Pierre Stéphan

Pierre Stéphan
French National Centre for Scientific Research | CNRS · Institut écologie et environnement (INEE)

PhD

About

170
Publications
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Publications

Publications (170)
Article
The multidisciplinary approach conducted on the coastal cores ANE-C3 and PADMé (48°38'54.5114"N; 4°10'21.3848"W; Kerallé watershed, NW Brittany, NW France) revealed paleoenvironmental trajectories under both relative sea level rise and anthropogenic dynamics during Middle to Late Holocene, in the research paper: “From a coastal plain to an anthropi...
Article
The Bay of Brest (BB, NW France) is a semi-enclosed basin of 180 km² subject to macro-tidal dynamics and to the fluvial influences of the rivers Aulne and Elorn, which combined drain watersheds of 2600 km². This coastal environment is subject to natural climate oscillations overlaid on the long-term landscape transformations inherited from the post...
Article
The Bay of Brest (BB) is a shallow estuarine environment in NW France. This semi-enclosed basin of 180 km² is subject to multiple hydrodynamic factors including the dual influence of oceanic currents and fluvial discharges (Aulne and Elorn main rivers) and resulting in complex hydro-climatic and hydro-sedimentary processes. This study investigates...
Article
Over the Holocene (last 11.7 kyr), the Brittany coastal region has undergone major changes in response to rising sea level, climatic fluctuations and increasing anthropogenic influence. This study aims to i) accurately reconstruct the paleoenvironmental evolution of a site located on the north Brittany coast (NW France), a sector that has not been...
Preprint
Full-text available
The stable oxygen isotopes ratio (δ18O) from marine mollusk carbonated shells is widely used as a palaeo-thermometer, as the main driver of this ratio is the temperature (coupled with the salinity) at which the carbonate precipitated. This method is also used on anthropogenic shell middens, as a proxy for past human practices and their use of marin...
Preprint
Classic Hodgkin Lymphoma (cHL) is a tumor composed of rare malignant Hodgkin and Reed-Sternberg (HRS) cells nested within a T-cell rich inflammatory immune infiltrate. cHL is associated with Epstein-Barr Virus (EBV) in ~25% of cases. The specific contributions of EBV to the pathogenesis of cHL remain largely unknown, in part due to technical barrie...
Article
Ce travail vise à déterminer l’évolution des conditions d’exploitation du sel autour du site du Pontet au cours du Néolithique récent et de l’âge du Fer par la confrontation des données archéologiques et environnementales. Le site principal du Pontet est un site fossoyé de plateau qui a été occupé principalement durant le Néolithique récent (3600-2...
Article
Full-text available
This article presents an interdisciplinary study of two Late/Final Neolithic gallery graves (Kernic and Lerret) located on the orthwestern coast of Brittany (Western France). These monuments show striking similarities in terms of architectural style and geographical position. This paper aims to provide a better understanding of the construction str...
Presentation
Full-text available
This project presents an interdisciplinary study carried out on two Recent/Final Neolithic gallery graves (Kernic and Lerret) located on the northwestern coast of Brittany (western France). These monuments show striking similarities in terms of architectural style and geographical position. This research aims to provide a better understanding of th...
Article
Full-text available
New findings acquired in Armorican shelf (core MD08-3204 CQ: Bay of Quiberon and core VK03-58bis: South Glénan islands) depict Holocene paleoenvironmental changes since 10 ka BP through a multi-proxy dataset including sedimentological and palynological data. First, grain-size analyses and AMS-¹⁴C dates show a common sedimentary history for both stu...
Conference Paper
Full-text available
L’objectif de cette étude est de mieux cerner les conséquences des variations relatives du niveau marin sur la transformation des paysages littoraux et leurs implications sur les sociétés humaines, en nous intéressant aux Pays de la Loire. Une première estimation de la remontée du niveau marin relatif est proposée sur les deux derniers millénaires...
Article
In the aftermath of the last ice age, when sea level rose along most of the world's coastline, the activities of coastal peoples were impacted by coastal submergence, land loss and sometimes isolation as offshore islands formed. In some parts of the world, there is clear evidence that people encoded their observations of postglacial sea-level rise...
Article
The morphodynamic functioning of the Sillon de Talbert gravel barrier spit is analyzed using a high‐frequency survey carried out between September 2012 and December 2019. It is based on beach profile measurements along two transects, modeling offshore wave data (WW3), tide gauge records, and shallow waves and water levels recorded in the intertidal...
Article
Sur la presqu’île de Crozon, non loin de Landévennec, derrière un double cordon de galets, un petit étang s’est formé et a donné son nom à l’anse : le Loc’h. L'ouverture d'une brèche dans le cordon a permis de mettre au jour des traces anthropiques médiévales, certaines datées par le radiocarbone permettant d’estimer aux ixe-xiie siècles la période...
Article
In preliterate contexts, diverse knowledge was accumulated, processed and communicated orally. Recent research demonstrates that observations of memorable events were transferred in this way for thousands of years sometimes. Much of this information was eventually written down to reach literate audiences, which commonly judge such ‘myths and legend...
Article
Full-text available
