The intertill deposits of the Kihnu Island in the Gulf of Riga, SW Estonia are according to their pollen content subdivided into two units: (1) the Late Saalian with a cold and drought-resistant pollen flora, and (2) the Early Weichselian with abundant redeposited Eemian pollen. Middle Weichselian interstadial deposits, overlain by till from the Late Weichselian stadial and underlain by the till from the Middle Weichselian, are known from the Vääna-Jõesuu site in NW Estonia. The erratic Holsteinian deposits at the Karuküla site, SW Estonia, previously dated as a Middle Weichselian Interglacial sediments, still complicate the Estonian till stratigraphy. According to the pollen content, the Late Weichselian late-glacial (Oldest Dryas, DR1) Haanja till in S Estonia cannot be correlated to the Late Weichselian till in N Estonia. Evidence for an Early Weichselian till is not known in Estonia.

According to published opinion based on analytical data, the secondary pollen of subglacial till in the eastern Baltic region of Europe reflect the pollen assemblages of the preceding interstadial or interglacial sediment, including abundant thermo-philous pollen. Tills and glaciolacustrine sediments from 10 sites in southern Ontario, including the Don Valley Brickyard section at Toronto, where polynologically investigated to compare the pollen content in glacigenic deposits of various ages. Only one site (upper Bradtville till) contained a secondary pollen assemblage with abundant deciduous pollen, like those found in a Yarmouthian interglacial deposit in Indiana. In all the others, pine (Pinus) pollen dominate. This phenomenon is explained by glacial incorporation of sediments enriched in overproduced Pinus pollen, which had accumulated during either (i) a lengthy cool transitional period between the warm phase of the Sangamonian Interglacial and the first major Early Wisconsinan glacial advance, (ii) the interstadial Middle Wisconsinan, or (iii) the cool nonglacial episode of Illinoian and pre-Illinoian time. Therefore, the northern European model for distinguishing tills of different ages by their secondary pollen assemblages is applicable to southern Ontario only in exceptional cases. Pollen in the glaciolacustrine Early Wisconsinan Sunnybrook Drift sediments resembles those of Sunnybrook till, but are more variable in their preservation and composition and contain more pre-Quaternary palynomorphs.

No abstract

The information obtained from a 21 m thick open-pit section of silty-clayey sediments in the Arumetsa bedrock valley, southwestern Estonia, revealed that lacustrine to glaciolacustrine sedimentation at the site started prior to 151 ka ago and lasted to about the end of marine isotope stage 6 (MIS6) at 130 ka. Further down from the 151 ka age-level to the bottom of the buried valley there are ca 60 m of lacustrine fine-grained sediments, the age of which remains still unclear. The Late Saalian sediments at Arumetsa are discordantly overlain by Middle Weichselian clay, silt and sand, deposited between ca 44 and 37 ka ago. As testified by optically stimulated luminescence (OSL) ages, and pollen and diatom record, the Middle Weichselian fine-grained sediments contain redeposited Holsteinian but no Eemian pollen, and have not been fully bleached during deposition. Chronological, microfossil and sedimentological data show two hiatuses in the Arumetsa section. The first hiatus has left no sedimentary evidence for the period between ca 130 ka and 44 ka ago (MIS5 to older half of MIS3). The younger hiatus from ca 37 to 22 ka occurs between the Middle Weichselian lacustrine silt and the Late Weichselian till layer on top of the section