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The aesthetic value of a wild and/or tourist cave is well known everywhere. Anyway, presently only few people are aware that caves are the most important natural laboratories, in which it is possible to complete studies and researches that, in some cases, would be impossible in any other place. The caves are normally characterized by low energy and by the absence, or at least scarcity, of perturbing factors characterizing the external environments. Therefore, natural cavities may be regarded as perfect accumulation traps, preserving all the materials falling inside them. In the last half century the importance of cave deposits grew enormously in the field of paleoenvironmental and paleoclimatological studies, often allowing to reconstruct the chronology of the events a given environment underwent. From this point of view speleothems are by far the most important cave deposits, because their layered structure is always chronologically ordered and several techniques allow for an easy absolute dating of even a single event. Moreover, all these events may sometimes be restricted to a single year interval (or even less) on the basis of the speleothem growth layers. The speleothem’s layered structure makes reasonable to consider each of them a “stone book”, where each growing layer corresponds to a “page” of a multidisciplinary encyclopaedia. We are still unable to extract most of the information recorded by them. But in the near future, when we will be able to read all the pages of these “stone books”, their scientific importance will grow exponentially.

Presentación de la comunicación oral del día 4 de septiembre de 2014 en la sesión "B27. "Megalithic biographies”: cycles of use and closure" of the XVII World UISPP Congress, celebrated in Burgos., Archaeological excavations carried out in Galicia (NW of Iberia) during the last 15 years, have shown that megalithic barrows had a complex and long-standing life. Not only in terms of later uses and reuses (something that has been already acknowledged in bibliography since many years) but also in terms of construction and ‘megalithic’ use. Today, we can assume that barrows life was not so simple as: construction, use and abandonment. Rather, barrows could be easily compared, for instance, to Christian churches, that once build up were permanently used and rebuild, their ‘form’ becoming either the expression or the result of a permanent negotiation between social and materialization processes. In this contribution, we review the empirical data from different well characterized barrows, such as Romea (with recognizable phases of rebuilding or use dating to 5920 – 5660calBP, 5320 – 5030calBP and 4970 – 4790calBP) and Forno dos Mouros (with a long time-span punctuated in 6510-6300calBP and 5070-4850calBP). From these data, we propose a hypothetical sequence of specific periods of building, use and rebuilding which we relate to social processes occurring on increasingly complex and progressively more unequal communities, even with changing individual identities. This hypothesis is contrasted with a large collection of C14 dates of Galician megaliths. Based on this, we propose that the traditional assumption of a continuous monumental activity from ca. 6,500 to 4,500 cal. BP should be revised since a discontinuous series of building activity and use is a more likely explanation for the chronologies. Activity seems to have been circumscribed to particular periods of monumental building, interspersed with long periods of inactivity, perhaps not shorter than a few centuries (200-300 years). We suggest that this interpretation may also apply to other megalithic European regions. Therefore, the research agenda on Megalithism should incorporate this topic in future investigations as it may demand a change in excavation strategies. In order to reconstruct the formation processes, we propose a methodological approach aiming to implement the techniques of stratigraphic excavation and the chemical and pedological characterization of the sediments in megalithic archaeological contexts. Ultimately, our proposal is to treat barrows as paleoenvironmental archives.

Les tourbières constituent une composante importante du paysage naturel de l’île d’Anticosti (Québec, Canada), recouvrant environ un quart de sa superficie terrestre. Ces milieux humides uniques fournissent plusieurs services écosystémiques et jouent un rôle fondamental dans l’atténuation naturelle des changements climatiques par la séquestration du carbone atmosphérique. Les tourbières maritimes de l’île d’Anticosti se distinguent par une biodiversité remarquable et par leurs archives paléoenvironnementales qui ont permis de retracer l’évolution du climat de la région du golfe du Saint-Laurent au cours des derniers millénaires. En effet, la reconstitution du développement de 2 tourbières (Perrier et collab., 2022) montre que les conditions écologiques et hydrologiques ainsi que la dynamique du carbone ont été sensibles aux variations passées du climat. Plus de 12 000 tonnes de carbone se sont accumulées sous les dômes ombrotrophes des 2 tourbières. Finalement, des observations inédites permettent d’émettre l’hypothèse de la présence d’un pergélisol relique possiblement formé au cours de la période froide du petit âge glaciaire (de 1350 à 1850 de notre ère). Cette contribution présente un résumé du patrimoine naturel exceptionnel des tourbières de l’île d’Anticosti afin d’appuyer la mise en valeur de ces écosystèmes., Peatlands are an important component of the natural landscape of Anticosti Island (Québec, Canada), covering approximately one quarter of its land area. These unique wetlands provide several ecosystem services and play a fundamental role in the natural mitigation of climate change through atmospheric carbon sequestration. The maritime peatlands of Anticosti Island stand out because of their exceptional biodiversity and their unique paleoenvironmental archives of climate variations in the Gulf of St. Lawrence region over recent millennia. The reconstruction of the development of 2 peatlands (Perrier et al., 2022) shows that the ecohydrological conditions and the carbon dynamics were sensitive to past climate variations. More than 12,000 tons of carbon have accumulated under the 2 ombrotrophic domes. In addition, new observations allow us to make the hypothesis of the presence of relic permafrost, most probably formed during the cold period of the Little Ice Age (between 1350 and 1850). This contribution presents a summary of the exceptional natural heritage of the peatlands of Anticosti Island and supports the promotion of their conservation.