Pollen analysis has been, and still is, one of the most widely used techniques in Quaternary sciences, especially to reconstruct vegetation history and climate variability. Fossil deposits of accumulating plants, such as peat sediments, were very early investigated as they are particularly suitable for the reception, storage and conservation of palynomorphs. Thanks to successive methodological innovations, palynological analyses then gradually developed by multiplying studies of diverse more mineral sedimentary materials (lake, stream and/or marine sediments, loess deposits, travertine, etc.). These new efficient techniques also led to an interest in archaeological sediments, allowing palaeoenvironmental reconstructions where no adequate Quaternary continental sedimentary records are available. Soon after the mid-20th century, caves and rock-shelters became then the favored studied places in karstic areas to approach the environment of prehistoric humans. However, the pollen record in caves is a complex phenomenon in which multiple geological, biological and atmospheric factors are involved and could lead to some distortions and discontinuities in the pollen assemblages. When not perceived, these pitfalls have sometimes generated some over or misinterpretations. After a keen interest, cave sediment sequences were thus considered as unattractive, presenting lot of alterations, difficult to correlate and with a low palaeoenvironmental potential. The validity and scope of the interpretation of palynological data from this type of deposits are still highly controversial and debatable. In Belgium, a systematic program of detailed stratigraphic recordings from caves associated with various palaeoenvironmental analyses has recently been undertaken in close collaboration with researchers from different disciplines. The objective was to better understand the sedimentary dynamics of these fillings and to test their potential as recorders of Quaternary climatic variations. In that context, new pollen data from two Belgian caves have been acquired and open new prospects for research work in this type of environments. In this paper, we present the state of the art of cave palynology, including the different parameters defining pollen taphonomy, the potentials and the limits of pollen analysis on Quaternary cave deposits. Through the examples of the caves Walou and Scladina, we show that good palynological results can be obtained in these contexts. These records are compared and evaluated in the light of multidisciplinary palaeoecological information from these two prehistoric settlements. When precautions are taken and a close link with geology and archaeology is maintained, local environment of the prehistoric populations, but also major trends in vegetation evolution and climate change during the Middle Paleolithic, can be accurately documented by pollen records from cave sequences.

Abstract of an Oral Presentation or a Poster