T1. Geochronology

The basic aim of geochronology is to place significant events (geological, climatological and archaeological events) in the Earth’s history within a common and absolute temporal framework. The dating techniques are very varied and can be either relative or absolute. Absolute geochronology, which is principally based on the use of radioactive phenomena, is invaluable for anchoring relative chronologies within an absolute timescale. The principal methods that we are developing are isotopic and magnetic stratigraphy (relative methods), and methods based on the analysis of uranium and thorium series, C14 dating, potassium/argon chronometry, tritium/helium-3 chronometry, and luminescence techniques (absolute dating methods). These different relative and absolute methods can be used in the study of climate archives (ice cores, continental and marine sediments, etc.), which provide us with a better understanding of the mechanisms governing our climate and which allow us to study the different dynamics at work in the environment (erosion, particulate and dissolved transfer, soils, groundwater, etc.), as well as the dynamics of human settlement and associated cultural transitions.