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less stable until then. After the end of that phase, a slight change from a freshwater
to a brackish environment has been detected for some areas of the Ancylus Lake,
indicating that salt water from the North Sea had started to flow into the Baltic basin
(Lemke
2004
).
The following phase, from 6,700 to 6,100 cal. BC, was characterized by constant
uplift in the northern part of the Baltic area and a strong salt water transgression in
its southern part (Lemke
2004
). According to Rößler (
2006
) the central part of the
Mecklenburgian Bight was not earlier affected by this development as recently as
6,100 cal. BC. It was caused by a rapid rise in the level of the North Sea and first led
to the inundation of the Danish belts and the Öresund and thus to a new connection
between the Baltic and the North Sea. In this phase, the Baltic Sea is called the
Littorina Sea; other than the substantial salt water transgression, it is characterized
by a brackish environment (Fig.
15.8
).
For the south-western Baltic coastal area, Kliewe and Janke (
1982
) estimated a
sea level rise of 2.5 cm/year. This development created a more structured coastline
with a constantly changing topography consisting of numerous small islands and
sea inlets. Not earlier than around 4,000 cal. BC, when the sea level had already
reached a level only 1 m lower than today, the rising sea level lost its force and
slowed down to 0.3 cm/century. The coastal landscape was consolidated and the
first compensatory processes set in motion (Schmölcke et al.
2006
).
The environmental conditions, too, changed considerably after the end of
deglaciation: the temperature rose rapidly during the Preboreal and caused changes
in the climate, the vegetation and the landscape (Schmölcke et al.
2006
). Forests
dominated by Scots pine and birch trees expanded more and more. Hazel quickly
spread into the southern Baltic area after 8,600 cal. BC and, finally, the elm and
oak arrived. These forests became the habitat of red and roe deer as well as wild
boar, moose and aurochs. Brown bears, the European otter, beavers and foxes were
also present. During the following Boreal millennia, lime and ash trees arrived in
the southern Baltic area to complete the deciduous forests of oak, elm, hazel and
birches.
Fig. 15.8
Model of the
Littorina Sea around
5,900 cal. BC (after Harff and
Meyer
2007
, fig. 11)
