Palynology in the study of present-day hillslope development

Abstract

It is pointed out that in measuring current geomorphological processes, which in general act either extremely slowly or, if more catastrophic in nature, at long intervals, knowledge of the recent geomorphological history is essential. This is particularly necessary, if the outcome of the measurements have to serve as a basis for prognosis, because an extrapolation of measurements alone is subject to a high degree of uncertainty. In the area near Bavigne (Luxembourg), where present day displacements of slope material are measured, loamy materials covering the slopes appear often to contain pollen in appreciable amounts. Pollen diagrams constructed from this sort of material show a considerable agreement with the corresponding sections of reference diagrams prepared from alluvial deposits. The disturbance of the pollen stratification by the decay of included contemporaneous pollen combined with a supply of younger pollen, which is considered to be common in sandy soils, apparently has been equally effective in the alluvial fills and in the soils developed in the slope-covering materials. Hence, the disturbance must have been of a similar order of magnitude in the alluvial as well as in the slope materials. The present authors therefore consider the palynological analysis under certain circumstances as an appropriate technique for collecting the necessary information in regolithic materials. The data obtained suggest that pollen analysis of these materials, in conjunction with lithological and pedological field evidence, not only may be used to date events, to which slope materials have been subjected in the recent past, but also to contribute to their reconstruction.