The added value of biomarker analysis in palaeopedology; reconstruction of the vegetation during stable periods in a polycyclic driftsand sequence in SE-Netherlands

Polycyclic driftsand sequences are records of alternating unstable periods with aeolian erosion and deposition and stable periods with soil formation. In numerous studies, pollen analysis, radiocarbon dating, and optically stimulated luminescence dating have been applied to collect palyno-ecological information and to establish a robust geochronology for the reconstruction of the profile genesis. A correct reconstruction of the local vegetation during stable periods in the profile evolution cannot be based on pollen spectra alone, because of the impossibility to separate pollen species produced in-situ and at distance. We considered biomarker analysis as a possibility to solve this problem. In a selected sequence with a well-established geochronology, we applied pollen and biomarker analysis on samples of humic Ah horizons of buried (initial) podzols. Based on species matching in soil pollen spectra and biomarker patterns of samples of (buried) humic horizons, it was possible to distinguish pollen species produced in-situ and at distance from the study site, and consequently to determine the plant species composing the vegetation during stable periods with soil formation.