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This article presents recent research on the sedimentary endokarstic infillings in connection with the new contributions of geochemical analysis by autoradiography and X-ray fluorescence (portable analyser, core scanner, micro-XRF, microprobe) in the context of the 'Climanthrope' ANR programme. Coupled with sedimentological analysis (stratigraphy, laser grain size analysis, micromineralogy, and micromorphology), geochemical analysis and imaging refine the study of underground deposits such as carbonated sediments (speleothems), rhythmites, subterranean ice, and prehistoric cave paintings. Formed following a seasonal cycle, stalagmites and rhythmites are likely to provide important data not only on the two main parameters of regional climate, i.e. hydrology and temperature, but also on human impacts (speleothems in urban tunnels) and the rural environment. The microdebris and dusts sampled in subterranean ice record the palaeoenvironment by snow trapping. Parietal paintings can be studied directly with a portable XRF analyser without sampling. In every case, the notion of the 'site effect' is discussed for four French examples (Pyrenees, Aquitaine, Charente, Rhône) and three foreign examples (Italy, Chile, China).
Full text document will be published online on December 2013.
Geochemical methods: autoradiography and X-ray fluorescence
Digital autoradiography: imaging of natural radioactivity (Beta Imager)
Portable XRF analyser
Avaatech XRF Core Scanner
Nuclear microprobe analysis
Results for speleothems, detrital rhythmites, ice, and prehistoric paintings
Pierre Saint-Martin Cave (Pyrenees, France) — Beta Imager and Microprobe
The karst of Entre-deux-Mers (Gironde, SW France) – Beta Imager and micro-XRF
Micro-XRF of a stalagmite formed in an urban environment: example of an underground tunnel of Lyon
Detrital rhythmites (France, China)
The karst of La Rochefoucauld (Charente, SW France) — Micro-XRF
The monsoon rhythmites of Dadong Cave (China)
Measurements on ice and prehistoric paintings in caves
Geochemical analysis of underground snow and ice: example of Scarasson Cave (Marguareis, Italy) – Micro-XRF
Example of a Pacific prehistoric cave (Patagonia, Chile) – Portable X-ray unit
Importance of the site effect (tab. 1 and fig. 18)
Characterisation of palaeoclimatic and palaeoenvironmental conditions
Characterisation of anthropogenic signals
Identification of radioactive levels and implication for radiometric dating
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Geochemical analysis is usually used for marine and continental sediments (Böning et al., 2007; Kido et al., 2006; Koshikawa et al., 2003) but has not been very developed for subterranean deposits (speleothems and detritic fillings) even though karst deposits are now recognised as good indicators of past and present environments all over the world (Renault, 1990; Maire et al., 1994; Genty, 2002; Fairchild et al., 2006; White, 2007; Vanara and Douat, 2010). This paper aims to show that geochemical analysis and imaging are an original and significant approach to: (i) characterise the nature of speleothems and detrital cave deposits (natural or anthropic contaminations, diagenesis, etc.); (ii) reveal the hydro-sedimentary dynamics; (iii) characterise palaeoclimate and palaeoenvironmental variations; and (iv) specify the geomorphological evolution. This paper is part of “Climanthrope” ANR programme managed by Richard Maire. The objective of this programme is to characterise ...
Grégory Dandurand, Richard Maire, Richard Ortega, Guillaume Devès, Benjamin Lans, Laurent Morel, Anne-Sophie Perroux, Nathalie Vanara, Laurent Bruxelles, Stéphane Jaillet, Isabelle Billy, Philippe Martinez, Bassam Ghaleb and François Valla, « X-ray fluorescence microchemical analysis and autoradiography applied to cave deposits: speleothems, detrital rhythmites, ice and prehistoric paintings », Géomorphologie : relief, processus, environnement, 4/2011 | 2011, 407-426.
Grégory Dandurand, Richard Maire, Richard Ortega, Guillaume Devès, Benjamin Lans, Laurent Morel, Anne-Sophie Perroux, Nathalie Vanara, Laurent Bruxelles, Stéphane Jaillet, Isabelle Billy, Philippe Martinez, Bassam Ghaleb and François Valla, « X-ray fluorescence microchemical analysis and autoradiography applied to cave deposits: speleothems, detrital rhythmites, ice and prehistoric paintings », Géomorphologie : relief, processus, environnement [Online], 4/2011 | 2011, Online since 08 December 2013, connection on 24 May 2013. URL : http://geomorphologie.revues.org/9623 ; DOI : 10.4000/geomorphologie.9623 Top of page