar of the dynamics of a Geopark. Discovery of the landscape and geological heritage cannot be relocated because it is based on the territory's assets. This logic led to the territory's involvement in labeling the Pont d'Arc ornate cave, known as the Chauvet Cave, as a World Heritage site, and above all to achieve the construction of the world's largest replica of such a cave. The discovery offer was certainly strengthened but the limited access for visitors did not make obvious the immediate economic benefits.

Without forgetting the scientific and educational dimensions, the priority for the 2010s was to increase the number of visitors to the area, in partic-ular by increasing the range of activities linked to volcanic heritage, which represents the majority of the 61 Geosites in the Monts d'Ardèche UNESCO Global Geopark.

To achieve this goal, a strategy was implemented based on a four-year cycle of validation periods for 2015-2018 then 2019-2022 (the 2023-2026 strategy is currently being drafted) [START_REF] Klee | Editorial : le Géoparc mondial UNES-CO des Monts d'Ardèche : quatre ans de valorisation des géopatrimoines ardéchois[END_REF]. The third axis of this strategy is entirely devoted to the promotion of geoheritage and the strengthening of the tourist offer. It has been conceived as a mix of:

-Scientific mediation by humans (specialists and guides), delivering of first information by the prescriptors (tourist offices, museums, and hotels).

-Digital tools: data online, creating a hiking application with heritage information (P.O.I.) and creating the first prototypes of virtual and augmented realities while waiting for them to become a reality.

-Paper: publication of brochures, maps and a walking guide.

-Physical support: through the development of sites and paths, installation of interpretation displays, and new museography.

The most visible aspect for the public -but the greatest financial impact -is probably the creation of signage and interpretation equipment for the geosites. During the past eight years, more than 120 totems have been installed at more than 60 sites to welcome visitors and explain the geological heritage (Fig. 19). They allow all visitors to have an initial presentation and explanation of the site they are about to discover. During this time, 25 geosites and visitior areas were equipped with interpretation tools to really immerse the visitor in the discovery of the site and to give meaning to the visit. In most cases, an original approach was chosen through a discovery scenario linking the geological heritage, the local buildings, the flora and fauna and the agricultural activities. The example of the Geosite of the prehistoric cliff of Longetraye is truly representative of the type of development that has been carried out on the sites (Fig. 9).

Human intervention and discovery panels on the geosites (Fig. 9, 17) are complementary approaches and address different audiences. Over eight years, more than 260 tourism professionals have been trained in the basics of the geology of the Monts d'Ardèche (Fig. 22). The idea is obviously not to turn them into geologists, but to give them the key elements to better understand geological history and to help them to be better advisers about sites and visitor activities. The other central point of the territorial dynamics is the annual animation program (Fig. 23). Since its launch in 2015, the 93 events organized or supported by Geopark have welcomed 4611 participants, a demonstration of the public's undeniable curiosity, if not for geology, at least for the discovery of landscape heritage in the broadest sense. Finally, in terms of communication, many efforts have been made to make the Geopark concept, on the one hand, and the geological history and geosites, on the other, as intelligible as possible for the inhabitants and visitors.

The geosite map, published every year in 20,000 copies, is the basic document that makes it easy to locate the places of interest. In addition, the booklet "Everything you need to know about the Monts d'Ardèche Geopark" provides a first level of reading with a quick presentation on the geological history of the region, and an in-depth look at two major subjects: volcanism and ichnology in the Monts d'Ardèche. The lithoscope, which is more educational, allows the reader to identify the rocks of the region and their use in buildings. The latest edition, the guide of walks and hikes uses these to bring a better understanding of the heritage encountered. Already reissued twice, it also witnesses the public's interest in discovering the area, through geology in the broad sense and volcanism as an essential component.

However, since the COVID-19 pandemic, tourist activity in the Geopark territory has changed. In 2022, Geopark welcomed 19.9 million excursionists (ADT/PNRMA/FVT 2022 data), an increase of 59 % compared to 2019, the reference year before the pandemic. There was a peak on 16th of July 2022 with 231,000 excursionists present in the area, whereas the 2019 peak was on 17th of August with 101,000 visitors. Visitor numbers exploded after the pandemic for many reasons that are now well documented (need to get away from it all, to reconnect with nature, etc.). Beyond the visiting activities, the number of overnight stays also rose sharply: + 9 % compared to 2019. On 13th August 2022, 85,175 people who do not live in the area all year round slept in the Monts d'Ardèche, which is much more than the number of permanent residents. The counters set up on many of the territory's volcanoes, at the Ray-Pic waterfall, at Mont Signon, at Mont Gerbier de Jonc, also showed an exponential increase in the number of visitors to the territory and to these volcanoes, the main places for excursions and walks. This significant increase in visitor numbers has had a number of impacts on the geosites: in the volcanic areas, erosion has been greatly accelerated in recent years, causing problems for the flora and landscape. The quality of the visitor experience has also been affected, with fewer positive feelings linked to parking difficulties, a feeling of saturation and less immersion in the landscape.

