Stéphane Jaillet

Further constraints on the Chauvet cave artwork elaboration

Since its discovery, the Chauvet cave elaborate artwork called into question our understanding of Palaeolithic art evolution and challenged traditional chronological benchmarks [Valladas H et al. (2001) Nature 413:419–479]. Chronological approaches revealing human presences in the cavity during the Aurignacian and the Gravettian are indeed still debated on the basis of stylistic criteria [Pettitt P (2008) J Hum Evol 55:908–917]. The presented 36Cl Cosmic Ray Exposure ages demonstrate that the cliff overhanging the Chauvet cave has collapsed several times since 29 ka until the sealing of the cavity entrance prohibited access to the cave at least 21 ka ago. Remarkably agreeing with the radiocarbon dates of the human and animal occupancy, this study confirms that the Chauvet cave paintings are the oldest and the most elaborate ever discovered, challenging our current knowledge of human cognitive evolution.

Digital Tools for Managing and Promoting Karst Geosites in Southeast France

This article provides an overview of the various digital tools we have used and developed to study and promote a range of karst geosites. Our work focused on the very high heritage value endokarst sites (caves or karst networks) in France’s Ardèche département (Chauvet Cave, Aven d’Orgnac) and Chartreuse (Granier cave network), Vercors (Choranche Caves) and Bauges (Prérouge Cave) Regional Parks. These tools were developed using innovative, high-tech digital monitoring and 3D modelling technologies and combined laser scanners, digital cameras and sensors with specialised software. The resulting tools are now being used in the management and promotion of these sites, which are important territorial and heritage resources in areas where geotourism is increasing and being integrated into local planning strategies.

Spatial distribution of soda straws growth rates of the Coufin Cave (Vercors, France).

2area of the roof of the Coufin Cave entrance chamber. Because of the very slow and sometimes inexistent water feeding of those stalactites, hydrochemistry analysis were not achieved and drop rate effect on growth were neglected; this study is based on a geomorphological and geostatistical work. By measuring a large number of soda straws in a very small area for which most of the parameters affecting stalactite growth could be considered uniform, and because flow rates are very slow (frequencies are always superior to 1 drop per half hour), we could ascribe differences in growth rates to variations in the global increase of water flow through the unsaturated matrix. Statistical and geostatistical analyses of the measurements showed that this set of similarly shaped stalactites actually consisted of three Gaussian populations with different mean growth rates: fast growth rate (FGR- mean of 0.92 mm.y -1 ), medium growth rate (MGR- mean of 0.47 mm.y -1 ) and low growth rate (LGR- 0.09 mm.y -1 ). Plotting the lengths and spatial distribution of the 20 longest FGR soda straws revealed that there is a rough pattern to the water flow through the cave roof. Even if no direction is statisticaly different from others, the observed directional pattern is consistent with local and regional tectonic observations. Plots of the spatial distribution of the soda straws show that FGR soda straws follow lines of regional geological stress, whereas MGR and LGR soda straws are more dispersed.

Multi-Annual Kinematics of an Active Rock Glacier Quantified from Very High-Resolution DEMs: An Application-Case in the French Alps

Rock glaciers result from the long-term creeping of ice-rich permafrost along mountain slopes. Under warming conditions, deformation is expected to increase, and potential destabilization of those landforms may lead to hazardous phenomena. Monitoring the kinematics of rock glaciers at fine spatial resolution is required to better understand at which rate, where and how they deform. We present here the results of several years of in situ surveys carried out between 2005 and 2015 on the Laurichard rock glacier, an active rock glacier located in the French Alps. Repeated terrestrial laser-scanning (TLS) together with aerial laser-scanning (ALS) and structure-from-motion-multi-view-stereophotogrammetry (SFM-MVS) were used to accurately quantify surface displacement of the Laurichard rock glacier at interannual and pluri-annual scales. Six very high-resolution digital elevation models (DEMs, pixel size <50 cm) of the rock glacier surface were generated, and their respective quality was assessed. The relative horizontal position accuracy (XY) of the individual DEMs is in general less than 2 cm with a co-registration error on stable areas ranging from 20–50 cm. The vertical accuracy is around 20 cm. The direction and amplitude of surface displacements computed between DEMs are very consistent with independent geodetic field measurements (e.g., DGPS). Using these datasets, local patterns of the Laurichard rock glacier kinematics were quantified, pointing out specific internal (rheological) and external (bed topography) controls. The evolution of the surface velocity shows few changes on the rock glacier’s snout for the first years of the observed period, followed by a major acceleration between 2012 and 2015 affecting the upper part of the tongue and the snout.

Flowstone growth in Gournier River (Vercors, France): a diachronic landscape analysis by 3D modelling and photo draping

*kim.genuite@univ-smb.fr Citation:

The Lower Ardèche River Karst Landscapes and Caves (Lower Rhône Valley): Unique Morphologies Induced by the Messinian Salinity Crisis

The lower Ardeche and Ceze valleys are famous for their touristic sites. Besides their dramatic karstic landscapes such as the natural arch of the Pont d’Arc or the deep canyon of the Ardeche River, they conceal prehistoric caves among which the famous Chauvet Cave discovered in 1994. These landscapes of high plateaus, canyons, and caves were formed by a catastrophic geologic event, the Messinian Salinity Crisis (MSC), which affected the entire Mediterranean Basin and the morphological evolution of the surrounding mountains and plateaus. More specifically, the Saint-Remeze Plateau displays some good evidences to demonstrate that the Mediterranean Sea was completely desiccated. The MSC was also responsible for the downcutting of the Ardeche and Rhone canyons in less than 100,000 years. This evolution was followed by the formation of deep karst drainages. The MSC ended by a sudden reflooding of the basin, characterized by a rapid rise of the Mediterranean base level responsible for large river aggradations. It also provoked the development of a per ascensum karst adaptation characterized by (1) large galleries in the Saint-Marcel and Chauvet caves and (2) huge chambers in the Aven d’Orgnac Cave. Nowadays, more than one million tourists visit the area every year, attracted by its natural biotopes and sites, by its caves like Saint-Marcel and Aven d’Orgnac. In the future, the Chauvet Cave, where the oldest paintings in the World were found, will hopefully be nominated as a UNESCO World Heritage.

Study of Subterranean Floods in OceanicSubpolar Karst of Madre de DiosArchipelago (Patagonia, Chile)

Madre de Dios archipelago is located, at 50°30′ S, on the Pacific front. The karst areas in the reef limestone of Upper Paleozoic of Chilean Patagonia have long remained unexplored because of their remoteness, difficult access and very inhospitable cold, wet and windy climate. The annual rainfall is 7–8 m/year and the average wind speed reaches 70 km/h almost unidirectional (W to NW), and involve strong floods at a high rate. To study the flood dynamics, several underground sites have been instrumented in 2008 and recovered in 2010.