Dévoluy is a mountain range located in the southern French Alps. It is the last foreland chain before the outer crystalline Pelvoux massif. The carbonate rocks that constitute it form a reservoir of several hundred meters thick, folded and fractured by Alpine orogeny during the Cenozoic. This reservoir, exposed to erosion, was then intensively karstified, creating a network of interconnected karstic conduits leading to a unique outlet: the Gillardes spring. Due to its position in the Southern Alps, a geographical area subject to increasing water stress in the context of climate change, the Dévoluy massif presents a major challenge in understanding and preserving the local groundwater reserves. The aim of this study is to provide an overall analysis of the evolution of this geological entity by applying a reservoir approach: understanding its evolution from its formation to its current state by analyzing each of its components. This section of the study focuses on the karst evolution by analyzing karstic sediments observed in the Rama-Aiguille cave. These sediments are represented by three poles: debris flow, speleothems and pseudo-varves. They are preserved in few outcrops in the cave and can reach up to ten meters thick. Paleomagnetic dating has been carried out in pseudo-varves showing some reverse polarities indicating an age of more than 780ka for those sediments. This shows that karstic systems are settled at least since more than 780ka and that conduits have undergone phases of clogging and unclogging. The next phases of the study will have to identify the stratigraphy of these fillings more precisely by understanding their origin and determining whether they are specific to the Rama-Aiguille network or whether they are evidence of a global karst filling phase in Dévoluy. It will give important information about the karstic reservoir evolution.