Late glacial multiproxy evidence of vegetation development and environmental change at Solova, southeastern Estonia

A Heinsalu,L Amon,S Veski

doi:10.3176/earth.2010.2.05

Abstract

Reinvestigation of the late glacial Solova (Remmeski) basin, based on plant macrofossil and diatom record, AMS 14C chronology and sediment composition (loss-on-ignition and magnetic susceptibility data), provided information on vegetation history and palaeoenvironmental and palaeoclimatic changes since the time of the deglaciation of the area around 14 000 cal yr BP. The chronology of the sequence is based on seven AMS dates on terrestrial macrofossils, providing evidence of rapid sedimentation in between 14 000 and 13 500 cal yr BP. Loss-onignition data show a clear short-lived warming episode centred to 13 800 cal yr BP, tentatively correlated with the GI-1c warming of the event stratigraphy of the Last Termination in the North Atlantic region, which suggests that at least parts of the Haanja Heights were ice-free by 14 000 cal yr BP. Macrofossil evidence indicates Betula nana-Dryas octopetala-dominated open tundra communities with Saxifraga on dry ground, and Carex sp. and Juncus on wet ground at that time. The first evidence of the postglacial presence of tree birch (Betula pendula) in Estonia is dated back to 13 500 cal yr BP. However, conifer remains were not found in the late glacial sediment sequence of Solova Bog. The late-Allerod (GI-1a) organic deposits, which are quite typical of other parts of Estonia and indicate general warming, are missing at Solova, most probably due to a hiatus in sedimentation in this very small and shallow upland basin.

Highlights

The Late Weichselian deglaciation and the following vegetation formation and succession pattern in the eastern Baltic area have been a topic of interest since Hausen (1913), who initially outlined the ice-marginal positions of the last glaciation in Estonia
The terrestrial vegetation record at Solova begins at approximately 14 000 cal yr BP (Fig. 3)
Correlation of the studied time interval with the ice core data suggests that the lower portion of the sedimentary record at Solova (660–557 cm) can be associated with the GI-1c event (Lowe et al 2008), a 650-year-long slightly warmer episode of the late glacial period

Summary

Introduction

The Late Weichselian deglaciation and the following vegetation formation and succession pattern in the eastern Baltic area have been a topic of interest since Hausen (1913), who initially outlined the ice-marginal positions of the last glaciation in Estonia. The southeasternmost part of Estonian territory was probably liberated from ice first, the exact time is still poorly known. This ice-divide might have served as a primary passage for migrating late glacial vegetation. Because of its geographical position at the southern border of Estonia, topographically rather high (168 m a.s.l.) on the Haanja Heights in the ice-shed zone, Solova is probably one of the oldest postglacial sedimentary basins on the current territory of Estonia, which has yielded evidence of late glacial warming. Present results, combined with recent palaeoecological and chronological data from the neighbouring areas (e.g. Stančikaitė et al 2008; Amon et al 2009; Heikkilä et al 2009; Saarse et al 2009; Amon & Saarse 2010), will contribute to our knowledge about deglaciation of the eastern Baltic area and ice sheet decay in the southeastern sector of the Scandinavian Ice Sheet, as well as about the vegetation succession pattern and timing in these areas

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