These new data and this new context requires a change of the objectives of the tourist component of the Geopark label: it is no longer a question of welcoming more but better, and above all of offering discoveries and providing knowledge to the inhabitants. The territory's volcanic heritage remains relatively unknown. Above all, knowledge of the "volcanic dimension" of the area needs to be strengthened. All the best-known sites in the area are volcanic ones: Mont Gerbier de Jonc, Mont Mézenc, the Ray-Pic waterfall, the village of Antraigues and the Devil's Bridge at Thueyts. The priority work of the post-pandemic years is, therefore, the presentation of the volcanic heritage of the Ardèche, which remains difficult to read and understand for most of the inhabitants. A particular focus is therefore placed on educational and pedagogical actions aimed at the inhabitants. The new communication campaign about the "Ardèche Young Volcanoes", for example, carried out by the Monts d'Ardèche Geopark and three tourist offices, is aimed primarily at residents of the region or secondary residents, and in particular families, through the prism of walks and familial games (Fig. 24).

Because of occasional over-visiting suffered by a number of the volcanic sites, the subject of conservation, which was not very present in the previous years of the label (except for the fossil sites), is now at the heart of discussion about site facilities and communication. The marketing strategy now aims both to deconcentrate visitor numbers on the major volcanic sites (Gerbier, Mézenc) and to preserve the lesser-known ones (Sara, Cinq Sucs). On the old volcanoes as well as on the more recent ones, the challenge of maintaining visitor numbers on the marked trails is a priority, both for reasons of erosion, particularly on the strombolian volcanoes, and for landscape reasons and to preserve the biodiversity linked to the volcanic rocks. On Mont Mézenc, a very substantial renaturation and erosion control operation has committed the Geopark to an intensive two years' work (Fig. 25). Glory's price.

Figure 1 .

 1 Figure 1. Geological simplified map of the Monts d'Ardèche UNESCO Global Geopark (modified) with position of the volcanic geosites (large dots). Geosites inside framed areas are presented in this paper.

Figure 2 .

 2 Figure 2. A) Stages in the construction of the central part of the Eastern Velay volcanic province (Mézenc-Gerbier massif and Hautes Boutières) (CAD E. Defive). B) The Mont Mézenc, also called the Cévennes Giant: a view from the top of the Mont Gerbier de Jonc (in the foreground) to the north (photo B. Gremen).

Figure 3 .

 3 Figure 3. Volcanism of the Coiron. A) Mirabel sector: the lava flow with regular columnar jointing and thick entablature overlies an alluvial sheet of the palaeo-Ardèche river (ochre level at the bottom). Megablocks fallen from the entablature are scattered on the slope below. B) Basaltic dyke at the Coulet de la Soulière (photos E. Defive).

Figure 4 .

 4 Figure 4. The Bas-Vivarais volcanic province. A) Location in France. B) Position of volcanoes and localities on the orographic 3D view (source: IGN Geoportail). C) Distribution and chrono-typology of the different volcanic features (afterRochette 1993, modified). The ages admitted before 2014, according to palaeomagnetism, TL, and 14C, are marked in red, green and orange[START_REF] Rochette | La province volcanique Pléistocène Supérieur du Bas-Vivarais (Ardèche, France) : propagation de fentes crustales en échelons ?[END_REF][START_REF] Guérin | Nouveaux éléments de chronologie du volcanisme Pléistocène du Bas Vivarais (Ardèche, France) par thermoluminescence[END_REF][START_REF] Pastre | Un téphra-repère du volcanisme phréatomagmatique du Vivarais dans la séquence pléistocène supérieur de l'abri Moula (Soyons, Ardèche, France)[END_REF][START_REF] Sanzelle | Datation par thermoluminescence: étude d'une corrélation possible entre le maar de la Vestide-du-Pal et un niveau de téphra de la Baume-Moula-Guercy (Ardèche, France)[END_REF]. The black numbers in the map are ka ages produced by 39Ar/40Ar method[START_REF] Nomade | Dating of the youngest volcanoes of Ardeche (Massif Central, France) using 40Ar/39Ar and unspiked K/Ar[END_REF][START_REF] Sasco | Développement d'un outil chronostratigraphique pour les archives[END_REF][START_REF] Sasco | 40Ar/39Ar and unspiked 40K-40Ar dating of upper Pleistocene volcanic activity in the Bas-Vivarais (Ardèche, France)[END_REF]. The bold black numbers in the map are ka ages produced by the authors (see[START_REF] Defive | New investigations about three young volcano-sedimentary systems of Velay-Vivarais (France) and co-evolution humans-volcanoes in perspective[END_REF]).

