Luminescence dating in archaeology from origins to optical
As soon as the mineral is exposed to sunlight, for example during its transport, trapped electrons absorb the photon energy (from the Sun), and are released from the traps.The rate of release depends on four main parameters: i) the kind of mineral: the eviction occurs faster for quartz than for feldspars (reduction of the luminescence signal by a factor of 100 in ~ 20 s for the former, but a few minutes for the latter; Godfrey-Smith , these are more efficient to stimulate and release the electrons.Après une présentation des principes physiques généraux, les procédures mises en œuvre aussi bien sur le terrain qu’en laboratoire sont abordées, à partir de l’exemple des analyses réalisées sur des alluvions sableuses issues d’une basse terrasse de la Moselle.La place des datations OSL dans la recherche géomorphologique en France et son potentiel pour les recherches futures sont décrits à travers une présentation de la diversité des environnements sédimentaires et des problématiques pouvant être traités.These procedures are described as clearly as possible in order to provide useful information for geomorphologists interested in the method, and illustrated by a case study that has involved luminescence dating of fluvial sands (samples LUM 975 and LUM 978) from the lower alluvial terrace of the Moselle River (M1 terrace as defined by S. However, it is essential to keep in mind that the protocols (preparation of the sediments, measurements) may vary from one laboratory to the other: the presentation does not aim to be exhaustive, but to reference the main procedures at each step of the dating.Finally the paper reviews the recent applications of OSL dating in France, and assesses the potential of applying the luminescence dating technique to a range of geomorphic research.
The intensity of the signal is proportional to the amount of released electrons.
They are now largely used to date not only palaeontological or organic remains, but also minerals that characterise detrital clastic sedimentary material.
The most common methods applied to minerals are cosmogenic radionuclides, electron spin resonance (ESR) and luminescence techniques.
This paper aims to provide an overview concerning the optically stimulated luminescence (OSL) dating method and its applications for geomorphological research in France.
An outline of the general physical principles of luminescence dating is given.