Abstract Raman spectroscopy allows thermal maturation of carbonaceous sediments to be determined. The technique has been employed on metamorphic samples exceeding temperatures of 270°C, but recently has been shown to be effective at lower temperatures. Thermal maturation techniques commonly depend on sample size, have varying efficacies at different temperatures and in different conditions. The underlying processes are not well understood, thus data interpretation can be ambiguous. Here we show the efficacy of Raman as a low-temperature thermal marker in a thrust belt. The Bornes region, in a French Subalpine chain, provides an opportunity to test the technique against published vitrinite reflectance data and thermal modelling for the first time. In doing so we show that Raman is an effective thermal marker to temperatures as low as 75°C, has a small error and is consistent with previous work. The Raman data allow us to postulate the relative thickness of the sedimentary succession across the chain, the timing of thermal maturation and the timing and thickness variations of the over-thrust Prealpine nappe. The work establishes Raman as a low-temperature thermal marker for correlation with other techniques to ensure effective and robust interpretation, that can readily be applied to fold–thrust belts in hydrocarbon provinces.

Abstract This paper traces the touristic trajectories of three spectacular gorges located in the Alpine foreland and the southern Jura: the gorges of the upper Rhône (Ain/Haute-Savoie), the Sierroz (Savoie) and the Fier (Haute-Savoie). All three are located within a distance of 50 km from each other. The upper Rhône gorge, already famous at the end of the eighteenth century, was drowned under the floodwaters of the Génissiat dam in 1948; only a significant iconography remains of two centuries of (geo)tourism. The Sierroz gorge, close to the spa resort of Aix-les-Bains, became famous after the dramatic and tragic death in 1810 of a young noblewoman. Following that event many tourists staying on the shore of the lake Bourget visited the gorge until 1970 when it was closed to the public. Since then, the gorge has gradually become a touristic wasteland. The Fier gorge near Annecy became a tourist attraction in 1869 with the opening of the nearby railway station of Lovagny; since then, visitors have been attracted to it in increasing numbers. The history of these three gorges illustrates how tourism and heritage are in constant interaction; however, the development of the one will not always ensure the protection of the other. Today, geoheritage assessment is based upon criteria that are as objective as is possible. The intrinsic geological and geomorphological characteristics are the initial geoheritage values, to which can be added the cultural value elements. Associated with the development of geotourism and geoparks, this new approach should ensure a better and sustainable use of these sites in the long term.