Figure 5 .

 5 Figure 5. Two aspects of the recent volcanoes of the Bas-Vivarais volcanic province. A) The Aizac volcano (photo S. Tripot, Aubenas-Vals/PNRMA Tourism Office). B) The Jaujac lava flow (photo E. Defive).

Figure 6 .

 6 Figure 6. The site of Longetraye. A) View towards the east from the vicinity of Massibrand with 1, in the background, the phonolitic peaks of the heart of the Mézenc massif (a, Taupernas; b, Montfol); 2, the Orcival valley; 3a and 3b, lava flows covering the granitic basement; 4, quarry; 5, location of the "cave" of the archaeological site. B) Stages in the evolution of the relief, with 1, ante-volcanic granitic plateau, crossed by watercourses spreading their alluviums with quartz and cherts pebbles; 2, setting up of the lava flows of the Béage plateau and reorganization of the hydrographic network; 3, down-cutting of the Orcival Valley in the lava flows and then in the basement (photo and CAD E. Defive).

Figure 7 .

 7 Figure 7. General layout of the Longetraye geosite on the right bank of the Orcival. A) Plan view on LIDAR background (2017). B) Stratigraphy of the deposits at the contact of the foot of the slope with the valley floor. C) Profile of the slope below the archaeological site and chronological milestones (CAD E. Defive).

Figure 8 .

 8 Figure 8. Snow cover on January 16th, 2021 at Longetraye (photos E. Defive). A) At the front of cave. B) Along the lava flow cliff on the path to the cave.

Figure 9 .

 9 Figure 9. Interpretation on the Longetraye geosite. A) Guided visit; the public in front of the cave (photo E. Defive). B) One of the tables set up in front of the cave (scientific content: J.P. Raynal and E. Defive; drawing P. Legobien).

Figure 10 .

 10 Figure 10. Geology of Borée territory and its surroundings (CAD E. Defive). A) A view towards south-east from Mézenc summit (photo E. Defive) with 1, Gerbier-de-Jonc; 2, Echamps plain and Echamps-Molines maar; 3, Roches de Borée; 4, Suc of Gouleïou; 5, Suc of Chabrières; 6, Suc of Touron; 7, Sara ring dyke; 8, Pradoux ring dyke; 9, Boutières cirque. B) Geological simplified map (after Boivin & Mergoil 2022, modified).

Figure 11 .

 11 Figure 11. The Cirque des Boutières site. A) Overview with 1, phreatomagmatic deposits at the bottom of the structure on the southern slope; 2, volcanic breccia; 3, hyaloclastic tuffs with palagonite; 4, lava flows; 5, top trachytic lava flow; 6, phonolitic intrusion. B) Detail of the hyaloclastic tuffs (3) intersected by a dyke of mugearite (7) (photos and CAD E. Defive).

Figure 12

 12 Figure 12. A) The Mont Mézenc complex (two coalescent domes and a dyke) with huge phonolitic screes on its southern and eastern slopes. B) Ring dyke of Pradoux. C) Simplified geological map of Pradoux-Sara ring dyke complex (after Goër & Mergoil 1971, modified) D) Ring dykes of Sara. (CAD and photos E. Defive).

Figure 13 .

 13 Figure 13. The hypovolcanic microlithic texture with aegirine minerals of the Sara tingaïte (agpaïtic phonolite). A) Dark veins of aegyrin near the edge zone of the ring dyke. B) Aegyrin crystals homogeneously distributed in the heart of the dyke (photos E. Defive).

Figure 14 .

 14 Figure 14. The Suc de Chabrières geosite (and the Mont Mézenc behind on the left). A) The "suc" with its phonolite screes ring, and the natural outcrops in the trachytic breccia down in the right. B) Extraction of a sequoia trunk from the trachytic breccia (photo R. Meucci; Naud 1998). C) Block of "ball phonolite". D) Two cumulates found in the trachytic breccia, which indicate the magmatic room emptying.

Figure 15 .

