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chronological stages: pre-transgressional, transgressional and post-transgressional
(Rimantiene
1998
).
In Estonia, too, the topographical location of Stone Age sites on former shores
is used to determine their chronology. Sixty Stone Age sites, originally located on
the Estonian Baltic coast, were recently integrated in a pilot project to prove that it
is possible to apply the shore-displacement chronology in this region (Jussila and
Kriiska
2004
). Based on the respective levels of the sites, eight shorelines were
reconstructed and dated with the help of
14
C dates from some of the archaeological
sites to the period between 5,700 and 2,600 cal. BC. Of special importance for
the study of shore displacement and settlement history was Hiiumaa island, to the
west of the Estonian mainland (Fig.
15.14
). On the oldest and westernmost part
of the island, called Kõpu, the remains of 22 ancient shorelines are preserved on
different levels, on clearly distinguishable ancient beach ridges (Raukas and Ratas
1995
). On these ridges, 12 Stone Age sites were identified that dated from the late
Mesolithic to the early Neolithic (Kriiska and Lõugas
1999
). Although only partly
excavated so far, these sites provide an excellent basis for the study of regional shore
displacements and settlement history (Lõugas et al.
1996
).
15.3.3 Seamen and Traders - The Post-Littorina and Limnaea
Seas as a Transportation and Communication Zone
As has already been pointed out, the global sea-level around 4,000 cal. BC was
1 m below the present sea level (Lampe et al.
2005
). Since then, the more or
less continuous, but minor, rise in sea level has to be considered as having been
periodically interrupted by phases of falling sea level (Kliewe and Schwarzer
2002
).
Nevertheless, the coastal landscape of the Baltic area experienced considerable
changes during the last six millennia, mostly caused by further substantial isostatic
rebound. The northern coast of the so-called Post-Littorina Sea, in particular, was
affected by a continuous land uplift of up to 90 cm/century, which means that the
former shores are now located more than 150 km from today's coastline and up to
280 m above the present sea level (Berglund
2008
). In comparison, the shoreline
changes in the eastern part of the southern Baltic area can be regarded as very mod-
erate; on the territories of Lithuania, Latvia and Estonia there was a slight uplift of
10-20 cm/century. By contrast, the south-western Baltic coast has been slowly but
continuously sinking, especially in the area of the Mecklenburgian Bight where it
amounts to -10 cm/century (Harff and Meyer
2007
, Rosentau et al.
2007
).
For the period from the turn of the eras until the 1500 AD, the exchange of water
between the North Sea and Baltic Sea has no longer reached the northern part of
the Baltic Sea. Consequently, there was again a shift from a brackish to a freshwater
environment that caused a migration of the freshwater snail
Limnaea
, which is why
this stage in the development of the Baltic Sea is called the
Limnaea
Sea by some
scholars (Kliewe and Schwarzer
2002
).
As already mentioned, the coastal zone lost its dominant importance for the
inhabitants' nutrition as a consequence of the introduction of agriculture and