While early maps are known from all over the world, the key questions always involve: what exactly do they show? And what spatial extent do they cover? In this context, we recently used 3D‐modelling to re‐examine a carved stone slab datable to the Early Bronze Age (c.2150–1600 BC) that was found at Saint‐Bélec in Brittany. We show that the surface...
Presentation
Rozwój i ewolucja wydm nadmorskich jest kontrolowana przez wiele czynników, takich jak bilans materiału osadowego, zmiany względnego poziomu morza, siła i kierunek wiatrów, czy stabilność szaty roślinnej. Na podstawie badań stratygraficznych, geomorfologicznych i chronologicznych przeprowadzonych wzdłuż atlantyckich wybrzeży Europy podkreślono zwią...
Article
Primarily monitored for its biodiversity and the ecosystem services it provides, the coastal environment is also the focus of major issues for the protection of cultural heritage. From the beginning of the Holocene marine transgression to the present day, these rich but fragile territories have been subject to continuous and extreme events, facing...
Article
The intricately carved Saint-Bélec slab found in the Leuhan parish (Finistère) was found within an early Bronze Age barrow in 1900 (fig. 1 and 2). A recent re-examination of the Saint-Bélec slab suggests that its sculptured surface and scattered motifs represent the surrounding landscape and a series of contemporary structures now known from archae...
Preprint
The Gironde estuary in SW France is the largest in Western Europe and has attracted human populations since prehistoric times. From the 1970s to the 1990s, intense archaeological research was undertaken on the long and highly dynamic coastline just south of the estuary mouth. In recent years, the combined action of increased coastal erosion and hum...
Article
We discuss paleoenvironments of north-western France over the last 7 kyrs in terms of: i) long-term changes (relative sea-level rise and boreal summer insolation), ii) rapid climate changes (millennial-scale Bond events and multi-decadal regimes of the North Atlantic Oscillation: NAO) and iii) growing human impacts in watersheds. Our study focuses...
Article
Full-text available
In the original article, there was a mistake in the legend for Figure 1 as published. After publication, it was brought to the authors’ attention that DEIMS-SDR also included not-LTER sites (Wohner et al., 2019) and the so called LTER “parent sites,” at the same hierarchical level of the research sites they are made of, generating some duplicates....
Article
Full-text available
This paper aims to analyze the shoreline changes of coastal accumulations (sandy and gravel beaches/barriers) of Brittany (Western France). Three long, medium, and short term spatio-temporal scale observations are taken into consideration for the assessment of shoreline dynamics at this regional scale. Firstly, the long-term shoreline position evol...
Article
Full-text available
Due to the richness of its coastal environments, particularly lagoons and mangrove, the low-lying areas of the Omani coastline attracted settlements very early. However, the low-lying coasts are highly mobile landscapes, whose evolution is controlled by multiple factors acting at different timescales, from episodic (extreme events) to millennial ti...
Article
Full-text available
On the seashore, archaeologi’cal remains appear well preserved and sometimes immediatly visible during erosion periods. But the constraints are accumulating at all levels : limited intervention time, water, movement of tides, rapid change due to erosion, access conditions to excavations, difficulty encountered in implementation of heavy infrastruct...
Article
This paper provides a synthesis of current knowledge concerning the morphological and landscape evolutions of the French Atlantic and English Channel coasts of France during the Pleistocene and Holocene periods. These changes are compared with archaeological data in order to better understand the distribution of human settlements and the environmen...
Article
Full-text available
Understanding the threats to global biodiversity and ecosystem services posed by human impacts on coastal and marine environments requires the establishment and maintenance of ecological observatories that integrate the biological, physical, geological, and biogeochemical aspects of ecosystems. This is crucial to provide scientists and stakeholders...
Article
Full-text available
In the North Médoc (Gironde department), between the communes of Soulac-sur-Mer and Montalivet-les-Bains, the sandy shoreline has been exposed to a very strong erosion. Dealing with a rich archaeological, historical and environmental heritage, an interdisciplinary team has been constituted, consisting of archaeologists, geomorphologists and biologi...
Article
Full-text available
The adaptation of territorial systems to the ongoing climate change is an issue which implies to test past populations abilities to cope, to “bounce back” or to adapt during similar past environmental changes. The chronostratigraphical and archaeological results, obtained in the frame of the LITAQ project, make it possible to better understand chan...
Article
Full-text available
Located at the mouth of the Gironde estuary (southwestern Atlantic coast of France), the Amélie beach recorded a huge coastal erosion during the recent stormy events, especially in the winter 2013-2014. The dune scarping and the sediment depletion on the beach uncovered a set of estuarine and aeolian sediment deposits containing numerous archaeolog...
Article
Full-text available
Pleistocene deposits exposed along the coast of the Médoc area, south‑west France, represent valuable palaeoenvironmental archives that have been the subject of extensive work in the past few decades. To further understand the palaeoenvironmental history and sedimentary dynamics of these deposits, a detailed lithostratigraphic study was performed o...
