Geoscience Reference
In-Depth Information
15.3.2 Mesolithic and Early Neolithic Hunter-Gatherers
and Fishermen on the Shores of the Ancylus Lake
and Littorina Sea
The ninth millennium BC was again a period of intense change in the development
of the Baltic basin. Due to the continuous isostatic uplift of its northern part, the
strait that had connected the Baltic area with the Kattegat for centuries gradually
closed and new land emerged in the area of present-day central Sweden (Fig.
15.7
).
The exchange of water was severely reduced, which led around 8,800 cal. BC to a
change in the character of the Baltic from a brackish to a freshwater environment.
In addition, the water level rose as a result of the damming of the so-called Ancylus
Lake. While the containment of this lake only influenced the shoreline in the north-
ern part of the Baltic to a small extent, because the on-going uplift compensated for
the rising water level, the consequences for the southern Baltic area were dramatic.
According to Björck (
1995
), the sea level here rose up to 10 m/century, so that vast
areas were successively inundated. This situation changed again around 8,400 cal.
BC, when a rapid regression has been recorded. For the following 200 years, the
water level in the Ancylus Lake was equal to that of the ocean. It is assumed that
there must have been a connection between the Baltic and the North Sea that permit-
ted the outflow of Baltic water, although there is no evidence of inflowing salt water.
Several possibilities for the location of this connection are still being discussed and
the clarification of this question is, therefore, a field for future research. However,
the connection between the Kattegat and the Ancylus Lake must have remained open
until 7,000 cal. BC as the environmental conditions along its shores were more or
Fig. 15.7
The Baltic basin during the phase of the Ancylus Lake (9,000-8,000 cal. BC).
1
. Stadium around 8,500 cal. BC at the maximum of its transgression,
2
Stadium around 8,100 cal.
BC when the former difference in level between the ocean and the Ancylus Lake was balanced
(after Lemke
2004
, fig. 1, 5-6, modified by the author)