 15 Figure 15. A geosite linked to the Bas-Vivarais volcanism: the maar of Échamps-Molines. A) View on the geosite from the top of Sara "suc" with 1, the Échamps plain perched above deep valleys; 2, the maar tuff ring in the Molines quarry; 3, Molines spring position above the hamlet; 4, overflow lava flow point position in the Azette valley; 5, way of the lava flow overflow in the Eysse valley; 6, Pialoux phonolite; 7, Soutron phonolite; 8, Roches de Borée phonolitic "sucs"; 9, Saint-Clément village and volcanic plateau (Eastern Velay volcanic province). B) Synthetic profile of the Échamps-Molines maar structure (after Mergoil & Boivin 1993, modified). C) Typical sedimentological features on the phreatomagmatic deposit lower part with 1, typical base surges; 2, anti-dunes; 3, bomb sag. D) Upper part of the Molines quarry with the transition from phreatomagmatic to strombolian deposits with 1, phreatomagmatic deposits with external dip; 2, channeled phreatomagmatic deposits with internal dip; 3, accretionary lapilli; 4, basaltic sill at the bottom of strombolian adventive volcano. E) Facies of lava and bombs of the eruption, from left to right: Échamps-Azette lava flow sample, bomb with enclave of peridotite and bomb with enclave of basement at Molines quarry. For the two bombs, the numbers correspond to: 1, juvenile magma; 2, peridotite enclave; 3, olivine crystals; 4, pyroxene crystals; 5, reheated basement enclave (buchite); 6, basement xenoliths in the basalt (photos E. Defive).

Figure 16 .

 16 Figure 16. Monumental scenery of the Hautes Boutières looking to the west from Molines quarry (photo E. Defive).

Figure 17 .

 17 Figure 17. Interpretation of Borée scenery. A) Tableextract(CAD E. Defive) with legend: 1, Crests, ledges and steep slopes where the rock (granite / flows / trachytes and phonolites) outcrops; 2, Screes formed a few thousand years ago during a cold period when frost action favored the fragmentation of rocks; 3, Large spruce plantations set up by the Government (end of the 19th century and 1950s); 4, "Postage stamp" afforestation on private plots of land that have been abandoned (1950s); 5, Beech forests naturally adapted to mountain conditions; 6, Mixed woodland (spruce and Scots pine / beech and coniferous) linked to the spontaneous spreading of trees; 7, Meadows (grass is mown for hay) and pastures (unmown plots); 8, Wasteland on abandoned plots of land because they are too poor or difficult to work; 9, Hedgerows useful to the traditional rural community (firewood, supplementary ash fodder, small crafts) and guarantors of biodiversity (refuges for fauna); 10, Church and cemetery: traditional gathering places of the village community; 11, Old buildings, made of local stone. At the peak of its population in the 19th century, Borée had more than 2000 inhabitants. Many buildings are now abandoned, sometimes saved from ruin by their conversion into second homes or places of social and cultural life; 12, Recent buildings (breeze blocks, tiles, plastering, hedges surrounding the property); 13, Low walls linked to the spalling of plots and the development of terraced slopes. They represent a constraint for modern mechanized agriculture; 14, The roads, narrow and winding, oblige one to calculate in travel time rather than in km; 15, Only a small number of the traditional network of paths through which humans, animals and goods used to circulate are still maintained. Tourism sometimes favors their reopening. B) the on-site table (photo E. Defive).

Figure 18 .

 18 Figure 18. Close view of the Ray-Pic volcano deposits. Section illustrating the transition from phreatomagmatic (A) to strombolian (B) activity at the eastern extremity of the crater (photos E. Defive).

Figure 19 .

 19 Figure 19. The Ray-Pic geosite. A) On-site Geopark welcom totem (photo E. Defive). B) The Bourges waters pouring out through the crater basaltic lava lake (photo E. Defive). C) A closer view of the waterfalls from an ancient postcard (1911).

Figure 20 .

 20 Figure 20. Optical microphotography showing a glassy inclusion (brown) containing a dark CO 2 bubble in the core of an olivine phenocryst in a basanite from the Bas-Vivarais volcanic province. The olivine phenocryst is embedded in a volcanic matrix (a mixture of microlites and interstitial glass) visible in the upper left and lower right corners (from Buso 2023).

Figure 21 .

 21 Figure 21. PRay-Pic volcano. Photograph of what is to our knowledge the largest peridotite found in the French Massif Central (photos: A) D. Laporte; B) E. Defive).

Figure 22 .

 22 Figure 22. Training of the tourism stakeholders: looking towards the Boutières scenery from the Croix de Boutières Pass (photo N. Klee).

Figure 23 .

 23 Figure 23. Geological rendez-vous at Issarlès lake. A) 7th of May 2022 (photo P. Bohle). B) 1 st of April 2023 (photo E. Defive).

Figure 24 .

 24 Figure 24. Discovery guide of the "Ardèche Young Volcanoes" (@PNRMA).

Figure 25 .

 25 Figure 25. Restoration work on the paths to channel visitors to the Mont Mézenc volcanic geosite (photo N. Klee).

Acknowledgments

Roxane Buso thanks the Région Auvergne-Rhône-Alpes for funding her doctoral thesis (project Vol-cAURA; Pack Ambition Recherche 2018).