Poster
Full-text available
To be efficient, fisheries need to be built in the intertidal range. Thus, the evolution of their geographical position in time highlights modifications of the coastlines, generally closely related to environmental changes. Along the island of Yeu (Mid-French Atlantic coast), dozens of fisheries were identified. Currently totally submerged, most of...
Article
Sedimentological, palynological, and micropalaeontological studies carried out throughout the first half of the Holocene, during the Mesolithic/Neolithic transition in the Bay of Brest (i.e. 9200–9000 and 6600–5300 cal. BP) and in the Bay of Douarnenez (i.e. 9200–8400 cal. BP), allowed characterizing coastal environmental changes under the increasi...
Technical Report
suivi morphosédimentaire du sillon de Talbert pour l'année 2018, commune de Pleubian (22)
Article
The Sillon de Talbert is situated on the Northern coast of Brittany; it is a large 3.5 km-long swash-aligned gravel spit barrier comprising a volume of sediment of 1.23x10 ⁶ m 3. Since 2002 a morphodynamic survey was carried out. It is based on annual DEMs and monthly beach proile measurements. Waves and water levels are also surveyed using modelli...
Article
High-quality relative sea-level (RSL) data reveal spatial and temporal variations in crustal movements during the Holocene, which are used for many applications, ranging from calibrating models of earth rheology and ice sheet reconstructions to the development of coastal lowlands and human occupation. Here, we present a Holocene RSL database for th...
Conference Paper
While recent studies highlighted the great mobility of boulder beaches related to the impact of storm waves, numerous researches are still needed to better understand the morphodynamic of coastal boulder accumulations. This paper provides original data about storm-induced geomorphic processes and their impact on the Valahnúkur coastal barrier. Firs...
Article
Full-text available
This paper reviews the reconstruction of European Atlantic storm events with the contribution of a new stormy reconstruction in its central part. Three marsh environments on the island of Yeu were chosen to identify disturbing storm events from the Mid- to Late Holocene with vibracore sampling, radiocarbon dating and sedimentary analysis. Nine prob...
Article
The Sillon de Talbert is a large swash-aligned gravel barrier spit of 3.5 km length, situated on the Northern coast of Brittany. Over the last decades, the spit experienced landward migration by rollover reaching 1.1 m yr⁻¹ at least since 1930, with maximum retreat rates of 1.35 m yr⁻¹ affecting the proximal section. This evolution has led to the c...
Article
Full-text available
he link between the shoreline changes and the variation of the meteo‑oceanic forcing of the Goulven Bay (north Brittany, France) is analyzed over a period of 70 years (1948‑2016). his analysis is based on a study of 7 km of shoreline changes by photo‑interpretation digital processing of 19 campaigns of aerial photographs (60 photos) and a DGPS ield...
Article
Phenotypic variation was characterized in 187 modern and archaeological specimens of the lesser white-toothed shrew (Crocidura suaveolens), obtained from both insular and continental European locations. Geometric morphometric methods were used to quantify variation in size and shape of the mandible. The phenotypic distance between populations, and...
Article
The Beg-er-Vil coastal site (Quiberon, Morbihan, France), initially excavated in the 1980s, and more extensively since 2012, is exposed to strong marine and anthropic erosion. At the present time, the main challenge is to define the status of the site by describing its formation dynamics. This necessitates investigating the taphonomic and erosive m...
Presentation
Les sociétés du Néolithique installées en Bretagne ont érigé de nombreux monuments mégalithiques en bord de mer. Aujourd'hui, plusieurs de ces vestiges, ensevelis sous les dunes ou submergés par la mer, sont des témoins spectaculaires des changements de l'environnement côtier qui s'y sont déroulées durant tout l’Holocène. Afin d'apporter un éclaira...
Article
Full-text available
This reports on a project that combined evidence gleaned from aerial photographs, place-names, interviews, topography, LIDAR data, and sonar bathymetry to locate stone tidal fish weirs in the Molène Archipelago. The results were verified by diver and pedestrian visual surveys. Models of Holocene sea-level change allowed a group of possibly Late Mes...
Conference Paper
Full-text available
During the winter 2013-2014, severe storm events caused a coastal erosion in the southern part of the Beniguet Island (Brittany, France). The associated shoreline retreat had uncovered three layers of shell middens interbedded into an aeolian sand dune deposit. From several radiocarbon dating crossed with the study of ceramic and lithic contents, t...
Poster
Full-text available
The chronology of the late-Holocene coastal storms was reconstructed from vibracore samplings, radiocarbon dating and sedimentary analysis from Yeu island (French Atlantic coast). The methodology used is based on the identification of disturbing sedimentary events recognized within three Holocene sedimentary transgressive sequences selected along t...
Presentation
Les sociétés du Néolithique et de l’âge du Bronze ancien installées en Bretagne ont érigé de nombreux monuments mégalithiques (tombes, pierres dressées) en bord de mer. Aujourd’hui plusieurs de ces vestiges, ensevelis sous les dunes ou submergés par la mer, sont des témoins spectaculaires des changements de l'environnement côtier (transgression mar...