Holocene buried organic sediments in Estonia

An overview of 85 sites of Holocene buried organic sediments in Estonia is presented. This number includes 45 sites of pre-Ancylus and Ancylus age, which were buried during the Ancylus transgression, 31 sites of pre-Litorina and Litorina age, buried under Litorina transgression sediments, and 9 sites formed after post-Litorina time and mostly covered by aeolian sand. According to radiocarbon dates, the Ancylus Lake transgression started about 9500 yr BP (10 800 cal BP), and culminated several hundred years later. Around 9000 yr BP (10 100 cal BP) a rather rapid regression followed. Its magnitude reached up to 30 m in the areas of rapid uplift. Pollen spectra of these beds are characterized by a high frequency of Pinus pollen, which seems to be typical of the coastal waterbodies of this age and confuses determination of their Preboreal age. 14C dates of Litorina buried beds differ considerably. We have evidence that the Litorina transgression started about 7500–7000 yr BP (8300–7800 cal BP) and culminated at different times in different regions. Pollen spectra of Litorina buried organic strata vary considerably between sites; however, their Atlantic age is easily discernible. The simulated isobases of the Ancylus Lake and Litorina Sea shorelines and organic beds showed discrepancy in the surroundings of Pärnu and Narva bays.